Merge branch 'mc-1.14.x' into mc-1.15.x

When calling .flip(), we limit the size of the buffer. However, this
limit is not reset when writing the next time, which means we get
out-of-bounds errors, even if the buffer is /technically/ big enough.

Clearing the buffer before drawing (rather than just resetting the
position) is enough to fix this.

Fixes #476 (and closes #477, which is a duplicate)

.github/workflows/main-ci.yml

@@ -32,6 +32,9 @@ jobs:
         name: CC-Tweaked
         path: build/libs
 
+    - name: Upload Coverage
+      run: bash <(curl -s https://codecov.io/bash)
+
   lint-lua:
     name: Lint Lua
     runs-on: ubuntu-latest

build.gradle

@@ -9,7 +9,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.google.code.gson:gson:2.8.1'
-        classpath 'net.minecraftforge.gradle:ForgeGradle:3.0.154'
+        classpath 'net.minecraftforge.gradle:ForgeGradle:3.0.169'
         classpath 'net.sf.proguard:proguard-gradle:6.1.0beta2'
         classpath 'org.ajoberstar.grgit:grgit-gradle:3.0.0'
     }
@@ -17,6 +17,7 @@ buildscript {
 
 plugins {
     id "checkstyle"
+    id "jacoco"
     id "com.github.hierynomus.license" version "0.15.0"
     id "com.matthewprenger.cursegradle" version "1.3.0"
     id "com.github.breadmoirai.github-release" version "2.2.4"
@@ -47,7 +48,7 @@ minecraft {
         }
 
         server {
-            workingDirectory project.file('run')
+            workingDirectory project.file("run/server-${mc_version}")
             property 'forge.logging.markers', 'REGISTRIES,REGISTRYDUMP'
             property 'forge.logging.console.level', 'debug'
 
@@ -99,15 +100,16 @@ dependencies {
 
     minecraft "net.minecraftforge:forge:${mc_version}-${forge_version}"
 
-    compileOnly fg.deobf("mezz.jei:jei-1.14.4:6.0.0.27:api")
-    compileOnly fg.deobf("com.blamejared.crafttweaker:CraftTweaker-1.14.4:5.0.1.162")
+    compileOnly fg.deobf("mezz.jei:jei-1.15.2:6.0.0.3:api")
+    compileOnly fg.deobf("com.blamejared.crafttweaker:CraftTweaker-1.15.2:6.0.0.9")
 
-    runtimeOnly fg.deobf("mezz.jei:jei-1.14.4:6.0.0.27")
+    runtimeOnly fg.deobf("mezz.jei:jei-1.15.2:6.0.0.3")
 
     shade 'org.squiddev:Cobalt:0.5.1-SNAPSHOT'
 
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.4.2'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.4.2'
+    testImplementation 'org.hamcrest:hamcrest:2.2'
 
     deployerJars "org.apache.maven.wagon:wagon-ssh:3.0.0"
 }
@@ -200,8 +202,6 @@ task proguardMove(dependsOn: proguard) {
     }
 }
 
-
-
 processResources {
     inputs.property "version", mod_version
     inputs.property "mcversion", mc_version
@@ -288,6 +288,15 @@ test {
     }
 }
 
+jacocoTestReport {
+    reports {
+        xml.enabled true
+        html.enabled true
+    }
+}
+
+check.dependsOn jacocoTestReport
+
 license {
     mapping("java", "SLASHSTAR_STYLE")
     strictCheck true

config/checkstyle/checkstyle.xml

@@ -10,6 +10,10 @@
         <property name="file" value="config/checkstyle/suppressions.xml" />
     </module>
 
+    <module name="BeforeExecutionExclusionFileFilter">
+        <property name="fileNamePattern" value="render_old"/>
+    </module>
+
     <module name="TreeWalker">
         <!-- Annotations -->
         <module name="AnnotationLocation" />
@@ -110,11 +114,11 @@
         </module>
         <module name="ParameterName" />
         <module name="StaticVariableName">
-            <property name="format" value="^[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z]+)?$" />
+            <property name="format" value="^[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z_]+)?$" />
             <property name="applyToPrivate" value="false" />
         </module>
         <module name="StaticVariableName">
-            <property name="format" value="^(s_)?[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z]+)?$" />
+            <property name="format" value="^(s_)?[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z_]+)?$" />
             <property name="applyToPrivate" value="true" />
         </module>
         <module name="TypeName" />

doc/stub/commands.lua

@@ -1,6 +1,77 @@
+--- Execute a specific command.
+--
+-- @tparam string command The command to execute.
+-- @treturn boolean Whether the command executed successfully.
+-- @treturn { string... } The output of this command, as a list of lines.
+-- @treturn number|nil The number of "affected" objects, or `nil` if the command
+-- failed. The definition of this varies from command to command.
+-- @usage Set the block above the command computer to stone.
+--
+--     commands.exec("setblock ~ ~1 ~ minecraft:stone")
 function exec(command) end
+
+--- Asynchronously execute a command.
+--
+-- Unlike @{exec}, this will immediately return, instead of waiting for the
+-- command to execute. This allows you to run multiple commands at the same
+-- time.
+--
+-- When this command has finished executing, it will queue a `task_complete`
+-- event containing the result of executing this command (what @{exec} would
+-- return).
+--
+-- @tparam string command The command to execute.
+-- @treturn number The "task id". When this command has been executed, it will
+-- queue a `task_complete` event with a matching id.
+-- @usage Asynchronously sets the block above the computer to stone.
+--
+--     commands.execAsync("~ ~1 ~ minecraft:stone")
+-- @see parallel One may also use the parallel API to run multiple commands at
+-- once.
 function execAsync(commad) end
+
+--- List all available commands which the computer has permission to execute.
+--
+-- @treturn { string... } A list of all available commands
 function list() end
+
+--- Get the position of the current command computer.
+--
+-- @treturn number This computer's x position.
+-- @treturn number This computer's y position.
+-- @treturn number This computer's z position.
+-- @see gps.locate To get the position of a non-command computer.
 function getBlockPosition() end
-function getBlockInfos(min_x, min_y, min_z, max_x, max_y, max_z) end
+
+--- Get some basic information about a block.
+--
+-- The returned table contains the current name, metadata and block state (as
+-- with @{turtle.inspect}). If there is a tile entity for that block, its NBT
+-- will also be returned.
+--
+-- @tparam number x The x position of the block to query.
+-- @tparam number y The y position of the block to query.
+-- @tparam number z The z position of the block to query.
+-- @treturn table The given block's information.
+-- @throws If the coordinates are not within the world, or are not currently
+-- loaded.
 function getBlockInfo(x, y, z) end
+
+--- Get information about a range of blocks.
+--
+-- This returns the same information as @{getBlockInfo}, just for multiple
+-- blocks at once.
+--
+-- Blocks are traversed by ascending y level, followed by z and x - the returned
+-- table may be indexed using `x + z*width + y*depth*depth`.
+--
+-- @tparam number min_x The start x coordinate of the range to query.
+-- @tparam number min_y The start y coordinate of the range to query.
+-- @tparam number min_z The start z coordinate of the range to query.
+-- @tparam number max_x The end x coordinate of the range to query.
+-- @tparam number max_y The end y coordinate of the range to query.
+-- @tparam number max_z The end z coordinate of the range to query.
+-- @treturn { table... } A list of information about each block.
+-- @throws If the coordinates are not within the world.
+-- @throws If trying to get information about more than 4096 blocks.
+function getBlockInfos(min_x, min_y, min_z, max_x, max_y, max_z) end

doc/stub/fs.lua

@@ -19,6 +19,48 @@ function getFreeSpace(path) end
 function find(pattern) end
 function getDir(path) end
 
+--- Returns true if a path is mounted to the parent filesystem.
+--
+-- The root filesystem "/" is considered a mount, along with disk folders and
+-- the rom folder. Other programs (such as network shares) can exstend this to
+-- make other mount types by correctly assigning their return value for getDrive.
+--
+-- @tparam string path The path to check.
+-- @treturn boolean If the path is mounted, rather than a normal file/folder.
+-- @throws If the path does not exist.
+-- @see getDrive
+function isDriveRoot(path) end
+
+--- Get the capacity of the drive at the given path.
+--
+-- This may be used in conjunction with @{getFreeSpace} to determine what
+-- percentage of this drive has been used.
+--
+-- @tparam string path The path of the drive to get.
+-- @treturn number This drive's capacity. This will be 0 for "read-only" drives,
+-- such as the ROM or treasure disks.
+function getCapacity(path) end
+
+--- Get attributes about a specific file or folder.
+--
+-- The returned attributes table contains information about the size of the
+-- file, whether it is a directory, and when it was created and last modified.
+--
+-- The creation and modification times are given as the number of milliseconds
+-- since the UNIX epoch. This may be given to @{os.date} in order to convert it
+-- to more usable form.
+--
+-- @tparam string path The path to get attributes for.
+-- @treturn { size = number, isDir = boolean, created = number, modified = number }
+-- The resulting attributes.
+-- @throws If the path does not exist.
+-- @see getSize If you only care about the file's size.
+-- @see isDir If you only care whether a path is a directory or not.
+function attributes(path) end
+
+-- Defined in bios.lua
+function complete(sPath, sLocation, bIncludeFiles, bIncludeDirs) end
+
 --- A file handle which can be read from.
 --
 -- @type ReadHandle

doc/stub/os.lua

@@ -15,3 +15,10 @@ function cancelTimer(id) end
 function cancelAlarm(id) end
 function epoch(timezone) end
 function date(format, time) end
+
+-- Defined in bios.lua
+function loadAPI(path) end
+function pullEvent(filter) end
+function pullEventRaw(filter) end
+function version() end
+function run(env, path, ...) end

doc/stub/pocket.lua

@@ -0,0 +1,28 @@
+--[[-
+Control the current pocket computer, adding or removing upgrades.
+
+This API is only available on pocket computers. As such, you may use its
+presence to determine what kind of computer you are using:
+
+```lua
+if pocket then
+  print("On a pocket computer")
+else
+  print("On something else")
+end
+```
+]]
+
+--- Search the player's inventory for another upgrade, replacing the existing
+-- one with that item if found.
+--
+-- This inventory search starts from the player's currently selected slot,
+-- allowing you to prioritise upgrades.
+--
+-- @throws If an upgrade cannot be found.
+function equipBack() end
+
+--- Remove the pocket computer's current upgrade.
+--
+-- @throws If this pocket computer does not currently have an upgrade.
+function unequipBack() end

doc/stub/redstone.lua

@@ -1,14 +1,120 @@
+--[[- Interact with redstone attached to this computer.
+
+The @{redstone} library exposes three "types" of redstone control:
+ - Binary input/output (@{setOutput}/@{getInput}): These simply check if a
+   redstone wire has any input or output. A signal strength of 1 and 15 are
+   treated the same.
+ - Analogue input/output (@{setAnalogueOutput}/@{getAnalogueInput}): These
+   work with the actual signal strength of the redstone wired, from 0 to 15.
+ - Bundled cables (@{setBundledOutput}/@{getBundledInput}): These interact with
+   "bundled" cables, such as those from Project:Red. These allow you to send
+   16 separate on/off signals. Each channel corresponds to a colour, with the
+   first being @{colors.white} and the last @{colors.black}.
+
+Whenever a redstone input changes, a `redstone` event will be fired. This may
+be used in or
+
+This module may also be referred to as `rs`. For example, one may call
+`rs.getSides()` instead of @{redstone.getSides}.
+
+@module redstone
+@usage Toggle the redstone signal above the computer every 0.5 seconds.
+
+    while true do
+        redstone.setOutput("top", not redstone.getOutput("top"))
+        sleep(0.5)
+    end
+@usage Mimic a redstone comparator in [subtraction mode][comparator].
+
+    while true do
+      local rear = rs.getAnalogueInput("back")
+      local sides = math.max(rs.getAnalogueInput("left"), rs.getAnalogueInput("right"))
+      rs.setAnalogueOutput("front", math.max(rear - sides, 0))
+
+      os.pullEvent("redstone") -- Wait for a change to inputs.
+    end
+
+[comparator]: https://minecraft.gamepedia.com/Redstone_Comparator#Subtract_signal_strength "Redstone Comparator on the Minecraft wiki."
+]]
+
+--- Returns a table containing the six sides of the computer. Namely, "top",
+-- "bottom", "left", "right", "front" and "back".
+--
+-- @treturn { string... } A table of valid sides.
 function getSides() end
+
+--- Turn the redstone signal of a specific side on or off.
+--
+-- @tparam string side The side to set.
+-- @tparam boolean on Whether the redstone signal should be on or off. When on,
+-- a signal strength of 15 is emitted.
 function setOutput(side, on) end
+
+--- Get the current redstone output of a specific side.
+--
+-- @tparam string side The side to get.
+-- @treturn boolean Whether the redstone output is on or off.
+-- @see setOutput
 function getOutput(side) end
+
+--- Get the current redstone input of a specific side.
+--
+-- @tparam string side The side to get.
+-- @treturn boolean Whether the redstone input is on or off.
 function getInput(side) end
-function setBundledOutput(side, output) end
-function getBundledOutput(side) end
-function getBundledInput(side) end
-function testBundledInput(side, mask) end
+
+--- Set the redstone signal strength for a specific side.
+--
+-- @tparam string side The side to set.
+-- @tparam number value The signal strength, between 0 and 15.
+-- @throws If `value` is not between 0 and 15.
 function setAnalogOutput(side, value) end
 setAnalogueOutput = setAnalogOutput
+
+--- Get the redstone output signal strength for a specific side.
+--
+-- @tparam string side The side to get.
+-- @treturn number The output signal strength, between 0 and 15.
+-- @see setAnalogueOutput
 function getAnalogOutput(sid) end
 getAnalogueOutput = getAnalogOutput
+
+--- Get the redstone input signal strength for a specific side.
+--
+-- @tparam string side The side to get.
+-- @treturn number The input signal strength, between 0 and 15.
 function getAnalogInput(side) end
-getAnalogueInput = getAnaloguInput
+getAnalogueInput = getAnalogInput
+
+--- Set the bundled cable output for a specific side.
+--
+-- @tparam string side The side to set.
+-- @tparam number The colour bitmask to set.
+-- @see colors.subtract For removing a colour from the bitmask.
+-- @see colors.combine For adding a colour to the bitmask.
+function setBundledOutput(side, output) end
+
+--- Get the bundled cable output for a specific side.
+--
+-- @tparam string side The side to get.
+-- @treturn number The bundled cable's output.
+function getBundledOutput(side) end
+
+--- Get the bundled cable input for a specific side.
+--
+-- @tparam string side The side to get.
+-- @treturn number The bundled cable's input.
+-- @see testBundledInput To determine if a specific colour is set.
+function getBundledInput(side) end
+
+--- Determine if a specific combination of colours are on for the given side.
+--
+-- @tparam string side The side to test.
+-- @tparam number mask The mask to test.
+-- @see getBundledInput
+-- @see colors.combine For adding a colour to the bitmask.
+-- @usage Check if @{colors.white} and @{colors.black} are on for above the
+-- computer.
+--
+--     print(redstone.testBundledInput("top", colors.combine(colors.white, colors.black)))
+function testBundledInput(side, mask) end

doc/stub/term.lua

@@ -15,14 +15,14 @@ isColor = isColour
 function getTextColour() end
 getTextColor = getTextColor
 function getBackgroundColour() end
-getBackgroundColour = getBackgroundColour
+getBackgroundColor = getBackgroundColour
 function blit(text, text_colours, background_colours) end
 function setPaletteColour(colour, ...) end
-setPaletteColour = setPaletteColour
+setPaletteColor = setPaletteColour
 function getPaletteColour(colour, ...) end
-getPaletteColour = getPaletteColour
+getPaletteColor = getPaletteColour
 function nativePaletteColour(colour) end
-nativePaletteColour = nativePaletteColour
+nativePaletteColor = nativePaletteColour
 
 --- @type Redirect
 local Redirect = {}

gradle.properties

@@ -1,7 +1,7 @@
 # Mod properties
-mod_version=1.87.1
+mod_version=1.89.1
 
 # Minecraft properties (update mods.toml when changing)
-mc_version=1.14.4
-forge_version=28.1.71
-mappings_version=20191123-1.14.3
+mc_version=1.15.2
+forge_version=31.1.41
+mappings_version=20200429-1.15.1

illuaminate.sexp

@@ -33,17 +33,27 @@
 
     ;; It's useful to name arguments for documentation, so we allow this. It'd
     ;; be good to find a compromise in the future, but this works for now.
-    -var:unused-arg
+    -var:unused-arg)
 
-    ;; Some APIS (keys, colour and os mainly) are incomplete right now.
-    -var:unresolved-member)
   (lint
     (bracket-spaces
       (call no-space)
       (function-args no-space)
       (parens no-space)
       (table space)
-      (index no-space))))
+      (index no-space))
+
+    ;; colours imports from colors, and we don't handle that right now.
+    ;; keys is entirely dynamic, so we skip it.
+    (dynamic-modules colours keys)
+
+    (globals
+      :max
+      _CC_DEFAULT_SETTINGS
+      _CC_DISABLE_LUA51_FEATURES
+      ;; Ideally we'd pick these up from bios.lua, but illuaminate currently
+      ;; isn't smart enough.
+      sleep write printError read rs)))
 
 ;; We disable the unused global linter in bios.lua and the APIs. In the future
 ;; hopefully we'll get illuaminate to handle this.
@@ -60,17 +70,13 @@
 
 ;; Suppress warnings for currently undocumented modules.
 (at
-  (/doc/stub/commands.lua
-   /doc/stub/fs.lua
+  (/doc/stub/fs.lua
    /doc/stub/http.lua
    /doc/stub/os.lua
-   /doc/stub/redstone.lua
    /doc/stub/term.lua
    /doc/stub/turtle.lua
-   /src/main/resources/*/computercraft/lua/rom/apis/command/commands.lua
    /src/main/resources/*/computercraft/lua/rom/apis/io.lua
-   /src/main/resources/*/computercraft/lua/rom/apis/window.lua
-   /src/main/resources/*/computercraft/lua/rom/modules/main/cc/shell/completion.lua)
+   /src/main/resources/*/computercraft/lua/rom/apis/window.lua)
 
   (linters -doc:undocumented -doc:undocumented-arg))
 
@@ -79,6 +85,11 @@
   (/src/main/resources/*/computercraft/lua/rom/apis/textutils.lua
    /src/main/resources/*/computercraft/lua/rom/modules/main/cc/completion.lua
    /src/main/resources/*/computercraft/lua/rom/modules/main/cc/shell/completion.lua
-   /src/main/resources/*/computercraft/lua/rom/programs/advanced/multishell.lua
    /src/main/resources/*/computercraft/lua/rom/programs/shell.lua)
   (linters -doc:unresolved-reference))
+
+(at /src/test/resources/test-rom
+  (lint
+    (globals
+      :max sleep write
+      cct_test describe expect howlci fail it pending stub)))

src/generated/resources/data/computercraft/loot_tables/blocks/computer_advanced.json

@@ -17,6 +17,9 @@
             {
               "condition": "computercraft:block_named"
             },
+            {
+              "condition": "computercraft:has_id"
+            },
             {
               "condition": "minecraft:inverted",
               "term": {

src/generated/resources/data/computercraft/loot_tables/blocks/computer_normal.json

@@ -17,6 +17,9 @@
             {
               "condition": "computercraft:block_named"
             },
+            {
+              "condition": "computercraft:has_id"
+            },
             {
               "condition": "minecraft:inverted",
               "term": {

src/generated/resources/data/computercraft/loot_tables/blocks/turtle_advanced.json

@@ -17,6 +17,9 @@
             {
               "condition": "computercraft:block_named"
             },
+            {
+              "condition": "computercraft:has_id"
+            },
             {
               "condition": "minecraft:inverted",
               "term": {

src/generated/resources/data/computercraft/loot_tables/blocks/turtle_normal.json

@@ -17,6 +17,9 @@
             {
               "condition": "computercraft:block_named"
             },
+            {
+              "condition": "computercraft:has_id"
+            },
             {
               "condition": "minecraft:inverted",
               "term": {

src/generated/resources/data/computercraft/loot_tables/treasure_disk.json

@@ -0,0 +1 @@
+{}

src/main/java/dan200/computercraft/ComputerCraft.java

@@ -6,7 +6,8 @@
 package dan200.computercraft;
 
 import dan200.computercraft.api.turtle.event.TurtleAction;
-import dan200.computercraft.core.apis.AddressPredicate;
+import dan200.computercraft.core.apis.http.options.Action;
+import dan200.computercraft.core.apis.http.options.AddressRule;
 import dan200.computercraft.shared.Config;
 import dan200.computercraft.shared.computer.blocks.BlockComputer;
 import dan200.computercraft.shared.computer.core.ClientComputerRegistry;
@@ -39,8 +40,13 @@ import org.apache.logging.log4j.Logger;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.Collections;
 import java.util.EnumSet;
+import java.util.List;
+import java.util.Objects;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 @Mod( ComputerCraft.MOD_ID )
 public final class ComputerCraft
@@ -50,8 +56,8 @@ public final class ComputerCraft
     public static final int DATAFIXER_VERSION = 0;
 
     // Configuration options
-    public static final String[] DEFAULT_HTTP_WHITELIST = new String[] { "*" };
-    public static final String[] DEFAULT_HTTP_BLACKLIST = new String[] {
+    public static final String[] DEFAULT_HTTP_ALLOW = new String[] { "*" };
+    public static final String[] DEFAULT_HTTP_DENY = new String[] {
         "127.0.0.0/8",
         "10.0.0.0/8",
         "172.16.0.0/12",
@@ -62,34 +68,38 @@ public final class ComputerCraft
     public static int computerSpaceLimit = 1000 * 1000;
     public static int floppySpaceLimit = 125 * 1000;
     public static int maximumFilesOpen = 128;
-    public static boolean disable_lua51_features = false;
-    public static String default_computer_settings = "";
-    public static boolean debug_enable = true;
-    public static boolean logPeripheralErrors = false;
+    public static boolean disableLua51Features = false;
+    public static String defaultComputerSettings = "";
+    public static boolean debugEnable = true;
+    public static boolean logComputerErrors = true;
+    public static boolean commandRequireCreative = true;
 
-    public static int computer_threads = 1;
+    public static int computerThreads = 1;
     public static long maxMainGlobalTime = TimeUnit.MILLISECONDS.toNanos( 10 );
     public static long maxMainComputerTime = TimeUnit.MILLISECONDS.toNanos( 5 );
 
-    public static boolean http_enable = true;
-    public static boolean http_websocket_enable = true;
-    public static AddressPredicate http_whitelist = new AddressPredicate( DEFAULT_HTTP_WHITELIST );
-    public static AddressPredicate http_blacklist = new AddressPredicate( DEFAULT_HTTP_BLACKLIST );
+    public static boolean httpEnabled = true;
+    public static boolean httpWebsocketEnabled = true;
+    public static List<AddressRule> httpRules = Collections.unmodifiableList( Stream.concat(
+        Stream.of( DEFAULT_HTTP_DENY )
+            .map( x -> AddressRule.parse( x, Action.DENY.toPartial() ) )
+            .filter( Objects::nonNull ),
+        Stream.of( DEFAULT_HTTP_ALLOW )
+            .map( x -> AddressRule.parse( x, Action.ALLOW.toPartial() ) )
+            .filter( Objects::nonNull )
+    ).collect( Collectors.toList() ) );
 
-    public static int httpTimeout = 30000;
     public static int httpMaxRequests = 16;
-    public static long httpMaxDownload = 16 * 1024 * 1024;
-    public static long httpMaxUpload = 4 * 1024 * 1024;
     public static int httpMaxWebsockets = 4;
-    public static int httpMaxWebsocketMessage = 128 * 1024;
 
     public static boolean enableCommandBlock = false;
-    public static int modem_range = 64;
-    public static int modem_highAltitudeRange = 384;
-    public static int modem_rangeDuringStorm = 64;
-    public static int modem_highAltitudeRangeDuringStorm = 384;
+    public static int modemRange = 64;
+    public static int modemHighAltitudeRange = 384;
+    public static int modemRangeDuringStorm = 64;
+    public static int modemHighAltitudeRangeDuringStorm = 384;
     public static int maxNotesPerTick = 8;
     public static MonitorRenderer monitorRenderer = MonitorRenderer.BEST;
+    public static long monitorBandwidth = 1_000_000;
 
     public static boolean turtlesNeedFuel = true;
     public static int turtleFuelLimit = 20000;
@@ -187,11 +197,6 @@ public final class ComputerCraft
         Config.load();
     }
 
-    public static String getVersion()
-    {
-        return "${version}";
-    }
-
     public static InputStream getResourceFile( String domain, String subPath )
     {
         IReloadableResourceManager manager = ServerLifecycleHooks.getCurrentServer().getResourceManager();

src/main/java/dan200/computercraft/ComputerCraftAPIImpl.java

@@ -5,7 +5,6 @@
  */
 package dan200.computercraft;
 
-import com.google.common.collect.MapMaker;
 import dan200.computercraft.api.ComputerCraftAPI.IComputerCraftAPI;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
@@ -24,39 +23,40 @@ import dan200.computercraft.core.filesystem.ResourceMount;
 import dan200.computercraft.shared.*;
 import dan200.computercraft.shared.peripheral.modem.wireless.WirelessNetwork;
 import dan200.computercraft.shared.util.IDAssigner;
-import dan200.computercraft.shared.wired.CapabilityWiredElement;
 import dan200.computercraft.shared.wired.WiredNode;
 import net.minecraft.resources.IReloadableResourceManager;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.Direction;
-import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.IBlockReader;
 import net.minecraft.world.World;
 import net.minecraftforge.common.util.LazyOptional;
+import net.minecraftforge.fml.ModList;
 import net.minecraftforge.fml.server.ServerLifecycleHooks;
 
 import javax.annotation.Nonnull;
 import java.io.File;
-import java.lang.ref.WeakReference;
-import java.util.Map;
+
+import static dan200.computercraft.shared.Capabilities.CAPABILITY_WIRED_ELEMENT;
 
 public final class ComputerCraftAPIImpl implements IComputerCraftAPI
 {
     public static final ComputerCraftAPIImpl INSTANCE = new ComputerCraftAPIImpl();
 
+    private String version;
+
     private ComputerCraftAPIImpl()
     {
     }
 
-    private WeakReference<IReloadableResourceManager> currentResources;
-    private final Map<ResourceLocation, ResourceMount> mountCache = new MapMaker().weakValues().concurrencyLevel( 1 ).makeMap();
-
     @Nonnull
     @Override
     public String getInstalledVersion()
     {
-        return "${version}";
+        if( version != null ) return version;
+        return version = ModList.get().getModContainerById( ComputerCraft.MOD_ID )
+            .map( x -> x.getModInfo().getVersion().toString() )
+            .orElse( "unknown" );
     }
 
     @Override
@@ -147,6 +147,6 @@ public final class ComputerCraftAPIImpl implements IComputerCraftAPI
     public LazyOptional<IWiredElement> getWiredElementAt( @Nonnull IBlockReader world, @Nonnull BlockPos pos, @Nonnull Direction side )
     {
         TileEntity tile = world.getTileEntity( pos );
-        return tile == null ? LazyOptional.empty() : tile.getCapability( CapabilityWiredElement.CAPABILITY, side );
+        return tile == null ? LazyOptional.empty() : tile.getCapability( CAPABILITY_WIRED_ELEMENT, side );
     }
 }

src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -43,9 +43,10 @@ public final class ComputerCraftAPI
     }
 
     @Nonnull
+    @Deprecated
     public static String getAPIVersion()
     {
-        return "${version}";
+        return getInstalledVersion();
     }
 
     /**
@@ -112,31 +113,6 @@ public final class ComputerCraftAPI
         return getInstance().createResourceMount( domain, subPath );
     }
 
-    /**
-     * Creates a file system mount to a resource folder, and returns it.
-     *
-     * Use in conjunction with {@link IComputerAccess#mount} or {@link IComputerAccess#mountWritable} to mount a
-     * resource folder onto a computer's file system.
-     *
-     * The files in this mount will be a combination of files in all mod jar, and data packs that contain
-     * resources with the same domain and path.
-     *
-     * @param klass   The mod class to which the files belong.
-     * @param domain  The domain under which to look for resources. eg: "mymod".
-     * @param subPath The subPath under which to look for resources. eg: "lua/myfiles".
-     * @return The mount, or {@code null} if it could be created for some reason.
-     * @see IComputerAccess#mount(String, IMount)
-     * @see IComputerAccess#mountWritable(String, IWritableMount)
-     * @see IMount
-     * @deprecated Use {@link #createResourceMount(String, String)} instead.
-     */
-    @Nullable
-    @Deprecated
-    public static IMount createResourceMount( Class<?> klass, @Nonnull String domain, @Nonnull String subPath )
-    {
-        return getInstance().createResourceMount( domain, subPath );
-    }
-
     /**
      * Registers a peripheral provider to convert blocks into {@link IPeripheral} implementations.
      *

src/main/java/dan200/computercraft/api/client/TransformedModel.java

@@ -0,0 +1,61 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.client;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.TransformationMatrix;
+import net.minecraft.client.renderer.model.IBakedModel;
+import net.minecraft.client.renderer.model.ModelManager;
+import net.minecraft.client.renderer.model.ModelResourceLocation;
+import net.minecraft.item.ItemStack;
+
+import javax.annotation.Nonnull;
+import java.util.Objects;
+
+/**
+ * A model to render, combined with a transformation matrix to apply.
+ */
+public final class TransformedModel
+{
+    private final IBakedModel model;
+    private final TransformationMatrix matrix;
+
+    public TransformedModel( @Nonnull IBakedModel model, @Nonnull TransformationMatrix matrix )
+    {
+        this.model = Objects.requireNonNull( model );
+        this.matrix = Objects.requireNonNull( matrix );
+    }
+
+    public TransformedModel( @Nonnull IBakedModel model )
+    {
+        this.model = Objects.requireNonNull( model );
+        this.matrix = TransformationMatrix.identity();
+    }
+
+    public static TransformedModel of( @Nonnull ModelResourceLocation location )
+    {
+        ModelManager modelManager = Minecraft.getInstance().getModelManager();
+        return new TransformedModel( modelManager.getModel( location ) );
+    }
+
+    public static TransformedModel of( @Nonnull ItemStack item, @Nonnull TransformationMatrix transform )
+    {
+        IBakedModel model = Minecraft.getInstance().getItemRenderer().getItemModelMesher().getItemModel( item );
+        return new TransformedModel( model, transform );
+    }
+
+    @Nonnull
+    public IBakedModel getModel()
+    {
+        return model;
+    }
+
+    @Nonnull
+    public TransformationMatrix getMatrix()
+    {
+        return matrix;
+    }
+}

src/main/java/dan200/computercraft/api/filesystem/IMount.java

@@ -11,8 +11,6 @@ import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
-import java.io.InputStream;
-import java.nio.channels.Channels;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.List;
@@ -23,10 +21,10 @@ import java.util.List;
  *
  * Ready made implementations of this interface can be created using
  * {@link ComputerCraftAPI#createSaveDirMount(World, String, long)} or
- * {@link ComputerCraftAPI#createResourceMount(Class, String, String)}, or you're free to implement it yourselves!
+ * {@link ComputerCraftAPI#createResourceMount(String, String)}, or you're free to implement it yourselves!
  *
  * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
- * @see ComputerCraftAPI#createResourceMount(Class, String, String)
+ * @see ComputerCraftAPI#createResourceMount(String, String)
  * @see IComputerAccess#mount(String, IMount)
  * @see IWritableMount
  */
@@ -68,18 +66,6 @@ public interface IMount
      */
     long getSize( @Nonnull String path ) throws IOException;
 
-    /**
-     * Opens a file with a given path, and returns an {@link InputStream} representing its contents.
-     *
-     * @param path A file path in normalised format, relative to the mount location. ie: "programs/myprogram".
-     * @return A stream representing the contents of the file.
-     * @throws IOException If the file does not exist, or could not be opened.
-     * @deprecated Use {@link #openChannelForRead(String)} instead
-     */
-    @Nonnull
-    @Deprecated
-    InputStream openForRead( @Nonnull String path ) throws IOException;
-
     /**
      * Opens a file with a given path, and returns an {@link ReadableByteChannel} representing its contents.
      *
@@ -90,10 +76,7 @@ public interface IMount
      * @throws IOException If the file does not exist, or could not be opened.
      */
     @Nonnull
-    default ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
-    {
-        return Channels.newChannel( openForRead( path ) );
-    }
+    ReadableByteChannel openForRead( @Nonnull String path ) throws IOException;
 
     /**
      * Get attributes about the given file.

src/main/java/dan200/computercraft/api/filesystem/IWritableMount.java

@@ -12,7 +12,6 @@ import net.minecraft.world.World;
 import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.io.OutputStream;
-import java.nio.channels.Channels;
 import java.nio.channels.WritableByteChannel;
 import java.util.OptionalLong;
 
@@ -46,18 +45,6 @@ public interface IWritableMount extends IMount
      */
     void delete( @Nonnull String path ) throws IOException;
 
-    /**
-     * Opens a file with a given path, and returns an {@link OutputStream} for writing to it.
-     *
-     * @param path A file path in normalised format, relative to the mount location. ie: "programs/myprogram".
-     * @return A stream for writing to
-     * @throws IOException If the file could not be opened for writing.
-     * @deprecated Use {@link #openChannelForWrite(String)} instead.
-     */
-    @Nonnull
-    @Deprecated
-    OutputStream openForWrite( @Nonnull String path ) throws IOException;
-
     /**
      * Opens a file with a given path, and returns an {@link OutputStream} for writing to it.
      *
@@ -67,22 +54,7 @@ public interface IWritableMount extends IMount
      * @throws IOException If the file could not be opened for writing.
      */
     @Nonnull
-    default WritableByteChannel openChannelForWrite( @Nonnull String path ) throws IOException
-    {
-        return Channels.newChannel( openForWrite( path ) );
-    }
-
-    /**
-     * Opens a file with a given path, and returns an {@link OutputStream} for appending to it.
-     *
-     * @param path A file path in normalised format, relative to the mount location. ie: "programs/myprogram".
-     * @return A stream for writing to.
-     * @throws IOException If the file could not be opened for writing.
-     * @deprecated Use {@link #openChannelForAppend(String)} instead.
-     */
-    @Nonnull
-    @Deprecated
-    OutputStream openForAppend( @Nonnull String path ) throws IOException;
+    WritableByteChannel openForWrite( @Nonnull String path ) throws IOException;
 
     /**
      * Opens a file with a given path, and returns an {@link OutputStream} for appending to it.
@@ -93,10 +65,7 @@ public interface IWritableMount extends IMount
      * @throws IOException If the file could not be opened for writing.
      */
     @Nonnull
-    default WritableByteChannel openChannelForAppend( @Nonnull String path ) throws IOException
-    {
-        return Channels.newChannel( openForAppend( path ) );
-    }
+    WritableByteChannel openForAppend( @Nonnull String path ) throws IOException;
 
     /**
      * Get the amount of free space on the mount, in bytes. You should decrease this value as the user writes to the

src/main/java/dan200/computercraft/api/lua/ArgumentHelper.java

@@ -1,334 +0,0 @@
-/*
- * This file is part of the public ComputerCraft API - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
- * For help using the API, and posting your mods, visit the forums at computercraft.info.
- */
-package dan200.computercraft.api.lua;
-
-import dan200.computercraft.api.peripheral.IComputerAccess;
-import dan200.computercraft.api.peripheral.IPeripheral;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import java.util.Map;
-
-/**
- * Provides methods for extracting values and validating Lua arguments, such as those provided to
- * {@link ILuaObject#callMethod(ILuaContext, int, Object[])} or
- * {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}.
- *
- * This provides two sets of functions: the {@code get*} methods, which require an argument to be valid, and
- * {@code opt*}, which accept a default value and return that if the argument was not present or was {@code null}.
- * If the argument is of the wrong type, a suitable error message will be thrown, with a similar format to Lua's own
- * error messages.
- *
- * <h2>Example usage:</h2>
- * <pre>
- * {@code
- * int slot = getInt( args, 0 );
- * int amount = optInt( args, 1, 64 );
- * }
- * </pre>
- */
-public final class ArgumentHelper
-{
-    private ArgumentHelper()
-    {
-    }
-
-    /**
-     * Get a string representation of the given value's type.
-     *
-     * @param value The value whose type we are trying to compute.
-     * @return A string representation of the given value's type, in a similar format to that provided by Lua's
-     * {@code type} function.
-     */
-    @Nonnull
-    public static String getType( @Nullable Object value )
-    {
-        if( value == null ) return "nil";
-        if( value instanceof String ) return "string";
-        if( value instanceof Boolean ) return "boolean";
-        if( value instanceof Number ) return "number";
-        if( value instanceof Map ) return "table";
-        return "userdata";
-    }
-
-    /**
-     * Construct a "bad argument" exception, from an expected type and the actual value provided.
-     *
-     * @param index    The argument number, starting from 0.
-     * @param expected The expected type for this argument.
-     * @param actual   The actual value provided for this argument.
-     * @return The constructed exception, which should be thrown immediately.
-     */
-    @Nonnull
-    public static LuaException badArgumentOf( int index, @Nonnull String expected, @Nullable Object actual )
-    {
-        return badArgument( index, expected, getType( actual ) );
-    }
-
-    /**
-     * Construct a "bad argument" exception, from an expected and actual type.
-     *
-     * @param index    The argument number, starting from 0.
-     * @param expected The expected type for this argument.
-     * @param actual   The provided type for this argument.
-     * @return The constructed exception, which should be thrown immediately.
-     */
-    @Nonnull
-    public static LuaException badArgument( int index, @Nonnull String expected, @Nonnull String actual )
-    {
-        return new LuaException( "bad argument #" + (index + 1) + " (" + expected + " expected, got " + actual + ")" );
-    }
-
-    /**
-     * Get an argument as a double.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a number.
-     * @see #getFiniteDouble(Object[], int) if you require this to be finite (i.e. not infinite or NaN).
-     */
-    public static double getDouble( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "number", "nil" );
-        Object value = args[index];
-        if( !(value instanceof Number) ) throw badArgumentOf( index, "number", value );
-        return ((Number) value).doubleValue();
-    }
-
-    /**
-     * Get an argument as an integer.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not an integer.
-     */
-    public static int getInt( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return (int) getLong( args, index );
-    }
-
-    /**
-     * Get an argument as a long.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a long.
-     */
-    public static long getLong( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "number", "nil" );
-        Object value = args[index];
-        if( !(value instanceof Number) ) throw badArgumentOf( index, "number", value );
-        return checkFinite( index, (Number) value ).longValue();
-    }
-
-    /**
-     * Get an argument as a finite number (not infinite or NaN).
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not finite.
-     */
-    public static double getFiniteDouble( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return checkFinite( index, getDouble( args, index ) );
-    }
-
-    /**
-     * Get an argument as a boolean.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a boolean.
-     */
-    public static boolean getBoolean( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "boolean", "nil" );
-        Object value = args[index];
-        if( !(value instanceof Boolean) ) throw badArgumentOf( index, "boolean", value );
-        return (Boolean) value;
-    }
-
-    /**
-     * Get an argument as a string.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a string.
-     */
-    @Nonnull
-    public static String getString( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "string", "nil" );
-        Object value = args[index];
-        if( !(value instanceof String) ) throw badArgumentOf( index, "string", value );
-        return (String) value;
-    }
-
-    /**
-     * Get an argument as a table.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a table.
-     */
-    @Nonnull
-    public static Map<?, ?> getTable( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "table", "nil" );
-        Object value = args[index];
-        if( !(value instanceof Map) ) throw badArgumentOf( index, "table", value );
-        return (Map<?, ?>) value;
-    }
-
-    /**
-     * Get an argument as a double.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a number.
-     */
-    public static double optDouble( @Nonnull Object[] args, int index, double def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof Number) ) throw badArgumentOf( index, "number", value );
-        return ((Number) value).doubleValue();
-    }
-
-    /**
-     * Get an argument as an int.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a number.
-     */
-    public static int optInt( @Nonnull Object[] args, int index, int def ) throws LuaException
-    {
-        return (int) optLong( args, index, def );
-    }
-
-    /**
-     * Get an argument as a long.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a number.
-     */
-    public static long optLong( @Nonnull Object[] args, int index, long def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof Number) ) throw badArgumentOf( index, "number", value );
-        return checkFinite( index, (Number) value ).longValue();
-    }
-
-    /**
-     * Get an argument as a finite number (not infinite or NaN).
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not finite.
-     */
-    public static double optFiniteDouble( @Nonnull Object[] args, int index, double def ) throws LuaException
-    {
-        return checkFinite( index, optDouble( args, index, def ) );
-    }
-
-    /**
-     * Get an argument as a boolean.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a boolean.
-     */
-    public static boolean optBoolean( @Nonnull Object[] args, int index, boolean def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof Boolean) ) throw badArgumentOf( index, "boolean", value );
-        return (Boolean) value;
-    }
-
-    /**
-     * Get an argument as a string.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a string.
-     */
-    public static String optString( @Nonnull Object[] args, int index, String def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof String) ) throw badArgumentOf( index, "string", value );
-        return (String) value;
-    }
-
-    /**
-     * Get an argument as a table.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a table.
-     */
-    public static Map<?, ?> optTable( @Nonnull Object[] args, int index, Map<Object, Object> def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof Map) ) throw badArgumentOf( index, "table", value );
-        return (Map<?, ?>) value;
-    }
-
-    private static Number checkFinite( int index, Number value ) throws LuaException
-    {
-        checkFinite( index, value.doubleValue() );
-        return value;
-    }
-
-    private static double checkFinite( int index, double value ) throws LuaException
-    {
-        if( !Double.isFinite( value ) ) throw badArgument( index, "number", getNumericType( value ) );
-        return value;
-    }
-
-    /**
-     * Returns a more detailed representation of this number's type. If this is finite, it will just return "number",
-     * otherwise it returns whether it is infinite or NaN.
-     *
-     * @param value The value to extract the type for.
-     * @return This value's numeric type.
-     */
-    @Nonnull
-    public static String getNumericType( double value )
-    {
-        if( Double.isNaN( value ) ) return "nan";
-        if( value == Double.POSITIVE_INFINITY ) return "inf";
-        if( value == Double.NEGATIVE_INFINITY ) return "-inf";
-        return "number";
-    }
-}

src/main/java/dan200/computercraft/api/lua/IArguments.java

@@ -0,0 +1,407 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
+import java.util.Map;
+import java.util.Optional;
+
+import static dan200.computercraft.api.lua.LuaValues.checkFinite;
+
+/**
+ * The arguments passed to a function.
+ */
+public interface IArguments
+{
+    /**
+     * Get the number of arguments passed to this function.
+     *
+     * @return The number of passed arguments.
+     */
+    int count();
+
+    /**
+     * Get the argument at the specific index. The returned value must obey the following conversion rules:
+     *
+     * <ul>
+     *   <li>Lua values of type "string" will be represented by a {@link String}.</li>
+     *   <li>Lua values of type "number" will be represented by a {@link Number}.</li>
+     *   <li>Lua values of type "boolean" will be represented by a {@link Boolean}.</li>
+     *   <li>Lua values of type "table" will be represented by a {@link Map}.</li>
+     *   <li>Lua values of any other type will be represented by a {@code null} value.</li>
+     * </ul>
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@code null} if not present.
+     */
+    @Nullable
+    Object get( int index );
+
+    /**
+     * Drop a number of arguments. The returned arguments instance will access arguments at position {@code i + count},
+     * rather than {@code i}. However, errors will still use the given argument index.
+     *
+     * @param count The number of arguments to drop.
+     * @return The new {@link IArguments} instance.
+     */
+    IArguments drop( int count );
+
+    default Object[] getAll()
+    {
+        Object[] result = new Object[count()];
+        for( int i = 0; i < result.length; i++ ) result[i] = get( i );
+        return result;
+    }
+
+    /**
+     * Get an argument as a double.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a number.
+     * @see #getFiniteDouble(int) if you require this to be finite (i.e. not infinite or NaN).
+     */
+    default double getDouble( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return ((Number) value).doubleValue();
+    }
+
+    /**
+     * Get an argument as an integer.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not an integer.
+     */
+    default int getInt( int index ) throws LuaException
+    {
+        return (int) getLong( index );
+    }
+
+    /**
+     * Get an argument as a long.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a long.
+     */
+    default long getLong( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return LuaValues.checkFiniteNum( index, (Number) value ).longValue();
+    }
+
+    /**
+     * Get an argument as a finite number (not infinite or NaN).
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not finite.
+     */
+    default double getFiniteDouble( int index ) throws LuaException
+    {
+        return checkFinite( index, getDouble( index ) );
+    }
+
+    /**
+     * Get an argument as a boolean.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a boolean.
+     */
+    default boolean getBoolean( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof Boolean) ) throw LuaValues.badArgumentOf( index, "boolean", value );
+        return (Boolean) value;
+    }
+
+    /**
+     * Get an argument as a string.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a string.
+     */
+    @Nonnull
+    default String getString( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof String) ) throw LuaValues.badArgumentOf( index, "string", value );
+        return (String) value;
+    }
+
+    /**
+     * Get a string argument as a byte array.
+     *
+     * @param index The argument number.
+     * @return The argument's value. This is a <em>read only</em> buffer.
+     * @throws LuaException If the value is not a string.
+     */
+    @Nonnull
+    default ByteBuffer getBytes( int index ) throws LuaException
+    {
+        return LuaValues.encode( getString( index ) );
+    }
+
+    /**
+     * Get a string argument as an enum value.
+     *
+     * @param index The argument number.
+     * @param klass The type of enum to parse.
+     * @param <T>   The type of enum to parse.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a string or not a valid option for this enum.
+     */
+    @Nonnull
+    default <T extends Enum<T>> T getEnum( int index, Class<T> klass ) throws LuaException
+    {
+        return LuaValues.checkEnum( index, klass, getString( index ) );
+    }
+
+    /**
+     * Get an argument as a table.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a table.
+     */
+    @Nonnull
+    default Map<?, ?> getTable( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof Map) ) throw LuaValues.badArgumentOf( index, "table", value );
+        return (Map<?, ?>) value;
+    }
+
+    /**
+     * Get an argument as a double.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a number.
+     */
+    @Nonnull
+    default Optional<Double> optDouble( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return Optional.of( ((Number) value).doubleValue() );
+    }
+
+    /**
+     * Get an argument as an int.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a number.
+     */
+    @Nonnull
+    default Optional<Integer> optInt( int index ) throws LuaException
+    {
+        return optLong( index ).map( Long::intValue );
+    }
+
+    /**
+     * Get an argument as a long.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a number.
+     */
+    default Optional<Long> optLong( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return Optional.of( LuaValues.checkFiniteNum( index, (Number) value ).longValue() );
+    }
+
+    /**
+     * Get an argument as a finite number (not infinite or NaN).
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not finite.
+     */
+    default Optional<Double> optFiniteDouble( int index ) throws LuaException
+    {
+        Optional<Double> value = optDouble( index );
+        if( value.isPresent() ) LuaValues.checkFiniteNum( index, value.get() );
+        return value;
+    }
+
+    /**
+     * Get an argument as a boolean.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a boolean.
+     */
+    default Optional<Boolean> optBoolean( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof Boolean) ) throw LuaValues.badArgumentOf( index, "boolean", value );
+        return Optional.of( (Boolean) value );
+    }
+
+    /**
+     * Get an argument as a string.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a string.
+     */
+    default Optional<String> optString( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof String) ) throw LuaValues.badArgumentOf( index, "string", value );
+        return Optional.of( (String) value );
+    }
+
+    /**
+     * Get a string argument as a byte array.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present. This is a <em>read only</em> buffer.
+     * @throws LuaException If the value is not a string.
+     */
+    default Optional<ByteBuffer> optBytes( int index ) throws LuaException
+    {
+        return optString( index ).map( LuaValues::encode );
+    }
+
+    /**
+     * Get a string argument as an enum value.
+     *
+     * @param index The argument number.
+     * @param klass The type of enum to parse.
+     * @param <T>   The type of enum to parse.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a string or not a valid option for this enum.
+     */
+    @Nonnull
+    default <T extends Enum<T>> Optional<T> optEnum( int index, Class<T> klass ) throws LuaException
+    {
+        Optional<String> str = optString( index );
+        return str.isPresent() ? Optional.of( LuaValues.checkEnum( index, klass, str.get() ) ) : Optional.empty();
+    }
+
+    /**
+     * Get an argument as a table.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a table.
+     */
+    default Optional<Map<?, ?>> optTable( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof Map) ) throw LuaValues.badArgumentOf( index, "map", value );
+        return Optional.of( (Map<?, ?>) value );
+    }
+
+    /**
+     * Get an argument as a double.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a number.
+     */
+    default double optDouble( int index, double def ) throws LuaException
+    {
+        return optDouble( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as an int.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a number.
+     */
+    default int optInt( int index, int def ) throws LuaException
+    {
+        return optInt( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a long.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a number.
+     */
+    default long optLong( int index, long def ) throws LuaException
+    {
+        return optLong( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a finite number (not infinite or NaN).
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not finite.
+     */
+    default double optFiniteDouble( int index, double def ) throws LuaException
+    {
+        return optFiniteDouble( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a boolean.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a boolean.
+     */
+    default boolean optBoolean( int index, boolean def ) throws LuaException
+    {
+        return optBoolean( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a string.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a string.
+     */
+    default String optString( int index, String def ) throws LuaException
+    {
+        return optString( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a table.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a table.
+     */
+    default Map<?, ?> optTable( int index, Map<Object, Object> def ) throws LuaException
+    {
+        return optTable( index ).orElse( def );
+    }
+}

src/main/java/dan200/computercraft/api/lua/IDynamicLuaObject.java

@@ -0,0 +1,45 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.peripheral.IDynamicPeripheral;
+
+import javax.annotation.Nonnull;
+
+/**
+ * An interface for representing custom objects returned by peripherals or other Lua objects.
+ *
+ * Generally, one does not need to implement this type - it is sufficient to return an object with some methods
+ * annotated with {@link LuaFunction}. {@link IDynamicLuaObject} is useful when you wish your available methods to
+ * change at runtime.
+ */
+public interface IDynamicLuaObject
+{
+    /**
+     * Get the names of the methods that this object implements. This should not change over the course of the object's
+     * lifetime.
+     *
+     * @return The method names this object provides.
+     * @see IDynamicPeripheral#getMethodNames()
+     */
+    @Nonnull
+    String[] getMethodNames();
+
+    /**
+     * Called when a user calls one of the methods that this object implements.
+     *
+     * @param context   The context of the currently running lua thread. This can be used to wait for events
+     *                  or otherwise yield.
+     * @param method    An integer identifying which method index from {@link #getMethodNames()} the computer wishes
+     *                  to call.
+     * @param arguments The arguments for this method.
+     * @return The result of this function. Either an immediate value ({@link MethodResult#of(Object...)} or an
+     * instruction to yield.
+     * @throws LuaException If the function threw an exception.
+     */
+    @Nonnull
+    MethodResult callMethod( @Nonnull ILuaContext context, int method, @Nonnull IArguments arguments ) throws LuaException;
+}

src/main/java/dan200/computercraft/api/lua/ILuaAPI.java

@@ -8,7 +8,8 @@ package dan200.computercraft.api.lua;
 import dan200.computercraft.api.ComputerCraftAPI;
 
