Merge branch 'master' into mc-1.14.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:3.0.169'
+        classpath 'net.minecraftforge.gradle:ForgeGradle:3.0.154'
         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/server-${mc_version}")
+            workingDirectory project.file('run')
             property 'forge.logging.markers', 'REGISTRIES,REGISTRYDUMP'
             property 'forge.logging.console.level', 'debug'
 
@@ -99,10 +100,10 @@ dependencies {
 
     minecraft "net.minecraftforge:forge:${mc_version}-${forge_version}"
 
-    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")
+    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")
 
-    runtimeOnly fg.deobf("mezz.jei:jei-1.15.2:6.0.0.3")
+    runtimeOnly fg.deobf("mezz.jei:jei-1.14.4:6.0.0.27")
 
     shade 'org.squiddev:Cobalt:0.5.1-SNAPSHOT'
 
@@ -288,6 +289,15 @@ test {
     }
 }
 
+jacocoTestReport {
+    reports {
+        xml.enabled true
+        html.enabled true
+    }
+}
+
+check.dependsOn jacocoTestReport
+
 license {
     mapping("java", "SLASHSTAR_STYLE")
     strictCheck true
@@ -373,7 +383,7 @@ curseforge {
     apiKey = project.hasProperty('curseForgeApiKey') ? project.curseForgeApiKey : ''
     project {
         id = '282001'
-        releaseType = 'alpha'
+        releaseType = 'release'
         changelog = "Release notes can be found on the GitHub repository (https://github.com/SquidDev-CC/CC-Tweaked/releases/tag/v${mc_version}-${mod_version})."
 
         relations {
@@ -451,7 +461,7 @@ githubRelease {
             .takeWhile { it != 'Type "help changelog" to see the full version history.' }
             .join("\n").trim()
     }
-    prerelease true
+    prerelease false
 }
 
 def uploadTasks = ["uploadArchives", "curseforge", "githubRelease"]

config/checkstyle/checkstyle.xml

@@ -10,10 +10,6 @@
         <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" />

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=1.15.2
-forge_version=31.1.41
-mappings_version=20200410-1.15.1
+mc_version=1.14.4
+forge_version=28.1.71
+mappings_version=20191123-1.14.3

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

@@ -6,7 +6,7 @@
 package dan200.computercraft;
 
 import dan200.computercraft.api.turtle.event.TurtleAction;
-import dan200.computercraft.core.apis.http.AddressRule;
+import dan200.computercraft.core.apis.AddressPredicate;
 import dan200.computercraft.shared.Config;
 import dan200.computercraft.shared.computer.blocks.BlockComputer;
 import dan200.computercraft.shared.computer.core.ClientComputerRegistry;
@@ -39,13 +39,8 @@ 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
@@ -55,8 +50,8 @@ public final class ComputerCraft
     public static final int DATAFIXER_VERSION = 0;
 
     // Configuration options
-    public static final String[] DEFAULT_HTTP_ALLOW = new String[] { "*" };
-    public static final String[] DEFAULT_HTTP_DENY = new String[] {
+    public static final String[] DEFAULT_HTTP_WHITELIST = new String[] { "*" };
+    public static final String[] DEFAULT_HTTP_BLACKLIST = new String[] {
         "127.0.0.0/8",
         "10.0.0.0/8",
         "172.16.0.0/12",
@@ -70,18 +65,17 @@ public final class ComputerCraft
     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 logPeripheralErrors = true;
+    public static boolean commandRequireCreative = true;
 
     public static int computer_threads = 1;
     public static long maxMainGlobalTime = TimeUnit.MILLISECONDS.toNanos( 10 );
     public static long maxMainComputerTime = TimeUnit.MILLISECONDS.toNanos( 5 );
 
-    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, AddressRule.Action.DENY ) ).filter( Objects::nonNull ),
-        Stream.of( DEFAULT_HTTP_ALLOW ).map( x -> AddressRule.parse( x, AddressRule.Action.ALLOW ) ).filter( Objects::nonNull )
-    ).collect( Collectors.toList() ) );
+    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 int httpTimeout = 30000;
     public static int httpMaxRequests = 16;
@@ -97,6 +91,7 @@ public final class ComputerCraft
     public static int modem_highAltitudeRangeDuringStorm = 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;

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

@@ -3,8 +3,10 @@
  * 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.turtle;
+package dan200.computercraft.api;
 
+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/ComputerCraftAPI.java

@@ -112,6 +112,31 @@ 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

@@ -1,61 +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.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

@@ -11,6 +11,8 @@ 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;
@@ -21,10 +23,10 @@ import java.util.List;
  *
  * Ready made implementations of this interface can be created using
  * {@link ComputerCraftAPI#createSaveDirMount(World, String, long)} or
- * {@link ComputerCraftAPI#createResourceMount(String, String)}, or you're free to implement it yourselves!
+ * {@link ComputerCraftAPI#createResourceMount(Class, String, String)}, or you're free to implement it yourselves!
  *
  * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
- * @see ComputerCraftAPI#createResourceMount(String, String)
+ * @see ComputerCraftAPI#createResourceMount(Class, String, String)
  * @see IComputerAccess#mount(String, IMount)
  * @see IWritableMount
  */
@@ -66,6 +68,18 @@ 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.
      *
@@ -76,7 +90,10 @@ public interface IMount
      * @throws IOException If the file does not exist, or could not be opened.
      */
     @Nonnull
-    ReadableByteChannel openForRead( @Nonnull String path ) throws IOException;
+    default ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
+    {
+        return Channels.newChannel( openForRead( path ) );
+    }
 
     /**
      * Get attributes about the given file.

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

@@ -12,6 +12,7 @@ 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;
 
@@ -45,6 +46,18 @@ 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.
      *
@@ -54,7 +67,22 @@ public interface IWritableMount extends IMount
      * @throws IOException If the file could not be opened for writing.
      */
     @Nonnull
-    WritableByteChannel openForWrite( @Nonnull String path ) throws IOException;
+    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;
 
     /**
      * Opens a file with a given path, and returns an {@link OutputStream} for appending to it.
@@ -65,7 +93,10 @@ public interface IWritableMount extends IMount
      * @throws IOException If the file could not be opened for writing.
      */
     @Nonnull
-    WritableByteChannel openForAppend( @Nonnull String path ) throws IOException;
+    default WritableByteChannel openChannelForAppend( @Nonnull String path ) throws IOException
+    {
+        return Channels.newChannel( openForAppend( path ) );
+    }
 
     /**
      * 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/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(String, String)
+     * @see dan200.computercraft.api.ComputerCraftAPI#createResourceMount(Class, String, String)
      */
     @Nullable
     default IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )

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

@@ -14,6 +14,7 @@ import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.Collections;
 import java.util.Map;
 
 /**
@@ -30,9 +31,9 @@ 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 NotAttachedException If the peripheral has been detached.
+     * @throws RuntimeException If the peripheral has been detached.
      * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see ComputerCraftAPI#createResourceMount(String, String)
+     * @see ComputerCraftAPI#createResourceMount(Class, String, String)
      * @see #mount(String, IMount, String)
      * @see #mountWritable(String, IWritableMount)
      * @see #unmount(String)
@@ -52,9 +53,9 @@ 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 NotAttachedException If the peripheral has been detached.
+     * @throws RuntimeException If the peripheral has been detached.
      * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see ComputerCraftAPI#createResourceMount(String, String)
+     * @see ComputerCraftAPI#createResourceMount(Class, String, String)
      * @see #mount(String, IMount)
      * @see #mountWritable(String, IWritableMount)
      * @see #unmount(String)
@@ -70,9 +71,9 @@ 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 NotAttachedException If the peripheral has been detached.
+     * @throws RuntimeException If the peripheral has been detached.
      * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see ComputerCraftAPI#createResourceMount(String, String)
+     * @see ComputerCraftAPI#createResourceMount(Class, String, String)
      * @see #mount(String, IMount)
      * @see #unmount(String)
      * @see IMount
@@ -91,9 +92,9 @@ 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 NotAttachedException If the peripheral has been detached.
+     * @throws RuntimeException If the peripheral has been detached.
      * @see ComputerCraftAPI#createSaveDirMount(World, String, long)
-     * @see ComputerCraftAPI#createResourceMount(String, String)
+     * @see ComputerCraftAPI#createResourceMount(Class, String, String)
      * @see #mount(String, IMount)
      * @see #unmount(String)
      * @see IMount
@@ -113,8 +114,8 @@ 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 NotAttachedException  If the peripheral has been detached.
-     * @throws IllegalStateException If the mount does not exist, or was mounted by another peripheral.
+     * @throws RuntimeException If the peripheral has been detached.
+     * @throws RuntimeException If the mount does not exist, or was mounted by another peripheral.
      * @see #mount(String, IMount)
      * @see #mountWritable(String, IWritableMount)
      */
@@ -145,7 +146,7 @@ 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 NotAttachedException If the peripheral has been detached.
+     * @throws RuntimeException If the peripheral has been detached.
      * @see IPeripheral#callMethod
      */
     void queueEvent( @Nonnull String event, @Nullable Object[] arguments );
@@ -158,7 +159,7 @@ public interface IComputerAccess
      * which peripheral the event came.
      *
      * @return A string unique to the computer, but not globally.
-     * @throws NotAttachedException If the peripheral has been detached.
+     * @throws RuntimeException If the peripheral has been detached.
      */
     @Nonnull
     String getAttachmentName();
@@ -169,12 +170,14 @@ 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
-    Map<String, IPeripheral> getAvailablePeripherals();
+    default Map<String, IPeripheral> getAvailablePeripherals()
+    {
+        return Collections.emptyMap();
+    }
 
     /**
      * Get a reachable peripheral with the given attachment name. This is a equivalent to
@@ -185,7 +188,10 @@ public interface IComputerAccess
      * @see #getAvailablePeripherals()
      */
     @Nullable
-    IPeripheral getAvailablePeripheral( @Nonnull String name );
+    default IPeripheral getAvailablePeripheral( @Nonnull String name )
+    {
+        return null;
+    }
 