 /**
- * Represents a {@link ILuaObject} which is stored as a global variable on computer startup.
+ * Represents a Lua object which is stored as a global variable on computer startup. This must either provide
+ * {@link LuaFunction} annotated functions or implement {@link IDynamicLuaObject}.
  *
  * Before implementing this interface, consider alternative methods of providing methods. It is generally preferred
  * to use peripherals to provide functionality to users.
@@ -16,7 +17,7 @@ import dan200.computercraft.api.ComputerCraftAPI;
  * @see ILuaAPIFactory
  * @see ComputerCraftAPI#registerAPIFactory(ILuaAPIFactory)
  */
-public interface ILuaAPI extends ILuaObject
+public interface ILuaAPI
 {
     /**
      * Get the globals this API will be assigned to. This will override any other global, so you should

src/main/java/dan200/computercraft/api/lua/ILuaCallback.java

@@ -0,0 +1,27 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nonnull;
+
+/**
+ * A continuation which is called when this coroutine is resumed.
+ *
+ * @see MethodResult#yield(Object[], ILuaCallback)
+ */
+public interface ILuaCallback
+{
+    /**
+     * Resume this coroutine.
+     *
+     * @param args The result of resuming this coroutine. These will have the same form as described in
+     *             {@link LuaFunction}.
+     * @return The result of this continuation. Either the result to return to the callee, or another yield.
+     * @throws LuaException On an error.
+     */
+    @Nonnull
+    MethodResult resume( Object[] args ) throws LuaException;
+}

src/main/java/dan200/computercraft/api/lua/ILuaContext.java

@@ -6,99 +6,25 @@
 package dan200.computercraft.api.lua;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 /**
- * An interface passed to peripherals and {@link ILuaObject}s by computers or turtles, providing methods
- * that allow the peripheral call to wait for events before returning, just like in lua. This is very useful if you need
- * to signal work to be performed on the main thread, and don't want to return until the work has been completed.
+ * An interface passed to peripherals and {@link IDynamicLuaObject}s by computers or turtles, providing methods
+ * that allow the peripheral call to interface with the computer.
  */
 public interface ILuaContext
 {
-    /**
-     * Wait for an event to occur on the computer, suspending the thread until it arises. This method is exactly
-     * equivalent to {@code os.pullEvent()} in lua.
-     *
-     * @param filter A specific event to wait for, or null to wait for any event.
-     * @return An object array containing the name of the event that occurred, and any event parameters.
-     * @throws LuaException         If the user presses CTRL+T to terminate the current program while pullEvent() is
-     *                              waiting for an event, a "Terminated" exception will be thrown here.
-     *
-     *                              Do not attempt to catch this exception. You should use {@link #pullEventRaw(String)}
-     *                              should you wish to disable termination.
-     * @throws InterruptedException If the user shuts down or reboots the computer while pullEvent() is waiting for an
-     *                              event, InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     */
-    @Nonnull
-    default Object[] pullEvent( @Nullable String filter ) throws LuaException, InterruptedException
-    {
-        Object[] results = pullEventRaw( filter );
-        if( results.length >= 1 && results[0].equals( "terminate" ) ) throw new LuaException( "Terminated", 0 );
-        return results;
-    }
-
-    /**
-     * The same as {@link #pullEvent(String)}, except "terminated" events are ignored. Only use this if you want to
-     * prevent program termination, which is not recommended. This method is exactly equivalent to
-     * {@code os.pullEventRaw()} in lua.
-     *
-     * @param filter A specific event to wait for, or null to wait for any event.
-     * @return An object array containing the name of the event that occurred, and any event parameters.
-     * @throws InterruptedException If the user shuts down or reboots the computer while pullEventRaw() is waiting for
-     *                              an event, InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     * @see #pullEvent(String)
-     */
-    @Nonnull
-    default Object[] pullEventRaw( @Nullable String filter ) throws InterruptedException
-    {
-        return yield( new Object[] { filter } );
-    }
-
-    /**
-     * Yield the current coroutine with some arguments until it is resumed. This method is exactly equivalent to
-     * {@code coroutine.yield()} in lua. Use {@code pullEvent()} if you wish to wait for events.
-     *
-     * @param arguments An object array containing the arguments to pass to coroutine.yield()
-     * @return An object array containing the return values from coroutine.yield()
-     * @throws InterruptedException If the user shuts down or reboots the computer the coroutine is suspended,
-     *                              InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     * @see #pullEvent(String)
-     */
-    @Nonnull
-    Object[] yield( @Nullable Object[] arguments ) throws InterruptedException;
-
-    /**
-     * Queue a task to be executed on the main server thread at the beginning of next tick, waiting for it to complete.
-     * This should be used when you need to interact with the world in a thread-safe manner.
-     *
-     * Note that the return values of your task are handled as events, meaning more complex objects such as maps or
-     * {@link ILuaObject} will not preserve their identities.
-     *
-     * @param task The task to execute on the main thread.
-     * @return The objects returned by {@code task}.
-     * @throws LuaException         If the task could not be queued, or if the task threw an exception.
-     * @throws InterruptedException If the user shuts down or reboots the computer the coroutine is suspended,
-     *                              InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     */
-    @Nullable
-    Object[] executeMainThreadTask( @Nonnull ILuaTask task ) throws LuaException, InterruptedException;
-
     /**
      * Queue a task to be executed on the main server thread at the beginning of next tick, but do not wait for it to
      * complete. This should be used when you need to interact with the world in a thread-safe manner but do not care
      * about the result or you wish to run asynchronously.
      *
      * When the task has finished, it will enqueue a {@code task_completed} event, which takes the task id, a success
-     * value and the return values, or an error message if it failed. If you need to wait on this event, it may be
-     * better to use {@link #executeMainThreadTask(ILuaTask)}.
+     * value and the return values, or an error message if it failed.
      *
      * @param task The task to execute on the main thread.
      * @return The "id" of the task. This will be the first argument to the {@code task_completed} event.
      * @throws LuaException If the task could not be queued.
+     * @see LuaFunction#mainThread() To run functions on the main thread and return their results synchronously.
      */
     long issueMainThreadTask( @Nonnull ILuaTask task ) throws LuaException;
 }

src/main/java/dan200/computercraft/api/lua/ILuaFunction.java

@@ -0,0 +1,29 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nonnull;
+
+/**
+ * A function, which can be called from Lua. If you need to return a table of functions, it is recommended to use
+ * an object with {@link LuaFunction} methods, or implement {@link IDynamicLuaObject}.
+ *
+ * @see MethodResult#of(Object)
+ */
+@FunctionalInterface
+public interface ILuaFunction
+{
+    /**
+     * Call this function with a series of arguments. Note, this will <em>always</em> be called on the computer thread,
+     * and so its implementation must be thread-safe.
+     *
+     * @param arguments The arguments for this function
+     * @return The result of calling this function.
+     * @throws LuaException Upon Lua errors.
+     */
+    @Nonnull
+    MethodResult call( @Nonnull IArguments arguments ) throws LuaException;
+}

src/main/java/dan200/computercraft/api/lua/ILuaObject.java

@@ -1,55 +0,0 @@
-/*
- * This file is part of the public ComputerCraft API - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
- * For help using the API, and posting your mods, visit the forums at computercraft.info.
- */
-package dan200.computercraft.api.lua;
-
-import dan200.computercraft.api.peripheral.IComputerAccess;
-import dan200.computercraft.api.peripheral.IPeripheral;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * An interface for representing custom objects returned by {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}
- * calls.
- *
- * Return objects implementing this interface to expose objects with methods to lua.
- */
-public interface ILuaObject
-{
-    /**
-     * Get the names of the methods that this object implements. This works the same as {@link IPeripheral#getMethodNames()}.
-     * See that method for detailed documentation.
-     *
-     * @return The method names this object provides.
-     * @see IPeripheral#getMethodNames()
-     */
-    @Nonnull
-    String[] getMethodNames();
-
-    /**
-     * Called when a user calls one of the methods that this object implements. This works the same as
-     * {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}}. See that method for detailed
-     * documentation.
-     *
-     * @param context   The context of the currently running lua thread. This can be used to wait for events
-     *                  or otherwise yield.
-     * @param method    An integer identifying which of the methods from getMethodNames() the computercraft
-     *                  wishes to call. The integer indicates the index into the getMethodNames() table
-     *                  that corresponds to the string passed into peripheral.call()
-     * @param arguments The arguments for this method. See {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}
-     *                  the possible values and conversion rules.
-     * @return An array of objects, representing the values you wish to return to the Lua program.
-     * See {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])} for the valid values and
-     * conversion rules.
-     * @throws LuaException         If the task could not be queued, or if the task threw an exception.
-     * @throws InterruptedException If the user shuts down or reboots the computer the coroutine is suspended,
-     *                              InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.w
-     * @see IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])
-     */
-    @Nullable
-    Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] arguments ) throws LuaException, InterruptedException;
-}

src/main/java/dan200/computercraft/api/lua/ILuaTask.java

@@ -8,11 +8,10 @@ package dan200.computercraft.api.lua;
 import javax.annotation.Nullable;
 
 /**
- * A task which can be executed via {@link ILuaContext#executeMainThreadTask(ILuaTask)} or
- * {@link ILuaContext#issueMainThreadTask(ILuaTask)}. This will be run on the main thread, at the beginning of the
+ * A task which can be executed via {@link ILuaContext#issueMainThreadTask(ILuaTask)} This will be run on the main
+ * thread, at the beginning of the
  * next tick.
  *
- * @see ILuaContext#executeMainThreadTask(ILuaTask)
  * @see ILuaContext#issueMainThreadTask(ILuaTask)
  */
 @FunctionalInterface
@@ -21,8 +20,7 @@ public interface ILuaTask
     /**
      * Execute this task.
      *
-     * @return The arguments to add to the {@code task_completed} event. These will be returned by
-     * {@link ILuaContext#executeMainThreadTask(ILuaTask)}.
+     * @return The arguments to add to the {@code task_completed} event.
      * @throws LuaException If you throw any exception from this function, a lua error will be raised with the
      *                      same message as your exception. Use this to throw appropriate errors if the wrong
      *                      arguments are supplied to your method.

src/main/java/dan200/computercraft/api/lua/LuaException.java

@@ -13,24 +13,33 @@ import javax.annotation.Nullable;
 public class LuaException extends Exception
 {
     private static final long serialVersionUID = -6136063076818512651L;
+    private final boolean hasLevel;
     private final int level;
 
-    public LuaException()
-    {
-        this( "error", 1 );
-    }
-
     public LuaException( @Nullable String message )
     {
-        this( message, 1 );
+        super( message );
+        this.hasLevel = false;
+        this.level = 1;
     }
 
     public LuaException( @Nullable String message, int level )
     {
         super( message );
+        this.hasLevel = true;
         this.level = level;
     }
 
+    /**
+     * Whether a level was explicitly specified when constructing. This is used to determine
+     *
+     * @return Whether this has an explicit level.
+     */
+    public boolean hasLevel()
+    {
+        return hasLevel;
+    }
+
     /**
      * The level this error is raised at. Level 1 is the function's caller, level 2 is that function's caller, and so
      * on.

src/main/java/dan200/computercraft/api/lua/LuaFunction.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.api.peripheral.IPeripheral;
+
+import java.lang.annotation.*;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * Used to mark a Java function which is callable from Lua.
+ *
+ * Methods annotated with {@link LuaFunction} must be public final instance methods. They can have any number of
+ * parameters, but they must be of the following types:
+ *
+ * <ul>
+ *   <li>{@link ILuaContext} (and {@link IComputerAccess} if on a {@link IPeripheral})</li>
+ *   <li>{@link IArguments}: The arguments supplied to this function.</li>
+ *   <li>
+ *     Alternatively, one may specify the desired arguments as normal parameters and the argument parsing code will
+ *     be generated automatically.
+ *
+ *     Each parameter must be one of the given types supported by {@link IArguments} (for instance, {@link int} or
+ *     {@link Map}). Optional values are supported by accepting a parameter of type {@link Optional}.
+ *   </li>
+ * </ul>
+ *
+ * This function may return {@link MethodResult}. However, if you simply return a value (rather than having to yield),
+ * you may return {@code void}, a single value (either an object or a primitive like {@code int}) or array of objects.
+ * These will be treated the same as {@link MethodResult#of()}, {@link MethodResult#of(Object)} and
+ * {@link MethodResult#of(Object...)}.
+ */
+@Documented
+@Retention( RetentionPolicy.RUNTIME )
+@Target( ElementType.METHOD )
+public @interface LuaFunction
+{
+    /**
+     * Explicitly specify the method names of this function. If not given, it uses the name of the annotated method.
+     *
+     * @return This function's name(s).
+     */
+    String[] value() default {};
+
+    /**
+     * Run this function on the main server thread. This should be specified for any method which interacts with
+     * Minecraft in a thread-unsafe manner.
+     *
+     * @return Whether this functi
+     * @see ILuaContext#issueMainThreadTask(ILuaTask)
+     */
+    boolean mainThread() default false;
+}

src/main/java/dan200/computercraft/api/lua/LuaValues.java

@@ -0,0 +1,152 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
+import java.util.Map;
+
+/**
+ * Various utility functions for operating with Lua values.
+ *
+ * @see IArguments
+ */
+public final class LuaValues
+{
+    private LuaValues()
+    {
+    }
+
+    /**
+     * Encode a Lua string into a read-only {@link ByteBuffer}.
+     *
+     * @param string The string to encode.
+     * @return The encoded string.
+     */
+    @Nonnull
+    public static ByteBuffer encode( @Nonnull String string )
+    {
+        byte[] chars = new byte[string.length()];
+        for( int i = 0; i < chars.length; i++ )
+        {
+            char c = string.charAt( i );
+            chars[i] = c < 256 ? (byte) c : 63;
+        }
+
+        return ByteBuffer.wrap( chars ).asReadOnlyBuffer();
+    }
+
+    /**
+     * Returns a more detailed representation of this number's type. If this is finite, it will just return "number",
+     * otherwise it returns whether it is infinite or NaN.
+     *
+     * @param value The value to extract the type for.
+     * @return This value's numeric type.
+     */
+    @Nonnull
+    public static String getNumericType( double value )
+    {
+        if( Double.isNaN( value ) ) return "nan";
+        if( value == Double.POSITIVE_INFINITY ) return "inf";
+        if( value == Double.NEGATIVE_INFINITY ) return "-inf";
+        return "number";
+    }
+
+    /**
+     * Get a string representation of the given value's type.
+     *
+     * @param value The value whose type we are trying to compute.
+     * @return A string representation of the given value's type, in a similar format to that provided by Lua's
+     * {@code type} function.
+     */
+    @Nonnull
+    public static String getType( @Nullable Object value )
+    {
+        if( value == null ) return "nil";
+        if( value instanceof String ) return "string";
+        if( value instanceof Boolean ) return "boolean";
+        if( value instanceof Number ) return "number";
+        if( value instanceof Map ) return "table";
+        return "userdata";
+    }
+
+    /**
+     * Construct a "bad argument" exception, from an expected type and the actual value provided.
+     *
+     * @param index    The argument number, starting from 0.
+     * @param expected The expected type for this argument.
+     * @param actual   The actual value provided for this argument.
+     * @return The constructed exception, which should be thrown immediately.
+     */
+    @Nonnull
+    public static LuaException badArgumentOf( int index, @Nonnull String expected, @Nullable Object actual )
+    {
+        return badArgument( index, expected, getType( actual ) );
+    }
+
+    /**
+     * Construct a "bad argument" exception, from an expected and actual type.
+     *
+     * @param index    The argument number, starting from 0.
+     * @param expected The expected type for this argument.
+     * @param actual   The provided type for this argument.
+     * @return The constructed exception, which should be thrown immediately.
+     */
+    @Nonnull
+    public static LuaException badArgument( int index, @Nonnull String expected, @Nonnull String actual )
+    {
+        return new LuaException( "bad argument #" + (index + 1) + " (" + expected + " expected, got " + actual + ")" );
+    }
+
+    /**
+     * Ensure a numeric argument is finite (i.e. not infinite or {@link Double#NaN}.
+     *
+     * @param index The argument index to check.
+     * @param value The value to check.
+     * @return The input {@code value}.
+     * @throws LuaException If this is not a finite number.
+     */
+    public static Number checkFiniteNum( int index, Number value ) throws LuaException
+    {
+        checkFinite( index, value.doubleValue() );
+        return value;
+    }
+
+    /**
+     * Ensure a numeric argument is finite (i.e. not infinite or {@link Double#NaN}.
+     *
+     * @param index The argument index to check.
+     * @param value The value to check.
+     * @return The input {@code value}.
+     * @throws LuaException If this is not a finite number.
+     */
+    public static double checkFinite( int index, double value ) throws LuaException
+    {
+        if( !Double.isFinite( value ) ) throw badArgument( index, "number", getNumericType( value ) );
+        return value;
+    }
+
+    /**
+     * Ensure a string is a valid enum value.
+     *
+     * @param index The argument index to check.
+     * @param klass The class of the enum instance.
+     * @param value The value to extract.
+     * @param <T>   The type of enum we are extracting.
+     * @return The parsed enum value.
+     * @throws LuaException If this is not a known enum value.
+     */
+    public static <T extends Enum<T>> T checkEnum( int index, Class<T> klass, String value ) throws LuaException
+    {
+        for( T possibility : klass.getEnumConstants() )
+        {
+            if( possibility.name().equalsIgnoreCase( value ) ) return possibility;
+        }
+
+        throw new LuaException( "bad argument #" + (index + 1) + " (unknown option " + value + ")" );
+    }
+}

src/main/java/dan200/computercraft/api/lua/MethodResult.java

@@ -0,0 +1,170 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.peripheral.IComputerAccess;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * The result of invoking a Lua method.
+ *
+ * Method results either return a value immediately ({@link #of(Object...)} or yield control to the parent coroutine.
+ * When the current coroutine is resumed, we invoke the provided {@link ILuaCallback#resume(Object[])} callback.
+ */
+public final class MethodResult
+{
+    private static final MethodResult empty = new MethodResult( null, null );
+
+    private final Object[] result;
+    private final ILuaCallback callback;
+    private final int adjust;
+
+    private MethodResult( Object[] arguments, ILuaCallback callback )
+    {
+        this.result = arguments;
+        this.callback = callback;
+        this.adjust = 0;
+    }
+
+    private MethodResult( Object[] arguments, ILuaCallback callback, int adjust )
+    {
+        this.result = arguments;
+        this.callback = callback;
+        this.adjust = adjust;
+    }
+
+    /**
+     * Return no values immediately.
+     *
+     * @return A method result which returns immediately with no values.
+     */
+    @Nonnull
+    public static MethodResult of()
+    {
+        return empty;
+    }
+
+    /**
+     * Return a single value immediately.
+     *
+     * Integers, doubles, floats, strings, booleans, {@link Map}, {@link Collection}s, arrays and {@code null} will be
+     * converted to their corresponding Lua type. {@code byte[]} and {@link ByteBuffer} will be treated as binary
+     * strings. {@link ILuaFunction} will be treated as a function.
+     *
+     * In order to provide a custom object with methods, one may return a {@link IDynamicLuaObject}, or an arbitrary
+     * class with {@link LuaFunction} annotations. Anything else will be converted to {@code nil}.
+     *
+     * @param value The value to return to the calling Lua function.
+     * @return A method result which returns immediately with the given value.
+     */
+    @Nonnull
+    public static MethodResult of( @Nullable Object value )
+    {
+        return new MethodResult( new Object[] { value }, null );
+    }
+
+    /**
+     * Return any number of values immediately.
+     *
+     * @param values The values to return. See {@link #of(Object)} for acceptable values.
+     * @return A method result which returns immediately with the given values.
+     */
+    @Nonnull
+    public static MethodResult of( @Nullable Object... values )
+    {
+        return values == null || values.length == 0 ? empty : new MethodResult( values, null );
+    }
+
+    /**
+     * Wait for an event to occur on the computer, suspending the thread until it arises. This method is exactly
+     * equivalent to {@code os.pullEvent()} in lua.
+     *
+     * @param filter   A specific event to wait for, or null to wait for any event.
+     * @param callback The callback to resume with the name of the event that occurred, and any event parameters.
+     * @return The method result which represents this yield.
+     * @see IComputerAccess#queueEvent(String, Object[])
+     */
+    @Nonnull
+    public static MethodResult pullEvent( @Nullable String filter, @Nonnull ILuaCallback callback )
+    {
+        Objects.requireNonNull( callback, "callback cannot be null" );
+        return new MethodResult( new Object[] { filter }, results -> {
+            if( results.length >= 1 && results[0].equals( "terminate" ) ) throw new LuaException( "Terminated", 0 );
+            return callback.resume( results );
+        } );
+    }
+
+    /**
+     * The same as {@link #pullEvent(String, ILuaCallback)}, except "terminated" events are ignored. Only use this if
+     * you want to prevent program termination, which is not recommended. This method is exactly equivalent to
+     * {@code os.pullEventRaw()} in Lua.
+     *
+     * @param filter   A specific event to wait for, or null to wait for any event.
+     * @param callback The callback to resume with the name of the event that occurred, and any event parameters.
+     * @return The method result which represents this yield.
+     * @see #pullEvent(String, ILuaCallback)
+     */
+    @Nonnull
+    public static MethodResult pullEventRaw( @Nullable String filter, @Nonnull ILuaCallback callback )
+    {
+        Objects.requireNonNull( callback, "callback cannot be null" );
+        return new MethodResult( new Object[] { filter }, callback );
+    }
+
+    /**
+     * Yield the current coroutine with some arguments until it is resumed. This method is exactly equivalent to
+     * {@code coroutine.yield()} in lua. Use {@code pullEvent()} if you wish to wait for events.
+     *
+     * @param arguments An object array containing the arguments to pass to coroutine.yield()
+     * @param callback  The callback to resume with an array containing the return values from coroutine.yield()
+     * @return The method result which represents this yield.
+     * @see #pullEvent(String, ILuaCallback)
+     */
+    @Nonnull
+    public static MethodResult yield( @Nullable Object[] arguments, @Nonnull ILuaCallback callback )
+    {
+        Objects.requireNonNull( callback, "callback cannot be null" );
+        return new MethodResult( arguments, callback );
+    }
+
+    @Nullable
+    public Object[] getResult()
+    {
+        return result;
+    }
+
+    @Nullable
+    public ILuaCallback getCallback()
+    {
+        return callback;
+    }
+
+    public int getErrorAdjust()
+    {
+        return adjust;
+    }
+
+    /**
+     * Increase the Lua error by a specific amount. One should never need to use this function - it largely exists for
+     * some CC internal code.
+     *
+     * @param adjust The amount to increase the level by.
+     * @return The new {@link MethodResult} with an adjusted error. This has no effect on immediate results.
+     */
+    @Nonnull
+    public MethodResult adjustError( int adjust )
+    {
+        if( adjust < 0 ) throw new IllegalArgumentException( "cannot adjust by a negative amount" );
+        if( adjust == 0 || callback == null ) return this;
+        return new MethodResult( result, callback, this.adjust + adjust );
+    }
+}

src/main/java/dan200/computercraft/api/lua/ObjectArguments.java

@@ -0,0 +1,66 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nullable;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * An implementation of {@link IArguments} which wraps an array of {@link Object}.
+ */
+public final class ObjectArguments implements IArguments
+{
+    private static final IArguments EMPTY = new ObjectArguments();
+    private final List<Object> args;
+
+    @Deprecated
+    @SuppressWarnings( "unused" )
+    public ObjectArguments( IArguments arguments )
+    {
+        throw new IllegalStateException();
+    }
+
+    public ObjectArguments( Object... args )
+    {
+        this.args = Arrays.asList( args );
+    }
+
+    public ObjectArguments( List<Object> args )
+    {
+        this.args = Objects.requireNonNull( args );
+    }
+
+    @Override
+    public int count()
+    {
+        return args.size();
+    }
+
+    @Override
+    public IArguments drop( int count )
+    {
+        if( count < 0 ) throw new IllegalStateException( "count cannot be negative" );
+        if( count == 0 ) return this;
+        if( count >= args.size() ) return EMPTY;
+
+        return new ObjectArguments( args.subList( count, args.size() ) );
+    }
+
+    @Nullable
+    @Override
+    public Object get( int index )
+    {
+        return index >= args.size() ? null : args.get( index );
+    }
+
+    @Override
+    public Object[] getAll()
+    {
+        return args.toArray();
+    }
+}

src/main/java/dan200/computercraft/api/media/IMedia.java

@@ -79,7 +79,7 @@ public interface IMedia
      * @see IMount
      * @see dan200.computercraft.api.filesystem.IWritableMount
      * @see dan200.computercraft.api.ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see dan200.computercraft.api.ComputerCraftAPI#createResourceMount(Class, String, String)
+     * @see dan200.computercraft.api.ComputerCraftAPI#createResourceMount(String, String)
      */
     @Nullable
     default IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )

src/main/java/dan200/computercraft/api/peripheral/IComputerAccess.java

@@ -8,13 +8,14 @@ package dan200.computercraft.api.peripheral;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.lua.ILuaCallback;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.ILuaTask;
+import dan200.computercraft.api.lua.MethodResult;
 import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.util.Collections;
 import java.util.Map;
 
 /**
@@ -31,9 +32,9 @@ public interface IComputerAccess
      * @param mount           The mount object to mount on the computer.
      * @return The location on the computer's file system where you the mount mounted, or {@code null} if there was already a
      * file in the desired location. Store this value if you wish to unmount the mount later.
-     * @throws RuntimeException If the peripheral has been detached.
+     * @throws NotAttachedException If the peripheral has been detached.
      * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see ComputerCraftAPI#createResourceMount(Class, String, String)
+     * @see ComputerCraftAPI#createResourceMount(String, String)
      * @see #mount(String, IMount, String)
      * @see #mountWritable(String, IWritableMount)
      * @see #unmount(String)
@@ -53,9 +54,9 @@ public interface IComputerAccess
      * @param driveName       A custom name to give for this mount location, as returned by {@code fs.getDrive()}.
      * @return The location on the computer's file system where you the mount mounted, or {@code null} if there was already a
      * file in the desired location. Store this value if you wish to unmount the mount later.
-     * @throws RuntimeException If the peripheral has been detached.
+     * @throws NotAttachedException If the peripheral has been detached.
      * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see ComputerCraftAPI#createResourceMount(Class, String, String)
+     * @see ComputerCraftAPI#createResourceMount(String, String)
      * @see #mount(String, IMount)
      * @see #mountWritable(String, IWritableMount)
      * @see #unmount(String)
@@ -71,9 +72,9 @@ public interface IComputerAccess
      * @param mount           The mount object to mount on the computer.
      * @return The location on the computer's file system where you the mount mounted, or null if there was already a
      * file in the desired location. Store this value if you wish to unmount the mount later.
-     * @throws RuntimeException If the peripheral has been detached.
+     * @throws NotAttachedException If the peripheral has been detached.
      * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see ComputerCraftAPI#createResourceMount(Class, String, String)
+     * @see ComputerCraftAPI#createResourceMount(String, String)
      * @see #mount(String, IMount)
      * @see #unmount(String)
      * @see IMount
@@ -92,9 +93,9 @@ public interface IComputerAccess
      * @param driveName       A custom name to give for this mount location, as returned by {@code fs.getDrive()}.
      * @return The location on the computer's file system where you the mount mounted, or null if there was already a
      * file in the desired location. Store this value if you wish to unmount the mount later.
-     * @throws RuntimeException If the peripheral has been detached.
+     * @throws NotAttachedException If the peripheral has been detached.
      * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see ComputerCraftAPI#createResourceMount(Class, String, String)
+     * @see ComputerCraftAPI#createResourceMount(String, String)
      * @see #mount(String, IMount)
      * @see #unmount(String)
      * @see IMount
@@ -114,8 +115,8 @@ public interface IComputerAccess
      * @param location The desired location in the computers file system of the directory to unmount.
      *                 This must be the location of a directory previously mounted by {@link #mount(String, IMount)} or
      *                 {@link #mountWritable(String, IWritableMount)}, as indicated by their return value.
-     * @throws RuntimeException If the peripheral has been detached.
-     * @throws RuntimeException If the mount does not exist, or was mounted by another peripheral.
+     * @throws NotAttachedException  If the peripheral has been detached.
+     * @throws IllegalStateException If the mount does not exist, or was mounted by another peripheral.
      * @see #mount(String, IMount)
      * @see #mountWritable(String, IWritableMount)
      */
@@ -146,10 +147,10 @@ public interface IComputerAccess
      *                  to lua data types in the same fashion as the return values of IPeripheral.callMethod().
      *
      *                  You may supply {@code null} to indicate that no arguments are to be supplied.
-     * @throws RuntimeException If the peripheral has been detached.
-     * @see IPeripheral#callMethod
+     * @throws NotAttachedException If the peripheral has been detached.
+     * @see MethodResult#pullEvent(String, ILuaCallback)
      */
-    void queueEvent( @Nonnull String event, @Nullable Object[] arguments );
+    void queueEvent( @Nonnull String event, @Nullable Object... arguments );
 
     /**
      * Get a string, unique to the computer, by which the computer refers to this peripheral.
@@ -159,7 +160,7 @@ public interface IComputerAccess
      * which peripheral the event came.
      *
      * @return A string unique to the computer, but not globally.
-     * @throws RuntimeException If the peripheral has been detached.
+     * @throws NotAttachedException If the peripheral has been detached.
      */
     @Nonnull
     String getAttachmentName();
@@ -170,14 +171,12 @@ public interface IComputerAccess
      * This may include other peripherals on the wired network or peripherals on other sides of the computer.
      *
      * @return All reachable peripherals
+     * @throws NotAttachedException If the peripheral has been detached.
      * @see #getAttachmentName()
      * @see #getAvailablePeripheral(String)
      */
     @Nonnull
-    default Map<String, IPeripheral> getAvailablePeripherals()
-    {
-        return Collections.emptyMap();
-    }
+    Map<String, IPeripheral> getAvailablePeripherals();
 
     /**
      * Get a reachable peripheral with the given attachment name. This is a equivalent to
@@ -188,10 +187,7 @@ public interface IComputerAccess
      * @see #getAvailablePeripherals()
      */
     @Nullable
-    default IPeripheral getAvailablePeripheral( @Nonnull String name )
-    {
-        return null;
-    }
+    IPeripheral getAvailablePeripheral( @Nonnull String name );
 
     /**
      * Get a {@link IWorkMonitor} for tasks your peripheral might execute on the main (server) thread.
@@ -205,10 +201,8 @@ public interface IComputerAccess
      * thread.
      *
      * @return The work monitor for the main thread, or {@code null} if this computer does not have one.
+     * @throws NotAttachedException If the peripheral has been detached.
      */
-    @Nullable
-    default IWorkMonitor getMainThreadMonitor()
-    {
-        return null;
-    }
+    @Nonnull
+    IWorkMonitor getMainThreadMonitor();
 }

src/main/java/dan200/computercraft/api/peripheral/IDynamicPeripheral.java

@@ -0,0 +1,53 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.peripheral;
+
+import dan200.computercraft.api.lua.*;
+
+import javax.annotation.Nonnull;
+
+/**
+ * A peripheral whose methods are not known at runtime.
+ *
+ * This behaves similarly to {@link IDynamicLuaObject}, though also accepting the current {@link IComputerAccess}.
+ * Generally one may use {@link LuaFunction} instead of implementing this interface.
+ */
+public interface IDynamicPeripheral extends IPeripheral
+{
+    /**
+     * Should return an array of strings that identify the methods that this peripheral exposes to Lua. This will be
+     * called once before each attachment, and should not change when called multiple times.
+     *
+     * @return An array of strings representing method names.
+     * @see #callMethod
+     */
+    @Nonnull
+    String[] getMethodNames();
+
+    /**
+     * This is called when a lua program on an attached computer calls {@code peripheral.call()} with
+     * one of the methods exposed by {@link #getMethodNames()}.
+     *
+     * Be aware that this will be called from the ComputerCraft Lua thread, and must be thread-safe when interacting
+     * with Minecraft objects.
+     *
+     * @param computer  The interface to the computer that is making the call. Remember that multiple
+     *                  computers can be attached to a peripheral at once.
+     * @param context   The context of the currently running lua thread. This can be used to wait for events
+     *                  or otherwise yield.
+     * @param method    An integer identifying which of the methods from getMethodNames() the computercraft
+     *                  wishes to call. The integer indicates the index into the getMethodNames() table
+     *                  that corresponds to the string passed into peripheral.call()
+     * @param arguments The arguments for this method.
+     * @return A {@link MethodResult} containing the values to return or the action to perform.
+     * @throws LuaException If you throw any exception from this function, a lua error will be raised with the
+     *                      same message as your exception. Use this to throw appropriate errors if the wrong
+     *                      arguments are supplied to your method.
+     * @see #getMethodNames()
+     */
+    @Nonnull
+    MethodResult callMethod( @Nonnull IComputerAccess computer, @Nonnull ILuaContext context, int method, @Nonnull IArguments arguments ) throws LuaException;
+}

src/main/java/dan200/computercraft/api/peripheral/IPeripheral.java

@@ -5,15 +5,21 @@
  */
 package dan200.computercraft.api.peripheral;
 
-import dan200.computercraft.api.lua.ArgumentHelper;
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
+import net.minecraftforge.common.capabilities.Capability;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 /**
- * The interface that defines a peripheral. See {@link IPeripheralProvider} for how to associate blocks with peripherals.
+ * The interface that defines a peripheral.
+ *
+ * In order to expose a peripheral for your block or tile entity, you may either attach a {@link Capability}, or
+ * register a {@link IPeripheralProvider}. It is <em>not</em> recommended to implement {@link IPeripheral} directly on
+ * the tile.
+ *
+ * Peripherals should provide a series of methods to the user, either using {@link LuaFunction} or by implementing
+ * {@link IDynamicPeripheral}.
  */
 public interface IPeripheral
 {
@@ -26,57 +32,6 @@ public interface IPeripheral
     @Nonnull
     String getType();
 
-    /**
-     * Should return an array of strings that identify the methods that this
-     * peripheral exposes to Lua. This will be called once before each attachment,
-     * and should not change when called multiple times.
-     *
-     * @return An array of strings representing method names.
-     * @see #callMethod
-     */
-    @Nonnull
-    String[] getMethodNames();
-
-    /**
-     * This is called when a lua program on an attached computer calls {@code peripheral.call()} with
-     * one of the methods exposed by {@link #getMethodNames()}.
-     *
-     * Be aware that this will be called from the ComputerCraft Lua thread, and must be thread-safe when interacting
-     * with Minecraft objects.
-     *
-     * @param computer  The interface to the computer that is making the call. Remember that multiple
-     *                  computers can be attached to a peripheral at once.
-     * @param context   The context of the currently running lua thread. This can be used to wait for events
-     *                  or otherwise yield.
-     * @param method    An integer identifying which of the methods from getMethodNames() the computercraft
-     *                  wishes to call. The integer indicates the index into the getMethodNames() table
-     *                  that corresponds to the string passed into peripheral.call()
-     * @param arguments An array of objects, representing the arguments passed into {@code peripheral.call()}.<br>
-     *                  Lua values of type "string" will be represented by Object type String.<br>
-     *                  Lua values of type "number" will be represented by Object type Double.<br>
-     *                  Lua values of type "boolean" will be represented by Object type Boolean.<br>
-     *                  Lua values of type "table" will be represented by Object type Map.<br>
-     *                  Lua values of any other type will be represented by a null object.<br>
-     *                  This array will be empty if no arguments are passed.
-     *
-     *                  It is recommended you use {@link ArgumentHelper} in order to validate and process arguments.
-     * @return An array of objects, representing values you wish to return to the lua program. Integers, Doubles, Floats,
-     * Strings, Booleans, Maps, ILuaObject and null be converted to their corresponding lua type. All other types will
-     * be converted to nil.
-     *
-     * You may return null to indicate no values should be returned.
-     * @throws LuaException         If you throw any exception from this function, a lua error will be raised with the
-     *                              same message as your exception. Use this to throw appropriate errors if the wrong
-     *                              arguments are supplied to your method.
-     * @throws InterruptedException If the user shuts down or reboots the computer the coroutine is suspended,
-     *                              InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     * @see #getMethodNames
-     * @see ArgumentHelper
-     */
-    @Nullable
-    Object[] callMethod( @Nonnull IComputerAccess computer, @Nonnull ILuaContext context, int method, @Nonnull Object[] arguments ) throws LuaException, InterruptedException;
-
     /**
      * Is called when when a computer is attaching to the peripheral.
      *
@@ -126,10 +81,10 @@ public interface IPeripheral
      *
      * @return The object this peripheral targets
      */
-    @Nonnull
+    @Nullable
     default Object getTarget()
     {
-        return this;
+        return null;
     }
 
     /**

src/main/java/dan200/computercraft/api/peripheral/IPeripheralProvider.java

@@ -9,14 +9,15 @@ import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.Direction;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
+import net.minecraftforge.common.util.LazyOptional;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 /**
  * This interface is used to create peripheral implementations for blocks.
  *
- * If you have a {@link TileEntity} which acts as a peripheral, you may alternatively implement {@link IPeripheralTile}.
+ * If you have a {@link TileEntity} which acts as a peripheral, you may alternatively expose the {@link IPeripheral}
+ * capability.
  *
  * @see dan200.computercraft.api.ComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
  */
@@ -29,9 +30,9 @@ public interface IPeripheralProvider
      * @param world The world the block is in.
      * @param pos   The position the block is at.
      * @param side  The side to get the peripheral from.
-     * @return A peripheral, or {@code null} if there is not a peripheral here you'd like to handle.
+     * @return A peripheral, or {@link LazyOptional#empty()} if there is not a peripheral here you'd like to handle.
      * @see dan200.computercraft.api.ComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
      */
-    @Nullable
-    IPeripheral getPeripheral( @Nonnull World world, @Nonnull BlockPos pos, @Nonnull Direction side );
+    @Nonnull
+    LazyOptional<IPeripheral> getPeripheral( @Nonnull World world, @Nonnull BlockPos pos, @Nonnull Direction side );
 }

src/main/java/dan200/computercraft/api/peripheral/IPeripheralTile.java

@@ -1,32 +0,0 @@
-/*
- * This file is part of the public ComputerCraft API - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
- * For help using the API, and posting your mods, visit the forums at computercraft.info.
- */
-package dan200.computercraft.api.peripheral;
-
-import net.minecraft.util.Direction;
-import net.minecraft.util.math.BlockPos;
-import net.minecraft.world.World;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * A {@link net.minecraft.tileentity.TileEntity} which may act as a peripheral.
- *
- * If you need more complex capabilities (such as handling TEs not belonging to your mod), you should use
- * {@link IPeripheralProvider}.
- */
-public interface IPeripheralTile
-{
-    /**
-     * Get the peripheral on the given {@code side}.
-     *
-     * @param side The side to get the peripheral from.
-     * @return A peripheral, or {@code null} if there is not a peripheral here.
-     * @see IPeripheralProvider#getPeripheral(World, BlockPos, Direction)
-     */
-    @Nullable
-    IPeripheral getPeripheral( @Nonnull Direction side );
-}

src/main/java/dan200/computercraft/api/peripheral/NotAttachedException.java

@@ -0,0 +1,25 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.peripheral;
+
+/**
+ * Thrown when performing operations on {@link IComputerAccess} when the current peripheral is no longer attached to
+ * the computer.
+ */
+public class NotAttachedException extends IllegalStateException
+{
+    private static final long serialVersionUID = 1221244785535553536L;
+
+    public NotAttachedException()
+    {
+        super( "You are not attached to this computer" );
+    }
+
+    public NotAttachedException( String s )
+    {
+        super( s );
+    }
+}

src/main/java/dan200/computercraft/api/turtle/AbstractTurtleUpgrade.java

@@ -3,10 +3,8 @@
  * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
-package dan200.computercraft.api;
+package dan200.computercraft.api.turtle;
 
-import dan200.computercraft.api.turtle.ITurtleUpgrade;
-import dan200.computercraft.api.turtle.TurtleUpgradeType;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.IItemProvider;
 import net.minecraft.util.ResourceLocation;

src/main/java/dan200/computercraft/api/turtle/ITurtleAccess.java

@@ -6,8 +6,8 @@
 package dan200.computercraft.api.turtle;
 
 import com.mojang.authlib.GameProfile;
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.ILuaCallback;
+import dan200.computercraft.api.lua.MethodResult;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import net.minecraft.inventory.IInventory;
 import net.minecraft.nbt.CompoundNBT;
@@ -228,21 +228,15 @@ public interface ITurtleAccess
      * be supplied as a parameter to a "turtle_response" event issued to the turtle after the command has completed. Look at the
      * lua source code for "rom/apis/turtle" for how to build a lua wrapper around this functionality.
      *
-     * @param context The Lua context to pull events from.
      * @param command An object which will execute the custom command when its point in the queue is reached
      * @return The objects the command returned when executed. you should probably return these to the player
      * unchanged if called from a peripheral method.
      * @throws UnsupportedOperationException When attempting to execute a command on the client side.
-     * @throws LuaException                  If the user presses CTRL+T to terminate the current program while {@code executeCommand()} is
-     *                                       waiting for an event, a "Terminated" exception will be thrown here.
-     * @throws InterruptedException          If the user shuts down or reboots the computer while pullEvent() is waiting for an
-     *                                       event, InterruptedException will be thrown. This exception must not be caught or
-     *                                       intercepted, or the computer will leak memory and end up in a broken state.
      * @see ITurtleCommand
-     * @see ILuaContext#pullEvent(String)
+     * @see MethodResult#pullEvent(String, ILuaCallback)
      */
     @Nonnull
-    Object[] executeCommand( @Nonnull ILuaContext context, @Nonnull ITurtleCommand command ) throws LuaException, InterruptedException;
+    MethodResult executeCommand( @Nonnull ITurtleCommand command );
 
     /**
      * Start playing a specific animation. This will prevent other turtle commands from executing until

src/main/java/dan200/computercraft/api/turtle/ITurtleCommand.java

@@ -5,14 +5,12 @@
  */
 package dan200.computercraft.api.turtle;
 
-import dan200.computercraft.api.lua.ILuaContext;
-
 import javax.annotation.Nonnull;
 