     /**
      * Get a {@link IWorkMonitor} for tasks your peripheral might execute on the main (server) thread.
@@ -199,8 +205,10 @@ 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.
      */
-    @Nonnull
-    IWorkMonitor getMainThreadMonitor();
+    @Nullable
+    default IWorkMonitor getMainThreadMonitor()
+    {
+        return null;
+    }
 }

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

@@ -1,25 +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;
-
-/**
- * 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/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;
@@ -18,9 +18,11 @@ 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
@@ -124,11 +126,12 @@ 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.
+     * @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.
      */
     @Nonnull
     @OnlyIn( Dist.CLIENT )
-    TransformedModel getModel( @Nullable ITurtleAccess turtle, @Nonnull TurtleSide side );
+    Pair<IBakedModel, Matrix4f> 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 #SHORT_WAIT
+     * @see #Wait
+     * @see #ShortWait
      */
-    NONE,
+    None,
 
     /**
      * Make the turtle move forward. Note that the animation starts from the block <em>behind</em> it, and
      * moves into this one.
      */
-    MOVE_FORWARD,
+    MoveForward,
 
     /**
      * Make the turtle move backwards. Note that the animation starts from the block <em>in front</em> it, and
      * moves into this one.
      */
-    MOVE_BACK,
+    MoveBack,
 
     /**
      * Make the turtle move backwards. Note that the animation starts from the block <em>above</em> it, and
      * moves into this one.
      */
-    MOVE_UP,
+    MoveUp,
 
     /**
      * Make the turtle move backwards. Note that the animation starts from the block <em>below</em> it, and
      * moves into this one.
      */
-    MOVE_DOWN,
+    MoveDown,
 
     /**
      * 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.
      */
-    TURN_LEFT,
+    TurnLeft,
 
     /**
      * 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.
      */
-    TURN_RIGHT,
+    TurnRight,
 
     /**
      * Swing the tool on the left.
      */
-    SWING_LEFT_TOOL,
+    SwingLeftTool,
 
     /**
      * Swing the tool on the right.
      */
-    SWING_RIGHT_TOOL,
+    SwingRightTool,
 
     /**
      * Wait until the animation has finished, performing no movement.
      *
-     * @see #SHORT_WAIT
-     * @see #NONE
+     * @see #ShortWait
+     * @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
      */
-    SHORT_WAIT,
+    ShortWait,
 }

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/client/ClientRegistry.java

@@ -11,19 +11,20 @@ import dan200.computercraft.shared.common.IColouredItem;
 import dan200.computercraft.shared.media.items.ItemDisk;
 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.inventory.container.PlayerContainer;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 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;
 
@@ -70,13 +71,13 @@ public final class ClientRegistry
     @SubscribeEvent
     public static void registerModels( ModelRegistryEvent event )
     {
-        ModelLoaderRegistry.registerLoader( new ResourceLocation( ComputerCraft.MOD_ID, "turtle" ), TurtleModelLoader.INSTANCE );
+        ModelLoaderRegistry.registerLoader( TurtleModelLoader.INSTANCE );
     }
 
     @SubscribeEvent
     public static void onTextureStitchEvent( TextureStitchEvent.Pre event )
     {
-        if( !event.getMap().getTextureLocation().equals( PlayerContainer.LOCATION_BLOCKS_TEXTURE ) ) return;
+        if( event.getMap() != Minecraft.getInstance().getTextureMap() ) return;
 
         for( String extra : EXTRA_TEXTURES )
         {
@@ -91,18 +92,29 @@ public final class ClientRegistry
         ModelLoader loader = event.getModelLoader();
         Map<ResourceLocation, IBakedModel> registry = event.getModelRegistry();
 
-        for( String modelName : EXTRA_MODELS )
+        for( String model : EXTRA_MODELS )
         {
-            ResourceLocation location = new ResourceLocation( ComputerCraft.MOD_ID, "item/" + modelName );
-            IUnbakedModel model = loader.getUnbakedModel( location );
-            model.getTextures( loader::getUnbakedModel, new HashSet<>() );
+            IBakedModel bakedModel = bake( loader, loader.getUnbakedModel( new ResourceLocation( ComputerCraft.MOD_ID, "item/" + model ) ) );
 
-            IBakedModel baked = model.bakeModel( loader, ModelLoader.defaultTextureGetter(), SimpleModelTransform.IDENTITY, location );
-            if( baked != null )
+            if( bakedModel != null )
             {
-                registry.put( new ModelResourceLocation( new ResourceLocation( ComputerCraft.MOD_ID, modelName ), "inventory" ), baked );
+                registry.put(
+                    new ModelResourceLocation( new ResourceLocation( ComputerCraft.MOD_ID, model ), "inventory" ),
+                    bakedModel
+                );
             }
         }
+
+        // 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
@@ -130,7 +142,7 @@ 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 );
@@ -141,4 +153,15 @@ 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.systems.RenderSystem;
-import com.mojang.blaze3d.vertex.IVertexBuilder;
+import com.mojang.blaze3d.platform.GlStateManager;
 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.*;
+import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.client.renderer.vertex.VertexFormat;
 import net.minecraft.util.ResourceLocation;
@@ -24,10 +24,21 @@ 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;
@@ -35,24 +46,21 @@ 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( Matrix4f transform, IVertexBuilder buffer, float x, float y, int index, float r, float g, float b )
+    private static void drawChar( BufferBuilder 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;
@@ -63,27 +71,27 @@ public final class FixedWidthFontRenderer
         int xStart = 1 + column * (FONT_WIDTH + 2);
         int yStart = 1 + row * (FONT_HEIGHT + 2);
 
-        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();
+        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();
     }
 
-    private static void drawQuad( Matrix4f transform, IVertexBuilder buffer, float x, float y, float width, float height, float r, float g, float b )
+    private static void drawQuad( BufferBuilder buffer, float x, float y, float width, float height, float r, float g, float b )
     {
-        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();
+        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();
     }
 
-    private static void drawQuad( Matrix4f transform, IVertexBuilder buffer, float x, float y, float width, float height, Palette palette, boolean greyscale, char colourIndex )
+    private static void drawQuad( BufferBuilder 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 )
         {
@@ -96,23 +104,23 @@ public final class FixedWidthFontRenderer
             b = (float) colour[2];
         }
 
-        drawQuad( transform, buffer, x, y, width, height, r, g, b );
+        drawQuad( buffer, x, y, width, height, r, g, b );
     }
 
     private static void drawBackground(
-        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder renderer, float x, float y,
+        @Nonnull BufferBuilder renderer, float x, float y,
         @Nonnull TextBuffer backgroundColour, @Nonnull Palette palette, boolean greyscale,
         float leftMarginSize, float rightMarginSize, float height
     )
     {
         if( leftMarginSize > 0 )
         {
-            drawQuad( transform, renderer, x - leftMarginSize, y, leftMarginSize, height, palette, greyscale, backgroundColour.charAt( 0 ) );
+            drawQuad( renderer, x - leftMarginSize, y, leftMarginSize, height, palette, greyscale, backgroundColour.charAt( 0 ) );
         }
 
         if( rightMarginSize > 0 )
         {
-            drawQuad( transform, renderer, x + backgroundColour.length() * FONT_WIDTH, y, rightMarginSize, height, palette, greyscale, backgroundColour.charAt( backgroundColour.length() - 1 ) );
+            drawQuad( renderer, x + backgroundColour.length() * FONT_WIDTH, y, rightMarginSize, height, palette, greyscale, backgroundColour.charAt( backgroundColour.length() - 1 ) );
         }
 
         // Batch together runs of identical background cells.
@@ -125,7 +133,7 @@ public final class FixedWidthFontRenderer
 
             if( blockColour != '\0' )
             {
-                drawQuad( transform, renderer, x + blockStart * FONT_WIDTH, y, FONT_WIDTH * (i - blockStart), height, palette, greyscale, blockColour );
+                drawQuad( renderer, x + blockStart * FONT_WIDTH, y, FONT_WIDTH * (i - blockStart), height, palette, greyscale, blockColour );
             }
 
             blockColour = colourIndex;
@@ -134,24 +142,24 @@ public final class FixedWidthFontRenderer
 
         if( blockColour != '\0' )
         {
-            drawQuad( transform, renderer, x + blockStart * FONT_WIDTH, y, FONT_WIDTH * (backgroundColour.length() - blockStart), height, palette, greyscale, blockColour );
+            drawQuad( renderer, x + blockStart * FONT_WIDTH, y, FONT_WIDTH * (backgroundColour.length() - blockStart), height, palette, greyscale, blockColour );
         }
     }
 
     public static void drawString(
-        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder renderer, float x, float y,
+        @Nonnull BufferBuilder 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( transform, renderer, x, y, backgroundColour, palette, greyscale, leftMarginSize, rightMarginSize, FONT_HEIGHT );
+            drawBackground( renderer, x, y, backgroundColour, palette, greyscale, leftMarginSize, rightMarginSize, FONT_HEIGHT );
         }
 
         for( int i = 0; i < text.length(); i++ )
         {
-            double[] colour = palette.getColour( 15 - "0123456789abcdef".indexOf( textColour.charAt( i ) ) );
+            double[] colour = palette.getColour( getColour( textColour.charAt( i ), Colour.White ) );
             float r, g, b;
             if( greyscale )
             {
@@ -167,7 +175,7 @@ public final class FixedWidthFontRenderer
             // Draw char
             int index = text.charAt( i );
             if( index > 255 ) index = '?';
-            drawChar( transform, renderer, x + i * FONT_WIDTH, y, index, r, g, b );
+            drawChar( renderer, x + i * FONT_WIDTH, y, index, r, g, b );
         }
 
     }
@@ -179,13 +187,15 @@ public final class FixedWidthFontRenderer
     {
         bindFont();
 