 /**
- * An interface for objects executing custom turtle commands, used with {@link ITurtleAccess#executeCommand(ILuaContext, ITurtleCommand)}.
+ * An interface for objects executing custom turtle commands, used with {@link ITurtleAccess#executeCommand(ITurtleCommand)}.
  *
- * @see ITurtleAccess#executeCommand(ILuaContext, ITurtleCommand)
+ * @see ITurtleAccess#executeCommand(ITurtleCommand)
  */
 @FunctionalInterface
 public interface ITurtleCommand
@@ -25,7 +23,7 @@ public interface ITurtleCommand
      *
      * @param turtle Access to the turtle for whom the command was issued.
      * @return A result, indicating whether this action succeeded or not.
-     * @see ITurtleAccess#executeCommand(ILuaContext, ITurtleCommand)
+     * @see ITurtleAccess#executeCommand(ITurtleCommand)
      * @see TurtleCommandResult#success()
      * @see TurtleCommandResult#failure(String)
      * @see TurtleCommandResult

src/main/java/dan200/computercraft/api/turtle/ITurtleUpgrade.java

@@ -6,10 +6,10 @@
 package dan200.computercraft.api.turtle;
 
 import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.api.client.TransformedModel;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.api.turtle.event.TurtleAttackEvent;
 import dan200.computercraft.api.turtle.event.TurtleBlockEvent;
-import net.minecraft.client.renderer.model.IBakedModel;
 import net.minecraft.client.renderer.model.ModelResourceLocation;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.Direction;
@@ -18,11 +18,9 @@ import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.api.distmarker.OnlyIn;
 import net.minecraftforge.event.entity.player.AttackEntityEvent;
 import net.minecraftforge.event.world.BlockEvent;
-import org.apache.commons.lang3.tuple.Pair;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import javax.vecmath.Matrix4f;
 
 /**
  * The primary interface for defining an update for Turtles. A turtle update
@@ -126,12 +124,11 @@ public interface ITurtleUpgrade
      *
      * @param turtle Access to the turtle that the upgrade resides on. This will be null when getting item models!
      * @param side   Which side of the turtle (left or right) the upgrade resides on.
-     * @return The model that you wish to be used to render your upgrade, and a transformation to apply to it. Returning
-     * a transformation of {@code null} has the same effect as the identify matrix.
+     * @return The model that you wish to be used to render your upgrade.
      */
     @Nonnull
     @OnlyIn( Dist.CLIENT )
-    Pair<IBakedModel, Matrix4f> getModel( @Nullable ITurtleAccess turtle, @Nonnull TurtleSide side );
+    TransformedModel getModel( @Nullable ITurtleAccess turtle, @Nonnull TurtleSide side );
 
     /**
      * Called once per tick for each turtle which has the upgrade equipped.

src/main/java/dan200/computercraft/api/turtle/TurtleAnimation.java

@@ -17,70 +17,70 @@ public enum TurtleAnimation
     /**
      * An animation which does nothing. This takes no time to complete.
      *
-     * @see #Wait
-     * @see #ShortWait
+     * @see #WAIT
+     * @see #SHORT_WAIT
      */
-    None,
+    NONE,
 
     /**
      * Make the turtle move forward. Note that the animation starts from the block <em>behind</em> it, and
      * moves into this one.
      */
-    MoveForward,
+    MOVE_FORWARD,
 
     /**
      * Make the turtle move backwards. Note that the animation starts from the block <em>in front</em> it, and
      * moves into this one.
      */
-    MoveBack,
+    MOVE_BACK,
 
     /**
      * Make the turtle move backwards. Note that the animation starts from the block <em>above</em> it, and
      * moves into this one.
      */
-    MoveUp,
+    MOVE_UP,
 
     /**
      * Make the turtle move backwards. Note that the animation starts from the block <em>below</em> it, and
      * moves into this one.
      */
-    MoveDown,
+    MOVE_DOWN,
 
     /**
      * Turn the turtle to the left. Note that the animation starts with the turtle facing <em>right</em>, and
      * the turtle turns to face in the current direction.
      */
-    TurnLeft,
+    TURN_LEFT,
 
     /**
      * Turn the turtle to the left. Note that the animation starts with the turtle facing <em>right</em>, and
      * the turtle turns to face in the current direction.
      */
-    TurnRight,
+    TURN_RIGHT,
 
     /**
      * Swing the tool on the left.
      */
-    SwingLeftTool,
+    SWING_LEFT_TOOL,
 
     /**
      * Swing the tool on the right.
      */
-    SwingRightTool,
+    SWING_RIGHT_TOOL,
 
     /**
      * Wait until the animation has finished, performing no movement.
      *
-     * @see #ShortWait
-     * @see #None
+     * @see #SHORT_WAIT
+     * @see #NONE
      */
-    Wait,
+    WAIT,
 
     /**
      * Wait until the animation has finished, performing no movement. This takes 4 ticks to complete.
      *
-     * @see #Wait
-     * @see #None
+     * @see #WAIT
+     * @see #NONE
      */
-    ShortWait,
+    SHORT_WAIT,
 }

src/main/java/dan200/computercraft/api/turtle/TurtleSide.java

@@ -13,10 +13,10 @@ public enum TurtleSide
     /**
      * The turtle's left side (where the pickaxe usually is on a Wireless Mining Turtle).
      */
-    Left,
+    LEFT,
 
     /**
      * The turtle's right side (where the modem usually is on a Wireless Mining Turtle).
      */
-    Right,
+    RIGHT,
 }

src/main/java/dan200/computercraft/api/turtle/TurtleUpgradeType.java

@@ -16,28 +16,28 @@ public enum TurtleUpgradeType
      * A tool is rendered as an item on the side of the turtle, and responds to the {@code turtle.dig()}
      * and {@code turtle.attack()} methods (Such as pickaxe or sword on Mining and Melee turtles).
      */
-    Tool,
+    TOOL,
 
     /**
      * A peripheral adds a special peripheral which is attached to the side of the turtle,
      * and can be interacted with the {@code peripheral} API (Such as the modem on Wireless Turtles).
      */
-    Peripheral,
+    PERIPHERAL,
 
     /**
      * An upgrade which provides both a tool and a peripheral. This can be used when you wish
      * your upgrade to also provide methods. For example, a pickaxe could provide methods
      * determining whether it can break the given block or not.
      */
-    Both;
+    BOTH;
 
     public boolean isTool()
     {
-        return this == Tool || this == Both;
+        return this == TOOL || this == BOTH;
     }
 
     public boolean isPeripheral()
     {
-        return this == Peripheral || this == Both;
+        return this == PERIPHERAL || this == BOTH;
     }
 }

src/main/java/dan200/computercraft/api/turtle/TurtleVerb.java

@@ -19,10 +19,10 @@ public enum TurtleVerb
     /**
      * The turtle called {@code turtle.dig()}, {@code turtle.digUp()} or {@code turtle.digDown()}.
      */
-    Dig,
+    DIG,
 
     /**
      * The turtle called {@code turtle.attack()}, {@code turtle.attackUp()} or {@code turtle.attackDown()}.
      */
-    Attack,
+    ATTACK,
 }

src/main/java/dan200/computercraft/api/turtle/event/TurtleBlockEvent.java

@@ -5,8 +5,7 @@
  */
 package dan200.computercraft.api.turtle.event;
 
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.api.lua.MethodResult;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
@@ -223,7 +222,7 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
          * Add new information to the inspection result. Note this will override fields with the same name.
          *
          * @param newData The data to add. Note all values should be convertible to Lua (see
-         *                {@link dan200.computercraft.api.peripheral.IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}).
+         *                {@link MethodResult#of(Object)}).
          */
         public void addData( @Nonnull Map<String, ?> newData )
         {

src/main/java/dan200/computercraft/api/turtle/event/TurtleInspectItemEvent.java

@@ -5,8 +5,7 @@
  */
 package dan200.computercraft.api.turtle.event;
 
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.api.lua.MethodResult;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import net.minecraft.item.ItemStack;
 
@@ -63,7 +62,7 @@ public class TurtleInspectItemEvent extends TurtleActionEvent
      * Add new information to the inspection result. Note this will override fields with the same name.
      *
      * @param newData The data to add. Note all values should be convertible to Lua (see
-     *                {@link dan200.computercraft.api.peripheral.IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}).
+     *                {@link MethodResult#of(Object)}).
      */
     public void addData( @Nonnull Map<String, ?> newData )
     {

src/main/java/dan200/computercraft/client/ClientRegistry.java

@@ -9,22 +9,22 @@ import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.render.TurtleModelLoader;
 import dan200.computercraft.shared.common.IColouredItem;
 import dan200.computercraft.shared.media.items.ItemDisk;
+import dan200.computercraft.shared.media.items.ItemTreasureDisk;
 import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
 import dan200.computercraft.shared.util.Colour;
-import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.model.IBakedModel;
 import net.minecraft.client.renderer.model.IUnbakedModel;
 import net.minecraft.client.renderer.model.ModelResourceLocation;
-import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.inventory.container.PlayerContainer;
 import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.client.event.ColorHandlerEvent;
 import net.minecraftforge.client.event.ModelBakeEvent;
 import net.minecraftforge.client.event.ModelRegistryEvent;
 import net.minecraftforge.client.event.TextureStitchEvent;
-import net.minecraftforge.client.model.BasicState;
 import net.minecraftforge.client.model.ModelLoader;
 import net.minecraftforge.client.model.ModelLoaderRegistry;
+import net.minecraftforge.client.model.SimpleModelTransform;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod;
 
@@ -71,13 +71,13 @@ public final class ClientRegistry
     @SubscribeEvent
     public static void registerModels( ModelRegistryEvent event )
     {
-        ModelLoaderRegistry.registerLoader( TurtleModelLoader.INSTANCE );
+        ModelLoaderRegistry.registerLoader( new ResourceLocation( ComputerCraft.MOD_ID, "turtle" ), TurtleModelLoader.INSTANCE );
     }
 
     @SubscribeEvent
     public static void onTextureStitchEvent( TextureStitchEvent.Pre event )
     {
-        if( event.getMap() != Minecraft.getInstance().getTextureMap() ) return;
+        if( !event.getMap().getTextureLocation().equals( PlayerContainer.LOCATION_BLOCKS_TEXTURE ) ) return;
 
         for( String extra : EXTRA_TEXTURES )
         {
@@ -92,29 +92,18 @@ public final class ClientRegistry
         ModelLoader loader = event.getModelLoader();
         Map<ResourceLocation, IBakedModel> registry = event.getModelRegistry();
 
-        for( String model : EXTRA_MODELS )
+        for( String modelName : EXTRA_MODELS )
         {
-            IBakedModel bakedModel = bake( loader, loader.getUnbakedModel( new ResourceLocation( ComputerCraft.MOD_ID, "item/" + model ) ) );
+            ResourceLocation location = new ResourceLocation( ComputerCraft.MOD_ID, "item/" + modelName );
+            IUnbakedModel model = loader.getUnbakedModel( location );
+            model.getTextures( loader::getUnbakedModel, new HashSet<>() );
 
-            if( bakedModel != null )
+            IBakedModel baked = model.bakeModel( loader, ModelLoader.defaultTextureGetter(), SimpleModelTransform.IDENTITY, location );
+            if( baked != null )
             {
-                registry.put(
-                    new ModelResourceLocation( new ResourceLocation( ComputerCraft.MOD_ID, model ), "inventory" ),
-                    bakedModel
-                );
+                registry.put( new ModelResourceLocation( new ResourceLocation( ComputerCraft.MOD_ID, modelName ), "inventory" ), baked );
             }
         }
-
-        // And load the custom turtle models in too.
-        registry.put(
-            new ModelResourceLocation( new ResourceLocation( ComputerCraft.MOD_ID, "turtle_normal" ), "inventory" ),
-            bake( loader, TurtleModelLoader.INSTANCE.loadModel( new ResourceLocation( ComputerCraft.MOD_ID, "item/turtle_normal" ) ) )
-        );
-
-        registry.put(
-            new ModelResourceLocation( new ResourceLocation( ComputerCraft.MOD_ID, "turtle_advanced" ), "inventory" ),
-            bake( loader, TurtleModelLoader.INSTANCE.loadModel( new ResourceLocation( ComputerCraft.MOD_ID, "item/turtle_advanced" ) ) )
-        );
     }
 
     @SubscribeEvent
@@ -131,6 +120,11 @@ public final class ClientRegistry
             ComputerCraft.Items.disk
         );
 
+        event.getItemColors().register(
+            ( stack, layer ) -> layer == 1 ? ItemTreasureDisk.getColour( stack ) : 0xFFFFFF,
+            ComputerCraft.Items.treasureDisk
+        );
+
         event.getItemColors().register( ( stack, layer ) -> {
             switch( layer )
             {
@@ -142,7 +136,7 @@ public final class ClientRegistry
                 case 2: // Light colour
                 {
                     int light = ItemPocketComputer.getLightState( stack );
-                    return light == -1 ? Colour.Black.getHex() : light;
+                    return light == -1 ? Colour.BLACK.getHex() : light;
                 }
             }
         }, ComputerCraft.Items.pocketComputerNormal, ComputerCraft.Items.pocketComputerAdvanced );
@@ -153,15 +147,4 @@ public final class ClientRegistry
             ComputerCraft.Blocks.turtleNormal, ComputerCraft.Blocks.turtleAdvanced
         );
     }
-
-    private static IBakedModel bake( ModelLoader loader, IUnbakedModel model )
-    {
-        model.getTextures( loader::getUnbakedModel, new HashSet<>() );
-
-        return model.bake(
-            loader,
-            ModelLoader.defaultTextureGetter(),
-            new BasicState( model.getDefaultState(), false ), DefaultVertexFormats.BLOCK
-        );
-    }
 }

src/main/java/dan200/computercraft/client/gui/FixedWidthFontRenderer.java

@@ -5,15 +5,15 @@
  */
 package dan200.computercraft.client.gui;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
+import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.client.FrameInfo;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.core.terminal.TextBuffer;
 import dan200.computercraft.shared.util.Colour;
 import dan200.computercraft.shared.util.Palette;
 import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.BufferBuilder;
-import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.*;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.client.renderer.vertex.VertexFormat;
 import net.minecraft.util.ResourceLocation;
@@ -24,21 +24,10 @@ import javax.annotation.Nullable;
 
 public final class FixedWidthFontRenderer
 {
+    private static final Matrix4f IDENTITY = TransformationMatrix.identity().getMatrix();
+
     private static final ResourceLocation FONT = new ResourceLocation( "computercraft", "textures/gui/term_font.png" );
 
-    /**
-     * Like {@link DefaultVertexFormats#POSITION_TEX_COLOR}, but flipped. This is backported from 1.15, hence the
-     * custom format.
-     */
-    public static final VertexFormat POSITION_COLOR_TEX = new VertexFormat();
-
-    static
-    {
-        POSITION_COLOR_TEX.addElement( DefaultVertexFormats.POSITION_3F );
-        POSITION_COLOR_TEX.addElement( DefaultVertexFormats.COLOR_4UB );
-        POSITION_COLOR_TEX.addElement( DefaultVertexFormats.TEX_2F );
-    }
-
     public static final int FONT_HEIGHT = 9;
     public static final int FONT_WIDTH = 6;
     public static final float WIDTH = 256.0f;
@@ -46,22 +35,23 @@ public final class FixedWidthFontRenderer
     public static final float BACKGROUND_START = (WIDTH - 6.0f) / WIDTH;
     public static final float BACKGROUND_END = (WIDTH - 4.0f) / WIDTH;
 
+    public static final RenderType TYPE = Type.MAIN;
+
     private FixedWidthFontRenderer()
     {
     }
 
-    private static float toGreyscale( double[] rgb )
+    public static float toGreyscale( double[] rgb )
     {
         return (float) ((rgb[0] + rgb[1] + rgb[2]) / 3);
     }
 
-    private static int getColour( char c )
+    public static int getColour( char c, Colour def )
     {
-        int i = "0123456789abcdef".indexOf( c );
-        return i < 0 ? 0 : 15 - i;
+        return 15 - Terminal.getColour( c, def );
     }
 
-    private static void drawChar( BufferBuilder buffer, float x, float y, int index, float r, float g, float b )
+    private static void drawChar( Matrix4f transform, IVertexBuilder buffer, float x, float y, int index, float r, float g, float b )
     {
         // Short circuit to avoid the common case - the texture should be blank here after all.
         if( index == '\0' || index == ' ' ) return;
@@ -72,27 +62,27 @@ public final class FixedWidthFontRenderer
         int xStart = 1 + column * (FONT_WIDTH + 2);
         int yStart = 1 + row * (FONT_HEIGHT + 2);
 
-        buffer.pos( x, y, 0f ).color( r, g, b, 1.0f ).tex( xStart / WIDTH, yStart / WIDTH ).endVertex();
-        buffer.pos( x, y + FONT_HEIGHT, 0f ).color( r, g, b, 1.0f ).tex( xStart / WIDTH, (yStart + FONT_HEIGHT) / WIDTH ).endVertex();
-        buffer.pos( x + FONT_WIDTH, y, 0f ).color( r, g, b, 1.0f ).tex( (xStart + FONT_WIDTH) / WIDTH, yStart / WIDTH ).endVertex();
-        buffer.pos( x + FONT_WIDTH, y, 0f ).color( r, g, b, 1.0f ).tex( (xStart + FONT_WIDTH) / WIDTH, yStart / WIDTH ).endVertex();
-        buffer.pos( x, y + FONT_HEIGHT, 0f ).color( r, g, b, 1.0f ).tex( xStart / WIDTH, (yStart + FONT_HEIGHT) / WIDTH ).endVertex();
-        buffer.pos( x + FONT_WIDTH, y + FONT_HEIGHT, 0f ).color( r, g, b, 1.0f ).tex( (xStart + FONT_WIDTH) / WIDTH, (yStart + FONT_HEIGHT) / WIDTH ).endVertex();
+        buffer.pos( transform, x, y, 0f ).color( r, g, b, 1.0f ).tex( xStart / WIDTH, yStart / WIDTH ).endVertex();
+        buffer.pos( transform, x, y + FONT_HEIGHT, 0f ).color( r, g, b, 1.0f ).tex( xStart / WIDTH, (yStart + FONT_HEIGHT) / WIDTH ).endVertex();
+        buffer.pos( transform, x + FONT_WIDTH, y, 0f ).color( r, g, b, 1.0f ).tex( (xStart + FONT_WIDTH) / WIDTH, yStart / WIDTH ).endVertex();
+        buffer.pos( transform, x + FONT_WIDTH, y, 0f ).color( r, g, b, 1.0f ).tex( (xStart + FONT_WIDTH) / WIDTH, yStart / WIDTH ).endVertex();
+        buffer.pos( transform, x, y + FONT_HEIGHT, 0f ).color( r, g, b, 1.0f ).tex( xStart / WIDTH, (yStart + FONT_HEIGHT) / WIDTH ).endVertex();
+        buffer.pos( transform, x + FONT_WIDTH, y + FONT_HEIGHT, 0f ).color( r, g, b, 1.0f ).tex( (xStart + FONT_WIDTH) / WIDTH, (yStart + FONT_HEIGHT) / WIDTH ).endVertex();
     }
 
-    private static void drawQuad( BufferBuilder buffer, float x, float y, float width, float height, float r, float g, float b )
+    private static void drawQuad( Matrix4f transform, IVertexBuilder buffer, float x, float y, float width, float height, float r, float g, float b )
     {
-        buffer.pos( x, y, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_START, BACKGROUND_START ).endVertex();
-        buffer.pos( x, y + height, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_START, BACKGROUND_END ).endVertex();
-        buffer.pos( x + width, y, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_END, BACKGROUND_START ).endVertex();
-        buffer.pos( x + width, y, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_END, BACKGROUND_START ).endVertex();
-        buffer.pos( x, y + height, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_START, BACKGROUND_END ).endVertex();
-        buffer.pos( x + width, y + height, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_END, BACKGROUND_END ).endVertex();
+        buffer.pos( transform, x, y, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_START, BACKGROUND_START ).endVertex();
+        buffer.pos( transform, x, y + height, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_START, BACKGROUND_END ).endVertex();
+        buffer.pos( transform, x + width, y, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_END, BACKGROUND_START ).endVertex();
+        buffer.pos( transform, x + width, y, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_END, BACKGROUND_START ).endVertex();
+        buffer.pos( transform, x, y + height, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_START, BACKGROUND_END ).endVertex();
+        buffer.pos( transform, x + width, y + height, 0 ).color( r, g, b, 1.0f ).tex( BACKGROUND_END, BACKGROUND_END ).endVertex();
     }
 
-    private static void drawQuad( BufferBuilder buffer, float x, float y, float width, float height, Palette palette, boolean greyscale, char colourIndex )
+    private static void drawQuad( Matrix4f transform, IVertexBuilder buffer, float x, float y, float width, float height, Palette palette, boolean greyscale, char colourIndex )
     {
-        double[] colour = palette.getColour( getColour( colourIndex ) );
+        double[] colour = palette.getColour( getColour( colourIndex, Colour.BLACK ) );
         float r, g, b;
         if( greyscale )
         {
@@ -105,23 +95,23 @@ public final class FixedWidthFontRenderer
             b = (float) colour[2];
         }
 
-        drawQuad( buffer, x, y, width, height, r, g, b );
+        drawQuad( transform, buffer, x, y, width, height, r, g, b );
     }
 
     private static void drawBackground(
-        @Nonnull BufferBuilder renderer, float x, float y,
+        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder renderer, float x, float y,
         @Nonnull TextBuffer backgroundColour, @Nonnull Palette palette, boolean greyscale,
         float leftMarginSize, float rightMarginSize, float height
     )
     {
         if( leftMarginSize > 0 )
         {
-            drawQuad( renderer, x - leftMarginSize, y, leftMarginSize, height, palette, greyscale, backgroundColour.charAt( 0 ) );
+            drawQuad( transform, renderer, x - leftMarginSize, y, leftMarginSize, height, palette, greyscale, backgroundColour.charAt( 0 ) );
         }
 
         if( rightMarginSize > 0 )
         {
-            drawQuad( renderer, x + backgroundColour.length() * FONT_WIDTH, y, rightMarginSize, height, palette, greyscale, backgroundColour.charAt( backgroundColour.length() - 1 ) );
+            drawQuad( transform, renderer, x + backgroundColour.length() * FONT_WIDTH, y, rightMarginSize, height, palette, greyscale, backgroundColour.charAt( backgroundColour.length() - 1 ) );
         }
 
         // Batch together runs of identical background cells.
@@ -134,7 +124,7 @@ public final class FixedWidthFontRenderer
 
             if( blockColour != '\0' )
             {
-                drawQuad( renderer, x + blockStart * FONT_WIDTH, y, FONT_WIDTH * (i - blockStart), height, palette, greyscale, blockColour );
+                drawQuad( transform, renderer, x + blockStart * FONT_WIDTH, y, FONT_WIDTH * (i - blockStart), height, palette, greyscale, blockColour );
             }
 
             blockColour = colourIndex;
@@ -143,24 +133,24 @@ public final class FixedWidthFontRenderer
 
         if( blockColour != '\0' )
         {
-            drawQuad( renderer, x + blockStart * FONT_WIDTH, y, FONT_WIDTH * (backgroundColour.length() - blockStart), height, palette, greyscale, blockColour );
+            drawQuad( transform, renderer, x + blockStart * FONT_WIDTH, y, FONT_WIDTH * (backgroundColour.length() - blockStart), height, palette, greyscale, blockColour );
         }
     }
 
     public static void drawString(
-        @Nonnull BufferBuilder renderer, float x, float y,
+        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder renderer, float x, float y,
         @Nonnull TextBuffer text, @Nonnull TextBuffer textColour, @Nullable TextBuffer backgroundColour,
         @Nonnull Palette palette, boolean greyscale, float leftMarginSize, float rightMarginSize
     )
     {
         if( backgroundColour != null )
         {
-            drawBackground( renderer, x, y, backgroundColour, palette, greyscale, leftMarginSize, rightMarginSize, FONT_HEIGHT );
+            drawBackground( transform, renderer, x, y, backgroundColour, palette, greyscale, leftMarginSize, rightMarginSize, FONT_HEIGHT );
         }
 
         for( int i = 0; i < text.length(); i++ )
         {
-            double[] colour = palette.getColour( getColour( textColour.charAt( i ) ) );
+            double[] colour = palette.getColour( getColour( textColour.charAt( i ), Colour.BLACK ) );
             float r, g, b;
             if( greyscale )
             {
@@ -176,7 +166,7 @@ public final class FixedWidthFontRenderer
             // Draw char
             int index = text.charAt( i );
             if( index > 255 ) index = '?';
-            drawChar( renderer, x + i * FONT_WIDTH, y, index, r, g, b );
+            drawChar( transform, renderer, x + i * FONT_WIDTH, y, index, r, g, b );
         }
 
     }
@@ -188,15 +178,13 @@ public final class FixedWidthFontRenderer
     {
         bindFont();
 
-        Tessellator tessellator = Tessellator.getInstance();
-        BufferBuilder buffer = tessellator.getBuffer();
-        begin( buffer );
-        drawString( buffer, x, y, text, textColour, backgroundColour, palette, greyscale, leftMarginSize, rightMarginSize );
-        tessellator.draw();
+        IRenderTypeBuffer.Impl renderer = Minecraft.getInstance().getRenderTypeBuffers().getBufferSource();
+        drawString( IDENTITY, ((IRenderTypeBuffer) renderer).getBuffer( TYPE ), x, y, text, textColour, backgroundColour, palette, greyscale, leftMarginSize, rightMarginSize );
+        renderer.finish();
     }
 
     public static void drawTerminalWithoutCursor(
-        @Nonnull BufferBuilder buffer, float x, float y,
+        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder buffer, float x, float y,
         @Nonnull Terminal terminal, boolean greyscale,
         float topMarginSize, float bottomMarginSize, float leftMarginSize, float rightMarginSize
     )
@@ -206,13 +194,13 @@ public final class FixedWidthFontRenderer
 
         // Top and bottom margins
         drawBackground(
-            buffer, x, y - topMarginSize,
+            transform, buffer, x, y - topMarginSize,
             terminal.getBackgroundColourLine( 0 ), palette, greyscale,
             leftMarginSize, rightMarginSize, topMarginSize
         );
 
         drawBackground(
-            buffer, x, y + height * FONT_HEIGHT,
+            transform, buffer, x, y + height * FONT_HEIGHT,
             terminal.getBackgroundColourLine( height - 1 ), palette, greyscale,
             leftMarginSize, rightMarginSize, bottomMarginSize
         );
@@ -221,7 +209,7 @@ public final class FixedWidthFontRenderer
         for( int i = 0; i < height; i++ )
         {
             drawString(
-                buffer, x, y + FixedWidthFontRenderer.FONT_HEIGHT * i,
+                transform, buffer, x, y + FixedWidthFontRenderer.FONT_HEIGHT * i,
                 terminal.getLine( i ), terminal.getTextColourLine( i ), terminal.getBackgroundColourLine( i ),
                 palette, greyscale, leftMarginSize, rightMarginSize
             );
@@ -229,7 +217,7 @@ public final class FixedWidthFontRenderer
     }
 
     public static void drawCursor(
-        @Nonnull BufferBuilder buffer, float x, float y,
+        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder buffer, float x, float y,
         @Nonnull Terminal terminal, boolean greyscale
     )
     {
@@ -254,75 +242,104 @@ public final class FixedWidthFontRenderer
                 b = (float) colour[2];
             }
 
-            drawChar( buffer, x + cursorX * FONT_WIDTH, y + cursorY * FONT_HEIGHT, '_', r, g, b );
+            drawChar( transform, buffer, x + cursorX * FONT_WIDTH, y + cursorY * FONT_HEIGHT, '_', r, g, b );
         }
     }
 
     public static void drawTerminal(
-        @Nonnull BufferBuilder buffer, float x, float y,
+        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder buffer, float x, float y,
         @Nonnull Terminal terminal, boolean greyscale,
         float topMarginSize, float bottomMarginSize, float leftMarginSize, float rightMarginSize
     )
     {
-        drawTerminalWithoutCursor( buffer, x, y, terminal, greyscale, topMarginSize, bottomMarginSize, leftMarginSize, rightMarginSize );
-        drawCursor( buffer, x, y, terminal, greyscale );
+        drawTerminalWithoutCursor( transform, buffer, x, y, terminal, greyscale, topMarginSize, bottomMarginSize, leftMarginSize, rightMarginSize );
+        drawCursor( transform, buffer, x, y, terminal, greyscale );
+    }
+
+    public static void drawTerminal(
+        @Nonnull Matrix4f transform, float x, float y, @Nonnull Terminal terminal, boolean greyscale,
+        float topMarginSize, float bottomMarginSize, float leftMarginSize, float rightMarginSize
+    )
+    {
+        bindFont();
+
+        IRenderTypeBuffer.Impl renderer = Minecraft.getInstance().getRenderTypeBuffers().getBufferSource();
+        IVertexBuilder buffer = renderer.getBuffer( TYPE );
+        drawTerminal( transform, buffer, x, y, terminal, greyscale, topMarginSize, bottomMarginSize, leftMarginSize, rightMarginSize );
+        renderer.finish( TYPE );
     }
 
     public static void drawTerminal(
         float x, float y, @Nonnull Terminal terminal, boolean greyscale,
         float topMarginSize, float bottomMarginSize, float leftMarginSize, float rightMarginSize
     )
+    {
+        drawTerminal( IDENTITY, x, y, terminal, greyscale, topMarginSize, bottomMarginSize, leftMarginSize, rightMarginSize );
+    }
+
+    public static void drawEmptyTerminal( @Nonnull Matrix4f transform, @Nonnull IRenderTypeBuffer renderer, float x, float y, float width, float height )
+    {
+        Colour colour = Colour.BLACK;
+        drawQuad( transform, renderer.getBuffer( TYPE ), x, y, width, height, colour.getR(), colour.getG(), colour.getB() );
+    }
+
+    public static void drawEmptyTerminal( @Nonnull Matrix4f transform, float x, float y, float width, float height )
     {
         bindFont();
 
-        Tessellator tessellator = Tessellator.getInstance();
-        BufferBuilder buffer = tessellator.getBuffer();
-        begin( buffer );
-        drawTerminal( buffer, x, y, terminal, greyscale, topMarginSize, bottomMarginSize, leftMarginSize, rightMarginSize );
-        tessellator.draw();
+        IRenderTypeBuffer.Impl renderer = Minecraft.getInstance().getRenderTypeBuffers().getBufferSource();
+        drawEmptyTerminal( transform, renderer, x, y, width, height );
+        renderer.finish();
     }
 
     public static void drawEmptyTerminal( float x, float y, float width, float height )
     {
-        bindFont();
-
-        Tessellator tessellator = Tessellator.getInstance();
-        BufferBuilder buffer = tessellator.getBuffer();
-        begin( buffer );
-
-        Colour colour = Colour.Black;
-        drawQuad( buffer, x, y, width, height, colour.getR(), colour.getG(), colour.getB() );
-
-        tessellator.draw();
+        drawEmptyTerminal( IDENTITY, x, y, width, height );
     }
 
-    public static void drawBlocker( @Nonnull BufferBuilder buffer, float x, float y, float width, float height )
+    public static void drawBlocker( @Nonnull Matrix4f transform, @Nonnull IRenderTypeBuffer renderer, float x, float y, float width, float height )
     {
-        Colour colour = Colour.Black;
-        drawQuad( buffer, x, y, width, height, colour.getR(), colour.getG(), colour.getB() );
+        Colour colour = Colour.BLACK;
+        drawQuad( transform, renderer.getBuffer( Type.BLOCKER ), x, y, width, height, colour.getR(), colour.getG(), colour.getB() );
     }
 
-    public static void drawBlocker( float x, float y, float width, float height )
-    {
-        bindFont();
-
-        Tessellator tessellator = Tessellator.getInstance();
-        BufferBuilder buffer = tessellator.getBuffer();
-        begin( buffer );
-        drawBlocker( buffer, x, y, width, height );
-        tessellator.draw();
-    }
-
-    public static void bindFont()
+    private static void bindFont()
     {
         Minecraft.getInstance().getTextureManager().bindTexture( FONT );
-        GlStateManager.texParameter( GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL11.GL_CLAMP );
-
-        GlStateManager.enableTexture();
+        RenderSystem.texParameter( GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL11.GL_CLAMP );
     }
 
-    public static void begin( BufferBuilder buffer )
+    private static final class Type extends RenderState
     {
-        buffer.begin( GL11.GL_TRIANGLES, POSITION_COLOR_TEX );
+        private static final int GL_MODE = GL11.GL_TRIANGLES;
+
+        private static final VertexFormat FORMAT = DefaultVertexFormats.POSITION_COLOR_TEX;
+
+        static final RenderType MAIN = RenderType.makeType(
+            "terminal_font", FORMAT, GL_MODE, 1024,
+            false, false, // useDelegate, needsSorting
+            RenderType.State.getBuilder()
+                .texture( new RenderState.TextureState( FONT, false, false ) ) // blur, minimap
+                .alpha( DEFAULT_ALPHA )
+                .lightmap( LIGHTMAP_DISABLED )
+                .writeMask( COLOR_WRITE )
+                .build( false )
+        );
+
+        static final RenderType BLOCKER = RenderType.makeType(
+            "terminal_blocker", FORMAT, GL_MODE, 256,
+            false, false, // useDelegate, needsSorting
+            RenderType.State.getBuilder()
+                .texture( new RenderState.TextureState( FONT, false, false ) ) // blur, minimap
+                .alpha( DEFAULT_ALPHA )
+                .writeMask( DEPTH_WRITE )
+                .lightmap( LIGHTMAP_DISABLED )
+                .build( false )
+        );
+
+        private Type( String name, Runnable setup, Runnable destroy )
+        {
+            super( name, setup, destroy );
+        }
     }
 }

src/main/java/dan200/computercraft/client/gui/GuiComputer.java

@@ -5,7 +5,7 @@
  */
 package dan200.computercraft.client.gui;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.gui.widgets.WidgetTerminal;
 import dan200.computercraft.client.gui.widgets.WidgetWrapper;
@@ -134,17 +134,17 @@ public final class GuiComputer<T extends ContainerComputerBase> extends Containe
         terminal.draw( terminalWrapper.getX(), terminalWrapper.getY() );
 
         // Draw a border around the terminal
-        GlStateManager.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
+        RenderSystem.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
         switch( m_family )
         {
-            case Normal:
+            case NORMAL:
             default:
                 minecraft.getTextureManager().bindTexture( BACKGROUND_NORMAL );
                 break;
-            case Advanced:
+            case ADVANCED:
                 minecraft.getTextureManager().bindTexture( BACKGROUND_ADVANCED );
                 break;
-            case Command:
+            case COMMAND:
                 minecraft.getTextureManager().bindTexture( BACKGROUND_COMMAND );
                 break;
         }

src/main/java/dan200/computercraft/client/gui/GuiDiskDrive.java

@@ -5,7 +5,7 @@
  */
 package dan200.computercraft.client.gui;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
 import dan200.computercraft.shared.peripheral.diskdrive.ContainerDiskDrive;
 import net.minecraft.client.gui.screen.inventory.ContainerScreen;
 import net.minecraft.entity.player.PlayerInventory;
@@ -32,7 +32,7 @@ public class GuiDiskDrive extends ContainerScreen<ContainerDiskDrive>
     @Override
     protected void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
-        GlStateManager.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+        RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
         minecraft.getTextureManager().bindTexture( BACKGROUND );
         blit( guiLeft, guiTop, 0, 0, xSize, ySize );
     }

src/main/java/dan200/computercraft/client/gui/GuiPrinter.java

@@ -5,7 +5,7 @@
  */
 package dan200.computercraft.client.gui;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
 import dan200.computercraft.shared.peripheral.printer.ContainerPrinter;
 import net.minecraft.client.gui.screen.inventory.ContainerScreen;
 import net.minecraft.client.resources.I18n;
@@ -33,7 +33,7 @@ public class GuiPrinter extends ContainerScreen<ContainerPrinter>
     @Override
     protected void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
-        GlStateManager.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+        RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
         minecraft.getTextureManager().bindTexture( BACKGROUND );
         blit( guiLeft, guiTop, 0, 0, xSize, ySize );
 

src/main/java/dan200/computercraft/client/gui/GuiPrintout.java

@@ -5,11 +5,15 @@
  */
 package dan200.computercraft.client.gui;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
 import dan200.computercraft.core.terminal.TextBuffer;
 import dan200.computercraft.shared.common.ContainerHeldItem;
 import dan200.computercraft.shared.media.items.ItemPrintout;
+import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.screen.inventory.ContainerScreen;
+import net.minecraft.client.renderer.IRenderTypeBuffer;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.TransformationMatrix;
 import net.minecraft.entity.player.PlayerInventory;
 import net.minecraft.util.text.ITextComponent;
 import org.lwjgl.glfw.GLFW;
@@ -18,6 +22,8 @@ import static dan200.computercraft.client.render.PrintoutRenderer.*;
 
 public class GuiPrintout extends ContainerScreen<ContainerHeldItem>
 {
+    private static final Matrix4f IDENTITY = TransformationMatrix.identity().getMatrix();
+
     private final boolean m_book;
     private final int m_pages;
     private final TextBuffer[] m_text;
@@ -88,20 +94,22 @@ public class GuiPrintout extends ContainerScreen<ContainerHeldItem>
     public void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
         // Draw the printout
-        GlStateManager.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
-        GlStateManager.enableDepthTest();
+        RenderSystem.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
+        RenderSystem.enableDepthTest();
 
-        drawBorder( guiLeft, guiTop, blitOffset, m_page, m_pages, m_book );
-        drawText( guiLeft + X_TEXT_MARGIN, guiTop + Y_TEXT_MARGIN, ItemPrintout.LINES_PER_PAGE * m_page, m_text, m_colours );
+        IRenderTypeBuffer.Impl renderer = Minecraft.getInstance().getRenderTypeBuffers().getBufferSource();
+        drawBorder( IDENTITY, renderer, guiLeft, guiTop, getBlitOffset(), m_page, m_pages, m_book );
+        drawText( IDENTITY, renderer, guiLeft + X_TEXT_MARGIN, guiTop + Y_TEXT_MARGIN, ItemPrintout.LINES_PER_PAGE * m_page, m_text, m_colours );
+        renderer.finish();
     }
 
     @Override
     public void render( int mouseX, int mouseY, float partialTicks )
     {
         // We must take the background further back in order to not overlap with our printed pages.
-        blitOffset--;
+        setBlitOffset( getBlitOffset() - 1 );
         renderBackground();
-        blitOffset++;
+        setBlitOffset( getBlitOffset() + 1 );
 
         super.render( mouseX, mouseY, partialTicks );
         renderHoveredToolTip( mouseX, mouseY );

src/main/java/dan200/computercraft/client/gui/GuiTurtle.java

@@ -5,7 +5,7 @@
  */
 package dan200.computercraft.client.gui;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.gui.widgets.WidgetTerminal;
 import dan200.computercraft.client.gui.widgets.WidgetWrapper;
@@ -98,7 +98,7 @@ public class GuiTurtle extends ContainerScreen<ContainerTurtle>
         int slot = m_container.getSelectedSlot();
         if( slot >= 0 )
         {
-            GlStateManager.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+            RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
             int slotX = slot % 4;
             int slotY = slot / 4;
             minecraft.getTextureManager().bindTexture( advanced ? BACKGROUND_ADVANCED : BACKGROUND_NORMAL );
@@ -110,11 +110,11 @@ public class GuiTurtle extends ContainerScreen<ContainerTurtle>
     protected void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
         // Draw term
-        boolean advanced = m_family == ComputerFamily.Advanced;
+        boolean advanced = m_family == ComputerFamily.ADVANCED;
         terminal.draw( terminalWrapper.getX(), terminalWrapper.getY() );
 
         // Draw border/inventory
-        GlStateManager.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+        RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
         minecraft.getTextureManager().bindTexture( advanced ? BACKGROUND_ADVANCED : BACKGROUND_NORMAL );
         blit( guiLeft, guiTop, 0, 0, xSize, ySize );
 

src/main/java/dan200/computercraft/client/gui/widgets/WidgetTerminal.java

@@ -17,6 +17,9 @@ import org.lwjgl.glfw.GLFW;
 import java.util.BitSet;
 import java.util.function.Supplier;
 
+import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
+import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_WIDTH;
+
 public class WidgetTerminal implements IGuiEventListener
 {
     private static final float TERMINATE_TIME = 0.5f;
@@ -173,8 +176,8 @@ public class WidgetTerminal implements IGuiEventListener
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FixedWidthFontRenderer.FONT_WIDTH);
-            int charY = (int) (mouseY / FixedWidthFontRenderer.FONT_HEIGHT);
+            int charX = (int) (mouseX / FONT_WIDTH);
+            int charY = (int) (mouseY / FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -197,8 +200,8 @@ public class WidgetTerminal implements IGuiEventListener
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FixedWidthFontRenderer.FONT_WIDTH);
-            int charY = (int) (mouseY / FixedWidthFontRenderer.FONT_HEIGHT);
+            int charX = (int) (mouseX / FONT_WIDTH);
+            int charY = (int) (mouseY / FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -224,8 +227,8 @@ public class WidgetTerminal implements IGuiEventListener
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FixedWidthFontRenderer.FONT_WIDTH);
-            int charY = (int) (mouseY / FixedWidthFontRenderer.FONT_HEIGHT);
+            int charX = (int) (mouseX / FONT_WIDTH);
+            int charY = (int) (mouseY / FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -249,8 +252,8 @@ public class WidgetTerminal implements IGuiEventListener
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FixedWidthFontRenderer.FONT_WIDTH);
-            int charY = (int) (mouseY / FixedWidthFontRenderer.FONT_HEIGHT);
+            int charX = (int) (mouseX / FONT_WIDTH);
+            int charY = (int) (mouseY / FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -318,19 +321,15 @@ public class WidgetTerminal implements IGuiEventListener
             Terminal terminal = computer != null ? computer.getTerminal() : null;
             if( terminal != null )
             {
-                FixedWidthFontRenderer.drawTerminal(
-                    originX, originY,
-                    terminal, !computer.isColour(), topMargin, bottomMargin, leftMargin, rightMargin
-                );
+                FixedWidthFontRenderer.drawTerminal( originX, originY, terminal, !computer.isColour(), topMargin, bottomMargin, leftMargin, rightMargin );
             }
             else
             {
-                int x = originX - leftMargin;
-                int y = originY - rightMargin;
-                int width = termWidth * FixedWidthFontRenderer.FONT_WIDTH + leftMargin + rightMargin;
-                int height = termHeight * FixedWidthFontRenderer.FONT_HEIGHT + topMargin + bottomMargin;
-
-                FixedWidthFontRenderer.drawEmptyTerminal( x, y, width, height );
+                FixedWidthFontRenderer.drawEmptyTerminal(
+                    originX - leftMargin, originY - rightMargin,
+                    termWidth * FONT_WIDTH + leftMargin + rightMargin,
+                    termHeight * FONT_HEIGHT + topMargin + bottomMargin
+                );
             }
         }
     }

src/main/java/dan200/computercraft/client/proxy/ComputerCraftProxyClient.java

@@ -7,7 +7,6 @@ package dan200.computercraft.client.proxy;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.gui.*;
-import dan200.computercraft.client.render.TileEntityCableRenderer;
 import dan200.computercraft.client.render.TileEntityMonitorRenderer;
 import dan200.computercraft.client.render.TileEntityTurtleRenderer;
 import dan200.computercraft.client.render.TurtlePlayerRenderer;
@@ -15,7 +14,6 @@ import dan200.computercraft.shared.common.ContainerHeldItem;
 import dan200.computercraft.shared.computer.inventory.ContainerComputer;
 import dan200.computercraft.shared.computer.inventory.ContainerViewComputer;
 import dan200.computercraft.shared.peripheral.diskdrive.ContainerDiskDrive;
-import dan200.computercraft.shared.peripheral.modem.wired.TileCable;
 import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
 import dan200.computercraft.shared.peripheral.printer.ContainerPrinter;
@@ -24,6 +22,8 @@ import dan200.computercraft.shared.turtle.blocks.TileTurtle;
 import dan200.computercraft.shared.turtle.core.TurtlePlayer;
 import dan200.computercraft.shared.turtle.inventory.ContainerTurtle;
 import net.minecraft.client.gui.ScreenManager;
+import net.minecraft.client.renderer.RenderType;
+import net.minecraft.client.renderer.RenderTypeLookup;
 import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.event.world.WorldEvent;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
@@ -40,12 +40,22 @@ public final class ComputerCraftProxyClient
     {
         registerContainers();
 
-        // Setup TESRs
-        ClientRegistry.bindTileEntitySpecialRenderer( TileMonitor.class, new TileEntityMonitorRenderer() );
-        ClientRegistry.bindTileEntitySpecialRenderer( TileCable.class, new TileEntityCableRenderer() );
-        ClientRegistry.bindTileEntitySpecialRenderer( TileTurtle.class, new TileEntityTurtleRenderer() );
+        // While turtles themselves are not transparent, their upgrades may be.
+        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.turtleNormal, RenderType.getTranslucent() );
+        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.turtleAdvanced, RenderType.getTranslucent() );
 
-        RenderingRegistry.registerEntityRenderingHandler( TurtlePlayer.class, TurtlePlayerRenderer::new );
+        // Monitors' textures have transparent fronts and so count as cutouts.
+        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.monitorNormal, RenderType.getCutout() );
+        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.monitorAdvanced, RenderType.getCutout() );
+
+        // Setup TESRs
+        ClientRegistry.bindTileEntityRenderer( TileMonitor.FACTORY_NORMAL, TileEntityMonitorRenderer::new );
+        ClientRegistry.bindTileEntityRenderer( TileMonitor.FACTORY_ADVANCED, TileEntityMonitorRenderer::new );
+        ClientRegistry.bindTileEntityRenderer( TileTurtle.FACTORY_NORMAL, TileEntityTurtleRenderer::new );
+        ClientRegistry.bindTileEntityRenderer( TileTurtle.FACTORY_ADVANCED, TileEntityTurtleRenderer::new );
+        // TODO: ClientRegistry.bindTileEntityRenderer( TileCable.FACTORY, x -> new TileEntityCableRenderer() );
+
+        RenderingRegistry.registerEntityRenderingHandler( TurtlePlayer.TYPE, TurtlePlayerRenderer::new );
     }
 
     private static void registerContainers()

src/main/java/dan200/computercraft/client/render/CableHighlightRenderer.java

@@ -5,26 +5,27 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.matrix.MatrixStack;
+import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.peripheral.modem.wired.BlockCable;
 import dan200.computercraft.shared.peripheral.modem.wired.CableShapes;
 import dan200.computercraft.shared.util.WorldUtil;
 import net.minecraft.block.BlockState;
-import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.ActiveRenderInfo;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.RenderType;
 import net.minecraft.client.renderer.WorldRenderer;
+import net.minecraft.entity.Entity;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.BlockRayTraceResult;
-import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.util.math.shapes.VoxelShape;
 import net.minecraft.world.World;
 import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.client.event.DrawBlockHighlightEvent;
+import net.minecraftforge.client.event.DrawHighlightEvent;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod;
-import org.lwjgl.opengl.GL11;
 