-        IRenderTypeBuffer.Impl renderer = Minecraft.getInstance().getRenderTypeBuffers().getBufferSource();
-        drawString( IDENTITY, ((IRenderTypeBuffer) renderer).getBuffer( TYPE ), x, y, text, textColour, backgroundColour, palette, greyscale, leftMarginSize, rightMarginSize );
-        renderer.finish();
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder buffer = tessellator.getBuffer();
+        begin( buffer );
+        drawString( buffer, x, y, text, textColour, backgroundColour, palette, greyscale, leftMarginSize, rightMarginSize );
+        tessellator.draw();
     }
 
     public static void drawTerminalWithoutCursor(
-        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder buffer, float x, float y,
+        @Nonnull BufferBuilder buffer, float x, float y,
         @Nonnull Terminal terminal, boolean greyscale,
         float topMarginSize, float bottomMarginSize, float leftMarginSize, float rightMarginSize
     )
@@ -195,13 +205,13 @@ public final class FixedWidthFontRenderer
 
         // Top and bottom margins
         drawBackground(
-            transform, buffer, x, y - topMarginSize,
+            buffer, x, y - topMarginSize,
             terminal.getBackgroundColourLine( 0 ), palette, greyscale,
             leftMarginSize, rightMarginSize, topMarginSize
         );
 
         drawBackground(
-            transform, buffer, x, y + height * FONT_HEIGHT,
+            buffer, x, y + height * FONT_HEIGHT,
             terminal.getBackgroundColourLine( height - 1 ), palette, greyscale,
             leftMarginSize, rightMarginSize, bottomMarginSize
         );
@@ -210,7 +220,7 @@ public final class FixedWidthFontRenderer
         for( int i = 0; i < height; i++ )
         {
             drawString(
-                transform, buffer, x, y + FixedWidthFontRenderer.FONT_HEIGHT * i,
+                buffer, x, y + FixedWidthFontRenderer.FONT_HEIGHT * i,
                 terminal.getLine( i ), terminal.getTextColourLine( i ), terminal.getBackgroundColourLine( i ),
                 palette, greyscale, leftMarginSize, rightMarginSize
             );
@@ -218,7 +228,7 @@ public final class FixedWidthFontRenderer
     }
 
     public static void drawCursor(
-        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder buffer, float x, float y,
+        @Nonnull BufferBuilder buffer, float x, float y,
         @Nonnull Terminal terminal, boolean greyscale
     )
     {
@@ -243,104 +253,75 @@ public final class FixedWidthFontRenderer
                 b = (float) colour[2];
             }
 
-            drawChar( transform, buffer, x + cursorX * FONT_WIDTH, y + cursorY * FONT_HEIGHT, '_', r, g, b );
+            drawChar( buffer, x + cursorX * FONT_WIDTH, y + cursorY * FONT_HEIGHT, '_', r, g, b );
         }
     }
 
     public static void drawTerminal(
-        @Nonnull Matrix4f transform, @Nonnull IVertexBuilder buffer, float x, float y,
+        @Nonnull BufferBuilder buffer, float x, float y,
         @Nonnull Terminal terminal, boolean greyscale,
         float topMarginSize, float bottomMarginSize, float leftMarginSize, float rightMarginSize
     )
     {
-        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 );
+        drawTerminalWithoutCursor( buffer, x, y, terminal, greyscale, topMarginSize, bottomMarginSize, leftMarginSize, rightMarginSize );
+        drawCursor( buffer, x, y, terminal, greyscale );
     }
 
     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();
 
-        IRenderTypeBuffer.Impl renderer = Minecraft.getInstance().getRenderTypeBuffers().getBufferSource();
-        drawEmptyTerminal( transform, renderer, x, y, width, height );
-        renderer.finish();
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder buffer = tessellator.getBuffer();
+        begin( buffer );
+        drawTerminal( buffer, x, y, terminal, greyscale, topMarginSize, bottomMarginSize, leftMarginSize, rightMarginSize );
+        tessellator.draw();
     }
 
     public static void drawEmptyTerminal( float x, float y, float width, float height )
     {
-        drawEmptyTerminal( IDENTITY, x, y, width, 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();
     }
 
-    public static void drawBlocker( @Nonnull Matrix4f transform, @Nonnull IRenderTypeBuffer renderer, float x, float y, float width, float height )
+    public static void drawBlocker( @Nonnull BufferBuilder buffer, float x, float y, float width, float height )
     {
-        Colour colour = Colour.BLACK;
-        drawQuad( transform, renderer.getBuffer( Type.BLOCKER ), x, y, width, height, colour.getR(), colour.getG(), colour.getB() );
+        Colour colour = Colour.Black;
+        drawQuad( buffer, x, y, width, height, colour.getR(), colour.getG(), colour.getB() );
     }
 
-    private static void bindFont()
+    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()
     {
         Minecraft.getInstance().getTextureManager().bindTexture( FONT );
-        RenderSystem.texParameter( GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL11.GL_CLAMP );
+        GlStateManager.texParameter( GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL11.GL_CLAMP );
+
+        GlStateManager.enableTexture();
     }
 
-    private static final class Type extends RenderState
+    public static void begin( BufferBuilder buffer )
     {
-        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 );
-        }
+        buffer.begin( GL11.GL_TRIANGLES, POSITION_COLOR_TEX );
     }
 }

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

@@ -5,7 +5,7 @@
  */
 package dan200.computercraft.client.gui;
 
-import com.mojang.blaze3d.systems.RenderSystem;
+import com.mojang.blaze3d.platform.GlStateManager;
 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
-        RenderSystem.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
+        GlStateManager.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.systems.RenderSystem;
+import com.mojang.blaze3d.platform.GlStateManager;
 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 )
     {
-        RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+        GlStateManager.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.systems.RenderSystem;
+import com.mojang.blaze3d.platform.GlStateManager;
 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 )
     {
-        RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+        GlStateManager.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

@@ -5,15 +5,11 @@
  */
 package dan200.computercraft.client.gui;
 
-import com.mojang.blaze3d.systems.RenderSystem;
+import com.mojang.blaze3d.platform.GlStateManager;
 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;
@@ -22,8 +18,6 @@ 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;
@@ -94,22 +88,20 @@ public class GuiPrintout extends ContainerScreen<ContainerHeldItem>
     public void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
         // Draw the printout
-        RenderSystem.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
-        RenderSystem.enableDepthTest();
+        GlStateManager.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
+        GlStateManager.enableDepthTest();
 
-        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();
+        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 );
     }
 
     @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.
-        setBlitOffset( getBlitOffset() - 1 );
+        blitOffset--;
         renderBackground();
-        setBlitOffset( getBlitOffset() + 1 );
+        blitOffset++;
 
         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.systems.RenderSystem;
+import com.mojang.blaze3d.platform.GlStateManager;
 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 )
         {
-            RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+            GlStateManager.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
-        RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+        GlStateManager.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

@@ -17,9 +17,6 @@ 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;
@@ -176,8 +173,8 @@ public class WidgetTerminal implements IGuiEventListener
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FONT_WIDTH);
-            int charY = (int) (mouseY / FONT_HEIGHT);
+            int charX = (int) (mouseX / FixedWidthFontRenderer.FONT_WIDTH);
+            int charY = (int) (mouseY / FixedWidthFontRenderer.FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -200,8 +197,8 @@ public class WidgetTerminal implements IGuiEventListener
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FONT_WIDTH);
-            int charY = (int) (mouseY / FONT_HEIGHT);
+            int charX = (int) (mouseX / FixedWidthFontRenderer.FONT_WIDTH);
+            int charY = (int) (mouseY / FixedWidthFontRenderer.FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -227,8 +224,8 @@ public class WidgetTerminal implements IGuiEventListener
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FONT_WIDTH);
-            int charY = (int) (mouseY / FONT_HEIGHT);
+            int charX = (int) (mouseX / FixedWidthFontRenderer.FONT_WIDTH);
+            int charY = (int) (mouseY / FixedWidthFontRenderer.FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -252,8 +249,8 @@ public class WidgetTerminal implements IGuiEventListener
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FONT_WIDTH);
-            int charY = (int) (mouseY / FONT_HEIGHT);
+            int charX = (int) (mouseX / FixedWidthFontRenderer.FONT_WIDTH);
+            int charY = (int) (mouseY / FixedWidthFontRenderer.FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -321,15 +318,19 @@ 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
             {
-                FixedWidthFontRenderer.drawEmptyTerminal(
-                    originX - leftMargin, originY - rightMargin,
-                    termWidth * FONT_WIDTH + leftMargin + rightMargin,
-                    termHeight * FONT_HEIGHT + topMargin + bottomMargin
-                );
+                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 );
             }
         }
     }

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

@@ -7,6 +7,7 @@ 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;
@@ -14,6 +15,7 @@ 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;
@@ -22,8 +24,6 @@ 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;
@@ -40,22 +40,12 @@ public final class ComputerCraftProxyClient
     {
         registerContainers();
 
-        // While turtles themselves are not transparent, their upgrades may be.
-        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.turtleNormal, RenderType.getTranslucent() );
-        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.turtleAdvanced, RenderType.getTranslucent() );
-
-        // 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() );
+        ClientRegistry.bindTileEntitySpecialRenderer( TileMonitor.class, new TileEntityMonitorRenderer() );
+        ClientRegistry.bindTileEntitySpecialRenderer( TileCable.class, new TileEntityCableRenderer() );
+        ClientRegistry.bindTileEntitySpecialRenderer( TileTurtle.class, new TileEntityTurtleRenderer() );
 
-        RenderingRegistry.registerEntityRenderingHandler( TurtlePlayer.TYPE, TurtlePlayerRenderer::new );
+        RenderingRegistry.registerEntityRenderingHandler( TurtlePlayer.class, TurtlePlayerRenderer::new );
     }
 
     private static void registerContainers()

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

@@ -5,27 +5,26 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.matrix.MatrixStack;
-import com.mojang.blaze3d.vertex.IVertexBuilder;
+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.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.DrawHighlightEvent;
+import net.minecraftforge.client.event.DrawBlockHighlightEvent;
 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
@@ -38,12 +37,14 @@ public final class CableHighlightRenderer
      * Draw an outline for a specific part of a cable "Multipart".
      *
      * @param event The event to observe
-     * @see WorldRenderer#drawSelectionBox(MatrixStack, IVertexBuilder, Entity, double, double, double, BlockPos, BlockState)
+     * @see WorldRenderer#drawSelectionBox(ActiveRenderInfo, RayTraceResult, int)
      */
     @SubscribeEvent
-    public static void drawHighlight( DrawHighlightEvent.HighlightBlock event )
+    public static void drawHighlight( DrawBlockHighlightEvent event )
     {
-        BlockRayTraceResult hit = event.getTarget();
+        if( event.getTarget().getType() != RayTraceResult.Type.BLOCK ) return;
+
+        BlockRayTraceResult hit = (BlockRayTraceResult) event.getTarget();
         BlockPos pos = hit.getPos();
         World world = event.getInfo().getRenderViewEntity().getEntityWorld();
         ActiveRenderInfo info = event.getInfo();
@@ -58,22 +59,31 @@ 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();
-        double xOffset = pos.getX() - cameraPos.getX();
-        double yOffset = pos.getY() - cameraPos.getY();
-        double zOffset = pos.getZ() - cameraPos.getZ();
+        WorldRenderer.drawShape(
+            shape, pos.getX() - cameraPos.getX(), pos.getY() - cameraPos.getY(), pos.getZ() - cameraPos.getZ(),
+            0.0F, 0.0F, 0.0F, 0.4F
+        );
 
-        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();
-        } );
+        GlStateManager.popMatrix();
+        GlStateManager.matrixMode( GL11.GL_MODELVIEW );
+        GlStateManager.depthMask( true );
+        GlStateManager.enableTexture();
+        GlStateManager.disableBlend();
     }
 }

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

@@ -5,12 +5,9 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.matrix.MatrixStack;
+import com.mojang.blaze3d.platform.GlStateManager;
 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;
@@ -22,118 +19,99 @@ public abstract class ItemMapLikeRenderer
     /**
      * The main rendering method for the item.
      *
-     * @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)
+     * @param stack The stack to render
+     * @see FirstPersonRenderer#renderMapFirstPerson(ItemStack)
      */
-    protected abstract void renderItem( MatrixStack transform, IRenderTypeBuffer render, ItemStack stack );
+    protected abstract void renderItem( ItemStack stack );
 
-    protected void renderItemFirstPerson( MatrixStack transform, IRenderTypeBuffer render, int lightTexture, Hand hand, float pitch, float equipProgress, float swingProgress, ItemStack stack )
+    protected void renderItemFirstPerson( Hand hand, float pitch, float equipProgress, float swingProgress, ItemStack stack )
     {
         PlayerEntity player = Minecraft.getInstance().player;
 
-        transform.push();
+        GlStateManager.pushMatrix();
         if( hand == Hand.MAIN_HAND && player.getHeldItemOffhand().isEmpty() )
         {
-            renderItemFirstPersonCenter( transform, render, lightTexture, pitch, equipProgress, swingProgress, stack );
+            renderItemFirstPersonCenter( pitch, equipProgress, swingProgress, stack );
         }
         else
         {
             renderItemFirstPersonSide(
-                transform, render, lightTexture,
                 hand == Hand.MAIN_HAND ? player.getPrimaryHand() : player.getPrimaryHand().opposite(),
                 equipProgress, swingProgress, stack
             );
         }
-        transform.pop();
+        GlStateManager.popMatrix();
     }
 
     /**
      * 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(MatrixStack, IRenderTypeBuffer, int, float, HandSide, float, ItemStack)
+     * @see FirstPersonRenderer#renderMapFirstPersonSide(float, HandSide, float, ItemStack)
      */
-    private void renderItemFirstPersonSide( MatrixStack transform, IRenderTypeBuffer render, int combinedLight, HandSide side, float equipProgress, float swingProgress, ItemStack stack )
+    private void renderItemFirstPersonSide( HandSide side, float equipProgress, float swingProgress, ItemStack stack )
     {
         Minecraft minecraft = Minecraft.getInstance();
         float offset = side == HandSide.RIGHT ? 1f : -1f;
-        transform.translate( offset * 0.125f, -0.125f, 0f );
+        GlStateManager.translatef( offset * 0.125f, -0.125f, 0f );
 
         // If the player is not invisible then render a single arm
         if( !minecraft.player.isInvisible() )
         {
-            transform.push();
-            transform.rotate( Vector3f.ZP.rotationDegrees( offset * 10f ) );
-            minecraft.getFirstPersonRenderer().renderArmFirstPerson( transform, render, combinedLight, equipProgress, swingProgress, side );
-            transform.pop();
+            GlStateManager.pushMatrix();
+            GlStateManager.rotatef( offset * 10f, 0f, 0f, 1f );
+            minecraft.getFirstPersonRenderer().renderArmFirstPerson( equipProgress, swingProgress, side );
+            GlStateManager.popMatrix();
         }
 
         // Setup the appropriate transformations. This is just copied from the
         // corresponding method in ItemRenderer.
-        transform.push();
-        transform.translate( offset * 0.51f, -0.08f + equipProgress * -1.2f, -0.75f );
+        GlStateManager.pushMatrix();
+        GlStateManager.translatef( 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 );
-        transform.translate( offset * f3, f4 - 0.3f * f2, f5 );
-        transform.rotate( Vector3f.XP.rotationDegrees( f2 * -45f ) );
-        transform.rotate( Vector3f.YP.rotationDegrees( offset * f2 * -30f ) );
+        GlStateManager.translatef( offset * f3, f4 - 0.3f * f2, f5 );
+        GlStateManager.rotatef( f2 * -45f, 1f, 0f, 0f );
+        GlStateManager.rotatef( offset * f2 * -30f, 0f, 1f, 0f );
 
-        renderItem( transform, render, stack );
+        renderItem( stack );
 
-        transform.pop();
+        GlStateManager.popMatrix();
     }
 
     /**
      * 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(MatrixStack, IRenderTypeBuffer, int, float, float, float)
+     * @see FirstPersonRenderer#renderMapFirstPerson(float, float, float)
      */
-    private void renderItemFirstPersonCenter( MatrixStack transform, IRenderTypeBuffer render, int combinedLight, float pitch, float equipProgress, float swingProgress, ItemStack stack )
+    private void renderItemFirstPersonCenter( float pitch, float equipProgress, float swingProgress, ItemStack stack )
     {
-        Minecraft minecraft = Minecraft.getInstance();
-        FirstPersonRenderer renderer = minecraft.getFirstPersonRenderer();
+        FirstPersonRenderer renderer = Minecraft.getInstance().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 );
-        transform.translate( 0, -tX / 2, tZ );
-
+        GlStateManager.translatef( 0f, -tX / 2f, tZ );
         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();
-        }
-
+        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 );
-        transform.rotate( Vector3f.XP.rotationDegrees( rX * 20.0F ) );
-        transform.scale( 2.0F, 2.0F, 2.0F );
+        GlStateManager.rotatef( rX * 20f, 1f, 0f, 0f );
+        GlStateManager.scalef( 2f, 2f, 2f );
 
-        renderItem( transform, render, stack );
+        renderItem( stack );
     }
 }

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

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

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

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

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

@@ -0,0 +1,269 @@
+/*
+ * 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

@@ -5,45 +5,49 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.matrix.MatrixStack;
-import com.mojang.blaze3d.vertex.IVertexBuilder;
+import com.mojang.blaze3d.platform.GlStateManager;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
-import net.minecraft.client.renderer.Matrix4f;
-import net.minecraft.client.renderer.RenderType;
+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.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.DrawHighlightEvent;
+import net.minecraftforge.client.event.DrawBlockHighlightEvent;
 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( DrawHighlightEvent.HighlightBlock event )
+    public static void drawHighlight( DrawBlockHighlightEvent event )
     {
-        // Preserve normal behaviour when crouching.
-        if( event.getInfo().getRenderViewEntity().isCrouching() ) return;
+        if( event.getTarget().getType() != RayTraceResult.Type.BLOCK || event.getInfo().getRenderViewEntity().isSneaking() )
+        {
+            return;
+        }
 
         World world = event.getInfo().getRenderViewEntity().getEntityWorld();
-        BlockPos pos = event.getTarget().getPos();
+        BlockPos pos = ((BlockRayTraceResult) event.getTarget()).getPos();
 
         TileEntity tile = world.getTileEntity( pos );
         if( !(tile instanceof TileMonitor) ) return;
@@ -60,37 +64,53 @@ public final class MonitorHighlightRenderer
         if( monitor.getYIndex() != 0 ) faces.remove( monitor.getDown().getOpposite() );
         if( monitor.getYIndex() != monitor.getHeight() - 1 ) faces.remove( monitor.getDown() );
 
-        MatrixStack transformStack = event.getMatrix();
+        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();
+
         Vec3d cameraPos = event.getInfo().getProjectedView();
-        transformStack.push();
-        transformStack.translate( pos.getX() - cameraPos.getX(), pos.getY() - cameraPos.getY(), pos.getZ() - cameraPos.getZ() );
+        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 );
 
         // I wish I could think of a better way to do this
-        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 );
+        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 );
 
-        transformStack.pop();
+        tessellator.draw();
+
+        GlStateManager.popMatrix();
+        GlStateManager.depthMask( true );
+        GlStateManager.enableTexture();
+        GlStateManager.disableBlend();
     }
 
-    private static void line( IVertexBuilder buffer, Matrix4f transform, float x, float y, float z, Direction direction )
+    private static void line( BufferBuilder buffer, int x, int y, int z, Direction direction )
     {
-        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()
+        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)
         ).color( 0, 0, 0, 0.4f ).endVertex();
     }
 }