 @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT )
 public final class CableHighlightRenderer
@@ -37,14 +38,12 @@ public final class CableHighlightRenderer
      * Draw an outline for a specific part of a cable "Multipart".
      *
      * @param event The event to observe
-     * @see WorldRenderer#drawSelectionBox(ActiveRenderInfo, RayTraceResult, int)
+     * @see WorldRenderer#drawSelectionBox(MatrixStack, IVertexBuilder, Entity, double, double, double, BlockPos, BlockState)
      */
     @SubscribeEvent
-    public static void drawHighlight( DrawBlockHighlightEvent event )
+    public static void drawHighlight( DrawHighlightEvent.HighlightBlock event )
     {
-        if( event.getTarget().getType() != RayTraceResult.Type.BLOCK ) return;
-
-        BlockRayTraceResult hit = (BlockRayTraceResult) event.getTarget();
+        BlockRayTraceResult hit = event.getTarget();
         BlockPos pos = hit.getPos();
         World world = event.getInfo().getRenderViewEntity().getEntityWorld();
         ActiveRenderInfo info = event.getInfo();
@@ -59,31 +58,22 @@ public final class CableHighlightRenderer
 
         event.setCanceled( true );
 
-        Minecraft mc = Minecraft.getInstance();
-
-        GlStateManager.enableBlend();
-        GlStateManager.blendFuncSeparate( GlStateManager.SourceFactor.SRC_ALPHA, GlStateManager.DestFactor.ONE_MINUS_SRC_ALPHA, GlStateManager.SourceFactor.ONE, GlStateManager.DestFactor.ZERO );
-        GlStateManager.lineWidth( Math.max( 2.5F, mc.mainWindow.getFramebufferWidth() / 1920.0F * 2.5F ) );
-        GlStateManager.disableTexture();
-        GlStateManager.depthMask( false );
-        GlStateManager.matrixMode( GL11.GL_PROJECTION );
-        GlStateManager.pushMatrix();
-        GlStateManager.scalef( 1.0F, 1.0F, 0.999F );
-
         VoxelShape shape = WorldUtil.isVecInside( CableShapes.getModemShape( state ), hit.getHitVec().subtract( pos.getX(), pos.getY(), pos.getZ() ) )
             ? CableShapes.getModemShape( state )
             : CableShapes.getCableShape( state );
 
         Vec3d cameraPos = info.getProjectedView();
-        WorldRenderer.drawShape(
-            shape, pos.getX() - cameraPos.getX(), pos.getY() - cameraPos.getY(), pos.getZ() - cameraPos.getZ(),
-            0.0F, 0.0F, 0.0F, 0.4F
-        );
+        double xOffset = pos.getX() - cameraPos.getX();
+        double yOffset = pos.getY() - cameraPos.getY();
+        double zOffset = pos.getZ() - cameraPos.getZ();
 
-        GlStateManager.popMatrix();
-        GlStateManager.matrixMode( GL11.GL_MODELVIEW );
-        GlStateManager.depthMask( true );
-        GlStateManager.enableTexture();
-        GlStateManager.disableBlend();
+        IVertexBuilder buffer = event.getBuffers().getBuffer( RenderType.getLines() );
+        Matrix4f matrix4f = event.getMatrix().getLast().getMatrix();
+        shape.forEachEdge( ( x1, y1, z1, x2, y2, z2 ) -> {
+            buffer.pos( matrix4f, (float) (x1 + xOffset), (float) (y1 + yOffset), (float) (z1 + zOffset) )
+                .color( 0, 0, 0, 0.4f ).endVertex();
+            buffer.pos( matrix4f, (float) (x2 + xOffset), (float) (y2 + yOffset), (float) (z2 + zOffset) )
+                .color( 0, 0, 0, 0.4f ).endVertex();
+        } );
     }
 }

src/main/java/dan200/computercraft/client/render/ItemMapLikeRenderer.java

@@ -5,9 +5,12 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.matrix.MatrixStack;
 import net.minecraft.client.Minecraft;
+import net.minecraft.client.entity.player.AbstractClientPlayerEntity;
 import net.minecraft.client.renderer.FirstPersonRenderer;
+import net.minecraft.client.renderer.IRenderTypeBuffer;
+import net.minecraft.client.renderer.Vector3f;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.Hand;
@@ -19,99 +22,118 @@ public abstract class ItemMapLikeRenderer
     /**
      * The main rendering method for the item.
      *
-     * @param stack The stack to render
-     * @see FirstPersonRenderer#renderMapFirstPerson(ItemStack)
+     * @param transform The matrix transformation stack
+     * @param render    The buffer to render to
+     * @param stack     The stack to render
+     * @see FirstPersonRenderer#renderItemInFirstPerson(AbstractClientPlayerEntity, float, float, Hand, float, ItemStack, float, MatrixStack, IRenderTypeBuffer, int)
      */
-    protected abstract void renderItem( ItemStack stack );
+    protected abstract void renderItem( MatrixStack transform, IRenderTypeBuffer render, ItemStack stack );
 
-    protected void renderItemFirstPerson( Hand hand, float pitch, float equipProgress, float swingProgress, ItemStack stack )
+    protected void renderItemFirstPerson( MatrixStack transform, IRenderTypeBuffer render, int lightTexture, Hand hand, float pitch, float equipProgress, float swingProgress, ItemStack stack )
     {
         PlayerEntity player = Minecraft.getInstance().player;
 
-        GlStateManager.pushMatrix();
+        transform.push();
         if( hand == Hand.MAIN_HAND && player.getHeldItemOffhand().isEmpty() )
         {
-            renderItemFirstPersonCenter( pitch, equipProgress, swingProgress, stack );
+            renderItemFirstPersonCenter( transform, render, lightTexture, pitch, equipProgress, swingProgress, stack );
         }
         else
         {
             renderItemFirstPersonSide(
+                transform, render, lightTexture,
                 hand == Hand.MAIN_HAND ? player.getPrimaryHand() : player.getPrimaryHand().opposite(),
                 equipProgress, swingProgress, stack
             );
         }
-        GlStateManager.popMatrix();
+        transform.pop();
     }
 
     /**
      * Renders the item to one side of the player.
      *
+     * @param transform     The matrix transformation stack
+     * @param render        The buffer to render to
+     * @param combinedLight The current light level
      * @param side          The side to render on
      * @param equipProgress The equip progress of this item
      * @param swingProgress The swing progress of this item
      * @param stack         The stack to render
-     * @see FirstPersonRenderer#renderMapFirstPersonSide(float, HandSide, float, ItemStack)
+     * @see FirstPersonRenderer#renderMapFirstPersonSide(MatrixStack, IRenderTypeBuffer, int, float, HandSide, float, ItemStack)
      */
-    private void renderItemFirstPersonSide( HandSide side, float equipProgress, float swingProgress, ItemStack stack )
+    private void renderItemFirstPersonSide( MatrixStack transform, IRenderTypeBuffer render, int combinedLight, HandSide side, float equipProgress, float swingProgress, ItemStack stack )
     {
         Minecraft minecraft = Minecraft.getInstance();
         float offset = side == HandSide.RIGHT ? 1f : -1f;
-        GlStateManager.translatef( offset * 0.125f, -0.125f, 0f );
+        transform.translate( offset * 0.125f, -0.125f, 0f );
 
         // If the player is not invisible then render a single arm
         if( !minecraft.player.isInvisible() )
         {
-            GlStateManager.pushMatrix();
-            GlStateManager.rotatef( offset * 10f, 0f, 0f, 1f );
-            minecraft.getFirstPersonRenderer().renderArmFirstPerson( equipProgress, swingProgress, side );
-            GlStateManager.popMatrix();
+            transform.push();
+            transform.rotate( Vector3f.ZP.rotationDegrees( offset * 10f ) );
+            minecraft.getFirstPersonRenderer().renderArmFirstPerson( transform, render, combinedLight, equipProgress, swingProgress, side );
+            transform.pop();
         }
 
         // Setup the appropriate transformations. This is just copied from the
         // corresponding method in ItemRenderer.
-        GlStateManager.pushMatrix();
-        GlStateManager.translatef( offset * 0.51f, -0.08f + equipProgress * -1.2f, -0.75f );
+        transform.push();
+        transform.translate( offset * 0.51f, -0.08f + equipProgress * -1.2f, -0.75f );
         float f1 = MathHelper.sqrt( swingProgress );
         float f2 = MathHelper.sin( f1 * (float) Math.PI );
         float f3 = -0.5f * f2;
         float f4 = 0.4f * MathHelper.sin( f1 * ((float) Math.PI * 2f) );
         float f5 = -0.3f * MathHelper.sin( swingProgress * (float) Math.PI );
-        GlStateManager.translatef( offset * f3, f4 - 0.3f * f2, f5 );
-        GlStateManager.rotatef( f2 * -45f, 1f, 0f, 0f );
-        GlStateManager.rotatef( offset * f2 * -30f, 0f, 1f, 0f );
+        transform.translate( offset * f3, f4 - 0.3f * f2, f5 );
+        transform.rotate( Vector3f.XP.rotationDegrees( f2 * -45f ) );
+        transform.rotate( Vector3f.YP.rotationDegrees( offset * f2 * -30f ) );
 
-        renderItem( stack );
+        renderItem( transform, render, stack );
 
-        GlStateManager.popMatrix();
+        transform.pop();
     }
 
     /**
      * Render an item in the middle of the screen.
      *
+     * @param transform     The matrix transformation stack
+     * @param render        The buffer to render to
+     * @param combinedLight The current light level
      * @param pitch         The pitch of the player
      * @param equipProgress The equip progress of this item
      * @param swingProgress The swing progress of this item
      * @param stack         The stack to render
-     * @see FirstPersonRenderer#renderMapFirstPerson(float, float, float)
+     * @see FirstPersonRenderer#renderMapFirstPerson(MatrixStack, IRenderTypeBuffer, int, float, float, float)
      */
-    private void renderItemFirstPersonCenter( float pitch, float equipProgress, float swingProgress, ItemStack stack )
+    private void renderItemFirstPersonCenter( MatrixStack transform, IRenderTypeBuffer render, int combinedLight, float pitch, float equipProgress, float swingProgress, ItemStack stack )
     {
-        FirstPersonRenderer renderer = Minecraft.getInstance().getFirstPersonRenderer();
+        Minecraft minecraft = Minecraft.getInstance();
+        FirstPersonRenderer renderer = minecraft.getFirstPersonRenderer();
 
         // Setup the appropriate transformations. This is just copied from the
         // corresponding method in ItemRenderer.
         float swingRt = MathHelper.sqrt( swingProgress );
         float tX = -0.2f * MathHelper.sin( swingProgress * (float) Math.PI );
         float tZ = -0.4f * MathHelper.sin( swingRt * (float) Math.PI );
-        GlStateManager.translatef( 0f, -tX / 2f, tZ );
-        float pitchAngle = renderer.getMapAngleFromPitch( pitch );
-        GlStateManager.translatef( 0f, 0.04f + equipProgress * -1.2f + pitchAngle * -0.5f, -0.72f );
-        GlStateManager.rotatef( pitchAngle * -85f, 1f, 0f, 0f );
-        renderer.renderArms();
-        float rX = MathHelper.sin( swingRt * (float) Math.PI );
-        GlStateManager.rotatef( rX * 20f, 1f, 0f, 0f );
-        GlStateManager.scalef( 2f, 2f, 2f );
+        transform.translate( 0, -tX / 2, tZ );
 
-        renderItem( stack );
+        float pitchAngle = renderer.getMapAngleFromPitch( pitch );
+        transform.translate( 0, 0.04F + equipProgress * -1.2f + pitchAngle * -0.5f, -0.72f );
+        transform.rotate( Vector3f.XP.rotationDegrees( pitchAngle * -85.0f ) );
+        if( !minecraft.player.isInvisible() )
+        {
+            transform.push();
+            transform.rotate( Vector3f.YP.rotationDegrees( 90.0F ) );
+            renderer.renderArm( transform, render, combinedLight, HandSide.RIGHT );
+            renderer.renderArm( transform, render, combinedLight, HandSide.LEFT );
+            transform.pop();
+        }
+
+        float rX = MathHelper.sin( swingRt * (float) Math.PI );
+        transform.rotate( Vector3f.XP.rotationDegrees( rX * 20.0F ) );
+        transform.scale( 2.0F, 2.0F, 2.0F );
+
+        renderItem( transform, render, stack );
     }
 }

src/main/java/dan200/computercraft/client/render/ItemPocketRenderer.java

@@ -5,7 +5,9 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.matrix.MatrixStack;
+import com.mojang.blaze3d.systems.RenderSystem;
+import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.gui.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.Terminal;
@@ -14,12 +16,11 @@ import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
 import dan200.computercraft.shared.util.Colour;
 import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.BufferBuilder;
-import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.*;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.client.event.RenderSpecificHandEvent;
+import net.minecraftforge.client.event.RenderHandEvent;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod;
 import org.lwjgl.opengl.GL11;
@@ -45,17 +46,20 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
     }
 
     @SubscribeEvent
-    public static void renderItem( RenderSpecificHandEvent event )
+    public static void onRenderInHand( RenderHandEvent event )
     {
         ItemStack stack = event.getItemStack();
         if( !(stack.getItem() instanceof ItemPocketComputer) ) return;
 
         event.setCanceled( true );
-        INSTANCE.renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
+        INSTANCE.renderItemFirstPerson(
+            event.getMatrixStack(), event.getBuffers(), event.getLight(),
+            event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack()
+        );
     }
 
     @Override
-    protected void renderItem( ItemStack stack )
+    protected void renderItem( MatrixStack transform, IRenderTypeBuffer render, ItemStack stack )
     {
         ClientComputer computer = ItemPocketComputer.createClientComputer( stack );
         Terminal terminal = computer == null ? null : computer.getTerminal();
@@ -77,50 +81,45 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
 
         // Setup various transformations. Note that these are partially adapted from the corresponding method
         // in ItemRenderer
-        GlStateManager.pushMatrix();
+        transform.push();
+        transform.rotate( Vector3f.YP.rotationDegrees( 180f ) );
+        transform.rotate( Vector3f.ZP.rotationDegrees( 180f ) );
+        transform.scale( 0.5f, 0.5f, 0.5f );
 
-        GlStateManager.disableLighting();
-        GlStateManager.disableDepthTest();
-
-        GlStateManager.rotatef( 180f, 0f, 1f, 0f );
-        GlStateManager.rotatef( 180f, 0f, 0f, 1f );
-        GlStateManager.scalef( 0.5f, 0.5f, 0.5f );
-
-        double scale = 0.75 / Math.max( width + FRAME * 2, height + FRAME * 2 + LIGHT_HEIGHT );
-        GlStateManager.scaled( scale, scale, 0 );
-        GlStateManager.translated( -0.5 * width, -0.5 * height, 0 );
+        float scale = 0.75f / Math.max( width + FRAME * 2, height + FRAME * 2 + LIGHT_HEIGHT );
+        transform.scale( scale, scale, 0 );
+        transform.translate( -0.5 * width, -0.5 * height, 0 );
 
         // Render the main frame
         ItemPocketComputer item = (ItemPocketComputer) stack.getItem();
         ComputerFamily family = item.getFamily();
         int frameColour = item.getColour( stack );
-        renderFrame( family, frameColour, width, height );
+
+        Matrix4f matrix = transform.getLast().getMatrix();
+        renderFrame( matrix, family, frameColour, width, height );
 
         // Render the light
         int lightColour = ItemPocketComputer.getLightState( stack );
-        if( lightColour == -1 ) lightColour = Colour.Black.getHex();
-        renderLight( lightColour, width, height );
+        if( lightColour == -1 ) lightColour = Colour.BLACK.getHex();
+        renderLight( matrix, lightColour, width, height );
 
         if( computer != null && terminal != null )
         {
-            FixedWidthFontRenderer.drawTerminal( MARGIN, MARGIN, terminal, !computer.isColour(), MARGIN, MARGIN, MARGIN, MARGIN );
+            FixedWidthFontRenderer.drawTerminal( matrix, MARGIN, MARGIN, terminal, !computer.isColour(), MARGIN, MARGIN, MARGIN, MARGIN );
         }
         else
         {
-            FixedWidthFontRenderer.drawEmptyTerminal( 0, 0, width, height );
+            FixedWidthFontRenderer.drawEmptyTerminal( matrix, 0, 0, width, height );
         }
 
-        GlStateManager.enableDepthTest();
-        GlStateManager.enableLighting();
-        GlStateManager.popMatrix();
+        transform.pop();
     }
 
-    private static void renderFrame( ComputerFamily family, int colour, int width, int height )
+    private static void renderFrame( Matrix4f transform, ComputerFamily family, int colour, int width, int height )
     {
-
         Minecraft.getInstance().getTextureManager().bindTexture( colour != -1
             ? BACKGROUND_COLOUR
-            : family == ComputerFamily.Normal ? BACKGROUND_NORMAL : BACKGROUND_ADVANCED
+            : family == ComputerFamily.NORMAL ? BACKGROUND_NORMAL : BACKGROUND_ADVANCED
         );
 
         float r = ((colour >>> 16) & 0xFF) / 255.0f;
@@ -129,38 +128,38 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
 
         Tessellator tessellator = Tessellator.getInstance();
         BufferBuilder buffer = tessellator.getBuffer();
-        buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_TEX_COLOR );
+        buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR_TEX );
 
         // Top left, middle, right
-        renderTexture( buffer, -FRAME, -FRAME, 12, 28, FRAME, FRAME, r, g, b );
-        renderTexture( buffer, 0, -FRAME, 0, 0, width, FRAME, r, g, b );
-        renderTexture( buffer, width, -FRAME, 24, 28, FRAME, FRAME, r, g, b );
+        renderTexture( transform, buffer, -FRAME, -FRAME, 12, 28, FRAME, FRAME, r, g, b );
+        renderTexture( transform, buffer, 0, -FRAME, 0, 0, width, FRAME, r, g, b );
+        renderTexture( transform, buffer, width, -FRAME, 24, 28, FRAME, FRAME, r, g, b );
 
         // Left and bright border
-        renderTexture( buffer, -FRAME, 0, 0, 28, FRAME, height, r, g, b );
-        renderTexture( buffer, width, 0, 36, 28, FRAME, height, r, g, b );
+        renderTexture( transform, buffer, -FRAME, 0, 0, 28, FRAME, height, r, g, b );
+        renderTexture( transform, buffer, width, 0, 36, 28, FRAME, height, r, g, b );
 
         // Bottom left, middle, right. We do this in three portions: the top inner corners, an extended region for
         // lights, and then the bottom outer corners.
-        renderTexture( buffer, -FRAME, height, 12, 40, FRAME, FRAME / 2, r, g, b );
-        renderTexture( buffer, 0, height, 0, 12, width, FRAME / 2, r, g, b );
-        renderTexture( buffer, width, height, 24, 40, FRAME, FRAME / 2, r, g, b );
+        renderTexture( transform, buffer, -FRAME, height, 12, 40, FRAME, FRAME / 2, r, g, b );
+        renderTexture( transform, buffer, 0, height, 0, 12, width, FRAME / 2, r, g, b );
+        renderTexture( transform, buffer, width, height, 24, 40, FRAME, FRAME / 2, r, g, b );
 
-        renderTexture( buffer, -FRAME, height + FRAME / 2, 12, 44, FRAME, LIGHT_HEIGHT, FRAME, 4, r, g, b );
-        renderTexture( buffer, 0, height + FRAME / 2, 0, 16, width, LIGHT_HEIGHT, FRAME, 4, r, g, b );
-        renderTexture( buffer, width, height + FRAME / 2, 24, 44, FRAME, LIGHT_HEIGHT, FRAME, 4, r, g, b );
+        renderTexture( transform, buffer, -FRAME, height + FRAME / 2, 12, 44, FRAME, LIGHT_HEIGHT, FRAME, 4, r, g, b );
+        renderTexture( transform, buffer, 0, height + FRAME / 2, 0, 16, width, LIGHT_HEIGHT, FRAME, 4, r, g, b );
+        renderTexture( transform, buffer, width, height + FRAME / 2, 24, 44, FRAME, LIGHT_HEIGHT, FRAME, 4, r, g, b );
 
-        renderTexture( buffer, -FRAME, height + LIGHT_HEIGHT + FRAME / 2, 12, 40 + FRAME / 2, FRAME, FRAME / 2, r, g, b );
-        renderTexture( buffer, 0, height + LIGHT_HEIGHT + FRAME / 2, 0, 12 + FRAME / 2, width, FRAME / 2, r, g, b );
-        renderTexture( buffer, width, height + LIGHT_HEIGHT + FRAME / 2, 24, 40 + FRAME / 2, FRAME, FRAME / 2, r, g, b );
+        renderTexture( transform, buffer, -FRAME, height + LIGHT_HEIGHT + FRAME / 2, 12, 40 + FRAME / 2, FRAME, FRAME / 2, r, g, b );
+        renderTexture( transform, buffer, 0, height + LIGHT_HEIGHT + FRAME / 2, 0, 12 + FRAME / 2, width, FRAME / 2, r, g, b );
+        renderTexture( transform, buffer, width, height + LIGHT_HEIGHT + FRAME / 2, 24, 40 + FRAME / 2, FRAME, FRAME / 2, r, g, b );
 
         tessellator.draw();
     }
 
-    private static void renderLight( int colour, int width, int height )
+    private static void renderLight( Matrix4f transform, int colour, int width, int height )
     {
-        GlStateManager.enableBlend();
-        GlStateManager.disableTexture();
+        RenderSystem.enableBlend();
+        RenderSystem.disableTexture();
 
         float r = ((colour >>> 16) & 0xFF) / 255.0f;
         float g = ((colour >>> 8) & 0xFF) / 255.0f;
@@ -169,26 +168,26 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
         Tessellator tessellator = Tessellator.getInstance();
         BufferBuilder buffer = tessellator.getBuffer();
         buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR );
-        buffer.pos( width - LIGHT_HEIGHT * 2, height + LIGHT_HEIGHT + FRAME / 2.0f, 0.0D ).color( r, g, b, 1.0f ).endVertex();
-        buffer.pos( width, height + LIGHT_HEIGHT + FRAME / 2.0f, 0.0D ).color( r, g, b, 1.0f ).endVertex();
-        buffer.pos( width, height + FRAME / 2.0f, 0.0D ).color( r, g, b, 1.0f ).endVertex();
-        buffer.pos( width - LIGHT_HEIGHT * 2, height + FRAME / 2.0f, 0.0D ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( transform, width - LIGHT_HEIGHT * 2, height + LIGHT_HEIGHT + FRAME / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( transform, width, height + LIGHT_HEIGHT + FRAME / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( transform, width, height + FRAME / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( transform, width - LIGHT_HEIGHT * 2, height + FRAME / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
 
         tessellator.draw();
-        GlStateManager.enableTexture();
+        RenderSystem.enableTexture();
     }
 
-    private static void renderTexture( BufferBuilder builder, int x, int y, int textureX, int textureY, int width, int height, float r, float g, float b )
+    private static void renderTexture( Matrix4f transform, IVertexBuilder builder, int x, int y, int textureX, int textureY, int width, int height, float r, float g, float b )
     {
-        renderTexture( builder, x, y, textureX, textureY, width, height, width, height, r, g, b );
+        renderTexture( transform, builder, x, y, textureX, textureY, width, height, width, height, r, g, b );
     }
 
-    private static void renderTexture( BufferBuilder builder, int x, int y, int textureX, int textureY, int width, int height, int textureWidth, int textureHeight, float r, float g, float b )
+    private static void renderTexture( Matrix4f transform, IVertexBuilder builder, int x, int y, int textureX, int textureY, int width, int height, int textureWidth, int textureHeight, float r, float g, float b )
     {
         float scale = 1 / 255.0f;
-        builder.pos( x, y + height, 0 ).tex( textureX * scale, (textureY + textureHeight) * scale ).color( r, g, b, 1.0f ).endVertex();
-        builder.pos( x + width, y + height, 0 ).tex( (textureX + textureWidth) * scale, (textureY + textureHeight) * scale ).color( r, g, b, 1.0f ).endVertex();
-        builder.pos( x + width, y, 0 ).tex( (textureX + textureWidth) * scale, textureY * scale ).color( r, g, b, 1.0f ).endVertex();
-        builder.pos( x, y, 0 ).tex( textureX * scale, textureY * scale ).color( r, g, b, 1.0f ).endVertex();
+        builder.pos( transform, x, y + height, 0 ).color( r, g, b, 1.0f ).tex( textureX * scale, (textureY + textureHeight) * scale ).endVertex();
+        builder.pos( transform, x + width, y + height, 0 ).color( r, g, b, 1.0f ).tex( (textureX + textureWidth) * scale, (textureY + textureHeight) * scale ).endVertex();
+        builder.pos( transform, x + width, y, 0 ).color( r, g, b, 1.0f ).tex( (textureX + textureWidth) * scale, textureY * scale ).endVertex();
+        builder.pos( transform, x, y, 0 ).color( r, g, b, 1.0f ).tex( textureX * scale, textureY * scale ).endVertex();
     }
 }

src/main/java/dan200/computercraft/client/render/ItemPrintoutRenderer.java

@@ -5,13 +5,16 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.matrix.MatrixStack;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.media.items.ItemPrintout;
+import net.minecraft.client.renderer.IRenderTypeBuffer;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.Vector3f;
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.client.event.RenderHandEvent;
 import net.minecraftforge.client.event.RenderItemInFrameEvent;
-import net.minecraftforge.client.event.RenderSpecificHandEvent;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod;
 
@@ -34,30 +37,26 @@ public final class ItemPrintoutRenderer extends ItemMapLikeRenderer
     }
 
     @SubscribeEvent
-    public static void onRenderInHand( RenderSpecificHandEvent event )
+    public static void onRenderInHand( RenderHandEvent event )
     {
         ItemStack stack = event.getItemStack();
         if( !(stack.getItem() instanceof ItemPrintout) ) return;
 
         event.setCanceled( true );
-        INSTANCE.renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
+        INSTANCE.renderItemFirstPerson(
+            event.getMatrixStack(), event.getBuffers(), event.getLight(),
+            event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack()
+        );
     }
 
     @Override
-    protected void renderItem( ItemStack stack )
+    protected void renderItem( MatrixStack transform, IRenderTypeBuffer render, ItemStack stack )
     {
-        // Setup various transformations. Note that these are partially adapated from the corresponding method
-        // in FirstPersonRenderer.renderFirstPersonMap
-        GlStateManager.disableLighting();
+        transform.rotate( Vector3f.XP.rotationDegrees( 180f ) );
+        transform.scale( 0.42f, 0.42f, -0.42f );
+        transform.translate( -0.5f, -0.48f, 0.0f );
 
-        GlStateManager.rotatef( 180f, 0f, 1f, 0f );
-        GlStateManager.rotatef( 180f, 0f, 0f, 1f );
-        GlStateManager.scalef( 0.42f, 0.42f, -0.42f );
-        GlStateManager.translatef( -0.5f, -0.48f, 0.0f );
-
-        drawPrintout( stack );
-
-        GlStateManager.enableLighting();
+        drawPrintout( transform, render, stack );
     }
 
     @SubscribeEvent
@@ -65,24 +64,20 @@ public final class ItemPrintoutRenderer extends ItemMapLikeRenderer
     {
         ItemStack stack = event.getItem();
         if( !(stack.getItem() instanceof ItemPrintout) ) return;
-
         event.setCanceled( true );
 
-        GlStateManager.disableLighting();
+        MatrixStack transform = event.getMatrix();
 
         // Move a little bit forward to ensure we're not clipping with the frame
-        GlStateManager.translatef( 0.0f, 0.0f, -0.001f );
-        GlStateManager.rotatef( 180f, 0f, 0f, 1f );
-        GlStateManager.scalef( 0.95f, 0.95f, -0.95f );
-        GlStateManager.translatef( -0.5f, -0.5f, 0.0f );
+        transform.translate( 0.0f, 0.0f, -0.001f );
+        transform.rotate( Vector3f.ZP.rotationDegrees( 180f ) );
+        transform.scale( 0.95f, 0.95f, -0.95f );
+        transform.translate( -0.5f, -0.5f, 0.0f );
 
-        drawPrintout( stack );
-
-        GlStateManager.enableLighting();
-        GlStateManager.disableBlend();
+        drawPrintout( transform, event.getBuffers(), stack );
     }
 
-    private static void drawPrintout( ItemStack stack )
+    private static void drawPrintout( MatrixStack transform, IRenderTypeBuffer render, ItemStack stack )
     {
         int pages = ItemPrintout.getPageCount( stack );
         boolean book = ((ItemPrintout) stack.getItem()).getType() == ItemPrintout.Type.BOOK;
@@ -105,11 +100,14 @@ public final class ItemPrintoutRenderer extends ItemMapLikeRenderer
         double max = Math.max( visualHeight, visualWidth );
 
         // Scale the printout to fit correctly.
-        double scale = 1.0 / max;
-        GlStateManager.scaled( scale, scale, scale );
-        GlStateManager.translated( (max - width) / 2.0, (max - height) / 2.0, 0.0 );
+        float scale = (float) (1.0 / max);
+        transform.scale( scale, scale, scale );
+        transform.translate( (max - width) / 2.0, (max - height) / 2.0, 0.0 );
 
-        drawBorder( 0, 0, -0.01, 0, pages, book );
-        drawText( X_TEXT_MARGIN, Y_TEXT_MARGIN, 0, ItemPrintout.getText( stack ), ItemPrintout.getColours( stack ) );
+        Matrix4f matrix = transform.getLast().getMatrix();
+        drawBorder( matrix, render, 0, 0, -0.01f, 0, pages, book );
+        drawText( matrix, render,
+            X_TEXT_MARGIN, Y_TEXT_MARGIN, 0, ItemPrintout.getText( stack ), ItemPrintout.getColours( stack )
+        );
     }
 }

src/main/java/dan200/computercraft/client/render/ModelTransformer.java

@@ -1,269 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.client.render;
-
-import net.minecraft.client.renderer.model.BakedQuad;
-import net.minecraft.client.renderer.texture.TextureAtlasSprite;
-import net.minecraft.client.renderer.vertex.VertexFormat;
-import net.minecraft.util.Direction;
-import net.minecraftforge.client.model.pipeline.IVertexConsumer;
-import net.minecraftforge.client.model.pipeline.LightUtil;
-import net.minecraftforge.client.model.pipeline.VertexTransformer;
-import net.minecraftforge.common.model.TRSRTransformation;
-
-import javax.annotation.Nonnull;
-import javax.vecmath.Matrix4f;
-import javax.vecmath.Point3f;
-import javax.vecmath.Vector3f;
-import java.util.List;
-
-/**
- * Transforms vertices of a model, remaining aware of winding order, and rearranging
- * vertices if needed.
- */
-public final class ModelTransformer
-{
-    private static final Matrix4f identity;
-
-    static
-    {
-        identity = new Matrix4f();
-        identity.setIdentity();
-    }
-
-    private ModelTransformer()
-    {
-    }
-
-    public static void transformQuadsTo( List<BakedQuad> output, List<BakedQuad> input, Matrix4f transform )
-    {
-        if( transform == null || transform.equals( identity ) )
-        {
-            output.addAll( input );
-        }
-        else
-        {
-            Matrix4f normalMatrix = new Matrix4f( transform );
-            normalMatrix.invert();
-            normalMatrix.transpose();
-
-            for( BakedQuad quad : input ) output.add( doTransformQuad( quad, transform, normalMatrix ) );
-        }
-    }
-
-    public static BakedQuad transformQuad( BakedQuad input, Matrix4f transform )
-    {
-        if( transform == null || transform.equals( identity ) ) return input;
-
-        Matrix4f normalMatrix = new Matrix4f( transform );
-        normalMatrix.invert();
-        normalMatrix.transpose();
-        return doTransformQuad( input, transform, normalMatrix );
-    }
-
-    private static BakedQuad doTransformQuad( BakedQuad input, Matrix4f positionMatrix, Matrix4f normalMatrix )
-    {
-
-        BakedQuadBuilder builder = new BakedQuadBuilder( input.getFormat() );
-        NormalAwareTransformer transformer = new NormalAwareTransformer( builder, positionMatrix, normalMatrix );
-        input.pipe( transformer );
-
-        if( transformer.areNormalsInverted() )
-        {
-            builder.swap( 1, 3 );
-            transformer.areNormalsInverted();
-        }
-
-        return builder.build();
-    }
-
-    /**
-     * A vertex transformer that tracks whether the normals have been inverted and so the vertices
-     * should be reordered so backface culling works as expected.
-     */
-    private static class NormalAwareTransformer extends VertexTransformer
-    {
-        private final Matrix4f positionMatrix;
-        private final Matrix4f normalMatrix;
-
-        private int vertexIndex = 0, elementIndex = 0;
-        private final Point3f[] before = new Point3f[4];
-        private final Point3f[] after = new Point3f[4];
-
-        NormalAwareTransformer( IVertexConsumer parent, Matrix4f positionMatrix, Matrix4f normalMatrix )
-        {
-            super( parent );
-            this.positionMatrix = positionMatrix;
-            this.normalMatrix = normalMatrix;
-        }
-
-        @Override
-        public void setQuadOrientation( @Nonnull Direction orientation )
-        {
-            super.setQuadOrientation( orientation == null ? orientation : TRSRTransformation.rotate( positionMatrix, orientation ) );
-        }
-
-        @Override
-        public void put( int element, @Nonnull float... data )
-        {
-            switch( getVertexFormat().getElement( element ).getUsage() )
-            {
-                case POSITION:
-                {
-                    Point3f vec = new Point3f( data );
-                    Point3f newVec = new Point3f();
-                    positionMatrix.transform( vec, newVec );
-
-                    float[] newData = new float[4];
-                    newVec.get( newData );
-                    super.put( element, newData );
-
-
-                    before[vertexIndex] = vec;
-                    after[vertexIndex] = newVec;
-                    break;
-                }
-                case NORMAL:
-                {
-                    Vector3f vec = new Vector3f( data );
-                    normalMatrix.transform( vec );
-
-                    float[] newData = new float[4];
-                    vec.get( newData );
-                    super.put( element, newData );
-                    break;
-                }
-                default:
-                    super.put( element, data );
-                    break;
-            }
-
-            elementIndex++;
-            if( elementIndex == getVertexFormat().getElementCount() )
-            {
-                vertexIndex++;
-                elementIndex = 0;
-            }
-        }
-
-        public boolean areNormalsInverted()
-        {
-            Vector3f temp1 = new Vector3f(), temp2 = new Vector3f();
-            Vector3f crossBefore = new Vector3f(), crossAfter = new Vector3f();
-
-            // Determine what cross product we expect to have
-            temp1.sub( before[1], before[0] );
-            temp2.sub( before[1], before[2] );
-            crossBefore.cross( temp1, temp2 );
-            normalMatrix.transform( crossBefore );
-
-            // And determine what cross product we actually have
-            temp1.sub( after[1], after[0] );
-            temp2.sub( after[1], after[2] );
-            crossAfter.cross( temp1, temp2 );
-
-            // If the angle between expected and actual cross product is greater than
-            // pi/2 radians then we will need to reorder our quads.
-            return Math.abs( crossBefore.angle( crossAfter ) ) >= Math.PI / 2;
-        }
-    }
-
-    /**
-     * A vertex consumer which is capable of building {@link BakedQuad}s.
-     *
-     * Equivalent to {@link net.minecraftforge.client.model.pipeline.UnpackedBakedQuad.Builder} but more memory
-     * efficient.
-     *
-     * This also provides the ability to swap vertices through {@link #swap(int, int)} to allow reordering.
-     */
-    private static final class BakedQuadBuilder implements IVertexConsumer
-    {
-        private final VertexFormat format;
-
-        private final int[] vertexData;
-        private int vertexIndex = 0, elementIndex = 0;
-
-        private Direction orientation;
-        private int quadTint;
-        private boolean diffuse;
-        private TextureAtlasSprite texture;
-
-        private BakedQuadBuilder( VertexFormat format )
-        {
-            this.format = format;
-            vertexData = new int[format.getSize()];
-        }
-
-        @Nonnull
-        @Override
-        public VertexFormat getVertexFormat()
-        {
-            return format;
-        }
-
-        @Override
-        public void setQuadTint( int tint )
-        {
-            quadTint = tint;
-        }
-
-        @Override
-        public void setQuadOrientation( @Nonnull Direction orientation )
-        {
-            this.orientation = orientation;
-        }
-
-        @Override
-        public void setApplyDiffuseLighting( boolean diffuse )
-        {
-            this.diffuse = diffuse;
-        }
-
-        @Override
-        public void setTexture( @Nonnull TextureAtlasSprite texture )
-        {
-            this.texture = texture;
-        }
-
-        @Override
-        public void put( int element, @Nonnull float... data )
-        {
-            LightUtil.pack( data, vertexData, format, vertexIndex, element );
-
-            elementIndex++;
-            if( elementIndex == getVertexFormat().getElementCount() )
-            {
-                vertexIndex++;
-                elementIndex = 0;
-            }
-        }
-
-        public void swap( int a, int b )
-        {
-            int length = vertexData.length / 4;
-            for( int i = 0; i < length; i++ )
-            {
-                int temp = vertexData[a * length + i];
-                vertexData[a * length + i] = vertexData[b * length + i];
-                vertexData[b * length + i] = temp;
-            }
-        }
-
-        public BakedQuad build()
-        {
-            if( elementIndex != 0 || vertexIndex != 4 )
-            {
-                throw new IllegalStateException( "Got an unexpected number of elements/vertices" );
-            }
-            if( texture == null )
-            {
-                throw new IllegalStateException( "Texture has not been set" );
-            }
-
-            return new BakedQuad( vertexData, quadTint, orientation, texture, diffuse, format );
-        }
-    }
-}

src/main/java/dan200/computercraft/client/render/MonitorHighlightRenderer.java

@@ -5,49 +5,45 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.matrix.MatrixStack;
+import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.BufferBuilder;
-import net.minecraft.client.renderer.Tessellator;
-import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.RenderType;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.Direction;
 import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.BlockRayTraceResult;
-import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
 import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.client.event.DrawBlockHighlightEvent;
+import net.minecraftforge.client.event.DrawHighlightEvent;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod;
-import org.lwjgl.opengl.GL11;
 
 import java.util.EnumSet;
 
 import static net.minecraft.util.Direction.*;
 
+/**
+ * Overrides monitor highlighting to only render the outline of the <em>whole</em> monitor, rather than the current
+ * block. This means you do not get an intrusive outline on top of the screen.
+ */
 @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT )
 public final class MonitorHighlightRenderer
 {
-    private static final float EXPAND = 0.002f;
-
     private MonitorHighlightRenderer()
     {
     }
 
     @SubscribeEvent
-    public static void drawHighlight( DrawBlockHighlightEvent event )
+    public static void drawHighlight( DrawHighlightEvent.HighlightBlock event )
     {
-        if( event.getTarget().getType() != RayTraceResult.Type.BLOCK || event.getInfo().getRenderViewEntity().isSneaking() )
-        {
-            return;
-        }
+        // Preserve normal behaviour when crouching.
+        if( event.getInfo().getRenderViewEntity().isCrouching() ) return;
 
         World world = event.getInfo().getRenderViewEntity().getEntityWorld();
-        BlockPos pos = ((BlockRayTraceResult) event.getTarget()).getPos();
+        BlockPos pos = event.getTarget().getPos();
 
         TileEntity tile = world.getTileEntity( pos );
         if( !(tile instanceof TileMonitor) ) return;
@@ -64,53 +60,37 @@ public final class MonitorHighlightRenderer
         if( monitor.getYIndex() != 0 ) faces.remove( monitor.getDown().getOpposite() );
         if( monitor.getYIndex() != monitor.getHeight() - 1 ) faces.remove( monitor.getDown() );
 
-        GlStateManager.enableBlend();
-        GlStateManager.blendFuncSeparate( GlStateManager.SourceFactor.SRC_ALPHA, GlStateManager.DestFactor.ONE_MINUS_SRC_ALPHA, GlStateManager.SourceFactor.ONE, GlStateManager.DestFactor.ZERO );
-        GlStateManager.lineWidth( Math.max( 2.5F, (float) Minecraft.getInstance().mainWindow.getFramebufferWidth() / 1920.0F * 2.5F ) );
-        GlStateManager.disableTexture();
-        GlStateManager.depthMask( false );
-        GlStateManager.pushMatrix();
-
+        MatrixStack transformStack = event.getMatrix();
         Vec3d cameraPos = event.getInfo().getProjectedView();
-        GlStateManager.translated( pos.getX() - cameraPos.getX(), pos.getY() - cameraPos.getY(), pos.getZ() - cameraPos.getZ() );
-
-        Tessellator tessellator = Tessellator.getInstance();
-        BufferBuilder buffer = tessellator.getBuffer();
-        buffer.begin( GL11.GL_LINES, DefaultVertexFormats.POSITION_COLOR );
+        transformStack.push();
+        transformStack.translate( pos.getX() - cameraPos.getX(), pos.getY() - cameraPos.getY(), pos.getZ() - cameraPos.getZ() );
 
         // I wish I could think of a better way to do this
-        if( faces.contains( NORTH ) || faces.contains( WEST ) ) line( buffer, 0, 0, 0, UP );
-        if( faces.contains( SOUTH ) || faces.contains( WEST ) ) line( buffer, 0, 0, 1, UP );
-        if( faces.contains( NORTH ) || faces.contains( EAST ) ) line( buffer, 1, 0, 0, UP );
-        if( faces.contains( SOUTH ) || faces.contains( EAST ) ) line( buffer, 1, 0, 1, UP );
-        if( faces.contains( NORTH ) || faces.contains( DOWN ) ) line( buffer, 0, 0, 0, EAST );
-        if( faces.contains( SOUTH ) || faces.contains( DOWN ) ) line( buffer, 0, 0, 1, EAST );
-        if( faces.contains( NORTH ) || faces.contains( UP ) ) line( buffer, 0, 1, 0, EAST );
-        if( faces.contains( SOUTH ) || faces.contains( UP ) ) line( buffer, 0, 1, 1, EAST );
-        if( faces.contains( WEST ) || faces.contains( DOWN ) ) line( buffer, 0, 0, 0, SOUTH );
-        if( faces.contains( EAST ) || faces.contains( DOWN ) ) line( buffer, 1, 0, 0, SOUTH );
-        if( faces.contains( WEST ) || faces.contains( UP ) ) line( buffer, 0, 1, 0, SOUTH );
-        if( faces.contains( EAST ) || faces.contains( UP ) ) line( buffer, 1, 1, 0, SOUTH );
+        IVertexBuilder buffer = event.getBuffers().getBuffer( RenderType.getLines() );
+        Matrix4f transform = transformStack.getLast().getMatrix();
+        if( faces.contains( NORTH ) || faces.contains( WEST ) ) line( buffer, transform, 0, 0, 0, UP );
+        if( faces.contains( SOUTH ) || faces.contains( WEST ) ) line( buffer, transform, 0, 0, 1, UP );
+        if( faces.contains( NORTH ) || faces.contains( EAST ) ) line( buffer, transform, 1, 0, 0, UP );
+        if( faces.contains( SOUTH ) || faces.contains( EAST ) ) line( buffer, transform, 1, 0, 1, UP );
+        if( faces.contains( NORTH ) || faces.contains( DOWN ) ) line( buffer, transform, 0, 0, 0, EAST );
+        if( faces.contains( SOUTH ) || faces.contains( DOWN ) ) line( buffer, transform, 0, 0, 1, EAST );
+        if( faces.contains( NORTH ) || faces.contains( UP ) ) line( buffer, transform, 0, 1, 0, EAST );
+        if( faces.contains( SOUTH ) || faces.contains( UP ) ) line( buffer, transform, 0, 1, 1, EAST );
+        if( faces.contains( WEST ) || faces.contains( DOWN ) ) line( buffer, transform, 0, 0, 0, SOUTH );
+        if( faces.contains( EAST ) || faces.contains( DOWN ) ) line( buffer, transform, 1, 0, 0, SOUTH );
+        if( faces.contains( WEST ) || faces.contains( UP ) ) line( buffer, transform, 0, 1, 0, SOUTH );
+        if( faces.contains( EAST ) || faces.contains( UP ) ) line( buffer, transform, 1, 1, 0, SOUTH );
 
-        tessellator.draw();
-
-        GlStateManager.popMatrix();
-        GlStateManager.depthMask( true );
-        GlStateManager.enableTexture();
-        GlStateManager.disableBlend();
+        transformStack.pop();
     }
 
-    private static void line( BufferBuilder buffer, int x, int y, int z, Direction direction )
+    private static void line( IVertexBuilder buffer, Matrix4f transform, float x, float y, float z, Direction direction )
     {
-        double minX = x == 0 ? -EXPAND : 1 + EXPAND;
-        double minY = y == 0 ? -EXPAND : 1 + EXPAND;
-        double minZ = z == 0 ? -EXPAND : 1 + EXPAND;
-
-        buffer.pos( minX, minY, minZ ).color( 0, 0, 0, 0.4f ).endVertex();
-        buffer.pos(
-            minX + direction.getXOffset() * (1 + EXPAND * 2),
-            minY + direction.getYOffset() * (1 + EXPAND * 2),
-            minZ + direction.getZOffset() * (1 + EXPAND * 2)
+        buffer.pos( transform, x, y, z ).color( 0, 0, 0, 0.4f ).endVertex();
+        buffer.pos( transform,
+            x + direction.getXOffset(),
+            y + direction.getYOffset(),
+            z + direction.getZOffset()
         ).color( 0, 0, 0, 0.4f ).endVertex();
     }
 }

src/main/java/dan200/computercraft/client/render/MonitorTextureBufferShader.java

@@ -0,0 +1,164 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.client.render;
+
+import com.google.common.base.Strings;
+import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.gui.FixedWidthFontRenderer;
+import dan200.computercraft.shared.util.Palette;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.texture.TextureUtil;
+import org.lwjgl.BufferUtils;
+import org.lwjgl.opengl.GL13;
+import org.lwjgl.opengl.GL20;
+
+import java.io.InputStream;
+import java.nio.FloatBuffer;
+
+class MonitorTextureBufferShader
+{
+    static final int TEXTURE_INDEX = GL13.GL_TEXTURE3;
+
+    private static final FloatBuffer MATRIX_BUFFER = BufferUtils.createFloatBuffer( 16 );
+    private static final FloatBuffer PALETTE_BUFFER = BufferUtils.createFloatBuffer( 16 * 3 );
+
+    private static int uniformMv;
+
+    private static int uniformFont;
+    private static int uniformWidth;
+    private static int uniformHeight;
+    private static int uniformTbo;
+    private static int uniformPalette;
+
+    private static boolean initialised;
+    private static boolean ok;
+    private static int program;
+
+    static void setupUniform( Matrix4f transform, int width, int height, Palette palette, boolean greyscale )
+    {
+        MATRIX_BUFFER.rewind();
+        transform.write( MATRIX_BUFFER );
+        MATRIX_BUFFER.rewind();
+        RenderSystem.glUniformMatrix4( uniformMv, false, MATRIX_BUFFER );
+
+        RenderSystem.glUniform1i( uniformWidth, width );
+        RenderSystem.glUniform1i( uniformHeight, height );
+
+        // TODO: Cache this? Maybe??
+        PALETTE_BUFFER.rewind();
+        for( int i = 0; i < 16; i++ )
+        {
+            double[] colour = palette.getColour( i );
+            if( greyscale )
+            {
+                float f = FixedWidthFontRenderer.toGreyscale( colour );
+                PALETTE_BUFFER.put( f ).put( f ).put( f );
+            }
+            else
+            {
+                PALETTE_BUFFER.put( (float) colour[0] ).put( (float) colour[1] ).put( (float) colour[2] );
+            }
+        }
+        PALETTE_BUFFER.flip();
+        RenderSystem.glUniform3( uniformPalette, PALETTE_BUFFER );
+    }
+
+    static boolean use()
+    {
+        if( initialised )
+        {
+            if( ok ) GlStateManager.useProgram( program );
+            return ok;
+        }
+
+        if( ok = load() )
+        {
+            GL20.glUseProgram( program );
+            RenderSystem.glUniform1i( uniformFont, 0 );
+            RenderSystem.glUniform1i( uniformTbo, TEXTURE_INDEX - GL13.GL_TEXTURE0 );
+        }
+
+        return ok;
+    }
+
+    private static boolean load()
+    {
+        initialised = true;
+
+        try
+        {
+            int vertexShader = loadShader( GL20.GL_VERTEX_SHADER, "assets/computercraft/shaders/monitor.vert" );
+            int fragmentShader = loadShader( GL20.GL_FRAGMENT_SHADER, "assets/computercraft/shaders/monitor.frag" );
+
+            program = GlStateManager.createProgram();
+            GlStateManager.attachShader( program, vertexShader );
+            GlStateManager.attachShader( program, fragmentShader );
+            GL20.glBindAttribLocation( program, 0, "v_pos" );
+
+            GlStateManager.linkProgram( program );
+            boolean ok = GlStateManager.getProgram( program, GL20.GL_LINK_STATUS ) != 0;
+            String log = GlStateManager.getProgramInfoLog( program, Short.MAX_VALUE ).trim();
+            if( !Strings.isNullOrEmpty( log ) )
+            {
+                ComputerCraft.log.warn( "Problems when linking monitor shader: {}", log );
+            }
+
+            GL20.glDetachShader( program, vertexShader );
+            GL20.glDetachShader( program, fragmentShader );
+            GlStateManager.deleteShader( vertexShader );
+            GlStateManager.deleteShader( fragmentShader );
+
+            if( !ok ) return false;
+
+            uniformMv = getUniformLocation( program, "u_mv" );
+            uniformFont = getUniformLocation( program, "u_font" );
+            uniformWidth = getUniformLocation( program, "u_width" );
+            uniformHeight = getUniformLocation( program, "u_height" );
+            uniformTbo = getUniformLocation( program, "u_tbo" );
+            uniformPalette = getUniformLocation( program, "u_palette" );
+
+            ComputerCraft.log.info( "Loaded monitor shader." );
+            return true;
+        }
+        catch( Exception e )
+        {
+            ComputerCraft.log.error( "Cannot load monitor shaders", e );
+            return false;
+        }
+    }
+
+    private static int loadShader( int kind, String path )
+    {
+        InputStream stream = TileEntityMonitorRenderer.class.getClassLoader().getResourceAsStream( path );
+        if( stream == null ) throw new IllegalArgumentException( "Cannot find " + path );
+        String contents = TextureUtil.readResourceAsString( stream );
+
+        int shader = GlStateManager.createShader( kind );
+
+        GlStateManager.shaderSource( shader, contents );
+        GlStateManager.compileShader( shader );
+
+        boolean ok = GlStateManager.getShader( shader, GL20.GL_COMPILE_STATUS ) != 0;
+        String log = GlStateManager.getShaderInfoLog( shader, Short.MAX_VALUE ).trim();
+        if( !Strings.isNullOrEmpty( log ) )
+        {
+            ComputerCraft.log.warn( "Problems when loading monitor shader {}: {}", path, log );
+        }
+
+        if( !ok ) throw new IllegalStateException( "Cannot compile shader " + path );
+        return shader;
+    }
+
+    private static int getUniformLocation( int program, String name )
+    {
+        int uniform = GlStateManager.getUniformLocation( program, name );
+        if( uniform == -1 ) throw new IllegalStateException( "Cannot find uniform " + name );
+        return uniform;
+    }
+}

src/main/java/dan200/computercraft/client/render/PrintoutRenderer.java

@@ -5,15 +5,14 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.platform.GlStateManager;
-import com.mojang.blaze3d.platform.GlStateManager.DestFactor;
-import com.mojang.blaze3d.platform.GlStateManager.SourceFactor;
+import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.client.gui.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.TextBuffer;
 import dan200.computercraft.shared.util.Palette;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.BufferBuilder;
-import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.IRenderTypeBuffer;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.RenderState;
+import net.minecraft.client.renderer.RenderType;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.util.ResourceLocation;
 import org.lwjgl.opengl.GL11;
@@ -24,7 +23,7 @@ import static dan200.computercraft.shared.media.items.ItemPrintout.LINES_PER_PAG
 public final class PrintoutRenderer
 {
     private static final ResourceLocation BG = new ResourceLocation( "computercraft", "textures/gui/printout.png" );
-    private static final double BG_SIZE = 256.0;
+    private static final float BG_SIZE = 256.0f;
 
     /**
      * Width of a page.
@@ -61,27 +60,24 @@ public final class PrintoutRenderer
 
     private PrintoutRenderer() {}
 
-    public static void drawText( int x, int y, int start, TextBuffer[] text, TextBuffer[] colours )
+    public static void drawText( Matrix4f transform, IRenderTypeBuffer renderer, int x, int y, int start, TextBuffer[] text, TextBuffer[] colours )
     {
+        IVertexBuilder buffer = renderer.getBuffer( FixedWidthFontRenderer.TYPE );
         for( int line = 0; line < LINES_PER_PAGE && line < text.length; line++ )
         {
-            FixedWidthFontRenderer.drawString(
+            FixedWidthFontRenderer.drawString( transform, buffer,
                 x, y + line * FONT_HEIGHT, text[start + line], colours[start + line], null, Palette.DEFAULT,
                 false, 0, 0
             );
         }
     }
 
-    public static void drawText( int x, int y, int start, String[] text, String[] colours )
+    public static void drawText( Matrix4f transform, IRenderTypeBuffer renderer, int x, int y, int start, String[] text, String[] colours )
     {
-        GlStateManager.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
-        GlStateManager.enableBlend();
-        GlStateManager.enableTexture();
-        GlStateManager.blendFuncSeparate( SourceFactor.SRC_ALPHA, DestFactor.ONE_MINUS_SRC_ALPHA, SourceFactor.ONE, DestFactor.ZERO );
-
+        IVertexBuilder buffer = renderer.getBuffer( FixedWidthFontRenderer.TYPE );
         for( int line = 0; line < LINES_PER_PAGE && line < text.length; line++ )
         {
-            FixedWidthFontRenderer.drawString(
+            FixedWidthFontRenderer.drawString( transform, buffer,
                 x, y + line * FONT_HEIGHT,
                 new TextBuffer( text[start + line] ), new TextBuffer( colours[start + line] ),
                 null, Palette.DEFAULT, false, 0, 0
@@ -89,55 +85,46 @@ public final class PrintoutRenderer
         }
     }
 
-    public static void drawBorder( double x, double y, double z, int page, int pages, boolean isBook )
+    public static void drawBorder( Matrix4f transform, IRenderTypeBuffer renderer, float x, float y, float z, int page, int pages, boolean isBook )
     {
-        GlStateManager.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
-        GlStateManager.enableBlend();
-        GlStateManager.enableTexture();
-        GlStateManager.blendFuncSeparate( SourceFactor.SRC_ALPHA, DestFactor.ONE_MINUS_SRC_ALPHA, SourceFactor.ONE, DestFactor.ZERO );
-
-        Minecraft.getInstance().getTextureManager().bindTexture( BG );
-
-        Tessellator tessellator = Tessellator.getInstance();
-        BufferBuilder buffer = tessellator.getBuffer();
-        buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_TEX );
-
         int leftPages = page;
         int rightPages = pages - page - 1;
 
+        IVertexBuilder buffer = renderer.getBuffer( Type.TYPE );
+
         if( isBook )
         {
             // Border
-            double offset = offsetAt( pages );
-            final double left = x - 4 - offset;
-            final double right = x + X_SIZE + offset - 4;
+            float offset = offsetAt( pages );
+            float left = x - 4 - offset;
+            float right = x + X_SIZE + offset - 4;
 
             // Left and right border
-            drawTexture( buffer, left - 4, y - 8, z - 0.02, COVER_X, 0, COVER_SIZE, Y_SIZE + COVER_SIZE * 2 );
-            drawTexture( buffer, right, y - 8, z - 0.02, COVER_X + COVER_SIZE, 0, COVER_SIZE, Y_SIZE + COVER_SIZE * 2 );
+            drawTexture( transform, buffer, left - 4, y - 8, z - 0.02f, COVER_X, 0, COVER_SIZE, Y_SIZE + COVER_SIZE * 2 );
+            drawTexture( transform, buffer, right, y - 8, z - 0.02f, COVER_X + COVER_SIZE, 0, COVER_SIZE, Y_SIZE + COVER_SIZE * 2 );
 
             // Draw centre panel (just stretched texture, sorry).
-            drawTexture( buffer,
-                x - offset, y, z - 0.02, X_SIZE + offset * 2, Y_SIZE,
+            drawTexture( transform, buffer,
+                x - offset, y, z - 0.02f, X_SIZE + offset * 2, Y_SIZE,
                 COVER_X + COVER_SIZE / 2.0f, COVER_SIZE, COVER_SIZE, Y_SIZE
             );
 
-            double borderX = left;
+            float borderX = left;
             while( borderX < right )
             {
                 double thisWidth = Math.min( right - borderX, X_SIZE );
-                drawTexture( buffer, borderX, y - 8, z - 0.02, 0, COVER_Y, thisWidth, COVER_SIZE );
-                drawTexture( buffer, borderX, y + Y_SIZE - 4, z - 0.02, 0, COVER_Y + COVER_SIZE, thisWidth, COVER_SIZE );
+                drawTexture( transform, buffer, borderX, y - 8, z - 0.02f, 0, COVER_Y, (float) thisWidth, COVER_SIZE );
+                drawTexture( transform, buffer, borderX, y + Y_SIZE - 4, z - 0.02f, 0, COVER_Y + COVER_SIZE, (float) thisWidth, COVER_SIZE );
                 borderX += thisWidth;
             }
         }
 
         // Left half
-        drawTexture( buffer, x, y, z, X_FOLD_SIZE * 2, 0, X_SIZE / 2.0f, Y_SIZE );
+        drawTexture( transform, buffer, x, y, z, X_FOLD_SIZE * 2, 0, X_SIZE / 2.0f, Y_SIZE );
         for( int n = 0; n <= leftPages; n++ )
         {
-            drawTexture( buffer,
-                x - offsetAt( n ), y, z - 1e-3 * n,
+            drawTexture( transform, buffer,
+                x - offsetAt( n ), y, z - 1e-3f * n,
                 // Use the left "bold" fold for the outermost page
                 n == leftPages ? 0 : X_FOLD_SIZE, 0,
                 X_FOLD_SIZE, Y_SIZE
@@ -145,38 +132,54 @@ public final class PrintoutRenderer
         }
 
         // Right half
-        drawTexture( buffer, x + X_SIZE / 2.0f, y, z, X_FOLD_SIZE * 2 + X_SIZE / 2.0f, 0, X_SIZE / 2.0f, Y_SIZE );
+        drawTexture( transform, buffer, x + X_SIZE / 2.0f, y, z, X_FOLD_SIZE * 2 + X_SIZE / 2.0f, 0, X_SIZE / 2.0f, Y_SIZE );
         for( int n = 0; n <= rightPages; n++ )
         {
-            drawTexture( buffer,
-                x + (X_SIZE - X_FOLD_SIZE) + offsetAt( n ), y, z - 1e-3 * n,
+            drawTexture( transform, buffer,
+                x + (X_SIZE - X_FOLD_SIZE) + offsetAt( n ), y, z - 1e-3f * n,
                 // Two folds, then the main page. Use the right "bold" fold for the outermost page.
                 X_FOLD_SIZE * 2 + X_SIZE + (n == rightPages ? X_FOLD_SIZE : 0), 0,
                 X_FOLD_SIZE, Y_SIZE
             );
         }
-
-        tessellator.draw();
     }
 
-    private static void drawTexture( BufferBuilder buffer, double x, double y, double z, double u, double v, double width, double height )
+    private static void drawTexture( Matrix4f matrix, IVertexBuilder buffer, float x, float y, float z, float u, float v, float width, float height )
     {
-        buffer.pos( x, y + height, z ).tex( u / BG_SIZE, (v + height) / BG_SIZE ).endVertex();
-        buffer.pos( x + width, y + height, z ).tex( (u + width) / BG_SIZE, (v + height) / BG_SIZE ).endVertex();
-        buffer.pos( x + width, y, z ).tex( (u + width) / BG_SIZE, v / BG_SIZE ).endVertex();
-        buffer.pos( x, y, z ).tex( u / BG_SIZE, v / BG_SIZE ).endVertex();
+        buffer.pos( matrix, x, y + height, z ).tex( u / BG_SIZE, (v + height) / BG_SIZE ).endVertex();
+        buffer.pos( matrix, x + width, y + height, z ).tex( (u + width) / BG_SIZE, (v + height) / BG_SIZE ).endVertex();
+        buffer.pos( matrix, x + width, y, z ).tex( (u + width) / BG_SIZE, v / BG_SIZE ).endVertex();
+        buffer.pos( matrix, x, y, z ).tex( u / BG_SIZE, v / BG_SIZE ).endVertex();
     }
 
-    private static void drawTexture( BufferBuilder buffer, double x, double y, double z, double width, double height, double u, double v, double tWidth, double tHeight )
+    private static void drawTexture( Matrix4f matrix, IVertexBuilder buffer, float x, float y, float z, float width, float height, float u, float v, float tWidth, float tHeight )
     {
-        buffer.pos( x, y + height, z ).tex( u / BG_SIZE, (v + tHeight) / BG_SIZE ).endVertex();
-        buffer.pos( x + width, y + height, z ).tex( (u + tWidth) / BG_SIZE, (v + tHeight) / BG_SIZE ).endVertex();
-        buffer.pos( x + width, y, z ).tex( (u + tWidth) / BG_SIZE, v / BG_SIZE ).endVertex();
-        buffer.pos( x, y, z ).tex( u / BG_SIZE, v / BG_SIZE ).endVertex();
+        buffer.pos( matrix, x, y + height, z ).tex( u / BG_SIZE, (v + tHeight) / BG_SIZE ).endVertex();
+        buffer.pos( matrix, x + width, y + height, z ).tex( (u + tWidth) / BG_SIZE, (v + tHeight) / BG_SIZE ).endVertex();
+        buffer.pos( matrix, x + width, y, z ).tex( (u + tWidth) / BG_SIZE, v / BG_SIZE ).endVertex();
+        buffer.pos( matrix, x, y, z ).tex( u / BG_SIZE, v / BG_SIZE ).endVertex();
     }
 
-    public static double offsetAt( int page )
+    public static float offsetAt( int page )
     {
-        return 32 * (1 - Math.pow( 1.2, -page ));
+        return (float) (32 * (1 - Math.pow( 1.2, -page )));
+    }
+
+    private static final class Type extends RenderState
+    {
+        static final RenderType TYPE = RenderType.makeType(
+            "printout_background", DefaultVertexFormats.POSITION_TEX, GL11.GL_QUADS, 1024,
+            false, false, // useDelegate, needsSorting
+            RenderType.State.getBuilder()
+                .texture( new RenderState.TextureState( BG, false, false ) ) // blur, minimap
+                .alpha( DEFAULT_ALPHA )
+                .lightmap( LIGHTMAP_DISABLED )
+                .build( false )
+        );
+
+        private Type( String name, Runnable setup, Runnable destroy )
+        {
+            super( name, setup, destroy );
+        }
     }
 }

src/main/java/dan200/computercraft/client/render/TileEntityCableRenderer.java

@@ -1,140 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.client.render;
-
-import com.mojang.blaze3d.platform.GlStateManager;
-import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.shared.peripheral.modem.wired.BlockCable;
-import dan200.computercraft.shared.peripheral.modem.wired.CableModemVariant;
-import dan200.computercraft.shared.peripheral.modem.wired.CableShapes;
-import dan200.computercraft.shared.peripheral.modem.wired.TileCable;
-import dan200.computercraft.shared.util.WorldUtil;
-import net.minecraft.block.Block;
-import net.minecraft.block.BlockState;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.BufferBuilder;
-import net.minecraft.client.renderer.Tessellator;
-import net.minecraft.client.renderer.WorldRenderer;
-import net.minecraft.client.renderer.model.IBakedModel;
-import net.minecraft.client.renderer.texture.TextureAtlasSprite;
-import net.minecraft.client.renderer.tileentity.TileEntityRenderer;
-import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
-import net.minecraft.util.BlockRenderLayer;
-import net.minecraft.util.ResourceLocation;
-import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.BlockRayTraceResult;
-import net.minecraft.util.math.RayTraceResult;
-import net.minecraft.world.World;
-import net.minecraftforge.client.ForgeHooksClient;
-import net.minecraftforge.client.model.data.EmptyModelData;
-import org.lwjgl.opengl.GL11;
-
-import javax.annotation.Nonnull;
-import java.util.Random;
-
-/**
- * Render breaking animation only over part of a {@link TileCable}.
- */
-public class TileEntityCableRenderer extends TileEntityRenderer<TileCable>
-{
-    private static final ResourceLocation[] DESTROY_STAGES = new ResourceLocation[10];
-    private static final Random random = new Random();
-
-    static
-    {
-        for( int i = 0; i < DESTROY_STAGES.length; i++ )
-        {
-            DESTROY_STAGES[i] = new ResourceLocation( "block/destroy_stage_" + i );
-        }
-    }
-
-    @Override
-    public void render( @Nonnull TileCable te, double x, double y, double z, float partialTicks, int destroyStage )
-    {
-        if( destroyStage < 0 ) return;
-
-        BlockPos pos = te.getPos();
-
-        Minecraft mc = Minecraft.getInstance();
-
-        RayTraceResult hit = mc.objectMouseOver;
-        if( hit == null || hit.getType() != RayTraceResult.Type.BLOCK || !((BlockRayTraceResult) hit).getPos().equals( pos ) )
-        {
-            return;
-        }
-
-        World world = te.getWorld();
-        BlockState state = world.getBlockState( pos );
-        Block block = state.getBlock();
-        if( block != ComputerCraft.Blocks.cable ) return;
-
-        state = WorldUtil.isVecInside( CableShapes.getModemShape( state ), hit.getHitVec().subtract( pos.getX(), pos.getY(), pos.getZ() ) )
-            ? block.getDefaultState().with( BlockCable.MODEM, state.get( BlockCable.MODEM ) )
-            : state.with( BlockCable.MODEM, CableModemVariant.None );
-
-        IBakedModel model = mc.getBlockRendererDispatcher().getModelForState( state );
-
-        preRenderDamagedBlocks();
-
-        ForgeHooksClient.setRenderLayer( block.getRenderLayer() );
-
-        // See BlockRendererDispatcher#renderBlockDamage
-        TextureAtlasSprite breakingTexture = mc.getTextureMap().getSprite( DESTROY_STAGES[destroyStage] );
-
-        BufferBuilder buffer = Tessellator.getInstance().getBuffer();
-        buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.BLOCK );
-        buffer.setTranslation( x - pos.getX(), y - pos.getY(), z - pos.getZ() );
-        buffer.noColor();
-
-        mc.getBlockRendererDispatcher().getBlockModelRenderer().renderModel(
-            world,
-            ForgeHooksClient.getDamageModel( model, breakingTexture, state, world, pos, 0 ),
-            state, pos, buffer, true, random, state.getPositionRandom( pos ), EmptyModelData.INSTANCE
-        );
-
-        ForgeHooksClient.setRenderLayer( BlockRenderLayer.SOLID );
-
-        buffer.setTranslation( 0, 0, 0 );
-        Tessellator.getInstance().draw();
-
-        postRenderDamagedBlocks();
-    }
-
-    /**
-     * Set up the state for rendering block-breaking progress.
-     *
-     * @see WorldRenderer#preRenderDamagedBlocks()
-     */
-    private void preRenderDamagedBlocks()
-    {
-        GlStateManager.disableLighting();
-
-        GlStateManager.enableBlend();
-        GlStateManager.blendFuncSeparate( GlStateManager.SourceFactor.DST_COLOR, GlStateManager.DestFactor.SRC_COLOR, GlStateManager.SourceFactor.ONE, GlStateManager.DestFactor.ZERO );
-        GlStateManager.enableBlend();
-        GlStateManager.color4f( 1.0F, 1.0F, 1.0F, 0.5F );
-        GlStateManager.polygonOffset( -3.0F, -3.0F );
-        GlStateManager.enablePolygonOffset();
-        GlStateManager.alphaFunc( 516, 0.1F );
-        GlStateManager.enableAlphaTest();
-        GlStateManager.pushMatrix();
-    }
-
-    /**
-     * Tear down the state for rendering block-breaking progress.
-     *
-     * @see WorldRenderer#postRenderDamagedBlocks()
-     */
-    private void postRenderDamagedBlocks()
-    {
-        GlStateManager.disableAlphaTest();
-        GlStateManager.polygonOffset( 0.0F, 0.0F );
-        GlStateManager.disablePolygonOffset();
-        GlStateManager.disablePolygonOffset();
-        GlStateManager.depthMask( true );
-        GlStateManager.popMatrix();
-    }
-}

src/main/java/dan200/computercraft/client/render/TileEntityMonitorRenderer.java

@@ -5,34 +5,53 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.platform.GLX;
+import com.mojang.blaze3d.matrix.MatrixStack;
 import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.client.FrameInfo;
 import dan200.computercraft.client.gui.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.core.terminal.TextBuffer;
 import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
 import dan200.computercraft.shared.peripheral.monitor.MonitorRenderer;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
+import dan200.computercraft.shared.util.Colour;
 import dan200.computercraft.shared.util.DirectionUtil;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.BufferBuilder;
-import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.*;
 import net.minecraft.client.renderer.tileentity.TileEntityRenderer;
+import net.minecraft.client.renderer.tileentity.TileEntityRendererDispatcher;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.client.renderer.vertex.VertexBuffer;
 import net.minecraft.util.Direction;
 import net.minecraft.util.math.BlockPos;
 import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL13;
+import org.lwjgl.opengl.GL20;
+import org.lwjgl.opengl.GL31;
 
 import javax.annotation.Nonnull;
+import java.nio.ByteBuffer;
 
-import static dan200.computercraft.shared.peripheral.monitor.TileMonitor.RENDER_MARGIN;
+import static dan200.computercraft.client.gui.FixedWidthFontRenderer.*;
 
 public class TileEntityMonitorRenderer extends TileEntityRenderer<TileMonitor>
 {
+    /**
+     * {@link TileMonitor#RENDER_MARGIN}, but a tiny bit of additional padding to ensure that there is no space between
+     * the monitor frame and contents.
+     */
     private static final float MARGIN = (float) (TileMonitor.RENDER_MARGIN * 1.1);
+    private static ByteBuffer tboContents;
+
+    private static final Matrix4f IDENTITY = TransformationMatrix.identity().getMatrix();
+
+    public TileEntityMonitorRenderer( TileEntityRendererDispatcher rendererDispatcher )
+    {
+        super( rendererDispatcher );
+    }
 
     @Override
-    public void render( @Nonnull TileMonitor monitor, double posX, double posY, double posZ, float f, int i )
+    public void render( @Nonnull TileMonitor monitor, float partialTicks, @Nonnull MatrixStack transform, @Nonnull IRenderTypeBuffer renderer, int lightmapCoord, int overlayLight )
     {
         // Render from the origin monitor
         ClientMonitor originTerminal = monitor.getClientMonitor();
@@ -54,9 +73,6 @@ public class TileEntityMonitorRenderer extends TileEntityRenderer<TileMonitor>
         originTerminal.lastRenderPos = monitorPos;
 
         BlockPos originPos = origin.getPos();
-        posX += originPos.getX() - monitorPos.getX();
-        posY += originPos.getY() - monitorPos.getY();
-        posZ += originPos.getZ() - monitorPos.getZ();
 
         // Determine orientation
         Direction dir = origin.getDirection();
@@ -64,130 +80,158 @@ public class TileEntityMonitorRenderer extends TileEntityRenderer<TileMonitor>
         float yaw = dir.getHorizontalAngle();
         float pitch = DirectionUtil.toPitchAngle( front );
 
-        GlStateManager.pushMatrix();
-
         // Setup initial transform
-        GlStateManager.translated( posX + 0.5, posY + 0.5, posZ + 0.5 );
-        GlStateManager.rotatef( -yaw, 0.0f, 1.0f, 0.0f );
-        GlStateManager.rotatef( pitch, 1.0f, 0.0f, 0.0f );
-        GlStateManager.translated(
-            -0.5 + TileMonitor.RENDER_BORDER + RENDER_MARGIN,
-            origin.getHeight() - 0.5 - (TileMonitor.RENDER_BORDER + RENDER_MARGIN) + 0,
+        transform.push();
+        transform.translate(
+            originPos.getX() - monitorPos.getX() + 0.5,
+            originPos.getY() - monitorPos.getY() + 0.5,
+            originPos.getZ() - monitorPos.getZ() + 0.5
+        );
+
+        transform.rotate( Vector3f.YN.rotationDegrees( yaw ) );
+        transform.rotate( Vector3f.XP.rotationDegrees( pitch ) );
+        transform.translate(
+            -0.5 + TileMonitor.RENDER_BORDER + TileMonitor.RENDER_MARGIN,
+            origin.getHeight() - 0.5 - (TileMonitor.RENDER_BORDER + TileMonitor.RENDER_MARGIN) + 0,
             0.5
         );
-        double xSize = origin.getWidth() - 2.0 * (RENDER_MARGIN + TileMonitor.RENDER_BORDER);
-        double ySize = origin.getHeight() - 2.0 * (RENDER_MARGIN + TileMonitor.RENDER_BORDER);
-
-        // Get renderers
-        Minecraft mc = Minecraft.getInstance();
-
-        // Set up render state for monitors. We disable writing to the depth buffer (we draw a "blocker" later),
-        // and setup lighting so that we render with a glow.
-        GlStateManager.depthMask( false );
-        GLX.glMultiTexCoord2f( GLX.GL_TEXTURE1, 0xFFFF, 0xFFFF );
-        GlStateManager.disableLighting();
-        mc.gameRenderer.disableLightmap();
+        double xSize = origin.getWidth() - 2.0 * (TileMonitor.RENDER_MARGIN + TileMonitor.RENDER_BORDER);
+        double ySize = origin.getHeight() - 2.0 * (TileMonitor.RENDER_MARGIN + TileMonitor.RENDER_BORDER);
 
+        // Draw the contents
         Terminal terminal = originTerminal.getTerminal();
         if( terminal != null )
         {
             // Draw a terminal
-            double xScale = xSize / (terminal.getWidth() * FixedWidthFontRenderer.FONT_WIDTH);
-            double yScale = ySize / (terminal.getHeight() * FixedWidthFontRenderer.FONT_HEIGHT);
+            int width = terminal.getWidth(), height = terminal.getHeight();
+            int pixelWidth = width * FONT_WIDTH, pixelHeight = height * FONT_HEIGHT;
+            double xScale = xSize / pixelWidth;
+            double yScale = ySize / pixelHeight;
+            transform.push();
+            transform.scale( (float) xScale, (float) -yScale, 1.0f );
 
-            GlStateManager.pushMatrix();
-            GlStateManager.scaled( (float) xScale, (float) -yScale, 1.0f );
+            Matrix4f matrix = transform.getLast().getMatrix();
 
-            renderTerminal( originTerminal, (float) (MARGIN / xScale), (float) (MARGIN / yScale) );
+            // Sneaky hack here: we get a buffer now in order to flush existing ones and set up the appropriate
+            // render state. I've no clue how well this'll work in future versions of Minecraft, but it does the trick
+            // for now.
+            IVertexBuilder buffer = renderer.getBuffer( FixedWidthFontRenderer.TYPE );
+            FixedWidthFontRenderer.TYPE.setupRenderState();
 
-            GlStateManager.popMatrix();
+            renderTerminal( matrix, originTerminal, (float) (MARGIN / xScale), (float) (MARGIN / yScale) );
+
+            // We don't draw the cursor with the VBO, as it's dynamic and so we'll end up refreshing far more than is
+            // reasonable.
+            FixedWidthFontRenderer.drawCursor( matrix, buffer, 0, 0, terminal, !originTerminal.isColour() );
+
+            transform.pop();
         }
         else
         {
             FixedWidthFontRenderer.drawEmptyTerminal(
+                transform.getLast().getMatrix(), renderer,
                 -MARGIN, MARGIN,
                 (float) (xSize + 2 * MARGIN), (float) -(ySize + MARGIN * 2)
             );
         }
 
-        // Tear down render state for monitors.
-        GlStateManager.depthMask( true );
-        mc.gameRenderer.enableLightmap();
-        GlStateManager.enableLighting();
-
-        // Draw the depth blocker
-        GlStateManager.colorMask( false, false, false, false );
         FixedWidthFontRenderer.drawBlocker(
+            transform.getLast().getMatrix(), renderer,
             (float) -TileMonitor.RENDER_MARGIN, (float) TileMonitor.RENDER_MARGIN,
             (float) (xSize + 2 * TileMonitor.RENDER_MARGIN), (float) -(ySize + TileMonitor.RENDER_MARGIN * 2)
         );
-        GlStateManager.colorMask( true, true, true, true );
 
-        GlStateManager.popMatrix();
+        transform.pop();
     }
 
-    private static void renderTerminal( ClientMonitor monitor, float xMargin, float yMargin )
+    private static void renderTerminal( Matrix4f matrix, ClientMonitor monitor, float xMargin, float yMargin )
     {
-        Tessellator tessellator = Tessellator.getInstance();
-        BufferBuilder buffer = tessellator.getBuffer();
+        Terminal terminal = monitor.getTerminal();
 
+        MonitorRenderer renderType = MonitorRenderer.current();
         boolean redraw = monitor.pollTerminalChanged();
+        if( monitor.createBuffer( renderType ) ) redraw = true;
 
-        // Setup the buffers if needed. We get the renderer here, to avoid the (unlikely) race condition between
-        // creating the buffers and rendering.
-        MonitorRenderer renderer = MonitorRenderer.current();
-        if( monitor.createBuffer( renderer ) ) redraw = true;
-
-        FixedWidthFontRenderer.bindFont();
-
-        switch( renderer )
+        switch( renderType )
         {
+            case TBO:
+            {
+                if( !MonitorTextureBufferShader.use() ) return;
+
+                int width = terminal.getWidth(), height = terminal.getHeight();
+                int pixelWidth = width * FONT_WIDTH, pixelHeight = height * FONT_HEIGHT;
+
+                if( redraw )
+                {
+                    int size = width * height * 3;
+                    if( tboContents == null || tboContents.capacity() < size )
+                    {
+                        tboContents = GLAllocation.createDirectByteBuffer( size );
+                    }
+
+                    ByteBuffer monitorBuffer = tboContents;
+                    monitorBuffer.clear();
+                    for( int y = 0; y < height; y++ )
+                    {
+                        TextBuffer text = terminal.getLine( y ), textColour = terminal.getTextColourLine( y ), background = terminal.getBackgroundColourLine( y );
+                        for( int x = 0; x < width; x++ )
+                        {
+                            monitorBuffer.put( (byte) (text.charAt( x ) & 0xFF) );
+                            monitorBuffer.put( (byte) getColour( textColour.charAt( x ), Colour.WHITE ) );
+                            monitorBuffer.put( (byte) getColour( background.charAt( x ), Colour.BLACK ) );
+                        }
+                    }
+                    monitorBuffer.flip();
+
+                    GlStateManager.bindBuffer( GL31.GL_TEXTURE_BUFFER, monitor.tboBuffer );
+                    GlStateManager.bufferData( GL31.GL_TEXTURE_BUFFER, monitorBuffer, GL20.GL_STATIC_DRAW );
+                    GlStateManager.bindBuffer( GL31.GL_TEXTURE_BUFFER, 0 );
+                }
+
+                // Nobody knows what they're doing!
+                GlStateManager.activeTexture( MonitorTextureBufferShader.TEXTURE_INDEX );
+                GL11.glBindTexture( GL31.GL_TEXTURE_BUFFER, monitor.tboTexture );
+                GlStateManager.activeTexture( GL13.GL_TEXTURE0 );
+
+                MonitorTextureBufferShader.setupUniform( matrix, width, height, terminal.getPalette(), !monitor.isColour() );
+
+                Tessellator tessellator = Tessellator.getInstance();
+                BufferBuilder buffer = tessellator.getBuffer();
+                buffer.begin( GL11.GL_TRIANGLE_STRIP, DefaultVertexFormats.POSITION );
+                buffer.pos( -xMargin, -yMargin, 0 ).endVertex();
+                buffer.pos( -xMargin, pixelHeight + yMargin, 0 ).endVertex();
+                buffer.pos( pixelWidth + xMargin, -yMargin, 0 ).endVertex();
+                buffer.pos( pixelWidth + xMargin, pixelHeight + yMargin, 0 ).endVertex();
+                tessellator.draw();
+
+                GlStateManager.useProgram( 0 );
+                break;
+            }
+
             case VBO:
             {
                 VertexBuffer vbo = monitor.buffer;
                 if( redraw )
                 {
-                    renderTerminalTo( monitor, buffer, xMargin, yMargin );
-                    buffer.finishDrawing();
-                    buffer.reset();
-                    vbo.bufferData( buffer.getByteBuffer() );
+                    Tessellator tessellator = Tessellator.getInstance();
+                    BufferBuilder builder = tessellator.getBuffer();
+                    builder.begin( FixedWidthFontRenderer.TYPE.getDrawMode(), FixedWidthFontRenderer.TYPE.getVertexFormat() );
+                    FixedWidthFontRenderer.drawTerminalWithoutCursor(
+                        IDENTITY, builder, 0, 0,
+                        terminal, !monitor.isColour(), yMargin, yMargin, xMargin, xMargin
+                    );
+
+                    builder.finishDrawing();
+                    vbo.upload( builder );
                 }
 
                 vbo.bindBuffer();
-                setupBufferFormat();
-                vbo.drawArrays( GL11.GL_TRIANGLES );
+                FixedWidthFontRenderer.TYPE.getVertexFormat().setupBufferState( 0L );
+                vbo.draw( matrix, FixedWidthFontRenderer.TYPE.getDrawMode() );
                 VertexBuffer.unbindBuffer();
-
+                FixedWidthFontRenderer.TYPE.getVertexFormat().clearBufferState();
                 break;
             }
         }
-
-        // We don't draw the cursor with a buffer, as it's dynamic and so we'll end up refreshing far more than is
-        // reasonable.
-        FixedWidthFontRenderer.begin( buffer );
-        FixedWidthFontRenderer.drawCursor( buffer, 0, 0, monitor.getTerminal(), !monitor.isColour() );
-        tessellator.draw();
-    }
-
-    private static void renderTerminalTo( ClientMonitor monitor, BufferBuilder buffer, float xMargin, float yMargin )
-    {
-        FixedWidthFontRenderer.begin( buffer );
-        FixedWidthFontRenderer.drawTerminalWithoutCursor(
-            buffer, 0, 0,
-            monitor.getTerminal(), !monitor.isColour(), yMargin, yMargin, xMargin, xMargin
-        );
-    }
-
-    public static void setupBufferFormat()
-    {
-        int stride = FixedWidthFontRenderer.POSITION_COLOR_TEX.getSize();
-        GlStateManager.vertexPointer( 3, GL11.GL_FLOAT, stride, 0 );
-        GlStateManager.enableClientState( GL11.GL_VERTEX_ARRAY );
-
-        GlStateManager.colorPointer( 4, GL11.GL_UNSIGNED_BYTE, stride, 12 );
-        GlStateManager.enableClientState( GL11.GL_COLOR_ARRAY );
-
-        GlStateManager.texCoordPointer( 2, GL11.GL_FLOAT, stride, 16 );
-        GlStateManager.enableClientState( GL11.GL_TEXTURE_COORD_ARRAY );
     }
 }

src/main/java/dan200/computercraft/client/render/TileEntityTurtleRenderer.java

@@ -5,7 +5,9 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.matrix.MatrixStack;
+import com.mojang.blaze3d.vertex.IVertexBuilder;
+import dan200.computercraft.api.client.TransformedModel;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
@@ -13,31 +15,26 @@ import dan200.computercraft.shared.turtle.blocks.TileTurtle;
 import dan200.computercraft.shared.util.DirectionUtil;
 import dan200.computercraft.shared.util.Holiday;
 import dan200.computercraft.shared.util.HolidayUtil;
-import net.minecraft.block.BlockState;
 import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.BufferBuilder;
-import net.minecraft.client.renderer.GameRenderer;
-import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.gui.FontRenderer;
+import net.minecraft.client.renderer.Atlases;
+import net.minecraft.client.renderer.IRenderTypeBuffer;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.Vector3f;
 import net.minecraft.client.renderer.model.BakedQuad;
 import net.minecraft.client.renderer.model.IBakedModel;
 import net.minecraft.client.renderer.model.ModelManager;
 import net.minecraft.client.renderer.model.ModelResourceLocation;
-import net.minecraft.client.renderer.texture.AtlasTexture;
 import net.minecraft.client.renderer.tileentity.TileEntityRenderer;
-import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
-import net.minecraft.client.renderer.vertex.VertexFormat;
+import net.minecraft.client.renderer.tileentity.TileEntityRendererDispatcher;
 import net.minecraft.util.Direction;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.BlockRayTraceResult;
 import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.math.Vec3d;
-import net.minecraftforge.client.ForgeHooksClient;
 import net.minecraftforge.client.model.data.EmptyModelData;
-import net.minecraftforge.client.model.pipeline.LightUtil;
-import org.apache.commons.lang3.tuple.Pair;
-import org.lwjgl.opengl.GL11;
 
-import javax.vecmath.Matrix4f;
+import javax.annotation.Nonnull;
 import java.util.List;
 import java.util.Random;
 
@@ -48,189 +45,147 @@ public class TileEntityTurtleRenderer extends TileEntityRenderer<TileTurtle>
     private static final ModelResourceLocation COLOUR_TURTLE_MODEL = new ModelResourceLocation( "computercraft:turtle_colour", "inventory" );
     private static final ModelResourceLocation ELF_OVERLAY_MODEL = new ModelResourceLocation( "computercraft:turtle_elf_overlay", "inventory" );
 
-    @Override
-    public void render( TileTurtle tileEntity, double posX, double posY, double posZ, float partialTicks, int breaking )
+    private final Random random = new Random( 0 );
+
+    public TileEntityTurtleRenderer( TileEntityRendererDispatcher renderDispatcher )
     {
-        if( tileEntity != null ) renderTurtleAt( tileEntity, posX, posY, posZ, partialTicks );
+        super( renderDispatcher );
     }
 
     public static ModelResourceLocation getTurtleModel( ComputerFamily family, boolean coloured )
     {
         switch( family )
         {
-            case Normal:
+            case NORMAL:
             default:
                 return coloured ? COLOUR_TURTLE_MODEL : NORMAL_TURTLE_MODEL;
-            case Advanced:
+            case ADVANCED:
                 return coloured ? COLOUR_TURTLE_MODEL : ADVANCED_TURTLE_MODEL;
         }
     }
 
     public static ModelResourceLocation getTurtleOverlayModel( ResourceLocation overlay, boolean christmas )
     {
-        if( overlay != null )
-        {
-            return new ModelResourceLocation( overlay, "inventory" );
-        }
-        else if( christmas )
-        {
-            return ELF_OVERLAY_MODEL;
-        }
-        else
-        {
-            return null;
-        }
+        if( overlay != null ) return new ModelResourceLocation( overlay, "inventory" );
+        if( christmas ) return ELF_OVERLAY_MODEL;
+        return null;
     }
 
-    private void renderTurtleAt( TileTurtle turtle, double posX, double posY, double posZ, float partialTicks )
+    @Override
+    public void render( @Nonnull TileTurtle turtle, float partialTicks, @Nonnull MatrixStack transform, @Nonnull IRenderTypeBuffer renderer, int lightmapCoord, int overlayLight )
     {
         // Render the label
         String label = turtle.createProxy().getLabel();
-        RayTraceResult hit = rendererDispatcher.cameraHitResult;
+        RayTraceResult hit = renderDispatcher.cameraHitResult;
         if( label != null && hit.getType() == RayTraceResult.Type.BLOCK && turtle.getPos().equals( ((BlockRayTraceResult) hit).getPos() ) )
         {
-            setLightmapDisabled( true );
-            GameRenderer.drawNameplate(
-                getFontRenderer(), label,
-                (float) posX + 0.5F, (float) posY + 1.2F, (float) posZ + 0.5F, 0,
-                rendererDispatcher.renderInfo.getYaw(), rendererDispatcher.renderInfo.getPitch(), false
-            );
-            setLightmapDisabled( false );
+            Minecraft mc = Minecraft.getInstance();
+            FontRenderer font = renderDispatcher.fontRenderer;
+
+            transform.push();
+            transform.translate( 0.5, 1.2, 0.5 );
+            transform.rotate( mc.getRenderManager().getCameraOrientation() );
+            transform.scale( -0.025f, -0.025f, 0.025f );
+
+            Matrix4f matrix = transform.getLast().getMatrix();
+            int opacity = (int) (mc.gameSettings.getTextBackgroundOpacity( 0.25f ) * 255) << 24;
+            float width = -font.getStringWidth( label ) / 2.0f;
+            font.renderString( label, width, (float) 0, 0x20ffffff, false, matrix, renderer, true, opacity, lightmapCoord );
+            font.renderString( label, width, (float) 0, 0xffffffff, false, matrix, renderer, false, 0, lightmapCoord );
+
+            transform.pop();
         }
 
-        GlStateManager.pushMatrix();
-        try
+        transform.push();
+
+        // Setup the transform.
+        Vec3d offset = turtle.getRenderOffset( partialTicks );
+        float yaw = turtle.getRenderYaw( partialTicks );
+        transform.translate( offset.x, offset.y, offset.z );
+
+        transform.translate( 0.5f, 0.5f, 0.5f );
+        transform.rotate( Vector3f.YP.rotationDegrees( 180.0f - yaw ) );
+        if( label != null && (label.equals( "Dinnerbone" ) || label.equals( "Grumm" )) )
         {
-            BlockState state = turtle.getBlockState();
-            // Setup the transform
-            Vec3d offset = turtle.getRenderOffset( partialTicks );
-            float yaw = turtle.getRenderYaw( partialTicks );
-            GlStateManager.translated( posX + offset.x, posY + offset.y, posZ + offset.z );
-            // Render the turtle
-            GlStateManager.translatef( 0.5f, 0.5f, 0.5f );
-            GlStateManager.rotatef( 180.0f - yaw, 0.0f, 1.0f, 0.0f );
-            if( label != null && (label.equals( "Dinnerbone" ) || label.equals( "Grumm" )) )
-            {
-                // Flip the model and swap the cull face as winding order will have changed.
-                GlStateManager.scalef( 1.0f, -1.0f, 1.0f );
-                GlStateManager.cullFace( GlStateManager.CullFace.FRONT );
-            }
-            GlStateManager.translatef( -0.5f, -0.5f, -0.5f );
-            // Render the turtle
-            int colour = turtle.getColour();
-            ComputerFamily family = turtle.getFamily();
-            ResourceLocation overlay = turtle.getOverlay();
-
-            renderModel( state, getTurtleModel( family, colour != -1 ), colour == -1 ? null : new int[] { colour } );
-
-            // Render the overlay
-            ModelResourceLocation overlayModel = getTurtleOverlayModel(
-                overlay,
-                HolidayUtil.getCurrentHoliday() == Holiday.Christmas
-            );
-            if( overlayModel != null )
-            {
-                GlStateManager.disableCull();
-                GlStateManager.enableBlend();
-                GlStateManager.blendFunc( GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA );
-                try
-                {
-                    renderModel( state, overlayModel, null );
-                }
-                finally
-                {
-                    GlStateManager.disableBlend();
-                    GlStateManager.enableCull();
-                }
-            }
-
-            // Render the upgrades
-            renderUpgrade( state, turtle, TurtleSide.Left, partialTicks );
-            renderUpgrade( state, turtle, TurtleSide.Right, partialTicks );
+            // Flip the model
+            transform.scale( 1.0f, -1.0f, 1.0f );
         }
-        finally
+        transform.translate( -0.5f, -0.5f, -0.5f );
+
+        // Render the turtle
+        int colour = turtle.getColour();
+        ComputerFamily family = turtle.getFamily();
+        ResourceLocation overlay = turtle.getOverlay();
+
+        IVertexBuilder buffer = renderer.getBuffer( Atlases.getTranslucentCullBlockType() );
+        renderModel( transform, buffer, lightmapCoord, overlayLight, getTurtleModel( family, colour != -1 ), colour == -1 ? null : new int[] { colour } );
+
+        // Render the overlay
+        ModelResourceLocation overlayModel = getTurtleOverlayModel( overlay, HolidayUtil.getCurrentHoliday() == Holiday.CHRISTMAS );
+        if( overlayModel != null )
         {
-            GlStateManager.popMatrix();
-            GlStateManager.cullFace( GlStateManager.CullFace.BACK );
+            renderModel( transform, buffer, lightmapCoord, overlayLight, overlayModel, null );
         }
+
+        // Render the upgrades
+        renderUpgrade( transform, buffer, lightmapCoord, overlayLight, turtle, TurtleSide.LEFT, partialTicks );
+        renderUpgrade( transform, buffer, lightmapCoord, overlayLight, turtle, TurtleSide.RIGHT, partialTicks );
+
+        transform.pop();
     }
 
-    private void renderUpgrade( BlockState state, TileTurtle turtle, TurtleSide side, float f )
+    private void renderUpgrade( @Nonnull MatrixStack transform, @Nonnull IVertexBuilder renderer, int lightmapCoord, int overlayLight, TileTurtle turtle, TurtleSide side, float f )
     {
         ITurtleUpgrade upgrade = turtle.getUpgrade( side );
-        if( upgrade != null )
-        {
-            GlStateManager.pushMatrix();
-            try
-            {
-                float toolAngle = turtle.getToolRenderAngle( side, f );
-                GlStateManager.translatef( 0.0f, 0.5f, 0.5f );
-                GlStateManager.rotatef( -toolAngle, 1.0f, 0.0f, 0.0f );
-                GlStateManager.translatef( 0.0f, -0.5f, -0.5f );
+        if( upgrade == null ) return;
+        transform.push();
 