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

@@ -0,0 +1,156 @@
+/*
+ * 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.GLX;
+import com.mojang.blaze3d.platform.TextureUtil;
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.gui.FixedWidthFontRenderer;
+import dan200.computercraft.shared.util.Palette;
+import org.lwjgl.BufferUtils;
+import org.lwjgl.opengl.GL13;
+import org.lwjgl.opengl.GL20;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.FloatBuffer;
+
+class MonitorTextureBufferShader
+{
+    static final int TEXTURE_INDEX = GL13.GL_TEXTURE3;
+
+    private static final FloatBuffer PALETTE_BUFFER = BufferUtils.createFloatBuffer( 16 * 3 );
+
+    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( int width, int height, Palette palette, boolean greyscale )
+    {
+        GLX.glUniform1i( uniformWidth, width );
+        GLX.glUniform1i( uniformHeight, height );
+
+        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();
+        GLX.glUniform3( uniformPalette, PALETTE_BUFFER );
+    }
+
+    static boolean use()
+    {
+        if( initialised )
+        {
+            if( ok ) GLX.glUseProgram( program );
+            return ok;
+        }
+
+        if( ok = load() )
+        {
+            GL20.glUseProgram( program );
+            GLX.glUniform1i( uniformFont, 0 );
+            GLX.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 = GLX.glCreateProgram();
+            GLX.glAttachShader( program, vertexShader );
+            GLX.glAttachShader( program, fragmentShader );
+            GL20.glBindAttribLocation( program, 0, "v_pos" );
+
+            GLX.glLinkProgram( program );
+            boolean ok = GLX.glGetProgrami( program, GL20.GL_LINK_STATUS ) != 0;
+            String log = GLX.glGetProgramInfoLog( 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 );
+            GLX.glDeleteShader( vertexShader );
+            GLX.glDeleteShader( fragmentShader );
+
+            if( !ok ) return false;
+
+            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 ) throws IOException
+    {
+        String contents;
+        try( InputStream stream = TileEntityMonitorRenderer.class.getClassLoader().getResourceAsStream( path ) )
+        {
+            if( stream == null ) throw new IllegalArgumentException( "Cannot find " + path );
+            contents = TextureUtil.readResourceAsString( stream );
+        }
+
+        int shader = GLX.glCreateShader( kind );
+
+        GLX.glShaderSource( shader, contents );
+        GLX.glCompileShader( shader );
+
+        boolean ok = GLX.glGetShaderi( shader, GL20.GL_COMPILE_STATUS ) != 0;
+        String log = GLX.glGetShaderInfoLog( 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 = GLX.glGetUniformLocation( program, name );
+        if( uniform == -1 ) throw new IllegalStateException( "Cannot find uniform " + name );
+        return uniform;
+    }
+}

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

@@ -5,14 +5,15 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.vertex.IVertexBuilder;
+import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.platform.GlStateManager.DestFactor;
+import com.mojang.blaze3d.platform.GlStateManager.SourceFactor;
 import dan200.computercraft.client.gui.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.TextBuffer;
 import dan200.computercraft.shared.util.Palette;
-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.Minecraft;
+import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.util.ResourceLocation;
 import org.lwjgl.opengl.GL11;
@@ -23,7 +24,7 @@ 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 float BG_SIZE = 256.0f;
+    private static final double BG_SIZE = 256.0;
 
     /**
      * Width of a page.
@@ -60,24 +61,27 @@ public final class PrintoutRenderer
 
     private PrintoutRenderer() {}
 
-    public static void drawText( Matrix4f transform, IRenderTypeBuffer renderer, int x, int y, int start, TextBuffer[] text, TextBuffer[] colours )
+    public static void drawText( 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( transform, buffer,
+            FixedWidthFontRenderer.drawString(
                 x, y + line * FONT_HEIGHT, text[start + line], colours[start + line], null, Palette.DEFAULT,
                 false, 0, 0
             );
         }
     }
 
-    public static void drawText( Matrix4f transform, IRenderTypeBuffer renderer, int x, int y, int start, String[] text, String[] colours )
+    public static void drawText( int x, int y, int start, String[] text, String[] colours )
     {
-        IVertexBuilder buffer = renderer.getBuffer( FixedWidthFontRenderer.TYPE );
+        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 );
+
         for( int line = 0; line < LINES_PER_PAGE && line < text.length; line++ )
         {
-            FixedWidthFontRenderer.drawString( transform, buffer,
+            FixedWidthFontRenderer.drawString(
                 x, y + line * FONT_HEIGHT,
                 new TextBuffer( text[start + line] ), new TextBuffer( colours[start + line] ),
                 null, Palette.DEFAULT, false, 0, 0
@@ -85,46 +89,55 @@ public final class PrintoutRenderer
         }
     }
 
-    public static void drawBorder( Matrix4f transform, IRenderTypeBuffer renderer, float x, float y, float z, int page, int pages, boolean isBook )
+    public static void drawBorder( double x, double y, double 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
-            float offset = offsetAt( pages );
-            float left = x - 4 - offset;
-            float right = x + X_SIZE + offset - 4;
+            double offset = offsetAt( pages );
+            final double left = x - 4 - offset;
+            final double right = x + X_SIZE + offset - 4;
 
             // Left and right border
-            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 );
+            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 );
 
             // Draw centre panel (just stretched texture, sorry).
-            drawTexture( transform, buffer,
-                x - offset, y, z - 0.02f, X_SIZE + offset * 2, Y_SIZE,
+            drawTexture( buffer,
+                x - offset, y, z - 0.02, X_SIZE + offset * 2, Y_SIZE,
                 COVER_X + COVER_SIZE / 2.0f, COVER_SIZE, COVER_SIZE, Y_SIZE
             );
 
-            float borderX = left;
+            double borderX = left;
             while( borderX < right )
             {
                 double thisWidth = Math.min( right - borderX, X_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 );
+                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 );
                 borderX += thisWidth;
             }
         }
 
         // Left half
-        drawTexture( transform, buffer, x, y, z, X_FOLD_SIZE * 2, 0, X_SIZE / 2.0f, Y_SIZE );
+        drawTexture( buffer, x, y, z, X_FOLD_SIZE * 2, 0, X_SIZE / 2.0f, Y_SIZE );
         for( int n = 0; n <= leftPages; n++ )
         {
-            drawTexture( transform, buffer,
-                x - offsetAt( n ), y, z - 1e-3f * n,
+            drawTexture( buffer,
+                x - offsetAt( n ), y, z - 1e-3 * n,
                 // Use the left "bold" fold for the outermost page
                 n == leftPages ? 0 : X_FOLD_SIZE, 0,
                 X_FOLD_SIZE, Y_SIZE
@@ -132,54 +145,38 @@ public final class PrintoutRenderer
         }
 
         // Right half
-        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 );
+        drawTexture( 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( transform, buffer,
-                x + (X_SIZE - X_FOLD_SIZE) + offsetAt( n ), y, z - 1e-3f * n,
+            drawTexture( buffer,
+                x + (X_SIZE - X_FOLD_SIZE) + offsetAt( n ), y, z - 1e-3 * 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( Matrix4f matrix, IVertexBuilder buffer, float x, float y, float z, float u, float v, float width, float height )
+    private static void drawTexture( BufferBuilder buffer, double x, double y, double z, double u, double v, double width, double height )
     {
-        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();
+        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();
     }
 
-    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 )
+    private static void drawTexture( BufferBuilder buffer, double x, double y, double z, double width, double height, double u, double v, double tWidth, double tHeight )
     {
-        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();
+        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();
     }
 
-    public static float offsetAt( int page )
+    public static double offsetAt( int 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 );
-        }
+        return 32 * (1 - Math.pow( 1.2, -page ));
     }
 }

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

@@ -0,0 +1,140 @@
+/*
+ * 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

@@ -5,41 +5,44 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.matrix.MatrixStack;
-import com.mojang.blaze3d.vertex.IVertexBuilder;
+import com.mojang.blaze3d.platform.GLX;
+import com.mojang.blaze3d.platform.GlStateManager;
 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.renderer.*;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.GLAllocation;
+import net.minecraft.client.renderer.Tessellator;
 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.GL15;
+import org.lwjgl.opengl.GL31;
 
 import javax.annotation.Nonnull;
+import java.nio.ByteBuffer;
+
+import static dan200.computercraft.client.gui.FixedWidthFontRenderer.*;
+import static dan200.computercraft.shared.peripheral.monitor.TileMonitor.RENDER_MARGIN;
 
 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 final Matrix4f IDENTITY = TransformationMatrix.identity().getMatrix();
-
-    public TileEntityMonitorRenderer( TileEntityRendererDispatcher rendererDispatcher )
-    {
-        super( rendererDispatcher );
-    }
+    private static ByteBuffer tboContents;
 
     @Override
-    public void render( @Nonnull TileMonitor monitor, float partialTicks, @Nonnull MatrixStack transform, @Nonnull IRenderTypeBuffer renderer, int lightmapCoord, int overlayLight )
+    public void render( @Nonnull TileMonitor monitor, double posX, double posY, double posZ, float f, int i )
     {
         // Render from the origin monitor
         ClientMonitor originTerminal = monitor.getClientMonitor();
@@ -61,6 +64,9 @@ 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();
@@ -68,94 +74,183 @@ public class TileEntityMonitorRenderer extends TileEntityRenderer<TileMonitor>
         float yaw = dir.getHorizontalAngle();
         float pitch = DirectionUtil.toPitchAngle( front );
 
-        // Setup initial transform
-        transform.push();
-        transform.translate(
-            originPos.getX() - monitorPos.getX() + 0.5,
-            originPos.getY() - monitorPos.getY() + 0.5,
-            originPos.getZ() - monitorPos.getZ() + 0.5
-        );
+        GlStateManager.pushMatrix();
 
-        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,
+        // 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,
             0.5
         );
-        double xSize = origin.getWidth() - 2.0 * (TileMonitor.RENDER_MARGIN + TileMonitor.RENDER_BORDER);
-        double ySize = origin.getHeight() - 2.0 * (TileMonitor.RENDER_MARGIN + TileMonitor.RENDER_BORDER);
+        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();
 