-                Pair<IBakedModel, Matrix4f> pair = upgrade.getModel( turtle.getAccess(), side );
-                if( pair != null )
-                {
-                    if( pair.getRight() != null )
-                    {
-                        ForgeHooksClient.multiplyCurrentGlMatrix( pair.getRight() );
-                    }
-                    if( pair.getLeft() != null )
-                    {
-                        renderModel( state, pair.getLeft(), null );
-                    }
-                }
-            }
-            finally
-            {
-                GlStateManager.popMatrix();
-            }
-        }
+        float toolAngle = turtle.getToolRenderAngle( side, f );
+        transform.translate( 0.0f, 0.5f, 0.5f );
+        transform.rotate( Vector3f.XN.rotationDegrees( toolAngle ) );
+        transform.translate( 0.0f, -0.5f, -0.5f );
+
+        TransformedModel model = upgrade.getModel( turtle.getAccess(), side );
+        model.getMatrix().push( transform );
+        renderModel( transform, renderer, lightmapCoord, overlayLight, model.getModel(), null );
+        transform.pop();
+
+        transform.pop();
     }
 
-    private void renderModel( BlockState state, ModelResourceLocation modelLocation, int[] tints )
+    private void renderModel( @Nonnull MatrixStack transform, @Nonnull IVertexBuilder renderer, int lightmapCoord, int overlayLight, ModelResourceLocation modelLocation, int[] tints )
     {
-        Minecraft mc = Minecraft.getInstance();
-        ModelManager modelManager = mc.getItemRenderer().getItemModelMesher().getModelManager();
-        renderModel( state, modelManager.getModel( modelLocation ), tints );
+        ModelManager modelManager = Minecraft.getInstance().getItemRenderer().getItemModelMesher().getModelManager();
+        renderModel( transform, renderer, lightmapCoord, overlayLight, modelManager.getModel( modelLocation ), tints );
     }
 
-    private void renderModel( BlockState state, IBakedModel model, int[] tints )
+    private void renderModel( @Nonnull MatrixStack transform, @Nonnull IVertexBuilder renderer, int lightmapCoord, int overlayLight, IBakedModel model, int[] tints )
     {
-        Random random = new Random( 0 );
-        Tessellator tessellator = Tessellator.getInstance();
-        rendererDispatcher.textureManager.bindTexture( AtlasTexture.LOCATION_BLOCKS_TEXTURE );
-        renderQuads( tessellator, model.getQuads( state, null, random, EmptyModelData.INSTANCE ), tints );
+        random.setSeed( 0 );
+        renderQuads( transform, renderer, lightmapCoord, overlayLight, model.getQuads( null, null, random, EmptyModelData.INSTANCE ), tints );
         for( Direction facing : DirectionUtil.FACINGS )
         {
-            renderQuads( tessellator, model.getQuads( state, facing, random, EmptyModelData.INSTANCE ), tints );
+            renderQuads( transform, renderer, lightmapCoord, overlayLight, model.getQuads( null, facing, random, EmptyModelData.INSTANCE ), tints );
         }
     }
 
-    private static void renderQuads( Tessellator tessellator, List<BakedQuad> quads, int[] tints )
+    private static void renderQuads( @Nonnull MatrixStack transform, @Nonnull IVertexBuilder buffer, int lightmapCoord, int overlayLight, List<BakedQuad> quads, int[] tints )
     {
-        BufferBuilder buffer = tessellator.getBuffer();
-        VertexFormat format = DefaultVertexFormats.ITEM;
-        buffer.begin( GL11.GL_QUADS, format );
-        for( BakedQuad quad : quads )
+        MatrixStack.Entry matrix = transform.getLast();
+
+        for( BakedQuad bakedquad : quads )
         {
-            VertexFormat quadFormat = quad.getFormat();
-            if( quadFormat != format )
+            int tint = -1;
+            if( tints != null && bakedquad.hasTintIndex() )
             {
-                tessellator.draw();
-                format = quadFormat;
-                buffer.begin( GL11.GL_QUADS, format );
+                int idx = bakedquad.getTintIndex();
+                if( idx >= 0 && idx < tints.length ) tint = tints[bakedquad.getTintIndex()];
             }
 
-            int colour = 0xFFFFFFFF;
-            if( quad.hasTintIndex() && tints != null )
-            {
-                int index = quad.getTintIndex();
-                if( index >= 0 && index < tints.length ) colour = tints[index] | 0xFF000000;
-            }
-
-            LightUtil.renderQuadColor( buffer, quad, colour );
+            float f = (float) (tint >> 16 & 255) / 255.0F;
+            float f1 = (float) (tint >> 8 & 255) / 255.0F;
+            float f2 = (float) (tint & 255) / 255.0F;
+            buffer.addVertexData( matrix, bakedquad, f, f1, f2, lightmapCoord, overlayLight, true );
         }
-        tessellator.draw();
     }
 }

src/main/java/dan200/computercraft/client/render/TurtleModelLoader.java

@@ -5,28 +5,27 @@
  */
 package dan200.computercraft.client.render;
 
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonObject;
+import com.mojang.datafixers.util.Pair;
 import dan200.computercraft.ComputerCraft;
-import net.minecraft.client.renderer.model.IBakedModel;
-import net.minecraft.client.renderer.model.IUnbakedModel;
-import net.minecraft.client.renderer.model.ModelBakery;
-import net.minecraft.client.renderer.texture.ISprite;
+import net.minecraft.client.renderer.model.*;
 import net.minecraft.client.renderer.texture.TextureAtlasSprite;
-import net.minecraft.client.renderer.vertex.VertexFormat;
 import net.minecraft.resources.IResourceManager;
+import net.minecraft.util.JSONUtils;
 import net.minecraft.util.ResourceLocation;
-import net.minecraftforge.client.model.ICustomModelLoader;
+import net.minecraftforge.client.model.IModelConfiguration;
+import net.minecraftforge.client.model.IModelLoader;
+import net.minecraftforge.client.model.geometry.IModelGeometry;
 
 import javax.annotation.Nonnull;
-import java.util.Arrays;
 import java.util.Collection;
+import java.util.HashSet;
 import java.util.Set;
 import java.util.function.Function;
-import java.util.stream.Collectors;
 
-public final class TurtleModelLoader implements ICustomModelLoader
+public final class TurtleModelLoader implements IModelLoader<TurtleModelLoader.TurtleModel>
 {
-    private static final ResourceLocation NORMAL_TURTLE_MODEL = new ResourceLocation( ComputerCraft.MOD_ID, "block/turtle_normal" );
-    private static final ResourceLocation ADVANCED_TURTLE_MODEL = new ResourceLocation( ComputerCraft.MOD_ID, "block/turtle_advanced" );
     private static final ResourceLocation COLOUR_TURTLE_MODEL = new ResourceLocation( ComputerCraft.MOD_ID, "block/turtle_colour" );
 
     public static final TurtleModelLoader INSTANCE = new TurtleModelLoader();
@@ -40,32 +39,15 @@ public final class TurtleModelLoader implements ICustomModelLoader
     {
     }
 
-    @Override
-    public boolean accepts( @Nonnull ResourceLocation name )
-    {
-        return name.getNamespace().equals( ComputerCraft.MOD_ID )
-            && (name.getPath().equals( "item/turtle_normal" ) || name.getPath().equals( "item/turtle_advanced" ));
-    }
-
     @Nonnull
     @Override
-    public IUnbakedModel loadModel( @Nonnull ResourceLocation name )
+    public TurtleModel read( @Nonnull JsonDeserializationContext deserializationContext, @Nonnull JsonObject modelContents )
     {
-        if( name.getNamespace().equals( ComputerCraft.MOD_ID ) )
-        {
-            switch( name.getPath() )
-            {
-                case "item/turtle_normal":
-                    return new TurtleModel( NORMAL_TURTLE_MODEL );
-                case "item/turtle_advanced":
-                    return new TurtleModel( ADVANCED_TURTLE_MODEL );
-            }
-        }
-
-        throw new IllegalStateException( "Loader does not accept " + name );
+        ResourceLocation model = new ResourceLocation( JSONUtils.getString( modelContents, "model" ) );
+        return new TurtleModel( model );
     }
 
-    private static final class TurtleModel implements IUnbakedModel
+    public static final class TurtleModel implements IModelGeometry<TurtleModel>
     {
         private final ResourceLocation family;
 
@@ -74,29 +56,21 @@ public final class TurtleModelLoader implements ICustomModelLoader
             this.family = family;
         }
 
-        @Nonnull
         @Override
-        public Collection<ResourceLocation> getDependencies()
+        public Collection<Material> getTextures( IModelConfiguration owner, Function<ResourceLocation, IUnbakedModel> modelGetter, Set<Pair<String, String>> missingTextureErrors )
         {
-            return Arrays.asList( family, COLOUR_TURTLE_MODEL );
+            Set<Material> materials = new HashSet<>();
+            materials.addAll( modelGetter.apply( family ).getTextures( modelGetter, missingTextureErrors ) );
+            materials.addAll( modelGetter.apply( COLOUR_TURTLE_MODEL ).getTextures( modelGetter, missingTextureErrors ) );
+            return materials;
         }
 
-        @Nonnull
         @Override
-        public Collection<ResourceLocation> getTextures( @Nonnull Function<ResourceLocation, IUnbakedModel> modelGetter, @Nonnull Set<String> missingTextureErrors )
-        {
-            return getDependencies().stream()
-                .flatMap( x -> modelGetter.apply( x ).getTextures( modelGetter, missingTextureErrors ).stream() )
-                .collect( Collectors.toSet() );
-        }
-
-        @Nonnull
-        @Override
-        public IBakedModel bake( @Nonnull ModelBakery bakery, @Nonnull Function<ResourceLocation, TextureAtlasSprite> spriteGetter, @Nonnull ISprite sprite, @Nonnull VertexFormat format )
+        public IBakedModel bake( IModelConfiguration owner, ModelBakery bakery, Function<Material, TextureAtlasSprite> spriteGetter, IModelTransform transform, ItemOverrideList overrides, ResourceLocation modelLocation )
         {
             return new TurtleSmartItemModel(
-                bakery.getBakedModel( family, sprite, spriteGetter, format ),
-                bakery.getBakedModel( COLOUR_TURTLE_MODEL, sprite, spriteGetter, format )
+                bakery.getBakedModel( family, transform, spriteGetter ),
+                bakery.getBakedModel( COLOUR_TURTLE_MODEL, transform, spriteGetter )
             );
         }
     }

src/main/java/dan200/computercraft/client/render/TurtleMultiModel.java

@@ -5,7 +5,9 @@
  */
 package dan200.computercraft.client.render;
 
+import dan200.computercraft.api.client.TransformedModel;
 import net.minecraft.block.BlockState;
+import net.minecraft.client.renderer.TransformationMatrix;
 import net.minecraft.client.renderer.model.BakedQuad;
 import net.minecraft.client.renderer.model.IBakedModel;
 import net.minecraft.client.renderer.model.ItemOverrideList;
@@ -13,32 +15,29 @@ import net.minecraft.client.renderer.texture.TextureAtlasSprite;
 import net.minecraft.util.Direction;
 import net.minecraftforge.client.model.data.EmptyModelData;
 import net.minecraftforge.client.model.data.IModelData;
+import net.minecraftforge.client.model.pipeline.BakedQuadBuilder;
+import net.minecraftforge.client.model.pipeline.TRSRTransformer;
 
 import javax.annotation.Nonnull;
-import javax.vecmath.Matrix4f;
 import java.util.*;
 
 public class TurtleMultiModel implements IBakedModel
 {
     private final IBakedModel m_baseModel;
     private final IBakedModel m_overlayModel;
-    private final Matrix4f m_generalTransform;
-    private final IBakedModel m_leftUpgradeModel;
-    private final Matrix4f m_leftUpgradeTransform;
-    private final IBakedModel m_rightUpgradeModel;
-    private final Matrix4f m_rightUpgradeTransform;
+    private final TransformationMatrix m_generalTransform;
+    private final TransformedModel m_leftUpgradeModel;
+    private final TransformedModel m_rightUpgradeModel;
     private List<BakedQuad> m_generalQuads = null;
     private Map<Direction, List<BakedQuad>> m_faceQuads = new EnumMap<>( Direction.class );
 
-    public TurtleMultiModel( IBakedModel baseModel, IBakedModel overlayModel, Matrix4f generalTransform, IBakedModel leftUpgradeModel, Matrix4f leftUpgradeTransform, IBakedModel rightUpgradeModel, Matrix4f rightUpgradeTransform )
+    public TurtleMultiModel( IBakedModel baseModel, IBakedModel overlayModel, TransformationMatrix generalTransform, TransformedModel leftUpgradeModel, TransformedModel rightUpgradeModel )
     {
         // Get the models
         m_baseModel = baseModel;
         m_overlayModel = overlayModel;
         m_leftUpgradeModel = leftUpgradeModel;
-        m_leftUpgradeTransform = leftUpgradeTransform;
         m_rightUpgradeModel = rightUpgradeModel;
-        m_rightUpgradeTransform = rightUpgradeTransform;
         m_generalTransform = generalTransform;
     }
 
@@ -69,30 +68,22 @@ public class TurtleMultiModel implements IBakedModel
     private List<BakedQuad> buildQuads( BlockState state, Direction side, Random rand )
     {
         ArrayList<BakedQuad> quads = new ArrayList<>();
-        ModelTransformer.transformQuadsTo( quads, m_baseModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), m_generalTransform );
+
+
+        transformQuadsTo( quads, m_baseModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), m_generalTransform );
         if( m_overlayModel != null )
         {
-            ModelTransformer.transformQuadsTo( quads, m_overlayModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), m_generalTransform );
+            transformQuadsTo( quads, m_overlayModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), m_generalTransform );
         }
         if( m_leftUpgradeModel != null )
         {
-            Matrix4f upgradeTransform = m_generalTransform;
-            if( m_leftUpgradeTransform != null )
-            {
-                upgradeTransform = new Matrix4f( m_generalTransform );
-                upgradeTransform.mul( m_leftUpgradeTransform );
-            }
-            ModelTransformer.transformQuadsTo( quads, m_leftUpgradeModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), upgradeTransform );
+            TransformationMatrix upgradeTransform = m_generalTransform.compose( m_leftUpgradeModel.getMatrix() );
+            transformQuadsTo( quads, m_leftUpgradeModel.getModel().getQuads( state, side, rand, EmptyModelData.INSTANCE ), upgradeTransform );
         }
         if( m_rightUpgradeModel != null )
         {
-            Matrix4f upgradeTransform = m_generalTransform;
-            if( m_rightUpgradeTransform != null )
-            {
-                upgradeTransform = new Matrix4f( m_generalTransform );
-                upgradeTransform.mul( m_rightUpgradeTransform );
-            }
-            ModelTransformer.transformQuadsTo( quads, m_rightUpgradeModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), upgradeTransform );
+            TransformationMatrix upgradeTransform = m_generalTransform.compose( m_rightUpgradeModel.getMatrix() );
+            transformQuadsTo( quads, m_rightUpgradeModel.getModel().getQuads( state, side, rand, EmptyModelData.INSTANCE ), upgradeTransform );
         }
         quads.trimToSize();
         return quads;
@@ -116,6 +107,12 @@ public class TurtleMultiModel implements IBakedModel
         return m_baseModel.isBuiltInRenderer();
     }
 
+    @Override
+    public boolean func_230044_c_()
+    {
+        return m_baseModel.func_230044_c_();
+    }
+
     @Nonnull
     @Override
     @Deprecated
@@ -138,4 +135,15 @@ public class TurtleMultiModel implements IBakedModel
     {
         return ItemOverrideList.EMPTY;
     }
+
+    private void transformQuadsTo( List<BakedQuad> output, List<BakedQuad> quads, TransformationMatrix transform )
+    {
+        for( BakedQuad quad : quads )
+        {
+            BakedQuadBuilder builder = new BakedQuadBuilder();
+            TRSRTransformer transformer = new TRSRTransformer( builder, transform );
+            quad.pipe( transformer );
+            output.add( builder.build() );
+        }
+    }
 }

src/main/java/dan200/computercraft/client/render/TurtlePlayerRenderer.java

@@ -6,14 +6,15 @@
 
 package dan200.computercraft.client.render;
 
-import dan200.computercraft.ComputerCraft;
+import com.mojang.blaze3d.matrix.MatrixStack;
+import dan200.computercraft.client.gui.GuiComputer;
 import dan200.computercraft.shared.turtle.core.TurtlePlayer;
+import net.minecraft.client.renderer.IRenderTypeBuffer;
 import net.minecraft.client.renderer.entity.EntityRenderer;
 import net.minecraft.client.renderer.entity.EntityRendererManager;
 import net.minecraft.util.ResourceLocation;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 public class TurtlePlayerRenderer extends EntityRenderer<TurtlePlayer>
 {
@@ -22,16 +23,15 @@ public class TurtlePlayerRenderer extends EntityRenderer<TurtlePlayer>
         super( renderManager );
     }
 
+    @Nonnull
     @Override
-    public void doRender( @Nonnull TurtlePlayer entity, double x, double y, double z, float entityYaw, float partialTicks )
+    public ResourceLocation getEntityTexture( @Nonnull TurtlePlayer entity )
     {
-        ComputerCraft.log.error( "Rendering TurtlePlayer on the client side, at {}", entity.getPosition() );
+        return GuiComputer.BACKGROUND_NORMAL;
     }
 
-    @Nullable
     @Override
-    protected ResourceLocation getEntityTexture( @Nonnull TurtlePlayer entity )
+    public void render( @Nonnull TurtlePlayer entityIn, float entityYaw, float partialTicks, @Nonnull MatrixStack transform, @Nonnull IRenderTypeBuffer buffer, int packedLightIn )
     {
-        return null;
     }
 }

src/main/java/dan200/computercraft/client/render/TurtleSmartItemModel.java

@@ -6,6 +6,8 @@
 package dan200.computercraft.client.render;
 
 import com.google.common.base.Objects;
+import com.mojang.blaze3d.matrix.MatrixStack;
+import dan200.computercraft.api.client.TransformedModel;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.shared.turtle.items.ItemTurtle;
@@ -13,6 +15,7 @@ import dan200.computercraft.shared.util.Holiday;
 import dan200.computercraft.shared.util.HolidayUtil;
 import net.minecraft.block.BlockState;
 import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.TransformationMatrix;
 import net.minecraft.client.renderer.model.*;
 import net.minecraft.client.renderer.texture.TextureAtlasSprite;
 import net.minecraft.entity.LivingEntity;
@@ -21,28 +24,25 @@ import net.minecraft.util.Direction;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.world.World;
 import net.minecraftforge.client.model.data.IModelData;
-import org.apache.commons.lang3.tuple.Pair;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import javax.vecmath.Matrix4f;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Random;
 
 public class TurtleSmartItemModel implements IBakedModel
 {
-    private static final Matrix4f s_identity, s_flip;
+    private static final TransformationMatrix identity, flip;
 
     static
     {
-        s_identity = new Matrix4f();
-        s_identity.setIdentity();
+        MatrixStack stack = new MatrixStack();
+        stack.scale( 0, -1, 0 );
+        stack.translate( 0, 0, 1 );
 
-        s_flip = new Matrix4f();
-        s_flip.setIdentity();
-        s_flip.m11 = -1; // Flip on the y axis
-        s_flip.m13 = 1; // Models go from (0,0,0) to (1,1,1), so push back up.
+        identity = TransformationMatrix.identity();
+        flip = new TransformationMatrix( stack.getLast().getMatrix() );
     }
 
     private static class TurtleModelCombination
@@ -97,15 +97,14 @@ public class TurtleSmartItemModel implements IBakedModel
     private final IBakedModel familyModel;
     private final IBakedModel colourModel;
 
-    private HashMap<TurtleModelCombination, IBakedModel> m_cachedModels;
-    private ItemOverrideList m_overrides;
+    private final HashMap<TurtleModelCombination, IBakedModel> m_cachedModels = new HashMap<>();
+    private final ItemOverrideList m_overrides;
 
     public TurtleSmartItemModel( IBakedModel familyModel, IBakedModel colourModel )
     {
         this.familyModel = familyModel;
         this.colourModel = colourModel;
 
-        m_cachedModels = new HashMap<>();
         m_overrides = new ItemOverrideList()
         {
             @Nonnull
@@ -114,10 +113,10 @@ public class TurtleSmartItemModel implements IBakedModel
             {
                 ItemTurtle turtle = (ItemTurtle) stack.getItem();
                 int colour = turtle.getColour( stack );
-                ITurtleUpgrade leftUpgrade = turtle.getUpgrade( stack, TurtleSide.Left );
-                ITurtleUpgrade rightUpgrade = turtle.getUpgrade( stack, TurtleSide.Right );
+                ITurtleUpgrade leftUpgrade = turtle.getUpgrade( stack, TurtleSide.LEFT );
+                ITurtleUpgrade rightUpgrade = turtle.getUpgrade( stack, TurtleSide.RIGHT );
                 ResourceLocation overlay = turtle.getOverlay( stack );
-                boolean christmas = HolidayUtil.getCurrentHoliday() == Holiday.Christmas;
+                boolean christmas = HolidayUtil.getCurrentHoliday() == Holiday.CHRISTMAS;
                 String label = turtle.getLabel( stack );
                 boolean flip = label != null && (label.equals( "Dinnerbone" ) || label.equals( "Grumm" ));
                 TurtleModelCombination combo = new TurtleModelCombination( colour != -1, leftUpgrade, rightUpgrade, overlay, christmas, flip );
@@ -144,25 +143,10 @@ public class TurtleSmartItemModel implements IBakedModel
 
         IBakedModel baseModel = combo.m_colour ? colourModel : familyModel;
         IBakedModel overlayModel = overlayModelLocation != null ? modelManager.getModel( overlayModelLocation ) : null;
-        Matrix4f transform = combo.m_flip ? s_flip : s_identity;
-        Pair<IBakedModel, Matrix4f> leftModel = combo.m_leftUpgrade != null ? combo.m_leftUpgrade.getModel( null, TurtleSide.Left ) : null;
-        Pair<IBakedModel, Matrix4f> rightModel = combo.m_rightUpgrade != null ? combo.m_rightUpgrade.getModel( null, TurtleSide.Right ) : null;
-        if( leftModel != null && rightModel != null )
-        {
-            return new TurtleMultiModel( baseModel, overlayModel, transform, leftModel.getLeft(), leftModel.getRight(), rightModel.getLeft(), rightModel.getRight() );
-        }
-        else if( leftModel != null )
-        {
-            return new TurtleMultiModel( baseModel, overlayModel, transform, leftModel.getLeft(), leftModel.getRight(), null, null );
-        }
-        else if( rightModel != null )
-        {
-            return new TurtleMultiModel( baseModel, overlayModel, transform, null, null, rightModel.getLeft(), rightModel.getRight() );
-        }
-        else
-        {
-            return new TurtleMultiModel( baseModel, overlayModel, transform, null, null, null, null );
-        }
+        TransformationMatrix transform = combo.m_flip ? flip : identity;
+        TransformedModel leftModel = combo.m_leftUpgrade != null ? combo.m_leftUpgrade.getModel( null, TurtleSide.LEFT ) : null;
+        TransformedModel rightModel = combo.m_rightUpgrade != null ? combo.m_rightUpgrade.getModel( null, TurtleSide.RIGHT ) : null;
+        return new TurtleMultiModel( baseModel, overlayModel, transform, leftModel, rightModel );
     }
 
     @Nonnull
@@ -199,6 +183,12 @@ public class TurtleSmartItemModel implements IBakedModel
         return familyModel.isBuiltInRenderer();
     }
 
+    @Override
+    public boolean func_230044_c_()
+    {
+        return familyModel.func_230044_c_();
+    }
+
     @Nonnull
     @Override
     @Deprecated

src/main/java/dan200/computercraft/core/apis/AddressPredicate.java

@@ -1,181 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.core.apis;
-
-import com.google.common.net.InetAddresses;
-import dan200.computercraft.ComputerCraft;
-
-import java.net.Inet6Address;
-import java.net.InetAddress;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.regex.Pattern;
-
-/**
- * Used to determine whether a domain or IP address matches a series of patterns.
- */
-public class AddressPredicate
-{
-    private static final class HostRange
-    {
-        private final byte[] min;
-        private final byte[] max;
-
-        private HostRange( byte[] min, byte[] max )
-        {
-            this.min = min;
-            this.max = max;
-        }
-
-        public boolean contains( InetAddress address )
-        {
-            byte[] entry = address.getAddress();
-            if( entry.length != min.length ) return false;
-
-            for( int i = 0; i < entry.length; i++ )
-            {
-                int value = 0xFF & entry[i];
-                if( value < (0xFF & min[i]) || value > (0xFF & max[i]) ) return false;
-            }
-
-            return true;
-        }
-    }
-
-    private final List<Pattern> wildcards;
-    private final List<HostRange> ranges;
-
-    public AddressPredicate( String... filters )
-    {
-        this( Arrays.asList( filters ) );
-    }
-
-    public AddressPredicate( Iterable<? extends String> filters )
-    {
-        List<Pattern> wildcards = this.wildcards = new ArrayList<>();
-        List<HostRange> ranges = this.ranges = new ArrayList<>();
-
-        for( String filter : filters )
-        {
-            int cidr = filter.indexOf( '/' );
-            if( cidr >= 0 )
-            {
-                String addressStr = filter.substring( 0, cidr );
-                String prefixSizeStr = filter.substring( cidr + 1 );
-
-                int prefixSize;
-                try
-                {
-                    prefixSize = Integer.parseInt( prefixSizeStr );
-                }
-                catch( NumberFormatException e )
-                {
-                    ComputerCraft.log.error(
-                        "Malformed http whitelist/blacklist entry '{}': Cannot extract size of CIDR mask from '{}'.",
-                        filter, prefixSizeStr
-                    );
-                    continue;
-                }
-
-                InetAddress address;
-                try
-                {
-                    address = InetAddresses.forString( addressStr );
-                }
-                catch( IllegalArgumentException e )
-                {
-                    ComputerCraft.log.error(
-                        "Malformed http whitelist/blacklist entry '{}': Cannot extract IP address from '{}'.",
-                        filter, prefixSizeStr
-                    );
-                    continue;
-                }
-
-                // Mask the bytes of the IP address.
-                byte[] minBytes = address.getAddress(), maxBytes = address.getAddress();
-                int size = prefixSize;
-                for( int i = 0; i < minBytes.length; i++ )
-                {
-                    if( size <= 0 )
-                    {
-                        minBytes[i] &= 0;
-                        maxBytes[i] |= 0xFF;
-                    }
-                    else if( size < 8 )
-                    {
-                        minBytes[i] &= 0xFF << (8 - size);
-                        maxBytes[i] |= ~(0xFF << (8 - size));
-                    }
-
-                    size -= 8;
-                }
-
-                ranges.add( new HostRange( minBytes, maxBytes ) );
-            }
-            else
-            {
-                wildcards.add( Pattern.compile( "^\\Q" + filter.replaceAll( "\\*", "\\\\E.*\\\\Q" ) + "\\E$" ) );
-            }
-        }
-    }
-
-    /**
-     * Determine whether a host name matches a series of patterns.
-     *
-     * This is intended to allow early exiting, before one has to look up the IP address. You should use
-     * {@link #matches(InetAddress)} instead of/in addition to this one.
-     *
-     * @param domain The domain to match.
-     * @return Whether the patterns were matched.
-     */
-    public boolean matches( String domain )
-    {
-        for( Pattern domainPattern : wildcards )
-        {
-            if( domainPattern.matcher( domain ).matches() ) return true;
-        }
-
-        return false;
-    }
-
-    private boolean matchesAddress( InetAddress address )
-    {
-        String addressString = address.getHostAddress();
-        for( Pattern domainPattern : wildcards )
-        {
-            if( domainPattern.matcher( addressString ).matches() ) return true;
-        }
-
-        for( HostRange range : ranges )
-        {
-            if( range.contains( address ) ) return true;
-        }
-
-        return false;
-    }
-
-    /**
-     * Determine whether the given address matches a series of patterns.
-     *
-     * @param address The address to check.
-     * @return Whether it matches any of these patterns.
-     */
-    public boolean matches( InetAddress address )
-    {
-        // Match the host name
-        String host = address.getHostName();
-        if( host != null && matches( host ) ) return true;
-
-        // Match the normal address
-        if( matchesAddress( address ) ) return true;
-
-        // If we're an IPv4 address in disguise then let's check that.
-        return address instanceof Inet6Address && InetAddresses.is6to4Address( (Inet6Address) address )
-            && matchesAddress( InetAddresses.get6to4IPv4Address( (Inet6Address) address ) );
-
-    }
-}

src/main/java/dan200/computercraft/core/apis/ArgumentHelper.java

@@ -1,117 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.core.apis;
-
-import dan200.computercraft.api.lua.LuaException;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import java.util.Map;
-
-/**
- * A stub for any mods which depended on this version of the argument helper.
- *
- * @deprecated Use {@link dan200.computercraft.api.lua.ArgumentHelper}.
- */
-@Deprecated
-public final class ArgumentHelper
-{
-    private ArgumentHelper()
-    {
-    }
-
-    @Nonnull
-    public static String getType( @Nullable Object type )
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.getType( type );
-    }
-
-    @Nonnull
-    public static LuaException badArgument( int index, @Nonnull String expected, @Nullable Object actual )
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.badArgumentOf( index, expected, actual );
-    }
-
-    @Nonnull
-    public static LuaException badArgument( int index, @Nonnull String expected, @Nonnull String actual )
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.badArgument( index, expected, actual );
-    }
-
-    public static double getNumber( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.getDouble( args, index );
-    }
-
-    public static int getInt( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.getInt( args, index );
-    }
-
-    public static long getLong( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.getLong( args, index );
-    }
-
-    public static double getReal( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.getFiniteDouble( args, index );
-    }
-
-    public static boolean getBoolean( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.getBoolean( args, index );
-    }
-
-    @Nonnull
-    public static String getString( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.getString( args, index );
-    }
-
-    @Nonnull
-    @SuppressWarnings( "unchecked" )
-    public static Map<Object, Object> getTable( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return (Map<Object, Object>) dan200.computercraft.api.lua.ArgumentHelper.getTable( args, index );
-    }
-
-    public static double optNumber( @Nonnull Object[] args, int index, double def ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.optDouble( args, index, def );
-    }
-
-    public static int optInt( @Nonnull Object[] args, int index, int def ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.optInt( args, index, def );
-    }
-
-    public static long optLong( @Nonnull Object[] args, int index, long def ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.optLong( args, index, def );
-    }
-
-    public static double optReal( @Nonnull Object[] args, int index, double def ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.optFiniteDouble( args, index, def );
-    }
-
-    public static boolean optBoolean( @Nonnull Object[] args, int index, boolean def ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.optBoolean( args, index, def );
-    }
-
-    public static String optString( @Nonnull Object[] args, int index, String def ) throws LuaException
-    {
-        return dan200.computercraft.api.lua.ArgumentHelper.optString( args, index, def );
-    }
-
-    @SuppressWarnings( "unchecked" )
-    public static Map<Object, Object> optTable( @Nonnull Object[] args, int index, Map<Object, Object> def ) throws LuaException
-    {
-        return (Map<Object, Object>) dan200.computercraft.api.lua.ArgumentHelper.optTable( args, index, def );
-    }
-}

src/main/java/dan200/computercraft/core/apis/ComputerAccess.java

@@ -13,7 +13,6 @@ import dan200.computercraft.core.filesystem.FileSystem;
 import dan200.computercraft.core.filesystem.FileSystemException;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import java.util.HashSet;
 import java.util.Objects;
 import java.util.Set;
@@ -117,13 +116,13 @@ public abstract class ComputerAccess implements IComputerAccess
     }
 
     @Override
-    public void queueEvent( @Nonnull final String event, final Object[] arguments )
+    public void queueEvent( @Nonnull String event, Object... arguments )
     {
         Objects.requireNonNull( event, "event cannot be null" );
         m_environment.queueEvent( event, arguments );
     }
 
-    @Nullable
+    @Nonnull
     @Override
     public IWorkMonitor getMainThreadMonitor()
     {

src/main/java/dan200/computercraft/core/apis/FSAPI.java

@@ -6,8 +6,8 @@
 package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.apis.handles.BinaryReadableHandle;
 import dan200.computercraft.core.apis.handles.BinaryWritableHandle;
 import dan200.computercraft.core.apis.handles.EncodedReadableHandle;
@@ -17,7 +17,6 @@ import dan200.computercraft.core.filesystem.FileSystemException;
 import dan200.computercraft.core.filesystem.FileSystemWrapper;
 import dan200.computercraft.core.tracking.TrackingField;
 
-import javax.annotation.Nonnull;
 import java.io.BufferedReader;
 import java.io.BufferedWriter;
 import java.nio.channels.ReadableByteChannel;
@@ -29,17 +28,14 @@ import java.util.Map;
 import java.util.OptionalLong;
 import java.util.function.Function;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.getString;
-
 public class FSAPI implements ILuaAPI
 {
-    private IAPIEnvironment m_env;
-    private FileSystem m_fileSystem;
+    private final IAPIEnvironment environment;
+    private FileSystem fileSystem = null;
 
     public FSAPI( IAPIEnvironment env )
     {
-        m_env = env;
-        m_fileSystem = null;
+        environment = env;
     }
 
     @Override
@@ -51,329 +47,280 @@ public class FSAPI implements ILuaAPI
     @Override
     public void startup()
     {
-        m_fileSystem = m_env.getFileSystem();
+        fileSystem = environment.getFileSystem();
     }
 
     @Override
     public void shutdown()
     {
-        m_fileSystem = null;
+        fileSystem = null;
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    @LuaFunction
+    public final String[] list( String path ) throws LuaException
     {
-        return new String[] {
-            "list",
-            "combine",
-            "getName",
-            "getSize",
-            "exists",
-            "isDir",
-            "isReadOnly",
-            "makeDir",
-            "move",
-            "copy",
-            "delete",
-            "open",
-            "getDrive",
-            "getFreeSpace",
-            "find",
-            "getDir",
-            "getCapacity",
-            "attributes",
-        };
-    }
-
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
-    {
-        switch( method )
+        environment.addTrackingChange( TrackingField.FS_OPS );
+        try
         {
-            case 0:
+            return fileSystem.list( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final String combine( String pathA, String pathB )
+    {
+        return fileSystem.combine( pathA, pathB );
+    }
+
+    @LuaFunction
+    public final String getName( String path )
+    {
+        return FileSystem.getName( path );
+    }
+
+    @LuaFunction
+    public final String getDir( String path )
+    {
+        return FileSystem.getDirectory( path );
+    }
+
+    @LuaFunction
+    public final long getSize( String path ) throws LuaException
+    {
+        try
+        {
+            return fileSystem.getSize( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final boolean exists( String path )
+    {
+        try
+        {
+            return fileSystem.exists( path );
+        }
+        catch( FileSystemException e )
+        {
+            return false;
+        }
+    }
+
+    @LuaFunction
+    public final boolean isDir( String path )
+    {
+        try
+        {
+            return fileSystem.isDir( path );
+        }
+        catch( FileSystemException e )
+        {
+            return false;
+        }
+    }
+
+    @LuaFunction
+    public final boolean isReadOnly( String path )
+    {
+        try
+        {
+            return fileSystem.isReadOnly( path );
+        }
+        catch( FileSystemException e )
+        {
+            return false;
+        }
+    }
+
+    @LuaFunction
+    public final void makeDir( String path ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            fileSystem.makeDir( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final void move( String path, String dest ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            fileSystem.move( path, dest );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final void copy( String path, String dest ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            fileSystem.copy( path, dest );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final void delete( String path ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            fileSystem.delete( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final Object[] open( String path, String mode ) throws LuaException
+    {
+        environment.addTrackingChange( TrackingField.FS_OPS );
+        try
+        {
+            switch( mode )
             {
-                // list
-                String path = getString( args, 0 );
-                m_env.addTrackingChange( TrackingField.FS_OPS );
-                try
+                case "r":
                 {
-                    return new Object[] { m_fileSystem.list( path ) };
+                    // Open the file for reading, then create a wrapper around the reader
+                    FileSystemWrapper<BufferedReader> reader = fileSystem.openForRead( path, EncodedReadableHandle::openUtf8 );
+                    return new Object[] { new EncodedReadableHandle( reader.get(), reader ) };
                 }
-                catch( FileSystemException e )
+                case "w":
                 {
-                    throw new LuaException( e.getMessage() );
+                    // Open the file for writing, then create a wrapper around the writer
+                    FileSystemWrapper<BufferedWriter> writer = fileSystem.openForWrite( path, false, EncodedWritableHandle::openUtf8 );
+                    return new Object[] { new EncodedWritableHandle( writer.get(), writer ) };
                 }
+                case "a":
+                {
+                    // Open the file for appending, then create a wrapper around the writer
+                    FileSystemWrapper<BufferedWriter> writer = fileSystem.openForWrite( path, true, EncodedWritableHandle::openUtf8 );
+                    return new Object[] { new EncodedWritableHandle( writer.get(), writer ) };
+                }
+                case "rb":
+                {
+                    // Open the file for binary reading, then create a wrapper around the reader
+                    FileSystemWrapper<ReadableByteChannel> reader = fileSystem.openForRead( path, Function.identity() );
+                    return new Object[] { BinaryReadableHandle.of( reader.get(), reader ) };
+                }
+                case "wb":
+                {
+                    // Open the file for binary writing, then create a wrapper around the writer
+                    FileSystemWrapper<WritableByteChannel> writer = fileSystem.openForWrite( path, false, Function.identity() );
+                    return new Object[] { BinaryWritableHandle.of( writer.get(), writer ) };
+                }
+                case "ab":
+                {
+                    // Open the file for binary appending, then create a wrapper around the reader
+                    FileSystemWrapper<WritableByteChannel> writer = fileSystem.openForWrite( path, true, Function.identity() );
+                    return new Object[] { BinaryWritableHandle.of( writer.get(), writer ) };
+                }
+                default:
+                    throw new LuaException( "Unsupported mode" );
             }
-            case 1:
-            {
-                // combine
-                String pathA = getString( args, 0 );
-                String pathB = getString( args, 1 );
-                return new Object[] { m_fileSystem.combine( pathA, pathB ) };
-            }
-            case 2:
-            {
-                // getName
-                String path = getString( args, 0 );
-                return new Object[] { FileSystem.getName( path ) };
-            }
-            case 3:
-            {
-                // getSize
-                String path = getString( args, 0 );
-                try
-                {
-                    return new Object[] { m_fileSystem.getSize( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 4:
-            {
-                // exists
-                String path = getString( args, 0 );
-                try
-                {
-                    return new Object[] { m_fileSystem.exists( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    return new Object[] { false };
-                }
-            }
-            case 5:
-            {
-                // isDir
-                String path = getString( args, 0 );
-                try
-                {
-                    return new Object[] { m_fileSystem.isDir( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    return new Object[] { false };
-                }
-            }
-            case 6:
-            {
-                // isReadOnly
-                String path = getString( args, 0 );
-                try
-                {
-                    return new Object[] { m_fileSystem.isReadOnly( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    return new Object[] { false };
-                }
-            }
-            case 7:
-            {
-                // makeDir
-                String path = getString( args, 0 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    m_fileSystem.makeDir( path );
-                    return null;
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 8:
-            {
-                // move
-                String path = getString( args, 0 );
-                String dest = getString( args, 1 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    m_fileSystem.move( path, dest );
-                    return null;
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 9:
-            {
-                // copy
-                String path = getString( args, 0 );
-                String dest = getString( args, 1 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    m_fileSystem.copy( path, dest );
-                    return null;
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 10:
-            {
-                // delete
-                String path = getString( args, 0 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    m_fileSystem.delete( path );
-                    return null;
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 11:
-            {
-                // open
-                String path = getString( args, 0 );
-                String mode = getString( args, 1 );
-                m_env.addTrackingChange( TrackingField.FS_OPS );
-                try
-                {
-                    switch( mode )
-                    {
-                        case "r":
-                        {
-                            // Open the file for reading, then create a wrapper around the reader
-                            FileSystemWrapper<BufferedReader> reader = m_fileSystem.openForRead( path, EncodedReadableHandle::openUtf8 );
-                            return new Object[] { new EncodedReadableHandle( reader.get(), reader ) };
-                        }
-                        case "w":
-                        {
-                            // Open the file for writing, then create a wrapper around the writer
-                            FileSystemWrapper<BufferedWriter> writer = m_fileSystem.openForWrite( path, false, EncodedWritableHandle::openUtf8 );
-                            return new Object[] { new EncodedWritableHandle( writer.get(), writer ) };
-                        }
-                        case "a":
-                        {
-                            // Open the file for appending, then create a wrapper around the writer
-                            FileSystemWrapper<BufferedWriter> writer = m_fileSystem.openForWrite( path, true, EncodedWritableHandle::openUtf8 );
-                            return new Object[] { new EncodedWritableHandle( writer.get(), writer ) };
-                        }
-                        case "rb":
-                        {
-                            // Open the file for binary reading, then create a wrapper around the reader
-                            FileSystemWrapper<ReadableByteChannel> reader = m_fileSystem.openForRead( path, Function.identity() );
-                            return new Object[] { new BinaryReadableHandle( reader.get(), reader ) };
-                        }
-                        case "wb":
-                        {
-                            // Open the file for binary writing, then create a wrapper around the writer
-                            FileSystemWrapper<WritableByteChannel> writer = m_fileSystem.openForWrite( path, false, Function.identity() );
-                            return new Object[] { new BinaryWritableHandle( writer.get(), writer ) };
-                        }
-                        case "ab":
-                        {
-                            // Open the file for binary appending, then create a wrapper around the reader
-                            FileSystemWrapper<WritableByteChannel> writer = m_fileSystem.openForWrite( path, true, Function.identity() );
-                            return new Object[] { new BinaryWritableHandle( writer.get(), writer ) };
-                        }
-                        default:
-                            throw new LuaException( "Unsupported mode" );
-                    }
-                }
-                catch( FileSystemException e )
-                {
-                    return new Object[] { null, e.getMessage() };
-                }
-            }
-            case 12:
-            {
-                // getDrive
-                String path = getString( args, 0 );
-                try
-                {
-                    if( !m_fileSystem.exists( path ) )
-                    {
-                        return null;
-                    }
-                    return new Object[] { m_fileSystem.getMountLabel( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 13:
-            {
-                // getFreeSpace
-                String path = getString( args, 0 );
-                try
-                {
-                    long freeSpace = m_fileSystem.getFreeSpace( path );
-                    if( freeSpace >= 0 )
-                    {
-                        return new Object[] { freeSpace };
-                    }
-                    return new Object[] { "unlimited" };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 14: // find
-            {
-                String path = getString( args, 0 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    return new Object[] { m_fileSystem.find( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 15: // getDir
-            {
-                String path = getString( args, 0 );
-                return new Object[] { FileSystem.getDirectory( path ) };
-            }
-            case 16: // getCapacity
-            {
-                String path = getString( args, 0 );
-                try
-                {
-                    OptionalLong capacity = m_fileSystem.getCapacity( path );
-                    return new Object[] { capacity.isPresent() ? capacity.getAsLong() : null };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 17: // attributes
-            {
-                String path = getString( args, 0 );
-                try
-                {
-                    BasicFileAttributes attributes = m_fileSystem.getAttributes( path );
-                    Map<String, Object> result = new HashMap<>();
-                    result.put( "modification", getFileTime( attributes.lastModifiedTime() ) );
-                    result.put( "created", getFileTime( attributes.creationTime() ) );
-                    result.put( "size", attributes.isDirectory() ? 0 : attributes.size() );
-                    result.put( "isDir", attributes.isDirectory() );
-                    return new Object[] { result };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            default:
-                assert false;
-                return null;
+        }
+        catch( FileSystemException e )
+        {
+            return new Object[] { null, e.getMessage() };
+        }
+    }
+
+    @LuaFunction
+    public final Object[] getDrive( String path ) throws LuaException
+    {
+        try
+        {
+            return fileSystem.exists( path ) ? new Object[] { fileSystem.getMountLabel( path ) } : null;
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final Object getFreeSpace( String path ) throws LuaException
+    {
+        try
+        {
+            long freeSpace = fileSystem.getFreeSpace( path );
+            return freeSpace >= 0 ? freeSpace : "unlimited";
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final String[] find( String path ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            return fileSystem.find( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final Object getCapacity( String path ) throws LuaException
+    {
+        try
+        {
+            OptionalLong capacity = fileSystem.getCapacity( path );
+            return capacity.isPresent() ? capacity.getAsLong() : null;
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final Map<String, Object> attributes( String path ) throws LuaException
+    {
+        try
+        {
+            BasicFileAttributes attributes = fileSystem.getAttributes( path );
+            Map<String, Object> result = new HashMap<>();
+            result.put( "modification", getFileTime( attributes.lastModifiedTime() ) );
+            result.put( "created", getFileTime( attributes.creationTime() ) );
+            result.put( "size", attributes.isDirectory() ? 0 : attributes.size() );
+            result.put( "isDir", attributes.isDirectory() );
+            return result;
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
         }
     }
 

src/main/java/dan200/computercraft/core/apis/HTTPAPI.java

@@ -6,9 +6,10 @@
 package dan200.computercraft.core.apis;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.apis.http.*;
 import dan200.computercraft.core.apis.http.request.HttpRequest;
 import dan200.computercraft.core.apis.http.websocket.Websocket;
@@ -21,8 +22,8 @@ import java.net.URI;
 import java.util.Collections;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.*;
 import static dan200.computercraft.core.apis.TableHelper.*;
 
 public class HTTPAPI implements ILuaAPI
@@ -68,135 +69,106 @@ public class HTTPAPI implements ILuaAPI
         Resource.cleanup();
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    @LuaFunction
+    public final Object[] request( IArguments args ) throws LuaException
     {
-        return new String[] {
-            "request",
-            "checkURL",
-            "websocket",
-        };
+        String address, postString, requestMethod;
+        Map<?, ?> headerTable;
+        boolean binary, redirect;
+
+        if( args.get( 0 ) instanceof Map )
+        {
+            Map<?, ?> options = args.getTable( 0 );
+            address = getStringField( options, "url" );
+            postString = optStringField( options, "body", null );
+            headerTable = optTableField( options, "headers", Collections.emptyMap() );
+            binary = optBooleanField( options, "binary", false );
+            requestMethod = optStringField( options, "method", null );
+            redirect = optBooleanField( options, "redirect", true );
+
+        }
+        else
+        {
+            // Get URL and post information
+            address = args.getString( 0 );
+            postString = args.optString( 1, null );
+            headerTable = args.optTable( 2, Collections.emptyMap() );
+            binary = args.optBoolean( 3, false );
+            requestMethod = null;
+            redirect = true;
+        }
+
+        HttpHeaders headers = getHeaders( headerTable );
+
+        HttpMethod httpMethod;
+        if( requestMethod == null )
+        {
+            httpMethod = postString == null ? HttpMethod.GET : HttpMethod.POST;
+        }
+        else
+        {
+            httpMethod = HttpMethod.valueOf( requestMethod.toUpperCase( Locale.ROOT ) );
+            if( httpMethod == null || requestMethod.equalsIgnoreCase( "CONNECT" ) )
+            {
+                throw new LuaException( "Unsupported HTTP method" );
+            }
+        }
+
+        try
+        {
+            URI uri = HttpRequest.checkUri( address );
+            HttpRequest request = new HttpRequest( requests, m_apiEnvironment, address, postString, headers, binary, redirect );
+
+            // Make the request
+            request.queue( r -> r.request( uri, httpMethod ) );
+
+            return new Object[] { true };
+        }
+        catch( HTTPRequestException e )
+        {
+            return new Object[] { false, e.getMessage() };
+        }
     }
 