-        // Draw the contents
         Terminal terminal = originTerminal.getTerminal();
         if( terminal != null )
         {
-            boolean redraw = originTerminal.pollTerminalChanged();
-            if( originTerminal.buffer == null )
-            {
-                originTerminal.createBuffer( MonitorRenderer.VBO );
-                redraw = true;
-            }
-            VertexBuffer vbo = originTerminal.buffer;
-
             // Draw a terminal
-            double xScale = xSize / (terminal.getWidth() * FixedWidthFontRenderer.FONT_WIDTH);
-            double yScale = ySize / (terminal.getHeight() * FixedWidthFontRenderer.FONT_HEIGHT);
-            transform.push();
-            transform.scale( (float) xScale, (float) -yScale, 1.0f );
+            double xScale = xSize / (terminal.getWidth() * FONT_WIDTH);
+            double yScale = ySize / (terminal.getHeight() * FONT_HEIGHT);
 
-            float xMargin = (float) (MARGIN / xScale);
-            float yMargin = (float) (MARGIN / yScale);
+            GlStateManager.pushMatrix();
+            GlStateManager.scaled( (float) xScale, (float) -yScale, 1.0f );
 
-            Matrix4f matrix = transform.getLast().getMatrix();
+            renderTerminal( originTerminal, (float) (MARGIN / xScale), (float) (MARGIN / yScale) );
 
-            if( redraw )
-            {
-                Tessellator tessellator = Tessellator.getInstance();
-                BufferBuilder builder = tessellator.getBuffer();
-                builder.begin( FixedWidthFontRenderer.TYPE.getDrawMode(), FixedWidthFontRenderer.TYPE.getVertexFormat() );
-                FixedWidthFontRenderer.drawTerminalWithoutCursor(
-                    IDENTITY, builder, 0, 0,
-                    terminal, !originTerminal.isColour(), yMargin, yMargin, xMargin, xMargin
-                );
-
-                builder.finishDrawing();
-                vbo.upload( builder );
-            }
-
-            // 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();
-
-            vbo.bindBuffer();
-            FixedWidthFontRenderer.TYPE.getVertexFormat().setupBufferState( 0L );
-            vbo.draw( matrix, FixedWidthFontRenderer.TYPE.getDrawMode() );
-            VertexBuffer.unbindBuffer();
-            FixedWidthFontRenderer.TYPE.getVertexFormat().clearBufferState();
-
-            // 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();
+            GlStateManager.popMatrix();
         }
         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 );
 
-        transform.pop();
+        GlStateManager.popMatrix();
+    }
+
+    private static void renderTerminal( ClientMonitor monitor, float xMargin, float yMargin )
+    {
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder buffer = tessellator.getBuffer();
+
+        boolean redraw = monitor.pollTerminalChanged();
+
+        // 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 )
+        {
+            case TBO:
+            {
+                if( !MonitorTextureBufferShader.use() ) return;
+
+                Terminal terminal = monitor.getTerminal();
+                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();
+
+                    GLX.glBindBuffer( GL31.GL_TEXTURE_BUFFER, monitor.tboBuffer );
+                    GLX.glBufferData( GL31.GL_TEXTURE_BUFFER, monitorBuffer, GL15.GL_STATIC_DRAW );
+                    GLX.glBindBuffer( GL31.GL_TEXTURE_BUFFER, 0 );
+                }
+
+                // Bind TBO texture and set up the uniforms. We've already set up the main font above.
+                GlStateManager.activeTexture( MonitorTextureBufferShader.TEXTURE_INDEX );
+                GL11.glBindTexture( GL31.GL_TEXTURE_BUFFER, monitor.tboTexture );
+                GlStateManager.activeTexture( GL13.GL_TEXTURE0 );
+
+                MonitorTextureBufferShader.setupUniform( width, height, terminal.getPalette(), !monitor.isColour() );
+
+                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();
+
+                GLX.glUseProgram( 0 );
+                break;
+            }
+
+            case VBO:
+            {
+                VertexBuffer vbo = monitor.buffer;
+                if( redraw )
+                {
+                    renderTerminalTo( monitor, buffer, xMargin, yMargin );
+                    buffer.finishDrawing();
+                    buffer.reset();
+                    vbo.bufferData( buffer.getByteBuffer() );
+                }
+
+                vbo.bindBuffer();
+                setupBufferFormat();
+                vbo.drawArrays( GL11.GL_TRIANGLES );
+                VertexBuffer.unbindBuffer();
+
+                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

@@ -5,9 +5,7 @@
  */
 package dan200.computercraft.client.render;
 
-import com.mojang.blaze3d.matrix.MatrixStack;
-import com.mojang.blaze3d.vertex.IVertexBuilder;
-import dan200.computercraft.api.client.TransformedModel;
+import com.mojang.blaze3d.platform.GlStateManager;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
@@ -15,26 +13,31 @@ 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.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.BufferBuilder;
+import net.minecraft.client.renderer.GameRenderer;
+import net.minecraft.client.renderer.Tessellator;
 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.tileentity.TileEntityRendererDispatcher;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.client.renderer.vertex.VertexFormat;
 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.annotation.Nonnull;
+import javax.vecmath.Matrix4f;
 import java.util.List;
 import java.util.Random;
 
@@ -45,147 +48,189 @@ 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" );
 
-    private final Random random = new Random( 0 );
-
-    public TileEntityTurtleRenderer( TileEntityRendererDispatcher renderDispatcher )
+    @Override
+    public void render( TileTurtle tileEntity, double posX, double posY, double posZ, float partialTicks, int breaking )
     {
-        super( renderDispatcher );
+        if( tileEntity != null ) renderTurtleAt( tileEntity, posX, posY, posZ, partialTicks );
     }
 
     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" );
-        if( christmas ) return ELF_OVERLAY_MODEL;
-        return null;
+        if( overlay != null )
+        {
+            return new ModelResourceLocation( overlay, "inventory" );
+        }
+        else if( christmas )
+        {
+            return ELF_OVERLAY_MODEL;
+        }
+        else
+        {
+            return null;
+        }
     }
 
-    @Override
-    public void render( @Nonnull TileTurtle turtle, float partialTicks, @Nonnull MatrixStack transform, @Nonnull IRenderTypeBuffer renderer, int lightmapCoord, int overlayLight )
+    private void renderTurtleAt( TileTurtle turtle, double posX, double posY, double posZ, float partialTicks )
     {
         // Render the label
         String label = turtle.createProxy().getLabel();
-        RayTraceResult hit = renderDispatcher.cameraHitResult;
+        RayTraceResult hit = rendererDispatcher.cameraHitResult;
         if( label != null && hit.getType() == RayTraceResult.Type.BLOCK && turtle.getPos().equals( ((BlockRayTraceResult) hit).getPos() ) )
         {
-            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();
+            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 );
         }
 
-        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" )) )
+        GlStateManager.pushMatrix();
+        try
         {
-            // Flip the model
-            transform.scale( 1.0f, -1.0f, 1.0f );
-        }
-        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 )
-        {
-            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( @Nonnull MatrixStack transform, @Nonnull IVertexBuilder renderer, int lightmapCoord, int overlayLight, TileTurtle turtle, TurtleSide side, float f )
-    {
-        ITurtleUpgrade upgrade = turtle.getUpgrade( side );
-        if( upgrade == null ) return;
-        transform.push();
-
-        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( @Nonnull MatrixStack transform, @Nonnull IVertexBuilder renderer, int lightmapCoord, int overlayLight, ModelResourceLocation modelLocation, int[] tints )
-    {
-        ModelManager modelManager = Minecraft.getInstance().getItemRenderer().getItemModelMesher().getModelManager();
-        renderModel( transform, renderer, lightmapCoord, overlayLight, modelManager.getModel( modelLocation ), tints );
-    }
-
-    private void renderModel( @Nonnull MatrixStack transform, @Nonnull IVertexBuilder renderer, int lightmapCoord, int overlayLight, IBakedModel model, int[] tints )
-    {
-        random.setSeed( 0 );
-        renderQuads( transform, renderer, lightmapCoord, overlayLight, model.getQuads( null, null, random, EmptyModelData.INSTANCE ), tints );
-        for( Direction facing : DirectionUtil.FACINGS )
-        {
-            renderQuads( transform, renderer, lightmapCoord, overlayLight, model.getQuads( null, facing, random, EmptyModelData.INSTANCE ), tints );
-        }
-    }
-
-    private static void renderQuads( @Nonnull MatrixStack transform, @Nonnull IVertexBuilder buffer, int lightmapCoord, int overlayLight, List<BakedQuad> quads, int[] tints )
-    {
-        MatrixStack.Entry matrix = transform.getLast();
-
-        for( BakedQuad bakedquad : quads )
-        {
-            int tint = -1;
-            if( tints != null && bakedquad.hasTintIndex() )
+            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" )) )
             {
-                int idx = bakedquad.getTintIndex();
-                if( idx >= 0 && idx < tints.length ) tint = tints[bakedquad.getTintIndex()];
+                // 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();
+                }
             }
 
-            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 );
+            // Render the upgrades
+            renderUpgrade( state, turtle, TurtleSide.Left, partialTicks );
+            renderUpgrade( state, turtle, TurtleSide.Right, partialTicks );
+        }
+        finally
+        {
+            GlStateManager.popMatrix();
+            GlStateManager.cullFace( GlStateManager.CullFace.BACK );
         }
     }
+
+    private void renderUpgrade( BlockState state, 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 );
+
+                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();
+            }
+        }
+    }
+
+    private void renderModel( BlockState state, ModelResourceLocation modelLocation, int[] tints )
+    {
+        Minecraft mc = Minecraft.getInstance();
+        ModelManager modelManager = mc.getItemRenderer().getItemModelMesher().getModelManager();
+        renderModel( state, modelManager.getModel( modelLocation ), tints );
+    }
+
+    private void renderModel( BlockState state, 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 );
+        for( Direction facing : DirectionUtil.FACINGS )
+        {
+            renderQuads( tessellator, model.getQuads( state, facing, random, EmptyModelData.INSTANCE ), tints );
+        }
+    }
+
+    private static void renderQuads( Tessellator tessellator, List<BakedQuad> quads, int[] tints )
+    {
+        BufferBuilder buffer = tessellator.getBuffer();
+        VertexFormat format = DefaultVertexFormats.ITEM;
+        buffer.begin( GL11.GL_QUADS, format );
+        for( BakedQuad quad : quads )
+        {
+            VertexFormat quadFormat = quad.getFormat();
+            if( quadFormat != format )
+            {
+                tessellator.draw();
+                format = quadFormat;
+                buffer.begin( GL11.GL_QUADS, format );
+            }
+
+            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 );
+        }
+        tessellator.draw();
+    }
 }

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

@@ -5,27 +5,28 @@
  */
 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.*;
+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.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.IModelConfiguration;
-import net.minecraftforge.client.model.IModelLoader;
-import net.minecraftforge.client.model.geometry.IModelGeometry;
+import net.minecraftforge.client.model.ICustomModelLoader;
 
 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 IModelLoader<TurtleModelLoader.TurtleModel>
+public final class TurtleModelLoader implements ICustomModelLoader
 {
+    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();
@@ -39,15 +40,32 @@ public final class TurtleModelLoader implements IModelLoader<TurtleModelLoader.T
     {
     }
 
-    @Nonnull
     @Override
-    public TurtleModel read( @Nonnull JsonDeserializationContext deserializationContext, @Nonnull JsonObject modelContents )
+    public boolean accepts( @Nonnull ResourceLocation name )
     {
-        ResourceLocation model = new ResourceLocation( JSONUtils.getString( modelContents, "model" ) );
-        return new TurtleModel( model );
+        return name.getNamespace().equals( ComputerCraft.MOD_ID )
+            && (name.getPath().equals( "item/turtle_normal" ) || name.getPath().equals( "item/turtle_advanced" ));
     }
 
-    public static final class TurtleModel implements IModelGeometry<TurtleModel>
+    @Nonnull
+    @Override
+    public IUnbakedModel loadModel( @Nonnull ResourceLocation name )
+    {
+        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 );
+    }
+
+    private static final class TurtleModel implements IUnbakedModel
     {
         private final ResourceLocation family;
 
@@ -56,21 +74,29 @@ public final class TurtleModelLoader implements IModelLoader<TurtleModelLoader.T
             this.family = family;
         }
 
+        @Nonnull
         @Override
-        public Collection<Material> getTextures( IModelConfiguration owner, Function<ResourceLocation, IUnbakedModel> modelGetter, Set<Pair<String, String>> missingTextureErrors )
+        public Collection<ResourceLocation> getDependencies()
         {
-            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;
+            return Arrays.asList( family, COLOUR_TURTLE_MODEL );
         }
 
+        @Nonnull
         @Override
-        public IBakedModel bake( IModelConfiguration owner, ModelBakery bakery, Function<Material, TextureAtlasSprite> spriteGetter, IModelTransform transform, ItemOverrideList overrides, ResourceLocation modelLocation )
+        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 )
         {
             return new TurtleSmartItemModel(
-                bakery.getBakedModel( family, transform, spriteGetter ),
-                bakery.getBakedModel( COLOUR_TURTLE_MODEL, transform, spriteGetter )
+                bakery.getBakedModel( family, sprite, spriteGetter, format ),
+                bakery.getBakedModel( COLOUR_TURTLE_MODEL, sprite, spriteGetter, format )
             );
         }
     }

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

@@ -5,9 +5,7 @@
  */
 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;
@@ -15,29 +13,32 @@ 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 TransformationMatrix m_generalTransform;
-    private final TransformedModel m_leftUpgradeModel;
-    private final TransformedModel m_rightUpgradeModel;
+    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 List<BakedQuad> m_generalQuads = null;
     private Map<Direction, List<BakedQuad>> m_faceQuads = new EnumMap<>( Direction.class );
 
-    public TurtleMultiModel( IBakedModel baseModel, IBakedModel overlayModel, TransformationMatrix generalTransform, TransformedModel leftUpgradeModel, TransformedModel rightUpgradeModel )
+    public TurtleMultiModel( IBakedModel baseModel, IBakedModel overlayModel, Matrix4f generalTransform, IBakedModel leftUpgradeModel, Matrix4f leftUpgradeTransform, IBakedModel rightUpgradeModel, Matrix4f rightUpgradeTransform )
     {
         // Get the models
         m_baseModel = baseModel;
         m_overlayModel = overlayModel;
         m_leftUpgradeModel = leftUpgradeModel;
+        m_leftUpgradeTransform = leftUpgradeTransform;
         m_rightUpgradeModel = rightUpgradeModel;
+        m_rightUpgradeTransform = rightUpgradeTransform;
         m_generalTransform = generalTransform;
     }
 
@@ -68,22 +69,30 @@ public class TurtleMultiModel implements IBakedModel
     private List<BakedQuad> buildQuads( BlockState state, Direction side, Random rand )
     {
         ArrayList<BakedQuad> quads = new ArrayList<>();
-
-
-        transformQuadsTo( quads, m_baseModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), m_generalTransform );
+        ModelTransformer.transformQuadsTo( quads, m_baseModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), m_generalTransform );
         if( m_overlayModel != null )
         {
-            transformQuadsTo( quads, m_overlayModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), m_generalTransform );
+            ModelTransformer.transformQuadsTo( quads, m_overlayModel.getQuads( state, side, rand, EmptyModelData.INSTANCE ), m_generalTransform );
         }
         if( m_leftUpgradeModel != null )
         {
-            TransformationMatrix upgradeTransform = m_generalTransform.compose( m_leftUpgradeModel.getMatrix() );
-            transformQuadsTo( quads, m_leftUpgradeModel.getModel().getQuads( state, side, rand, EmptyModelData.INSTANCE ), upgradeTransform );
+            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 );
         }
         if( m_rightUpgradeModel != null )
         {
-            TransformationMatrix upgradeTransform = m_generalTransform.compose( m_rightUpgradeModel.getMatrix() );
-            transformQuadsTo( quads, m_rightUpgradeModel.getModel().getQuads( state, side, rand, EmptyModelData.INSTANCE ), upgradeTransform );
+            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 );
         }
         quads.trimToSize();
         return quads;
@@ -107,12 +116,6 @@ public class TurtleMultiModel implements IBakedModel
         return m_baseModel.isBuiltInRenderer();
     }
 
-    @Override
-    public boolean func_230044_c_()
-    {
-        return m_baseModel.func_230044_c_();
-    }
-
     @Nonnull
     @Override
     @Deprecated
@@ -135,15 +138,4 @@ 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

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

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

@@ -6,8 +6,6 @@
 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;
@@ -15,7 +13,6 @@ 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;
@@ -24,25 +21,28 @@ 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 TransformationMatrix identity, flip;
+    private static final Matrix4f s_identity, s_flip;
 
     static
     {
-        MatrixStack stack = new MatrixStack();
-        stack.scale( 0, -1, 0 );
-        stack.translate( 0, 0, 1 );
+        s_identity = new Matrix4f();
+        s_identity.setIdentity();
 
-        identity = TransformationMatrix.identity();
-        flip = new TransformationMatrix( stack.getLast().getMatrix() );
+        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.
     }
 
     private static class TurtleModelCombination
@@ -97,14 +97,15 @@ public class TurtleSmartItemModel implements IBakedModel
     private final IBakedModel familyModel;
     private final IBakedModel colourModel;
 
-    private final HashMap<TurtleModelCombination, IBakedModel> m_cachedModels = new HashMap<>();
-    private final ItemOverrideList m_overrides;
+    private HashMap<TurtleModelCombination, IBakedModel> m_cachedModels;
+    private ItemOverrideList m_overrides;
 
     public TurtleSmartItemModel( IBakedModel familyModel, IBakedModel colourModel )
     {
         this.familyModel = familyModel;
         this.colourModel = colourModel;
 
+        m_cachedModels = new HashMap<>();
         m_overrides = new ItemOverrideList()
         {
             @Nonnull
@@ -113,10 +114,10 @@ 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 );
@@ -143,10 +144,25 @@ public class TurtleSmartItemModel implements IBakedModel
 
         IBakedModel baseModel = combo.m_colour ? colourModel : familyModel;
         IBakedModel overlayModel = overlayModelLocation != null ? modelManager.getModel( overlayModelLocation ) : 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 );
+        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 );
+        }
     }
 
     @Nonnull
@@ -183,12 +199,6 @@ 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

@@ -0,0 +1,181 @@
+/*
+ * 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

@@ -0,0 +1,117 @@
+/*
+ * 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

@@ -13,6 +13,7 @@ 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;
@@ -122,7 +123,7 @@ public abstract class ComputerAccess implements IComputerAccess
         m_environment.queueEvent( event, arguments );
     }
 
-    @Nonnull
+    @Nullable
     @Override
     public IWorkMonitor getMainThreadMonitor()
     {

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

@@ -173,7 +173,7 @@ public class HTTPAPI implements ILuaAPI
                 String address = getString( args, 0 );
                 Map<?, ?> headerTbl = optTable( args, 1, Collections.emptyMap() );
 
-                if( !ComputerCraft.httpWebsocketEnabled )
+                if( !ComputerCraft.http_websocket_enable )
                 {
                     throw new LuaException( "Websocket connections are disabled" );
                 }

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

@@ -0,0 +1,24 @@
+/*
+ * 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/PeripheralAPI.java

@@ -11,8 +11,6 @@ import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.api.peripheral.IWorkMonitor;
-import dan200.computercraft.api.peripheral.NotAttachedException;
 import dan200.computercraft.core.computer.ComputerSide;
 import dan200.computercraft.core.tracking.TrackingField;
 
@@ -124,35 +122,53 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public synchronized String mount( @Nonnull String desiredLoc, @Nonnull IMount mount, @Nonnull String driveName )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !m_attached )
+            {
+                throw new RuntimeException( "You are not attached to this Computer" );
+            }
+
             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 NotAttachedException();
+            if( !m_attached )
+            {
+                throw new RuntimeException( "You are not attached to this Computer" );
+            }
+
             return super.mountWritable( desiredLoc, mount, driveName );
         }
 