-    @Override
-    @SuppressWarnings( "resource" )
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    @LuaFunction
+    public final Object[] checkURL( String address )
     {
-        switch( method )
+        try
         {
-            case 0: // request
+            URI uri = HttpRequest.checkUri( address );
+            new CheckUrl( checkUrls, m_apiEnvironment, address, uri ).queue( CheckUrl::run );
+
+            return new Object[] { true };
+        }
+        catch( HTTPRequestException e )
+        {
+            return new Object[] { false, e.getMessage() };
+        }
+    }
+
+    @LuaFunction
+    public final Object[] websocket( String address, Optional<Map<?, ?>> headerTbl ) throws LuaException
+    {
+        if( !ComputerCraft.httpWebsocketEnabled )
+        {
+            throw new LuaException( "Websocket connections are disabled" );
+        }
+
+        HttpHeaders headers = getHeaders( headerTbl.orElse( Collections.emptyMap() ) );
+
+        try
+        {
+            URI uri = Websocket.checkUri( address );
+            if( !new Websocket( websockets, m_apiEnvironment, uri, address, headers ).queue( Websocket::connect ) )
             {
-                String address, postString, requestMethod;
-                Map<?, ?> headerTable;
-                boolean binary, redirect;
-
-                if( args.length >= 1 && args[0] instanceof Map )
-                {
-                    Map<?, ?> options = (Map<?, ?>) args[0];
-                    address = getStringField( options, "url" );
-                    postString = optStringField( options, "body", null );
-                    headerTable = optTableField( options, "headers", Collections.emptyMap() );
-                    binary = optBooleanField( options, "binary", false );
-                    requestMethod = optStringField( options, "method", null );
-                    redirect = optBooleanField( options, "redirect", true );
-
-                }
-                else
-                {
-                    // Get URL and post information
-                    address = getString( args, 0 );
-                    postString = optString( args, 1, null );
-                    headerTable = optTable( args, 2, Collections.emptyMap() );
-                    binary = optBoolean( args, 3, false );
-                    requestMethod = null;
-                    redirect = true;
-                }
-
-                HttpHeaders headers = getHeaders( headerTable );
-
-
-                HttpMethod httpMethod;
-                if( requestMethod == null )
-                {
-                    httpMethod = postString == null ? HttpMethod.GET : HttpMethod.POST;
-                }
-                else
-                {
-                    httpMethod = HttpMethod.valueOf( requestMethod.toUpperCase( Locale.ROOT ) );
-                    if( httpMethod == null || requestMethod.equalsIgnoreCase( "CONNECT" ) )
-                    {
-                        throw new LuaException( "Unsupported HTTP method" );
-                    }
-                }
-
-                try
-                {
-                    URI uri = HttpRequest.checkUri( address );
-                    HttpRequest request = new HttpRequest( requests, m_apiEnvironment, address, postString, headers, binary, redirect );
-
-                    long requestBody = request.body().readableBytes() + HttpRequest.getHeaderSize( headers );
-                    if( ComputerCraft.httpMaxUpload != 0 && requestBody > ComputerCraft.httpMaxUpload )
-                    {
-                        throw new HTTPRequestException( "Request body is too large" );
-                    }
-
-                    // Make the request
-                    request.queue( r -> r.request( uri, httpMethod ) );
-
-                    return new Object[] { true };
-                }
-                catch( HTTPRequestException e )
-                {
-                    return new Object[] { false, e.getMessage() };
-                }
+                throw new LuaException( "Too many websockets already open" );
             }
-            case 1: // checkURL
-            {
-                String address = getString( args, 0 );
 
-                // Check URL
-                try
-                {
-                    URI uri = HttpRequest.checkUri( address );
-                    new CheckUrl( checkUrls, m_apiEnvironment, address, uri ).queue( CheckUrl::run );
-
-                    return new Object[] { true };
-                }
-                catch( HTTPRequestException e )
-                {
-                    return new Object[] { false, e.getMessage() };
-                }
-            }
-            case 2: // websocket
-            {
-                String address = getString( args, 0 );
-                Map<?, ?> headerTbl = optTable( args, 1, Collections.emptyMap() );
-
-                if( !ComputerCraft.http_websocket_enable )
-                {
-                    throw new LuaException( "Websocket connections are disabled" );
-                }
-
-                HttpHeaders headers = getHeaders( headerTbl );
-
-                try
-                {
-                    URI uri = Websocket.checkUri( address );
-                    if( !new Websocket( websockets, m_apiEnvironment, uri, address, headers ).queue( Websocket::connect ) )
-                    {
-                        throw new LuaException( "Too many websockets already open" );
-                    }
-
-                    return new Object[] { true };
-                }
-                catch( HTTPRequestException e )
-                {
-                    return new Object[] { false, e.getMessage() };
-                }
-            }
-            default:
-                return null;
+            return new Object[] { true };
+        }
+        catch( HTTPRequestException e )
+        {
+            return new Object[] { false, e.getMessage() };
         }
     }
 

src/main/java/dan200/computercraft/core/apis/IAPIEnvironment.java

@@ -43,7 +43,7 @@ public interface IAPIEnvironment
 
     void reboot();
 
-    void queueEvent( String event, Object[] args );
+    void queueEvent( String event, Object... args );
 
     void setOutput( ComputerSide side, int output );
 

src/main/java/dan200/computercraft/core/apis/ILuaAPI.java

@@ -1,24 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.core.apis;
-
-/**
- * This exists purely to ensure binary compatibility.
- *
- * @see dan200.computercraft.api.lua.ILuaAPI
- * @deprecated Use the version in the public API. Only exists for compatibility with CCEmuX.
- */
-@Deprecated
-public interface ILuaAPI extends dan200.computercraft.api.lua.ILuaAPI
-{
-    void advance( double v );
-
-    @Override
-    default void update()
-    {
-        advance( 0.05 );
-    }
-}

src/main/java/dan200/computercraft/core/apis/OSAPI.java

@@ -5,9 +5,10 @@
  */
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.shared.util.StringUtil;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
@@ -20,11 +21,11 @@ import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatterBuilder;
 import java.util.*;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.*;
+import static dan200.computercraft.api.lua.LuaValues.checkFinite;
 
 public class OSAPI implements ILuaAPI
 {
-    private IAPIEnvironment m_apiEnvironment;
+    private final IAPIEnvironment apiEnvironment;
 
     private final Int2ObjectMap<Alarm> m_alarms = new Int2ObjectOpenHashMap<>();
     private int m_clock;
@@ -55,11 +56,9 @@ public class OSAPI implements ILuaAPI
 
     public OSAPI( IAPIEnvironment environment )
     {
-        m_apiEnvironment = environment;
+        apiEnvironment = environment;
     }
 
-    // ILuaAPI implementation
-
     @Override
     public String[] getNames()
     {
@@ -69,8 +68,8 @@ public class OSAPI implements ILuaAPI
     @Override
     public void startup()
     {
-        m_time = m_apiEnvironment.getComputerEnvironment().getTimeOfDay();
-        m_day = m_apiEnvironment.getComputerEnvironment().getDay();
+        m_time = apiEnvironment.getComputerEnvironment().getTimeOfDay();
+        m_day = apiEnvironment.getComputerEnvironment().getDay();
         m_clock = 0;
 
         synchronized( m_alarms )
@@ -89,8 +88,8 @@ public class OSAPI implements ILuaAPI
         {
             double previousTime = m_time;
             int previousDay = m_day;
-            double time = m_apiEnvironment.getComputerEnvironment().getTimeOfDay();
-            int day = m_apiEnvironment.getComputerEnvironment().getDay();
+            double time = apiEnvironment.getComputerEnvironment().getTimeOfDay();
+            int day = apiEnvironment.getComputerEnvironment().getDay();
 
             if( time > previousTime || day > previousDay )
             {
@@ -103,7 +102,7 @@ public class OSAPI implements ILuaAPI
                     double t = alarm.m_day * 24.0 + alarm.m_time;
                     if( now >= t )
                     {
-                        queueLuaEvent( "alarm", new Object[] { entry.getKey() } );
+                        apiEnvironment.queueEvent( "alarm", entry.getIntKey() );
                         it.remove();
                     }
                 }
@@ -123,31 +122,6 @@ public class OSAPI implements ILuaAPI
         }
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
-    {
-        return new String[] {
-            "queueEvent",
-            "startTimer",
-            "setAlarm",
-            "shutdown",
-            "reboot",
-            "computerID",
-            "getComputerID",
-            "setComputerLabel",
-            "computerLabel",
-            "getComputerLabel",
-            "clock",
-            "time",
-            "day",
-            "cancelTimer",
-            "cancelAlarm",
-            "epoch",
-            "date",
-        };
-    }
-
     private static float getTimeForCalendar( Calendar c )
     {
         float time = c.get( Calendar.HOUR_OF_DAY );
@@ -174,214 +148,174 @@ public class OSAPI implements ILuaAPI
         return c.getTime().getTime();
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    @LuaFunction
+    public final void queueEvent( String name, IArguments args )
     {
-        switch( method )
+        apiEnvironment.queueEvent( name, args.drop( 1 ).getAll() );
+    }
+
+    @LuaFunction
+    public final int startTimer( double timer ) throws LuaException
+    {
+        return apiEnvironment.startTimer( Math.round( checkFinite( 0, timer ) / 0.05 ) );
+    }
+
+    @LuaFunction
+    public final void cancelTimer( int token )
+    {
+        apiEnvironment.cancelTimer( token );
+    }
+
+    @LuaFunction
+    public final int setAlarm( double time ) throws LuaException
+    {
+        checkFinite( 0, time );
+        if( time < 0.0 || time >= 24.0 ) throw new LuaException( "Number out of range" );
+        synchronized( m_alarms )
         {
-            case 0: // queueEvent
-                queueLuaEvent( getString( args, 0 ), trimArray( args, 1 ) );
-                return null;
-            case 1:
-            {
-                // startTimer
-                double timer = getFiniteDouble( args, 0 );
-                int id = m_apiEnvironment.startTimer( Math.round( timer / 0.05 ) );
-                return new Object[] { id };
-            }
-            case 2:
-            {
-                // setAlarm
-                double time = getFiniteDouble( args, 0 );
-                if( time < 0.0 || time >= 24.0 )
-                {
-                    throw new LuaException( "Number out of range" );
-                }
-                synchronized( m_alarms )
-                {
-                    int day = time > m_time ? m_day : m_day + 1;
-                    m_alarms.put( m_nextAlarmToken, new Alarm( time, day ) );
-                    return new Object[] { m_nextAlarmToken++ };
-                }
-            }
-            case 3: // shutdown
-                m_apiEnvironment.shutdown();
-                return null;
-            case 4: // reboot
-                m_apiEnvironment.reboot();
-                return null;
-            case 5:
-            case 6: // computerID/getComputerID
-                return new Object[] { getComputerID() };
-            case 7:
-            {
-                // setComputerLabel
-                String label = optString( args, 0, null );
-                m_apiEnvironment.setLabel( StringUtil.normaliseLabel( label ) );
-                return null;
-            }
-            case 8:
-            case 9:
-            {
-                // computerLabel/getComputerLabel
-                String label = m_apiEnvironment.getLabel();
-                if( label != null )
-                {
-                    return new Object[] { label };
-                }
-                return null;
-            }
-            case 10: // clock
-                return new Object[] { m_clock * 0.05 };
-            case 11:
-            {
-                // time
-                Object value = args.length > 0 ? args[0] : null;
-                if( value instanceof Map ) return new Object[] { LuaDateTime.fromTable( (Map<?, ?>) value ) };
-
-                String param = optString( args, 0, "ingame" );
-                switch( param.toLowerCase( Locale.ROOT ) )
-                {
-                    case "utc":
-                    {
-                        // Get Hour of day (UTC)
-                        Calendar c = Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) );
-                        return new Object[] { getTimeForCalendar( c ) };
-                    }
-                    case "local":
-                    {
-                        // Get Hour of day (local time)
-                        Calendar c = Calendar.getInstance();
-                        return new Object[] { getTimeForCalendar( c ) };
-                    }
-                    case "ingame":
-                        // Get ingame hour
-                        synchronized( m_alarms )
-                        {
-                            return new Object[] { m_time };
-                        }
-                    default:
-                        throw new LuaException( "Unsupported operation" );
-                }
-            }
-            case 12:
-            {
-                // day
-                String param = optString( args, 0, "ingame" );
-                switch( param.toLowerCase( Locale.ROOT ) )
-                {
-                    case "utc":
-                    {
-                        // Get numbers of days since 1970-01-01 (utc)
-                        Calendar c = Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) );
-                        return new Object[] { getDayForCalendar( c ) };
-                    }
-                    case "local":
-                    {
-                        // Get numbers of days since 1970-01-01 (local time)
-                        Calendar c = Calendar.getInstance();
-                        return new Object[] { getDayForCalendar( c ) };
-                    }
-                    case "ingame":
-                        // Get game day
-                        synchronized( m_alarms )
-                        {
-                            return new Object[] { m_day };
-                        }
-                    default:
-                        throw new LuaException( "Unsupported operation" );
-                }
-            }
-            case 13:
-            {
-                // cancelTimer
-                int token = getInt( args, 0 );
-                m_apiEnvironment.cancelTimer( token );
-                return null;
-            }
-            case 14:
-            {
-                // cancelAlarm
-                int token = getInt( args, 0 );
-                synchronized( m_alarms )
-                {
-                    m_alarms.remove( token );
-                }
-                return null;
-            }
-            case 15: // epoch
-            {
-                String param = optString( args, 0, "ingame" );
-                switch( param.toLowerCase( Locale.ROOT ) )
-                {
-                    case "utc":
-                    {
-                        // Get utc epoch
-                        Calendar c = Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) );
-                        return new Object[] { getEpochForCalendar( c ) };
-                    }
-                    case "local":
-                    {
-                        // Get local epoch
-                        Calendar c = Calendar.getInstance();
-                        return new Object[] { getEpochForCalendar( c ) };
-                    }
-                    case "ingame":
-                        // Get in-game epoch
-                        synchronized( m_alarms )
-                        {
-                            return new Object[] { m_day * 86400000 + (int) (m_time * 3600000.0f) };
-                        }
-                    default:
-                        throw new LuaException( "Unsupported operation" );
-                }
-            }
-            case 16: // date
-            {
-                String format = optString( args, 0, "%c" );
-                long time = optLong( args, 1, Instant.now().getEpochSecond() );
-
-                Instant instant = Instant.ofEpochSecond( time );
-                ZonedDateTime date;
-                ZoneOffset offset;
-                if( format.startsWith( "!" ) )
-                {
-                    offset = ZoneOffset.UTC;
-                    date = ZonedDateTime.ofInstant( instant, offset );
-                    format = format.substring( 1 );
-                }
-                else
-                {
-                    ZoneId id = ZoneId.systemDefault();
-                    offset = id.getRules().getOffset( instant );
-                    date = ZonedDateTime.ofInstant( instant, id );
-                }
-
-                if( format.equals( "*t" ) ) return new Object[] { LuaDateTime.toTable( date, offset, instant ) };
-
-                DateTimeFormatterBuilder formatter = new DateTimeFormatterBuilder();
-                LuaDateTime.format( formatter, format, offset );
-                return new Object[] { formatter.toFormatter( Locale.ROOT ).format( date ) };
-            }
-            default:
-                return null;
+            int day = time > m_time ? m_day : m_day + 1;
+            m_alarms.put( m_nextAlarmToken, new Alarm( time, day ) );
+            return m_nextAlarmToken++;
         }
     }
 
-    // Private methods
-
-    private void queueLuaEvent( String event, Object[] args )
+    @LuaFunction
+    public final void cancelAlarm( int token )
     {
-        m_apiEnvironment.queueEvent( event, args );
+        synchronized( m_alarms )
+        {
+            m_alarms.remove( token );
+        }
     }
 
-    private Object[] trimArray( Object[] array, int skip )
+    @LuaFunction( "shutdown" )
+    public final void doShutdown()
     {
-        return Arrays.copyOfRange( array, skip, array.length );
+        apiEnvironment.shutdown();
     }
 
-    private int getComputerID()
+    @LuaFunction( "reboot" )
+    public final void doReboot()
     {
-        return m_apiEnvironment.getComputerID();
+        apiEnvironment.reboot();
     }
+
+    @LuaFunction( { "getComputerID", "computerID" } )
+    public final int getComputerID()
+    {
+        return apiEnvironment.getComputerID();
+    }
+
+    @LuaFunction( { "getComputerLabel", "computerLabel" } )
+    public final Object[] getComputerLabel()
+    {
+        String label = apiEnvironment.getLabel();
+        return label == null ? null : new Object[] { label };
+    }
+
+    @LuaFunction
+    public final void setComputerLabel( Optional<String> label )
+    {
+        apiEnvironment.setLabel( StringUtil.normaliseLabel( label.orElse( null ) ) );
+    }
+
+    @LuaFunction
+    public final double clock()
+    {
+        return m_clock * 0.05;
+    }
+
+    @LuaFunction
+    public final Object time( IArguments args ) throws LuaException
+    {
+        Object value = args.get( 0 );
+        if( value instanceof Map ) return LuaDateTime.fromTable( (Map<?, ?>) value );
+
+        String param = args.optString( 0, "ingame" );
+        switch( param.toLowerCase( Locale.ROOT ) )
+        {
+            case "utc": // Get Hour of day (UTC)
+                return getTimeForCalendar( Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) ) );
+            case "local": // Get Hour of day (local time)
+                return getTimeForCalendar( Calendar.getInstance() );
+            case "ingame": // Get in-game hour
+                return m_time;
+            default:
+                throw new LuaException( "Unsupported operation" );
+        }
+    }
+
+    @LuaFunction
+    public final int day( Optional<String> args ) throws LuaException
+    {
+        switch( args.orElse( "ingame" ).toLowerCase( Locale.ROOT ) )
+        {
+            case "utc":     // Get numbers of days since 1970-01-01 (utc)
+                return getDayForCalendar( Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) ) );
+            case "local": // Get numbers of days since 1970-01-01 (local time)
+                return getDayForCalendar( Calendar.getInstance() );
+            case "ingame":// Get game day
+                return m_day;
+            default:
+                throw new LuaException( "Unsupported operation" );
+        }
+    }
+
+    @LuaFunction
+    public final long epoch( Optional<String> args ) throws LuaException
+    {
+        switch( args.orElse( "ingame" ).toLowerCase( Locale.ROOT ) )
+        {
+            case "utc":
+            {
+                // Get utc epoch
+                Calendar c = Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) );
+                return getEpochForCalendar( c );
+            }
+            case "local":
+            {
+                // Get local epoch
+                Calendar c = Calendar.getInstance();
+                return getEpochForCalendar( c );
+            }
+            case "ingame":
+                // Get in-game epoch
+                synchronized( m_alarms )
+                {
+                    return m_day * 86400000 + (int) (m_time * 3600000.0f);
+                }
+            default:
+                throw new LuaException( "Unsupported operation" );
+        }
+    }
+
+    @LuaFunction
+    public final Object date( Optional<String> formatA, Optional<Long> timeA ) throws LuaException
+    {
+        String format = formatA.orElse( "%c" );
+        long time = timeA.orElseGet( () -> Instant.now().getEpochSecond() );
+
+        Instant instant = Instant.ofEpochSecond( time );
+        ZonedDateTime date;
+        ZoneOffset offset;
+        if( format.startsWith( "!" ) )
+        {
+            offset = ZoneOffset.UTC;
+            date = ZonedDateTime.ofInstant( instant, offset );
+            format = format.substring( 1 );
+        }
+        else
+        {
+            ZoneId id = ZoneId.systemDefault();
+            offset = id.getRules().getOffset( instant );
+            date = ZonedDateTime.ofInstant( instant, id );
+        }
+
+        if( format.equals( "*t" ) ) return LuaDateTime.toTable( date, offset, instant );
+
+        DateTimeFormatterBuilder formatter = new DateTimeFormatterBuilder();
+        LuaDateTime.format( formatter, format, offset );
+        return formatter.toFormatter( Locale.ROOT ).format( date );
+    }
+
 }

src/main/java/dan200/computercraft/core/apis/PeripheralAPI.java

@@ -7,86 +7,74 @@ package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
-import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.*;
+import dan200.computercraft.api.peripheral.IDynamicPeripheral;
 import dan200.computercraft.api.peripheral.IPeripheral;
+import dan200.computercraft.api.peripheral.IWorkMonitor;
+import dan200.computercraft.api.peripheral.NotAttachedException;
+import dan200.computercraft.core.asm.LuaMethod;
+import dan200.computercraft.core.asm.NamedMethod;
+import dan200.computercraft.core.asm.PeripheralMethod;
 import dan200.computercraft.core.computer.ComputerSide;
 import dan200.computercraft.core.tracking.TrackingField;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-
-import static dan200.computercraft.api.lua.ArgumentHelper.getString;
+import java.util.*;
 
 public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChangeListener
 {
     private class PeripheralWrapper extends ComputerAccess
     {
-        private final String m_side;
-        private final IPeripheral m_peripheral;
+        private final String side;
+        private final IPeripheral peripheral;
 
-        private String m_type;
-        private String[] m_methods;
-        private Map<String, Integer> m_methodMap;
-        private boolean m_attached;
+        private final String type;
+        private final Map<String, PeripheralMethod> methodMap;
+        private boolean attached;
 
         PeripheralWrapper( IPeripheral peripheral, String side )
         {
-            super( m_environment );
-            m_side = side;
-            m_peripheral = peripheral;
-            m_attached = false;
+            super( environment );
+            this.side = side;
+            this.peripheral = peripheral;
+            attached = false;
 
-            m_type = peripheral.getType();
-            m_methods = peripheral.getMethodNames();
-            assert m_type != null;
-            assert m_methods != null;
+            type = Objects.requireNonNull( peripheral.getType(), "Peripheral type cannot be null" );
 
-            m_methodMap = new HashMap<>();
-            for( int i = 0; i < m_methods.length; i++ )
-            {
-                if( m_methods[i] != null )
-                {
-                    m_methodMap.put( m_methods[i], i );
-                }
-            }
+            methodMap = PeripheralAPI.getMethods( peripheral );
         }
 
         public IPeripheral getPeripheral()
         {
-            return m_peripheral;
+            return peripheral;
         }
 
         public String getType()
         {
-            return m_type;
+            return type;
         }
 
-        public String[] getMethods()
+        public Collection<String> getMethods()
         {
-            return m_methods;
+            return methodMap.keySet();
         }
 
         public synchronized boolean isAttached()
         {
-            return m_attached;
+            return attached;
         }
 
         public synchronized void attach()
         {
-            m_attached = true;
-            m_peripheral.attach( this );
+            attached = true;
+            peripheral.attach( this );
         }
 
         public void detach()
         {
             // Call detach
-            m_peripheral.detach( this );
+            peripheral.detach( this );
 
             synchronized( this )
             {
@@ -94,81 +82,56 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
                 unmountAll();
             }
 
-            m_attached = false;
+            attached = false;
         }
 
-        public Object[] call( ILuaContext context, String methodName, Object[] arguments ) throws LuaException, InterruptedException
+        public MethodResult call( ILuaContext context, String methodName, IArguments arguments ) throws LuaException
         {
-            int method = -1;
+            PeripheralMethod method;
             synchronized( this )
             {
-                if( m_methodMap.containsKey( methodName ) )
-                {
-                    method = m_methodMap.get( methodName );
-                }
-            }
-            if( method >= 0 )
-            {
-                m_environment.addTrackingChange( TrackingField.PERIPHERAL_OPS );
-                return m_peripheral.callMethod( this, context, method, arguments );
-            }
-            else
-            {
-                throw new LuaException( "No such method " + methodName );
+                method = methodMap.get( methodName );
             }
+
+            if( method == null ) throw new LuaException( "No such method " + methodName );
+
+            environment.addTrackingChange( TrackingField.PERIPHERAL_OPS );
+            return method.apply( peripheral, context, this, arguments );
         }
 
         // IComputerAccess implementation
         @Override
         public synchronized String mount( @Nonnull String desiredLoc, @Nonnull IMount mount, @Nonnull String driveName )
         {
-            if( !m_attached )
-            {
-                throw new RuntimeException( "You are not attached to this Computer" );
-            }
-
+            if( !attached ) throw new NotAttachedException();
             return super.mount( desiredLoc, mount, driveName );
         }
 
         @Override
         public synchronized String mountWritable( @Nonnull String desiredLoc, @Nonnull IWritableMount mount, @Nonnull String driveName )
         {
-            if( !m_attached )
-            {
-                throw new RuntimeException( "You are not attached to this Computer" );
-            }
-
+            if( !attached ) throw new NotAttachedException();
             return super.mountWritable( desiredLoc, mount, driveName );
         }
 
         @Override
         public synchronized void unmount( String location )
         {
-            if( !m_attached )
-            {
-                throw new RuntimeException( "You are not attached to this Computer" );
-            }
-
+            if( !attached ) throw new NotAttachedException();
             super.unmount( location );
         }
 
         @Override
         public int getID()
         {
-            if( !m_attached )
-            {
-                throw new RuntimeException( "You are not attached to this Computer" );
-            }
+            if( !attached ) throw new NotAttachedException();
             return super.getID();
         }
 
         @Override
-        public void queueEvent( @Nonnull final String event, final Object[] arguments )
+        public void queueEvent( @Nonnull String event, Object... arguments )
         {
-            if( !m_attached )
-            {
-                throw new RuntimeException( "You are not attached to this Computer" );
-            }
+            if( !attached ) throw new NotAttachedException();
             super.queueEvent( event, arguments );
         }
 
@@ -176,24 +139,18 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public String getAttachmentName()
         {
-            if( !m_attached )
-            {
-                throw new RuntimeException( "You are not attached to this Computer" );
-            }
-            return m_side;
+            if( !attached ) throw new NotAttachedException();
+            return side;
         }
 
         @Nonnull
         @Override
         public Map<String, IPeripheral> getAvailablePeripherals()
         {
-            if( !m_attached )
-            {
-                throw new RuntimeException( "You are not attached to this Computer" );
-            }
+            if( !attached ) throw new NotAttachedException();
 
             Map<String, IPeripheral> peripherals = new HashMap<>();
-            for( PeripheralWrapper wrapper : m_peripherals )
+            for( PeripheralWrapper wrapper : PeripheralAPI.this.peripherals )
             {
                 if( wrapper != null && wrapper.isAttached() )
                 {
@@ -208,12 +165,9 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public IPeripheral getAvailablePeripheral( @Nonnull String name )
         {
-            if( !m_attached )
-            {
-                throw new RuntimeException( "You are not attached to this Computer" );
-            }
+            if( !attached ) throw new NotAttachedException();
 
-            for( PeripheralWrapper wrapper : m_peripherals )
+            for( PeripheralWrapper wrapper : peripherals )
             {
                 if( wrapper != null && wrapper.isAttached() && wrapper.getAttachmentName().equals( name ) )
                 {
@@ -222,24 +176,25 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             }
             return null;
         }
+
+        @Nonnull
+        @Override
+        public IWorkMonitor getMainThreadMonitor()
+        {
+            if( !attached ) throw new NotAttachedException();
+            return super.getMainThreadMonitor();
+        }
     }
 
-    private final IAPIEnvironment m_environment;
-    private final PeripheralWrapper[] m_peripherals;
-    private boolean m_running;
+    private final IAPIEnvironment environment;
+    private final PeripheralWrapper[] peripherals = new PeripheralWrapper[6];
+    private boolean running;
 
     public PeripheralAPI( IAPIEnvironment environment )
     {
-        m_environment = environment;
-        m_environment.setPeripheralChangeListener( this );
-
-        m_peripherals = new PeripheralWrapper[6];
-        for( int i = 0; i < 6; i++ )
-        {
-            m_peripherals[i] = null;
-        }
-
-        m_running = false;
+        this.environment = environment;
+        this.environment.setPeripheralChangeListener( this );
+        running = false;
     }
 
     // IPeripheralChangeListener
@@ -247,37 +202,35 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     @Override
     public void onPeripheralChanged( ComputerSide side, IPeripheral newPeripheral )
     {
-        synchronized( m_peripherals )
+        synchronized( peripherals )
         {
             int index = side.ordinal();
-            if( m_peripherals[index] != null )
+            if( peripherals[index] != null )
             {
                 // Queue a detachment
-                final PeripheralWrapper wrapper = m_peripherals[index];
+                final PeripheralWrapper wrapper = peripherals[index];
                 if( wrapper.isAttached() ) wrapper.detach();
 
                 // Queue a detachment event
-                m_environment.queueEvent( "peripheral_detach", new Object[] { side.getName() } );
+                environment.queueEvent( "peripheral_detach", side.getName() );
             }
 
             // Assign the new peripheral
-            m_peripherals[index] = newPeripheral == null ? null
+            peripherals[index] = newPeripheral == null ? null
                 : new PeripheralWrapper( newPeripheral, side.getName() );
 
-            if( m_peripherals[index] != null )
+            if( peripherals[index] != null )
             {
                 // Queue an attachment
-                final PeripheralWrapper wrapper = m_peripherals[index];
-                if( m_running && !wrapper.isAttached() ) wrapper.attach();
+                final PeripheralWrapper wrapper = peripherals[index];
+                if( running && !wrapper.isAttached() ) wrapper.attach();
 
                 // Queue an attachment event
-                m_environment.queueEvent( "peripheral", new Object[] { side.getName() } );
+                environment.queueEvent( "peripheral", side.getName() );
             }
         }
     }
 
-    // ILuaAPI implementation
-
     @Override
     public String[] getNames()
     {
@@ -287,12 +240,12 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     @Override
     public void startup()
     {
-        synchronized( m_peripherals )
+        synchronized( peripherals )
         {
-            m_running = true;
+            running = true;
             for( int i = 0; i < 6; i++ )
             {
-                PeripheralWrapper wrapper = m_peripherals[i];
+                PeripheralWrapper wrapper = peripherals[i];
                 if( wrapper != null && !wrapper.isAttached() ) wrapper.attach();
             }
         }
@@ -301,12 +254,12 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     @Override
     public void shutdown()
     {
-        synchronized( m_peripherals )
+        synchronized( peripherals )
         {
-            m_running = false;
+            running = false;
             for( int i = 0; i < 6; i++ )
             {
-                PeripheralWrapper wrapper = m_peripherals[i];
+                PeripheralWrapper wrapper = peripherals[i];
                 if( wrapper != null && wrapper.isAttached() )
                 {
                     wrapper.detach();
@@ -315,98 +268,95 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         }
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    @LuaFunction
+    public final boolean isPresent( String sideName )
     {
-        return new String[] {
-            "isPresent",
-            "getType",
-            "getMethods",
-            "call",
-        };
+        ComputerSide side = ComputerSide.valueOfInsensitive( sideName );
+        if( side != null )
+        {
+            synchronized( peripherals )
+            {
+                PeripheralWrapper p = peripherals[side.ordinal()];
+                if( p != null ) return true;
+            }
+        }
+        return false;
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException, InterruptedException
+    @LuaFunction
+    public final Object[] getType( String sideName )
     {
-        switch( method )
+        ComputerSide side = ComputerSide.valueOfInsensitive( sideName );
+        if( side == null ) return null;
+
+        synchronized( peripherals )
         {
-            case 0:
-            {
-                // isPresent
-                boolean present = false;
-                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-                if( side != null )
-                {
-                    synchronized( m_peripherals )
-                    {
-                        PeripheralWrapper p = m_peripherals[side.ordinal()];
-                        if( p != null ) present = true;
-                    }
-                }
-                return new Object[] { present };
-            }
-            case 1:
-            {
-                // getType
-                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-                if( side != null )
-                {
-                    synchronized( m_peripherals )
-                    {
-                        PeripheralWrapper p = m_peripherals[side.ordinal()];
-                        if( p != null ) return new Object[] { p.getType() };
-                    }
-                }
-                return null;
-            }
-            case 2:
-            {
-                // getMethods
-                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-                if( side != null )
-                {
-                    synchronized( m_peripherals )
-                    {
-                        PeripheralWrapper p = m_peripherals[side.ordinal()];
-                        if( p != null ) return new Object[] { p.getMethods() };
-                    }
-                }
+            PeripheralWrapper p = peripherals[side.ordinal()];
+            if( p != null ) return new Object[] { p.getType() };
+        }
+        return null;
+    }
 
-                return null;
-            }
-            case 3:
-            {
-                // call
-                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-                String methodName = getString( args, 1 );
-                Object[] methodArgs = Arrays.copyOfRange( args, 2, args.length );
+    @LuaFunction
+    public final Object[] getMethods( String sideName )
+    {
+        ComputerSide side = ComputerSide.valueOfInsensitive( sideName );
+        if( side == null ) return null;
 
-                if( side == null ) throw new LuaException( "No peripheral attached" );
+        synchronized( peripherals )
+        {
+            PeripheralWrapper p = peripherals[side.ordinal()];
+            if( p != null ) return new Object[] { p.getMethods() };
+        }
+        return null;
+    }
 
-                PeripheralWrapper p;
-                synchronized( m_peripherals )
-                {
-                    p = m_peripherals[side.ordinal()];
-                }
-                if( p == null ) throw new LuaException( "No peripheral attached" );
+    @LuaFunction
+    public final MethodResult call( ILuaContext context, IArguments args ) throws LuaException
+    {
+        ComputerSide side = ComputerSide.valueOfInsensitive( args.getString( 0 ) );
+        String methodName = args.getString( 1 );
+        IArguments methodArgs = args.drop( 2 );
 
-                try
-                {
-                    return p.call( context, methodName, methodArgs );
-                }
-                catch( LuaException e )
-                {
-                    // We increase the error level by one in order to shift the error level to where peripheral.call was
-                    // invoked. It would be possible to do it in Lua code, but would add significantly more overhead.
-                    if( e.getLevel() > 0 ) throw new FastLuaException( e.getMessage(), e.getLevel() + 1 );
-                    throw e;
-                }
-            }
-            default:
-                return null;
+        if( side == null ) throw new LuaException( "No peripheral attached" );
+
+        PeripheralWrapper p;
+        synchronized( peripherals )
+        {
+            p = peripherals[side.ordinal()];
+        }
+        if( p == null ) throw new LuaException( "No peripheral attached" );
+
+        try
+        {
+            return p.call( context, methodName, methodArgs ).adjustError( 1 );
+        }
+        catch( LuaException e )
+        {
+            // We increase the error level by one in order to shift the error level to where peripheral.call was
+            // invoked. It would be possible to do it in Lua code, but would add significantly more overhead.
+            if( e.getLevel() > 0 ) throw new FastLuaException( e.getMessage(), e.getLevel() + 1 );
+            throw e;
         }
     }
 
+    public static Map<String, PeripheralMethod> getMethods( IPeripheral peripheral )
+    {
+        String[] dynamicMethods = peripheral instanceof IDynamicPeripheral
+            ? Objects.requireNonNull( ((IDynamicPeripheral) peripheral).getMethodNames(), "Peripheral methods cannot be null" )
+            : LuaMethod.EMPTY_METHODS;
+
+        List<NamedMethod<PeripheralMethod>> methods = PeripheralMethod.GENERATOR.getMethods( peripheral.getClass() );
+
+        Map<String, PeripheralMethod> methodMap = new HashMap<>( methods.size() + dynamicMethods.length );
+        for( int i = 0; i < dynamicMethods.length; i++ )
+        {
+            methodMap.put( dynamicMethods[i], PeripheralMethod.DYNAMIC.get( i ) );
+        }
+        for( NamedMethod<PeripheralMethod> method : methods )
+        {
+            methodMap.put( method.getName(), method.getMethod() );
+        }
+        return methodMap;
+    }
 }

src/main/java/dan200/computercraft/core/apis/RedstoneAPI.java

@@ -6,21 +6,17 @@
 package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.computer.ComputerSide;
 
-import javax.annotation.Nonnull;
-
-import static dan200.computercraft.api.lua.ArgumentHelper.*;
-
 public class RedstoneAPI implements ILuaAPI
 {
-    private IAPIEnvironment m_environment;
+    private final IAPIEnvironment environment;
 
     public RedstoneAPI( IAPIEnvironment environment )
     {
-        m_environment = environment;
+        this.environment = environment;
     }
 
     @Override
@@ -29,95 +25,71 @@ public class RedstoneAPI implements ILuaAPI
         return new String[] { "rs", "redstone" };
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    @LuaFunction
+    public final String[] getSides()
     {
-        return new String[] {
-            "getSides",
-            "setOutput",
-            "getOutput",
-            "getInput",
-            "setBundledOutput",
-            "getBundledOutput",
-            "getBundledInput",
-            "testBundledInput",
-            "setAnalogOutput",
-            "setAnalogueOutput",
-            "getAnalogOutput",
-            "getAnalogueOutput",
-            "getAnalogInput",
-            "getAnalogueInput",
-        };
+        return ComputerSide.NAMES;
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    @LuaFunction
+    public final void setOutput( ComputerSide side, boolean output )
     {
-        switch( method )
-        {
-            case 0: // getSides
-                return new Object[] { ComputerSide.NAMES };
-            case 1:
-            {
-                // setOutput
-                ComputerSide side = parseSide( args );
-                boolean output = getBoolean( args, 1 );
-                m_environment.setOutput( side, output ? 15 : 0 );
-                return null;
-            }
-            case 2: // getOutput
-                return new Object[] { m_environment.getOutput( parseSide( args ) ) > 0 };
-            case 3: // getInput
-                return new Object[] { m_environment.getInput( parseSide( args ) ) > 0 };
-            case 4:
-            {
-                // setBundledOutput
-                ComputerSide side = parseSide( args );
-                int output = getInt( args, 1 );
-                m_environment.setBundledOutput( side, output );
-                return null;
-            }
-            case 5: // getBundledOutput
-                return new Object[] { m_environment.getBundledOutput( parseSide( args ) ) };
-            case 6: // getBundledInput
-                return new Object[] { m_environment.getBundledInput( parseSide( args ) ) };
-            case 7:
-            {
-                // testBundledInput
-                ComputerSide side = parseSide( args );
-                int mask = getInt( args, 1 );
-                int input = m_environment.getBundledInput( side );
-                return new Object[] { (input & mask) == mask };
-            }
-            case 8:
-            case 9:
-            {
-                // setAnalogOutput/setAnalogueOutput
-                ComputerSide side = parseSide( args );
-                int output = getInt( args, 1 );
-                if( output < 0 || output > 15 )
-                {
-                    throw new LuaException( "Expected number in range 0-15" );
-                }
-                m_environment.setOutput( side, output );
-                return null;
-            }
-            case 10:
-            case 11: // getAnalogOutput/getAnalogueOutput
-                return new Object[] { m_environment.getOutput( parseSide( args ) ) };
-            case 12:
-            case 13: // getAnalogInput/getAnalogueInput
-                return new Object[] { m_environment.getInput( parseSide( args ) ) };
-            default:
-                return null;
-        }
+        environment.setOutput( side, output ? 15 : 0 );
     }
 
-    private static ComputerSide parseSide( Object[] args ) throws LuaException
+    @LuaFunction
+    public final boolean getOutput( ComputerSide side )
     {
-        ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-        if( side == null ) throw new LuaException( "Invalid side." );
-        return side;
+        return environment.getOutput( side ) > 0;
+    }
+
+    @LuaFunction
+    public final boolean getInput( ComputerSide side )
+    {
+        return environment.getInput( side ) > 0;
+    }
+
+    @LuaFunction( { "setAnalogOutput", "setAnalogueOutput" } )
+    public final void setAnalogOutput( ComputerSide side, int output ) throws LuaException
+    {
+        if( output < 0 || output > 15 ) throw new LuaException( "Expected number in range 0-15" );
+        environment.setOutput( side, output );
+    }
+
+    @LuaFunction( { "getAnalogOutput", "getAnalogueOutput" } )
+    public final int getAnalogOutput( ComputerSide side )
+    {
+        return environment.getOutput( side );
+    }
+
+    @LuaFunction( { "getAnalogInput", "getAnalogueInput" } )
+    public final int getAnalogInput( ComputerSide side )
+    {
+        return environment.getInput( side );
+    }
+
+    @LuaFunction
+    public final void setBundledOutput( ComputerSide side, int output )
+    {
+        environment.setBundledOutput( side, output );
+    }
+
+    @LuaFunction
+    public final int getBundledOutput( ComputerSide side )
+    {
+        return environment.getBundledOutput( side );
+    }
+
+    @LuaFunction
+    public final int getBundledInput( ComputerSide side )
+    {
+        return environment.getBundledOutput( side );
+    }
+
+    @LuaFunction
+    public final boolean testBundledInput( ComputerSide side, int mask )
+    {
+        int input = environment.getBundledInput( side );
+        return (input & mask) == mask;
     }
 }

src/main/java/dan200/computercraft/core/apis/TableHelper.java

@@ -5,14 +5,14 @@
  */
 package dan200.computercraft.core.apis;
 
-import dan200.computercraft.api.lua.ArgumentHelper;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaValues;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import java.util.Map;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.getNumericType;
+import static dan200.computercraft.api.lua.LuaValues.getNumericType;
 
 /**
  * Various helpers for tables.
@@ -27,7 +27,7 @@ public final class TableHelper
     @Nonnull
     public static LuaException badKey( @Nonnull String key, @Nonnull String expected, @Nullable Object actual )
     {
-        return badKey( key, expected, ArgumentHelper.getType( actual ) );
+        return badKey( key, expected, LuaValues.getType( actual ) );
     }
 
     @Nonnull

src/main/java/dan200/computercraft/core/apis/TermAPI.java

@@ -6,27 +6,23 @@
 package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.computer.IComputerEnvironment;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.util.Colour;
-import dan200.computercraft.shared.util.Palette;
-import org.apache.commons.lang3.ArrayUtils;
 
 import javax.annotation.Nonnull;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.*;
-
-public class TermAPI implements ILuaAPI
+public class TermAPI extends TermMethods implements ILuaAPI
 {
-    private final Terminal m_terminal;
-    private final IComputerEnvironment m_environment;
+    private final Terminal terminal;
+    private final IComputerEnvironment environment;
 
     public TermAPI( IAPIEnvironment environment )
     {
-        m_terminal = environment.getTerminal();
-        m_environment = environment.getComputerEnvironment();
+        terminal = environment.getTerminal();
+        this.environment = environment.getComputerEnvironment();
     }
 
     @Override
@@ -35,262 +31,29 @@ public class TermAPI implements ILuaAPI
         return new String[] { "term" };
     }
 
+    @LuaFunction( { "nativePaletteColour", "nativePaletteColor" } )
+    public final Object[] nativePaletteColour( int colourArg ) throws LuaException
+    {
+        int colour = 15 - parseColour( colourArg );
+        Colour c = Colour.fromInt( colour );
+
+        float[] rgb = c.getRGB();
+
+        Object[] rgbObj = new Object[rgb.length];
+        for( int i = 0; i < rgbObj.length; ++i ) rgbObj[i] = rgb[i];
+        return rgbObj;
+    }
+
     @Nonnull
     @Override
-    public String[] getMethodNames()
+    public Terminal getTerminal()
     {
-        return new String[] {
-            "write",
-            "scroll",
-            "setCursorPos",
-            "setCursorBlink",
-            "getCursorPos",
-            "getSize",
-            "clear",
-            "clearLine",
-            "setTextColour",
-            "setTextColor",
-            "setBackgroundColour",
-            "setBackgroundColor",
-            "isColour",
-            "isColor",
-            "getTextColour",
-            "getTextColor",
-            "getBackgroundColour",
-            "getBackgroundColor",
-            "blit",
-            "setPaletteColour",
-            "setPaletteColor",
-            "getPaletteColour",
-            "getPaletteColor",
-            "nativePaletteColour",
-            "nativePaletteColor",
-            "getCursorBlink",
-        };
-    }
-
-    public static int parseColour( Object[] args ) throws LuaException
-    {
-        int colour = getInt( args, 0 );
-        if( colour <= 0 )
-        {
-            throw new LuaException( "Colour out of range" );
-        }
-        colour = getHighestBit( colour ) - 1;
-        if( colour < 0 || colour > 15 )
-        {
-            throw new LuaException( "Colour out of range" );
-        }
-        return colour;
-    }
-
-    public static Object[] encodeColour( int colour ) throws LuaException
-    {
-        return new Object[] { 1 << colour };
-    }
-
-    public static void setColour( Terminal terminal, int colour, double r, double g, double b )
-    {
-        if( terminal.getPalette() != null )
-        {
-            terminal.getPalette().setColour( colour, r, g, b );
-            terminal.setChanged();
-        }
+        return terminal;
     }
 
     @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    public boolean isColour()
     {
-        switch( method )
-        {
-            case 0:
-            {
-                // write
-                String text = args.length > 0 && args[0] != null ? args[0].toString() : "";
-                synchronized( m_terminal )
-                {
-                    m_terminal.write( text );
-                    m_terminal.setCursorPos( m_terminal.getCursorX() + text.length(), m_terminal.getCursorY() );
-                }
-                return null;
-            }
-            case 1:
-            {
-                // scroll
-                int y = getInt( args, 0 );
-                synchronized( m_terminal )
-                {
-                    m_terminal.scroll( y );
-                }
-                return null;
-            }
-            case 2:
-            {
-                // setCursorPos
-                int x = getInt( args, 0 ) - 1;
-                int y = getInt( args, 1 ) - 1;
-                synchronized( m_terminal )
-                {
-                    m_terminal.setCursorPos( x, y );
-                }
-                return null;
-            }
-            case 3:
-            {
-                // setCursorBlink
-                boolean b = getBoolean( args, 0 );
-                synchronized( m_terminal )
-                {
-                    m_terminal.setCursorBlink( b );
-                }
-                return null;
-            }
-            case 4:
-            {
-                // getCursorPos
-                int x, y;
-                synchronized( m_terminal )
-                {
-                    x = m_terminal.getCursorX();
-                    y = m_terminal.getCursorY();
-                }
-                return new Object[] { x + 1, y + 1 };
-            }
-            case 5:
-            {
-                // getSize
-                int width, height;
-                synchronized( m_terminal )
-                {
-                    width = m_terminal.getWidth();
-                    height = m_terminal.getHeight();
-                }
-                return new Object[] { width, height };
-            }
-            case 6: // clear
-                synchronized( m_terminal )
-                {
-                    m_terminal.clear();
-                }
-                return null;
-            case 7: // clearLine
-                synchronized( m_terminal )
-                {
-                    m_terminal.clearLine();
-                }
-                return null;
-            case 8:
-            case 9:
-            {
-                // setTextColour/setTextColor
-                int colour = parseColour( args );
-                synchronized( m_terminal )
-                {
-                    m_terminal.setTextColour( colour );
-                }
-                return null;
-            }
-            case 10:
-            case 11:
-            {
-                // setBackgroundColour/setBackgroundColor
-                int colour = parseColour( args );
-                synchronized( m_terminal )
-                {
-                    m_terminal.setBackgroundColour( colour );
-                }
-                return null;
-            }
-            case 12:
-            case 13: // isColour/isColor
-                return new Object[] { m_environment.isColour() };
-            case 14:
-            case 15: // getTextColour/getTextColor
-                return encodeColour( m_terminal.getTextColour() );
-            case 16:
-            case 17: // getBackgroundColour/getBackgroundColor
-                return encodeColour( m_terminal.getBackgroundColour() );
-            case 18:
-            {
-                // blit
-                String text = getString( args, 0 );
-                String textColour = getString( args, 1 );
-                String backgroundColour = getString( args, 2 );
-                if( textColour.length() != text.length() || backgroundColour.length() != text.length() )
-                {
-                    throw new LuaException( "Arguments must be the same length" );
-                }
-
-                synchronized( m_terminal )
-                {
-                    m_terminal.blit( text, textColour, backgroundColour );
-                    m_terminal.setCursorPos( m_terminal.getCursorX() + text.length(), m_terminal.getCursorY() );
-                }
-                return null;
-            }
-            case 19:
-            case 20:
-            {
-                // setPaletteColour/setPaletteColor
-                int colour = 15 - parseColour( args );
-                if( args.length == 2 )
-                {
-                    int hex = getInt( args, 1 );
-                    double[] rgb = Palette.decodeRGB8( hex );
-                    setColour( m_terminal, colour, rgb[0], rgb[1], rgb[2] );
-                }
-                else
-                {
-                    double r = getFiniteDouble( args, 1 );
-                    double g = getFiniteDouble( args, 2 );
-                    double b = getFiniteDouble( args, 3 );
-                    setColour( m_terminal, colour, r, g, b );
-                }
-                return null;
-            }
-            case 21:
-            case 22:
-            {
-                // getPaletteColour/getPaletteColor
-                int colour = 15 - parseColour( args );
-                synchronized( m_terminal )
-                {
-                    if( m_terminal.getPalette() != null )
-                    {
-                        return ArrayUtils.toObject( m_terminal.getPalette().getColour( colour ) );
-                    }
-                }
-                return null;
-            }
-            case 23:
-            case 24:
-            {
-                // nativePaletteColour/nativePaletteColor
-                int colour = 15 - parseColour( args );
-                Colour c = Colour.fromInt( colour );
-
-                float[] rgb = c.getRGB();
-
-                Object[] rgbObj = new Object[rgb.length];
-                for( int i = 0; i < rgbObj.length; ++i ) rgbObj[i] = rgb[i];
-                return rgbObj;
-            }
-            case 25:
-                // getCursorBlink
-                return new Object[] { m_terminal.getCursorBlink() };
-            default:
-                return null;
-        }
-    }
-
-    private static int getHighestBit( int group )
-    {
-        int bit = 0;
-        while( group > 0 )
-        {
-            group >>= 1;
-            bit++;
-        }
-        return bit;
+        return environment.isColour();
     }
 }

src/main/java/dan200/computercraft/core/apis/TermMethods.java

@@ -0,0 +1,222 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.apis;
+
+import dan200.computercraft.api.lua.IArguments;
+import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.shared.util.Palette;
+import dan200.computercraft.shared.util.StringUtil;
+import org.apache.commons.lang3.ArrayUtils;
+
+import javax.annotation.Nonnull;
+
+/**
+ * A base class for all objects which interact with a terminal. Namely the {@link TermAPI} and monitors.
+ */
+public abstract class TermMethods
+{
+    private static int getHighestBit( int group )
+    {
+        int bit = 0;
+        while( group > 0 )
+        {
+            group >>= 1;
+            bit++;
+        }
+        return bit;
+    }
+
+    @Nonnull
+    public abstract Terminal getTerminal() throws LuaException;
+
+    public abstract boolean isColour() throws LuaException;
+
+    @LuaFunction
+    public final void write( IArguments arguments ) throws LuaException
+    {
+        String text = StringUtil.toString( arguments.get( 0 ) );
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.write( text );
+            terminal.setCursorPos( terminal.getCursorX() + text.length(), terminal.getCursorY() );
+        }
+    }
+
+    @LuaFunction
+    public final void scroll( int y ) throws LuaException
+    {
+        getTerminal().scroll( y );
+    }
+
+    @LuaFunction
+    public final Object[] getCursorPos() throws LuaException
+    {
+        Terminal terminal = getTerminal();
+        return new Object[] { terminal.getCursorX() + 1, terminal.getCursorY() + 1 };
+    }
+
+    @LuaFunction
+    public final void setCursorPos( int x, int y ) throws LuaException
+    {
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.setCursorPos( x - 1, y - 1 );
+        }
+    }
+
+    @LuaFunction
+    public final boolean getCursorBlink() throws LuaException
+    {
+        return getTerminal().getCursorBlink();
+    }
+
+    @LuaFunction
+    public final void setCursorBlink( boolean blink ) throws LuaException
+    {
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.setCursorBlink( blink );
+        }
+    }
+
+    @LuaFunction
+    public final Object[] getSize() throws LuaException
+    {
+        Terminal terminal = getTerminal();
+        return new Object[] { terminal.getWidth(), terminal.getHeight() };
+    }
+
+    @LuaFunction
+    public final void clear() throws LuaException
+    {
+        getTerminal().clear();
+    }
+
+    @LuaFunction
+    public final void clearLine() throws LuaException
+    {
+        getTerminal().clearLine();
+    }
+
+    @LuaFunction( { "getTextColour", "getTextColor" } )
+    public final int getTextColour() throws LuaException
+    {
+        return encodeColour( getTerminal().getTextColour() );
+    }
+
+    @LuaFunction( { "setTextColour", "setTextColor" } )
+    public final void setTextColour( int colourArg ) throws LuaException
+    {
+        int colour = parseColour( colourArg );
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.setTextColour( colour );
+        }
+    }
+
+    @LuaFunction( { "getBackgroundColour", "getBackgroundColor" } )
+    public final int getBackgroundColour() throws LuaException
+    {
+        return encodeColour( getTerminal().getBackgroundColour() );
+    }
+
+    @LuaFunction( { "setBackgroundColour", "setBackgroundColor" } )
+    public final void setBackgroundColour( int colourArg ) throws LuaException
+    {
+        int colour = parseColour( colourArg );
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.setBackgroundColour( colour );
+        }
+    }
+
+    @LuaFunction( { "isColour", "isColor" } )
+    public final boolean getIsColour() throws LuaException
+    {
+        return isColour();
+    }
+
+    @LuaFunction
+    public final void blit( String text, String textColour, String backgroundColour ) throws LuaException
+    {
+        if( textColour.length() != text.length() || backgroundColour.length() != text.length() )
+        {
+            throw new LuaException( "Arguments must be the same length" );
+        }
+
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.blit( text, textColour, backgroundColour );
+            terminal.setCursorPos( terminal.getCursorX() + text.length(), terminal.getCursorY() );
+        }
+    }
+
+    @LuaFunction( { "setPaletteColour", "setPaletteColor" } )
+    public final void setPaletteColour( IArguments args ) throws LuaException
+    {
+        int colour = 15 - parseColour( args.getInt( 0 ) );
+        if( args.count() == 2 )
+        {
+            int hex = args.getInt( 1 );
+            double[] rgb = Palette.decodeRGB8( hex );
+            setColour( getTerminal(), colour, rgb[0], rgb[1], rgb[2] );
+        }
+        else
+        {
+            double r = args.getFiniteDouble( 1 );
+            double g = args.getFiniteDouble( 2 );
+            double b = args.getFiniteDouble( 3 );
+            setColour( getTerminal(), colour, r, g, b );
+        }
+    }
+
+    @LuaFunction( { "getPaletteColour", "getPaletteColor" } )
+    public final Object[] getPaletteColour( int colourArg ) throws LuaException
+    {
+        int colour = 15 - parseColour( colourArg );
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            if( terminal.getPalette() != null )
+            {
+                return ArrayUtils.toObject( terminal.getPalette().getColour( colour ) );
+            }
+        }
+        return null;
+    }
+
+    public static int parseColour( int colour ) throws LuaException
+    {
+        if( colour <= 0 ) throw new LuaException( "Colour out of range" );
+        colour = getHighestBit( colour ) - 1;
+        if( colour < 0 || colour > 15 ) throw new LuaException( "Colour out of range" );
+        return colour;
+    }
+
+
+    public static int encodeColour( int colour )
+    {
+        return 1 << colour;
+    }
+
+    public static void setColour( Terminal terminal, int colour, double r, double g, double b )
+    {
+        if( terminal.getPalette() != null )
+        {
+            terminal.getPalette().setColour( colour, r, g, b );
+            terminal.setChanged();
+        }
+    }
+}

src/main/java/dan200/computercraft/core/apis/handles/BinaryReadableHandle.java

@@ -5,11 +5,10 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import com.google.common.collect.ObjectArrays;
-import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 
-import javax.annotation.Nonnull;
 import java.io.ByteArrayOutputStream;
 import java.io.Closeable;
 import java.io.IOException;
@@ -17,208 +16,205 @@ import java.nio.ByteBuffer;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.SeekableByteChannel;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
-
-import static dan200.computercraft.api.lua.ArgumentHelper.getInt;
-import static dan200.computercraft.api.lua.ArgumentHelper.optBoolean;
+import java.util.Optional;
 
 public class BinaryReadableHandle extends HandleGeneric
 {
     private static final int BUFFER_SIZE = 8192;
 
-    private static final String[] METHOD_NAMES = new String[] { "read", "readAll", "readLine", "close" };
-    private static final String[] METHOD_SEEK_NAMES = ObjectArrays.concat( METHOD_NAMES, new String[] { "seek" }, String.class );
-
-    private final ReadableByteChannel m_reader;
-    private final SeekableByteChannel m_seekable;
+    private final ReadableByteChannel reader;
+    final SeekableByteChannel seekable;
     private final ByteBuffer single = ByteBuffer.allocate( 1 );
 
-    public BinaryReadableHandle( ReadableByteChannel channel, Closeable closeable )
+    protected BinaryReadableHandle( ReadableByteChannel reader, SeekableByteChannel seekable, Closeable closeable )
     {
         super( closeable );
-        m_reader = channel;
-        m_seekable = asSeekable( channel );
+        this.reader = reader;
+        this.seekable = seekable;
     }
 
-    public BinaryReadableHandle( ReadableByteChannel channel )
+    public static BinaryReadableHandle of( ReadableByteChannel channel, Closeable closeable )
     {
-        this( channel, channel );
+        SeekableByteChannel seekable = asSeekable( channel );
+        return seekable == null ? new BinaryReadableHandle( channel, null, closeable ) : new Seekable( seekable, closeable );
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    public static BinaryReadableHandle of( ReadableByteChannel channel )
     {
-        return m_seekable == null ? METHOD_NAMES : METHOD_SEEK_NAMES;
+        return of( channel, channel );
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    @LuaFunction
+    public final Object[] read( Optional<Integer> countArg ) throws LuaException
     {
-        switch( method )
+        checkOpen();
+        try
         {
-            case 0: // read
-                checkOpen();
-                try
-                {
-                    if( args.length > 0 && args[0] != null )
-                    {
-                        int count = getInt( args, 0 );
-                        if( count < 0 )
-                        {
-                            throw new LuaException( "Cannot read a negative number of bytes" );
-                        }
-                        else if( count == 0 && m_seekable != null )
-                        {
-                            return m_seekable.position() >= m_seekable.size() ? null : new Object[] { "" };
-                        }
-
-                        if( count <= BUFFER_SIZE )
-                        {
-                            ByteBuffer buffer = ByteBuffer.allocate( count );
-
-                            int read = m_reader.read( buffer );
-                            if( read < 0 ) return null;
-                            return new Object[] { read < count ? Arrays.copyOf( buffer.array(), read ) : buffer.array() };
-                        }
-                        else
-                        {
-                            // Read the initial set of characters, failing if none are read.
-                            ByteBuffer buffer = ByteBuffer.allocate( BUFFER_SIZE );
-                            int read = m_reader.read( buffer );
-                            if( read < 0 ) return null;
-
-                            // If we failed to read "enough" here, let's just abort
-                            if( read >= count || read < BUFFER_SIZE )
-                            {
-                                return new Object[] { Arrays.copyOf( buffer.array(), read ) };
-                            }
-
-                            // Build up an array of ByteBuffers. Hopefully this means we can perform less allocation
-                            // than doubling up the buffer each time.
-                            int totalRead = read;
-                            List<ByteBuffer> parts = new ArrayList<>( 4 );
-                            parts.add( buffer );
-                            while( read >= BUFFER_SIZE && totalRead < count )
-                            {
-                                buffer = ByteBuffer.allocate( Math.min( BUFFER_SIZE, count - totalRead ) );
-                                read = m_reader.read( buffer );
-                                if( read < 0 ) break;
-
-                                totalRead += read;
-                                parts.add( buffer );
-                            }
-
-                            // Now just copy all the bytes across!
-                            byte[] bytes = new byte[totalRead];
-                            int pos = 0;
-                            for( ByteBuffer part : parts )
-                            {
-                                System.arraycopy( part.array(), 0, bytes, pos, part.position() );
-                                pos += part.position();
-                            }
-                            return new Object[] { bytes };
-                        }
-                    }
-                    else
-                    {
-                        single.clear();
-                        int b = m_reader.read( single );
-                        return b == -1 ? null : new Object[] { single.get( 0 ) & 0xFF };
-                    }
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 1: // readAll
-                checkOpen();
-                try
-                {
-                    int expected = 32;
-                    if( m_seekable != null )
-                    {
-                        expected = Math.max( expected, (int) (m_seekable.size() - m_seekable.position()) );
-                    }
-                    ByteArrayOutputStream stream = new ByteArrayOutputStream( expected );
-
-                    ByteBuffer buf = ByteBuffer.allocate( 8192 );
-                    boolean readAnything = false;
-                    while( true )
-                    {
-                        buf.clear();
-                        int r = m_reader.read( buf );
-                        if( r == -1 ) break;
-
-                        readAnything = true;
-                        stream.write( buf.array(), 0, r );
-                    }
-                    return readAnything ? new Object[] { stream.toByteArray() } : null;
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 2: // readLine
+            if( countArg.isPresent() )
             {
-                checkOpen();
-                boolean withTrailing = optBoolean( args, 0, false );
-                try
+                int count = countArg.get();
+                if( count < 0 ) throw new LuaException( "Cannot read a negative number of bytes" );
+                if( count == 0 && seekable != null )
                 {
-                    ByteArrayOutputStream stream = new ByteArrayOutputStream();
-
-                    boolean readAnything = false, readRc = false;
-                    while( true )
-                    {
-                        single.clear();
-                        int read = m_reader.read( single );
-                        if( read <= 0 )
-                        {
-                            // Nothing else to read, and we saw no \n. Return the array. If we saw a \r, then add it
-                            // back.
-                            if( readRc ) stream.write( '\r' );
-                            return readAnything ? new Object[] { stream.toByteArray() } : null;
-                        }
-
-                        readAnything = true;
-
-                        byte chr = single.get( 0 );
-                        if( chr == '\n' )
-                        {
-                            if( withTrailing )
-                            {
-                                if( readRc ) stream.write( '\r' );
-                                stream.write( chr );
-                            }
-                            return new Object[] { stream.toByteArray() };
-                        }
-                        else
-                        {
-                            // We want to skip \r\n, but obviously need to include cases where \r is not followed by \n.
-                            // Note, this behaviour is non-standard compliant (strictly speaking we should have no
-                            // special logic for \r), but we preserve compatibility with EncodedReadableHandle and
-                            // previous behaviour of the io library.
-                            if( readRc ) stream.write( '\r' );
-                            readRc = chr == '\r';
-                            if( !readRc ) stream.write( chr );
-                        }
-                    }
+                    return seekable.position() >= seekable.size() ? null : new Object[] { "" };
                 }
-                catch( IOException e )
+
+                if( count <= BUFFER_SIZE )
                 {
-                    return null;
+                    ByteBuffer buffer = ByteBuffer.allocate( count );
+
+                    int read = reader.read( buffer );
+                    if( read < 0 ) return null;
+                    buffer.flip();
+                    return new Object[] { buffer };
+                }
+                else
+                {
+                    // Read the initial set of characters, failing if none are read.
+                    ByteBuffer buffer = ByteBuffer.allocate( BUFFER_SIZE );
+                    int read = reader.read( buffer );
+                    if( read < 0 ) return null;
+
+                    // If we failed to read "enough" here, let's just abort
+                    if( read >= count || read < BUFFER_SIZE )
+                    {
+                        buffer.flip();
+                        return new Object[] { buffer };
+                    }
+
+                    // Build up an array of ByteBuffers. Hopefully this means we can perform less allocation
+                    // than doubling up the buffer each time.
+                    int totalRead = read;
+                    List<ByteBuffer> parts = new ArrayList<>( 4 );
+                    parts.add( buffer );
+                    while( read >= BUFFER_SIZE && totalRead < count )
+                    {
+                        buffer = ByteBuffer.allocate( Math.min( BUFFER_SIZE, count - totalRead ) );
+                        read = reader.read( buffer );
+                        if( read < 0 ) break;
+
+                        totalRead += read;
+                        parts.add( buffer );
+                    }
+
+                    // Now just copy all the bytes across!
+                    byte[] bytes = new byte[totalRead];
+                    int pos = 0;
+                    for( ByteBuffer part : parts )
+                    {
+                        System.arraycopy( part.array(), 0, bytes, pos, part.position() );
+                        pos += part.position();
+                    }
+                    return new Object[] { bytes };
                 }
             }
-            case 3: // close
-                checkOpen();
-                close();
-                return null;
-            case 4: // seek
-                checkOpen();
-                return handleSeek( m_seekable, args );
-            default:
-                return null;
+            else
+            {
+                single.clear();
+                int b = reader.read( single );
+                return b == -1 ? null : new Object[] { single.get( 0 ) & 0xFF };
+            }
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
+    }
+
+    @LuaFunction
+    public final Object[] readAll() throws LuaException
+    {
+        checkOpen();
+        try
+        {
+            int expected = 32;
+            if( seekable != null ) expected = Math.max( expected, (int) (seekable.size() - seekable.position()) );
+            ByteArrayOutputStream stream = new ByteArrayOutputStream( expected );
+
+            ByteBuffer buf = ByteBuffer.allocate( 8192 );
+            boolean readAnything = false;
+            while( true )
+            {
+                buf.clear();
+                int r = reader.read( buf );
+                if( r == -1 ) break;
+
+                readAnything = true;
+                stream.write( buf.array(), 0, r );
+            }
+            return readAnything ? new Object[] { stream.toByteArray() } : null;
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
+    }
+
+    @LuaFunction
+    public final Object[] readLine( Optional<Boolean> withTrailingArg ) throws LuaException
+    {
+        checkOpen();
+        boolean withTrailing = withTrailingArg.orElse( false );
+        try
+        {
+            ByteArrayOutputStream stream = new ByteArrayOutputStream();
+
+            boolean readAnything = false, readRc = false;
+            while( true )
+            {
+                single.clear();
+                int read = reader.read( single );
+                if( read <= 0 )
+                {
+                    // Nothing else to read, and we saw no \n. Return the array. If we saw a \r, then add it
+                    // back.
+                    if( readRc ) stream.write( '\r' );
+                    return readAnything ? new Object[] { stream.toByteArray() } : null;
+                }
+
+                readAnything = true;
+
+                byte chr = single.get( 0 );
+                if( chr == '\n' )
+                {
+                    if( withTrailing )
+                    {
+                        if( readRc ) stream.write( '\r' );
+                        stream.write( chr );
+                    }
+                    return new Object[] { stream.toByteArray() };
+                }
+                else
+                {
+                    // We want to skip \r\n, but obviously need to include cases where \r is not followed by \n.
+                    // Note, this behaviour is non-standard compliant (strictly speaking we should have no
+                    // special logic for \r), but we preserve compatibility with EncodedReadableHandle and
+                    // previous behaviour of the io library.
+                    if( readRc ) stream.write( '\r' );
+                    readRc = chr == '\r';
+                    if( !readRc ) stream.write( chr );
+                }
+            }
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
+    }
+
+    public static class Seekable extends BinaryReadableHandle
+    {
+        public Seekable( SeekableByteChannel seekable, Closeable closeable )
+        {
+            super( seekable, seekable, closeable );
+        }
+
+        @LuaFunction
+        public final Object[] seek( IArguments arguments ) throws LuaException
+        {
+            checkOpen();
+            return handleSeek( seekable, arguments );
         }
     }
 }

src/main/java/dan200/computercraft/core/apis/handles/BinaryWritableHandle.java

@@ -5,13 +5,11 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import com.google.common.collect.ObjectArrays;
-import dan200.computercraft.api.lua.ArgumentHelper;
-import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.LuaException;
-import dan200.computercraft.shared.util.StringUtil;
+import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.api.lua.LuaValues;
 
-import javax.annotation.Nonnull;
 import java.io.Closeable;
 import java.io.IOException;
 import java.nio.ByteBuffer;
@@ -21,87 +19,85 @@ import java.nio.channels.WritableByteChannel;
 
 public class BinaryWritableHandle extends HandleGeneric
 {
-    private static final String[] METHOD_NAMES = new String[] { "write", "flush", "close" };
-    private static final String[] METHOD_SEEK_NAMES = ObjectArrays.concat( METHOD_NAMES, new String[] { "seek" }, String.class );
-
-    private final WritableByteChannel m_writer;
-    private final SeekableByteChannel m_seekable;
+    private final WritableByteChannel writer;
+    final SeekableByteChannel seekable;
     private final ByteBuffer single = ByteBuffer.allocate( 1 );
 
-    public BinaryWritableHandle( WritableByteChannel channel, Closeable closeable )
+    protected BinaryWritableHandle( WritableByteChannel writer, SeekableByteChannel seekable, Closeable closeable )
     {
         super( closeable );
-        m_writer = channel;
-        m_seekable = asSeekable( channel );
+        this.writer = writer;
+        this.seekable = seekable;
     }
 
-    public BinaryWritableHandle( WritableByteChannel channel )
+    public static BinaryWritableHandle of( WritableByteChannel channel, Closeable closeable )
     {
-        this( channel, channel );
+        SeekableByteChannel seekable = asSeekable( channel );
+        return seekable == null ? new BinaryWritableHandle( channel, null, closeable ) : new Seekable( seekable, closeable );
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    public static BinaryWritableHandle of( WritableByteChannel channel )
     {
-        return m_seekable == null ? METHOD_NAMES : METHOD_SEEK_NAMES;
+        return of( channel, channel );
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    @LuaFunction
+    public final void write( IArguments arguments ) throws LuaException
     {
-        switch( method )
+        checkOpen();
+        try
         {
-            case 0: // write
-                checkOpen();
-                try
-                {
-                    if( args.length > 0 && args[0] instanceof Number )
-                    {
-                        int number = ((Number) args[0]).intValue();
-                        single.clear();
-                        single.put( (byte) number );
-                        single.flip();
+            Object arg = arguments.get( 0 );
+            if( arg instanceof Number )
+            {
+                int number = ((Number) arg).intValue();
+                single.clear();
+                single.put( (byte) number );
+                single.flip();
 
-                        m_writer.write( single );
-                    }
-                    else if( args.length > 0 && args[0] instanceof String )
-                    {
-                        String value = (String) args[0];
-                        m_writer.write( ByteBuffer.wrap( StringUtil.encodeString( value ) ) );
-                    }
-                    else
-                    {
-                        throw ArgumentHelper.badArgumentOf( 0, "string or number", args.length > 0 ? args[0] : null );
-                    }
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            case 1: // flush
-                checkOpen();
-                try
-                {
-                    // Technically this is not needed
-                    if( m_writer instanceof FileChannel ) ((FileChannel) m_writer).force( false );
+                writer.write( single );
+            }
+            else if( arg instanceof String )
+            {
+                writer.write( arguments.getBytes( 0 ) );
+            }
+            else
+            {
+                throw LuaValues.badArgumentOf( 0, "string or number", arg );
+            }
+        }
+        catch( IOException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
 
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 2: // close
-                checkOpen();
-                close();
-                return null;
-            case 3: // seek
-                checkOpen();
-                return handleSeek( m_seekable, args );
-            default:
-                return null;
+    @LuaFunction
+    public final void flush() throws LuaException
+    {
+        checkOpen();
+        try
+        {
+            // Technically this is not needed
+            if( writer instanceof FileChannel ) ((FileChannel) writer).force( false );
+        }
+        catch( IOException ignored )
+        {
+        }
+    }
+
+    public static class Seekable extends BinaryWritableHandle
+    {
+        public Seekable( SeekableByteChannel seekable, Closeable closeable )
+        {
+            super( seekable, seekable, closeable );
+        }
+
+        @LuaFunction
+        public final Object[] seek( IArguments args ) throws LuaException
+        {
+            checkOpen();
+            return handleSeek( seekable, args );
         }
     }
 }

src/main/java/dan200/computercraft/core/apis/handles/EncodedReadableHandle.java

@@ -5,8 +5,8 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 
 import javax.annotation.Nonnull;
 import java.io.BufferedReader;
@@ -18,20 +18,18 @@ import java.nio.charset.Charset;
 import java.nio.charset.CharsetDecoder;
 import java.nio.charset.CodingErrorAction;
 import java.nio.charset.StandardCharsets;
-
-import static dan200.computercraft.api.lua.ArgumentHelper.optBoolean;
-import static dan200.computercraft.api.lua.ArgumentHelper.optInt;
+import java.util.Optional;
 
 public class EncodedReadableHandle extends HandleGeneric
 {
     private static final int BUFFER_SIZE = 8192;
 
-    private BufferedReader m_reader;
+    private final BufferedReader reader;
 
     public EncodedReadableHandle( @Nonnull BufferedReader reader, @Nonnull Closeable closable )
     {
         super( closable );
-        m_reader = reader;
+        this.reader = reader;
     }
 
     public EncodedReadableHandle( @Nonnull BufferedReader reader )
@@ -39,123 +37,107 @@ public class EncodedReadableHandle extends HandleGeneric
         this( reader, reader );
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    @LuaFunction
+    public final Object[] readLine( Optional<Boolean> withTrailingArg ) throws LuaException
     {
-        return new String[] {
-            "readLine",
-            "readAll",
-            "read",
-            "close",
-        };
+        checkOpen();
+        boolean withTrailing = withTrailingArg.orElse( false );
+        try
+        {
+            String line = reader.readLine();
+            if( line != null )
+            {
+                // While this is technically inaccurate, it's better than nothing
+                if( withTrailing ) line += "\n";
+                return new Object[] { line };
+            }
+            else
+            {
+                return null;
+            }
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    @LuaFunction
+    public final Object[] readAll() throws LuaException
     {
-        switch( method )
+        checkOpen();
+        try
         {
-            case 0: // readLine
+            StringBuilder result = new StringBuilder();
+            String line = reader.readLine();
+            while( line != null )
             {
-                checkOpen();
-                boolean withTrailing = optBoolean( args, 0, false );
-                try
+                result.append( line );
+                line = reader.readLine();
+                if( line != null )
                 {
-                    String line = m_reader.readLine();
-                    if( line != null )
-                    {
-                        // While this is technically inaccurate, it's better than nothing
-                        if( withTrailing ) line += "\n";
-                        return new Object[] { line };
-                    }
-                    else
-                    {
-                        return null;
-                    }
-                }
-                catch( IOException e )
-                {
-                    return null;
+                    result.append( "\n" );
                 }
             }
-            case 1: // readAll
-                checkOpen();
-                try
+            return new Object[] { result.toString() };
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
+    }
+
+    @LuaFunction
+    public final Object[] read( Optional<Integer> countA ) throws LuaException
+    {
+        checkOpen();
+        try
+        {
+            int count = countA.orElse( 1 );
+            if( count < 0 )
+            {
+                // Whilst this may seem absurd to allow reading 0 characters, PUC Lua it so
+                // it seems best to remain somewhat consistent.
+                throw new LuaException( "Cannot read a negative number of characters" );
+            }
+            else if( count <= BUFFER_SIZE )
+            {
+                // If we've got a small count, then allocate that and read it.
+                char[] chars = new char[count];
+                int read = reader.read( chars );
+
+                return read < 0 ? null : new Object[] { new String( chars, 0, read ) };
+            }
+            else
+            {
+                // If we've got a large count, read in bunches of 8192.
+                char[] buffer = new char[BUFFER_SIZE];
+
+                // Read the initial set of characters, failing if none are read.
+                int read = reader.read( buffer, 0, Math.min( buffer.length, count ) );
+                if( read < 0 ) return null;
+
+                StringBuilder out = new StringBuilder( read );
+                int totalRead = read;
+                out.append( buffer, 0, read );
+
+                // Otherwise read until we either reach the limit or we no longer consume
+                // the full buffer.
+                while( read >= BUFFER_SIZE && totalRead < count )
                 {
-                    StringBuilder result = new StringBuilder();
-                    String line = m_reader.readLine();
-                    while( line != null )
-                    {
-                        result.append( line );
-                        line = m_reader.readLine();
-                        if( line != null )
-                        {
-                            result.append( "\n" );
-                        }
-                    }
-                    return new Object[] { result.toString() };
+                    read = reader.read( buffer, 0, Math.min( BUFFER_SIZE, count - totalRead ) );
+                    if( read < 0 ) break;
+
+                    totalRead += read;
+                    out.append( buffer, 0, read );
                 }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 2: // read
-                checkOpen();
-                try
-                {
-                    int count = optInt( args, 0, 1 );
-                    if( count < 0 )
-                    {
-                        // Whilst this may seem absurd to allow reading 0 characters, PUC Lua it so
-                        // it seems best to remain somewhat consistent.
-                        throw new LuaException( "Cannot read a negative number of characters" );
-                    }
-                    else if( count <= BUFFER_SIZE )
-                    {
-                        // If we've got a small count, then allocate that and read it.
-                        char[] chars = new char[count];
-                        int read = m_reader.read( chars );
 
-                        return read < 0 ? null : new Object[] { new String( chars, 0, read ) };
-                    }
-                    else
-                    {
-                        // If we've got a large count, read in bunches of 8192.
-                        char[] buffer = new char[BUFFER_SIZE];
-
-                        // Read the initial set of characters, failing if none are read.
-                        int read = m_reader.read( buffer, 0, Math.min( buffer.length, count ) );
-                        if( read < 0 ) return null;
-
-                        StringBuilder out = new StringBuilder( read );
-                        int totalRead = read;
-                        out.append( buffer, 0, read );
-
-                        // Otherwise read until we either reach the limit or we no longer consume
-                        // the full buffer.
-                        while( read >= BUFFER_SIZE && totalRead < count )
-                        {
-                            read = m_reader.read( buffer, 0, Math.min( BUFFER_SIZE, count - totalRead ) );
-                            if( read < 0 ) break;
-
-                            totalRead += read;
-                            out.append( buffer, 0, read );
-                        }
-
-                        return new Object[] { out.toString() };
-                    }
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 3: // close
-                checkOpen();
-                close();
-                return null;
-            default:
-                return null;
+                return new Object[] { out.toString() };
+            }
+        }
+        catch( IOException e )
+        {
+            return null;
         }
     }
 

src/main/java/dan200/computercraft/core/apis/handles/EncodedWritableHandle.java

@@ -5,8 +5,10 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.shared.util.StringUtil;
 
 import javax.annotation.Nonnull;
 import java.io.BufferedWriter;
@@ -21,85 +23,57 @@ import java.nio.charset.StandardCharsets;
 
 public class EncodedWritableHandle extends HandleGeneric
 {
-    private BufferedWriter m_writer;
+    private final BufferedWriter writer;
 
     public EncodedWritableHandle( @Nonnull BufferedWriter writer, @Nonnull Closeable closable )
     {
         super( closable );
-        m_writer = writer;
+        this.writer = writer;
     }
 
-    public EncodedWritableHandle( @Nonnull BufferedWriter writer )
+    @LuaFunction
+    public final void write( IArguments args ) throws LuaException
     {
-        this( writer, writer );
-    }
-
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
-    {
-        return new String[] {
-            "write",
-            "writeLine",
-            "flush",
-            "close",
-        };
-    }
-
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
-    {
-        switch( method )
+        checkOpen();
+        String text = StringUtil.toString( args.get( 0 ) );
+        try
         {
-            case 0: // write
-            {
-                checkOpen();
-                String text = args.length > 0 && args[0] != null ? args[0].toString() : "";
-                try
-                {
-                    m_writer.write( text, 0, text.length() );
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 1: // writeLine
-            {
-                checkOpen();
-                String text = args.length > 0 && args[0] != null ? args[0].toString() : "";
-                try
-                {
-                    m_writer.write( text, 0, text.length() );
-                    m_writer.newLine();
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 2: // flush
-                checkOpen();
-                try
-                {
-                    m_writer.flush();
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 3: // close
-                checkOpen();
-                close();
-                return null;
-            default:
-                return null;
+            writer.write( text, 0, text.length() );
+        }
+        catch( IOException e )
+        {
+            throw new LuaException( e.getMessage() );
         }
     }
 
+    @LuaFunction
+    public final void writeLine( IArguments args ) throws LuaException
+    {
+        checkOpen();
+        String text = StringUtil.toString( args.get( 0 ) );
+        try
+        {
+            writer.write( text, 0, text.length() );
+            writer.newLine();
+        }
+        catch( IOException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    @LuaFunction
+    public final void flush() throws LuaException
+    {
+        checkOpen();
+        try
+        {
+            writer.flush();
+        }
+        catch( IOException ignored )
+        {
+        }
+    }
 
     public static BufferedWriter openUtf8( WritableByteChannel channel )
     {

src/main/java/dan200/computercraft/core/apis/handles/HandleGeneric.java

@@ -5,8 +5,9 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import dan200.computercraft.api.lua.ILuaObject;
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.shared.util.IoUtil;
 
 import javax.annotation.Nonnull;
@@ -15,36 +16,37 @@ import java.io.IOException;
 import java.nio.channels.Channel;
 import java.nio.channels.SeekableByteChannel;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.optLong;
-import static dan200.computercraft.api.lua.ArgumentHelper.optString;
-
-public abstract class HandleGeneric implements ILuaObject
+public abstract class HandleGeneric
 {
-    private Closeable m_closable;
-    private boolean m_open = true;
+    private Closeable closable;
+    private boolean open = true;
 
     protected HandleGeneric( @Nonnull Closeable closable )
     {
-        m_closable = closable;
+        this.closable = closable;
     }
 
     protected void checkOpen() throws LuaException
     {
-        if( !m_open ) throw new LuaException( "attempt to use a closed file" );
+        if( !open ) throw new LuaException( "attempt to use a closed file" );
     }
 
     protected final void close()
     {
-        m_open = false;
+        open = false;
 
-        Closeable closeable = m_closable;
-        if( closeable != null )
-        {
-            IoUtil.closeQuietly( closeable );
-            m_closable = null;
-        }
+        IoUtil.closeQuietly( closable );
+        closable = null;
     }
 
+    @LuaFunction( "close" )
+    public final void doClose() throws LuaException
+    {
+        checkOpen();
+        close();
+    }
+
+
     /**
      * Shared implementation for various file handle types.
      *
@@ -54,12 +56,12 @@ public abstract class HandleGeneric implements ILuaObject
      * @throws LuaException If the arguments were invalid
      * @see <a href="https://www.lua.org/manual/5.1/manual.html#pdf-file:seek">{@code file:seek} in the Lua manual.</a>
      */
-    protected static Object[] handleSeek( SeekableByteChannel channel, Object[] args ) throws LuaException
+    protected static Object[] handleSeek( SeekableByteChannel channel, IArguments args ) throws LuaException
     {
+        String whence = args.optString( 0, "cur" );
+        long offset = args.optLong( 1, 0 );
         try
         {
-            String whence = optString( args, 0, "cur" );
-            long offset = optLong( args, 1, 0 );
             switch( whence )
             {
                 case "set":

src/main/java/dan200/computercraft/core/apis/http/CheckUrl.java

@@ -7,6 +7,7 @@ package dan200.computercraft.core.apis.http;
 
 import dan200.computercraft.core.apis.IAPIEnvironment;
 
+import java.net.InetSocketAddress;
 import java.net.URI;
 import java.util.concurrent.Future;
 
@@ -46,12 +47,14 @@ public class CheckUrl extends Resource<CheckUrl>
 
         try
         {
-            NetworkUtils.getAddress( host, 80, false );
-            if( tryClose() ) environment.queueEvent( EVENT, new Object[] { address, true } );
+            InetSocketAddress netAddress = NetworkUtils.getAddress( host, 80, false );
+            NetworkUtils.getOptions( host, netAddress );
+
+            if( tryClose() ) environment.queueEvent( EVENT, address, true );
         }
         catch( HTTPRequestException e )
         {
-            if( tryClose() ) environment.queueEvent( EVENT, new Object[] { address, false, e.getMessage() } );
+            if( tryClose() ) environment.queueEvent( EVENT, address, false, e.getMessage() );
         }
     }
 

src/main/java/dan200/computercraft/core/apis/http/NetworkUtils.java

@@ -6,6 +6,9 @@
 package dan200.computercraft.core.apis.http;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.core.apis.http.options.Action;
+import dan200.computercraft.core.apis.http.options.AddressRule;
+import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.shared.util.ThreadUtils;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.EventLoopGroup;
@@ -15,7 +18,6 @@ import io.netty.handler.ssl.SslContextBuilder;
 
 import javax.net.ssl.SSLException;
 import javax.net.ssl.TrustManagerFactory;
-import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.security.KeyStore;
 import java.util.concurrent.ExecutorService;
@@ -97,20 +99,6 @@ public final class NetworkUtils
         }
     }
 
-    /**
-     * Checks a host is allowed.
-     *
-     * @param host The domain to check against
-     * @throws HTTPRequestException If the host is not permitted.
-     */
-    public static void checkHost( String host ) throws HTTPRequestException
-    {
-        if( !ComputerCraft.http_whitelist.matches( host ) || ComputerCraft.http_blacklist.matches( host ) )
-        {
-            throw new HTTPRequestException( "Domain not permitted" );
-        }
-    }
-
     /**
      * Create a {@link InetSocketAddress} from the resolved {@code host} and port.
      *
@@ -120,24 +108,31 @@ public final class NetworkUtils
      * @param port The port, or -1 if not defined.
      * @param ssl  Whether to connect with SSL. This is used to find the default port if not otherwise specified.
      * @return The resolved address.
-     * @throws HTTPRequestException If the host is not permitted.
+     * @throws HTTPRequestException If the host is not malformed.
      */
     public static InetSocketAddress getAddress( String host, int port, boolean ssl ) throws HTTPRequestException
     {
         if( port < 0 ) port = ssl ? 443 : 80;
-
         InetSocketAddress socketAddress = new InetSocketAddress( host, port );
         if( socketAddress.isUnresolved() ) throw new HTTPRequestException( "Unknown host" );
-
-        InetAddress address = socketAddress.getAddress();
-        if( !ComputerCraft.http_whitelist.matches( address ) || ComputerCraft.http_blacklist.matches( address ) )
-        {
-            throw new HTTPRequestException( "Domain not permitted" );
-        }
-
         return socketAddress;
     }
 
+    /**
+     * Get options for a specific domain.
+     *
+     * @param host    The host to resolve.
+     * @param address The address, resolved by {@link #getAddress(String, int, boolean)}.
+     * @return The options for this host.
+     * @throws HTTPRequestException If the host is not permitted
+     */
+    public static Options getOptions( String host, InetSocketAddress address ) throws HTTPRequestException
+    {
+        Options options = AddressRule.apply( ComputerCraft.httpRules, host, address.getAddress() );
+        if( options.action == Action.DENY ) throw new HTTPRequestException( "Domain not permitted" );
+        return options;
+    }
+
     /**
      * Read a {@link ByteBuf} into a byte array.
      *

src/main/java/dan200/computercraft/core/apis/http/Resource.java

@@ -106,7 +106,7 @@ public abstract class Resource<T extends Resource<T>> implements Closeable
 
     protected static <T extends Closeable> T closeCloseable( T closeable )
     {
-        if( closeable != null ) IoUtil.closeQuietly( closeable );
+        IoUtil.closeQuietly( closeable );
         return null;
     }
 

src/main/java/dan200/computercraft/core/apis/http/options/Action.java

@@ -0,0 +1,23 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.apis.http.options;
+
+import javax.annotation.Nonnull;
+
+public enum Action
+{
+    ALLOW,
+    DENY;
+
+    private final PartialOptions partial = new PartialOptions( this, null, null, null, null );
+
+    @Nonnull
+    public PartialOptions toPartial()
+    {
+        return partial;
+    }
+}

src/main/java/dan200/computercraft/core/apis/http/options/AddressRule.java

@@ -0,0 +1,186 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.core.apis.http.options;
+
+import com.google.common.net.InetAddresses;
+import dan200.computercraft.ComputerCraft;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.util.regex.Pattern;
+
+/**
+ * A pattern which matches an address, and controls whether it is accessible or not.
+ */
+public final class AddressRule
+{
+    public static final long MAX_DOWNLOAD = 16 * 1024 * 1024;
+    public static final long MAX_UPLOAD = 4 * 1024 * 1024;
+    public static final int TIMEOUT = 30_000;
+    public static final int WEBSOCKET_MESSAGE = 128 * 1024;
+
+    private static final class HostRange
+    {
+        private final byte[] min;
+        private final byte[] max;
+
+        private HostRange( byte[] min, byte[] max )
+        {
+            this.min = min;
+            this.max = max;
+        }
+
+        public boolean contains( InetAddress address )
+        {
+            byte[] entry = address.getAddress();
+            if( entry.length != min.length ) return false;
+
+            for( int i = 0; i < entry.length; i++ )
+            {
+                int value = 0xFF & entry[i];
+                if( value < (0xFF & min[i]) || value > (0xFF & max[i]) ) return false;
+            }
+
+            return true;
+        }
+    }
+
+    private final HostRange ip;
+    private final Pattern domainPattern;
+    private final PartialOptions partial;
+
+    private AddressRule( @Nullable HostRange ip, @Nullable Pattern domainPattern, @Nonnull PartialOptions partial )
+    {
+        this.ip = ip;
+        this.domainPattern = domainPattern;
+        this.partial = partial;
+    }
+
+    @Nullable
+    public static AddressRule parse( String filter, @Nonnull PartialOptions partial )
+    {
+        int cidr = filter.indexOf( '/' );
+        if( cidr >= 0 )
+        {
+            String addressStr = filter.substring( 0, cidr );
+            String prefixSizeStr = filter.substring( cidr + 1 );
+
+            int prefixSize;
+            try
+            {
+                prefixSize = Integer.parseInt( prefixSizeStr );
+            }
+            catch( NumberFormatException e )
+            {
+                ComputerCraft.log.error(
+                    "Malformed http whitelist/blacklist entry '{}': Cannot extract size of CIDR mask from '{}'.",
+                    filter, prefixSizeStr
+                );
+                return null;
+            }
+
+            InetAddress address;
+            try
+            {
+                address = InetAddresses.forString( addressStr );
+            }
+            catch( IllegalArgumentException e )
+            {
+                ComputerCraft.log.error(
+                    "Malformed http whitelist/blacklist entry '{}': Cannot extract IP address from '{}'.",
+                    filter, prefixSizeStr
+                );
+                return null;
+            }
+
+            // Mask the bytes of the IP address.
+            byte[] minBytes = address.getAddress(), maxBytes = address.getAddress();
+            int size = prefixSize;
+            for( int i = 0; i < minBytes.length; i++ )
+            {
+                if( size <= 0 )
+                {
+                    minBytes[i] &= 0;
+                    maxBytes[i] |= 0xFF;
+                }
+                else if( size < 8 )
+                {
+                    minBytes[i] &= 0xFF << (8 - size);
+                    maxBytes[i] |= ~(0xFF << (8 - size));
+                }
+
+                size -= 8;
+            }
+
+            return new AddressRule( new HostRange( minBytes, maxBytes ), null, partial );
+        }
+        else
+        {
+            Pattern pattern = Pattern.compile( "^\\Q" + filter.replaceAll( "\\*", "\\\\E.*\\\\Q" ) + "\\E$" );
+            return new AddressRule( null, pattern, partial );
+        }
+    }
+
+    /**
+     * Determine whether the given address matches a series of patterns.
+     *
+     * @param domain  The domain to match
+     * @param address The address to check.
+     * @return Whether it matches any of these patterns.
+     */
+    private boolean matches( String domain, InetAddress address )
+    {
+        if( domainPattern != null )
+        {
+            if( domainPattern.matcher( domain ).matches() ) return true;
+            if( domainPattern.matcher( address.getHostName() ).matches() ) return true;
+        }
+
+        // Match the normal address
+        if( matchesAddress( address ) ) return true;
+
+        // If we're an IPv4 address in disguise then let's check that.
+        return address instanceof Inet6Address && InetAddresses.is6to4Address( (Inet6Address) address )
+            && matchesAddress( InetAddresses.get6to4IPv4Address( (Inet6Address) address ) );
+    }
+
+    private boolean matchesAddress( InetAddress address )
+    {
+        if( domainPattern != null && domainPattern.matcher( address.getHostAddress() ).matches() ) return true;
+        return ip != null && ip.contains( address );
+    }
+
+    public static Options apply( Iterable<? extends AddressRule> rules, String domain, InetAddress address )
+    {
+        PartialOptions options = null;
+        boolean hasMany = false;
+
+        for( AddressRule rule : rules )
+        {
+            if( !rule.matches( domain, address ) ) continue;
+
+            if( options == null )
+            {
+                options = rule.partial;
+            }
+            else
+            {
+
+                if( !hasMany )
+                {
+                    options = options.copy();
+                    hasMany = true;
+                }
+
+                options.merge( rule.partial );
+            }
+        }
+
+        return (options == null ? PartialOptions.DEFAULT : options).toOptions();
+    }
+}