         @Override
         public synchronized void unmount( String location )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !m_attached )
+            {
+                throw new RuntimeException( "You are not attached to this Computer" );
+            }
+
             super.unmount( location );
         }
 
         @Override
         public int getID()
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !m_attached )
+            {
+                throw new RuntimeException( "You are not attached to this Computer" );
+            }
             return super.getID();
         }
 
         @Override
         public void queueEvent( @Nonnull final String event, final Object[] arguments )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !m_attached )
+            {
+                throw new RuntimeException( "You are not attached to this Computer" );
+            }
             super.queueEvent( event, arguments );
         }
 
@@ -160,7 +176,10 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public String getAttachmentName()
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !m_attached )
+            {
+                throw new RuntimeException( "You are not attached to this Computer" );
+            }
             return m_side;
         }
 
@@ -168,7 +187,10 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public Map<String, IPeripheral> getAvailablePeripherals()
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !m_attached )
+            {
+                throw new RuntimeException( "You are not attached to this Computer" );
+            }
 
             Map<String, IPeripheral> peripherals = new HashMap<>();
             for( PeripheralWrapper wrapper : m_peripherals )
@@ -186,7 +208,10 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public IPeripheral getAvailablePeripheral( @Nonnull String name )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !m_attached )
+            {
+                throw new RuntimeException( "You are not attached to this Computer" );
+            }
 
             for( PeripheralWrapper wrapper : m_peripherals )
             {
@@ -197,14 +222,6 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             }
             return null;
         }
-
-        @Nonnull
-        @Override
-        public IWorkMonitor getMainThreadMonitor()
-        {
-            if( !m_attached ) throw new NotAttachedException();
-            return super.getMainThreadMonitor();
-        }
     }
 
     private final IAPIEnvironment m_environment;

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

@@ -16,11 +16,11 @@ 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
@@ -63,31 +63,31 @@ public class RedstoneAPI implements ILuaAPI
                 // setOutput
                 ComputerSide side = parseSide( args );
                 boolean output = getBoolean( args, 1 );
-                m_environment.setOutput( side, output ? 15 : 0 );
+                environment.setOutput( side, output ? 15 : 0 );
                 return null;
             }
             case 2: // getOutput
-                return new Object[] { m_environment.getOutput( parseSide( args ) ) > 0 };
+                return new Object[] { environment.getOutput( parseSide( args ) ) > 0 };
             case 3: // getInput
-                return new Object[] { m_environment.getInput( parseSide( args ) ) > 0 };
+                return new Object[] { environment.getInput( parseSide( args ) ) > 0 };
             case 4:
             {
                 // setBundledOutput
                 ComputerSide side = parseSide( args );
                 int output = getInt( args, 1 );
-                m_environment.setBundledOutput( side, output );
+                environment.setBundledOutput( side, output );
                 return null;
             }
             case 5: // getBundledOutput
-                return new Object[] { m_environment.getBundledOutput( parseSide( args ) ) };
+                return new Object[] { environment.getBundledOutput( parseSide( args ) ) };
             case 6: // getBundledInput
-                return new Object[] { m_environment.getBundledInput( parseSide( args ) ) };
+                return new Object[] { environment.getBundledInput( parseSide( args ) ) };
             case 7:
             {
                 // testBundledInput
                 ComputerSide side = parseSide( args );
                 int mask = getInt( args, 1 );
-                int input = m_environment.getBundledInput( side );
+                int input = environment.getBundledInput( side );
                 return new Object[] { (input & mask) == mask };
             }
             case 8:
@@ -100,15 +100,15 @@ public class RedstoneAPI implements ILuaAPI
                 {
                     throw new LuaException( "Expected number in range 0-15" );
                 }
-                m_environment.setOutput( side, output );
+                environment.setOutput( side, output );
                 return null;
             }
             case 10:
             case 11: // getAnalogOutput/getAnalogueOutput
-                return new Object[] { m_environment.getOutput( parseSide( args ) ) };
+                return new Object[] { environment.getOutput( parseSide( args ) ) };
             case 12:
             case 13: // getAnalogInput/getAnalogueInput
-                return new Object[] { m_environment.getInput( parseSide( args ) ) };
+                return new Object[] { environment.getInput( parseSide( args ) ) };
             default:
                 return null;
         }

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

@@ -37,12 +37,8 @@ public abstract class HandleGeneric implements ILuaObject
     {
         m_open = false;
 
-        Closeable closeable = m_closable;
-        if( closeable != null )
-        {
-            IoUtil.closeQuietly( closeable );
-            m_closable = null;
-        }
+        IoUtil.closeQuietly( m_closable );
+        m_closable = null;
     }
 
     /**

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

@@ -1,167 +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.http;
-
-import com.google.common.net.InetAddresses;
-import dan200.computercraft.ComputerCraft;
-
-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
-{
-    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;
-        }
-    }
-
-    public enum Action
-    {
-        ALLOW,
-        DENY,
-    }
-
-    private final HostRange ip;
-    private final Pattern domainPattern;
-    private final Action action;
-
-    private AddressRule( HostRange ip, Pattern domainPattern, Action action )
-    {
-        this.ip = ip;
-        this.domainPattern = domainPattern;
-        this.action = action;
-    }
-
-    @Nullable
-    public static AddressRule parse( String filter, Action action )
-    {
-        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, action );
-        }
-        else
-        {
-            Pattern pattern = Pattern.compile( "^\\Q" + filter.replaceAll( "\\*", "\\\\E.*\\\\Q" ) + "\\E$" );
-            return new AddressRule( null, pattern, action );
-        }
-    }
-
-    /**
-     * 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.
-     */
-    public 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 Action apply( Iterable<? extends AddressRule> rules, String domain, InetAddress address )
-    {
-        for( AddressRule rule : rules )
-        {
-            if( rule.matches( domain, address ) ) return rule.action;
-        }
-
-        return Action.DENY;
-    }
-}

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

@@ -97,6 +97,20 @@ 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.
      *
@@ -116,7 +130,7 @@ public final class NetworkUtils
         if( socketAddress.isUnresolved() ) throw new HTTPRequestException( "Unknown host" );
 
         InetAddress address = socketAddress.getAddress();
-        if( AddressRule.apply( ComputerCraft.httpRules, host, address ) == AddressRule.Action.DENY )
+        if( !ComputerCraft.http_whitelist.matches( address ) || ComputerCraft.http_blacklist.matches( address ) )
         {
             throw new HTTPRequestException( "Domain not permitted" );
         }

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/request/HttpRequest.java

@@ -119,6 +119,8 @@ public class HttpRequest extends Resource<HttpRequest>
         {
             throw new HTTPRequestException( "Invalid protocol '" + scheme + "'" );
         }
+
+        NetworkUtils.checkHost( url.getHost() );
     }
 
     public void request( URI uri, HttpMethod method )

src/main/java/dan200/computercraft/core/apis/http/websocket/Websocket.java

@@ -110,6 +110,7 @@ public class Websocket extends Resource<Websocket>
             throw new HTTPRequestException( "Invalid scheme '" + scheme + "'" );
         }
 
+        NetworkUtils.checkHost( uri.getHost() );
         return uri;
     }
 
@@ -220,7 +221,7 @@ public class Websocket extends Resource<Websocket>
 
         WeakReference<WebsocketHandle> websocketHandleRef = websocketHandle;
         WebsocketHandle websocketHandle = websocketHandleRef == null ? null : websocketHandleRef.get();
-        if( websocketHandle != null ) IoUtil.closeQuietly( websocketHandle );
+        IoUtil.closeQuietly( websocketHandle );
         this.websocketHandle = null;
     }
 

src/main/java/dan200/computercraft/core/computer/ComputerExecutor.java

@@ -171,7 +171,7 @@ final class ComputerExecutor
         apis.add( new FSAPI( environment ) );
         apis.add( new PeripheralAPI( environment ) );
         apis.add( new OSAPI( environment ) );
-        if( ComputerCraft.httpEnabled ) apis.add( new HTTPAPI( environment ) );
+        if( ComputerCraft.http_enable ) apis.add( new HTTPAPI( environment ) );
 
         // Load in the externally registered APIs.
         for( ILuaAPIFactory factory : ApiFactories.getAll() )
@@ -611,7 +611,7 @@ final class ComputerExecutor
         terminal.reset();
 
         // Display our primary error message
-        if( colour ) terminal.setTextColour( 15 - Colour.RED.ordinal() );
+        if( colour ) terminal.setTextColour( 15 - Colour.Red.ordinal() );
         terminal.write( message );
 
         if( extra != null )
@@ -624,7 +624,7 @@ final class ComputerExecutor
 
         // And display our generic "CC may be installed incorrectly" message.
         terminal.setCursorPos( 0, terminal.getCursorY() + 1 );
-        if( colour ) terminal.setTextColour( 15 - Colour.WHITE.ordinal() );
+        if( colour ) terminal.setTextColour( 15 - Colour.White.ordinal() );
         terminal.write( "ComputerCraft may be installed incorrectly" );
     }
 

src/main/java/dan200/computercraft/core/computer/ComputerSystem.java

@@ -9,15 +9,12 @@ import dan200.computercraft.api.filesystem.IFileSystem;
 import dan200.computercraft.api.lua.IComputerSystem;
 import dan200.computercraft.api.lua.ILuaAPIFactory;
 import dan200.computercraft.api.peripheral.IComputerAccess;
-import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.apis.ComputerAccess;
 import dan200.computercraft.core.apis.IAPIEnvironment;
 import dan200.computercraft.core.filesystem.FileSystem;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.util.Collections;
-import java.util.Map;
 
 /**
  * Implementation of {@link IComputerAccess}/{@link IComputerSystem} for usage by externally registered APIs.
@@ -57,19 +54,4 @@ public class ComputerSystem extends ComputerAccess implements IComputerSystem
     {
         return environment.getLabel();
     }
-
-    @Nonnull
-    @Override
-    public Map<String, IPeripheral> getAvailablePeripherals()
-    {
-        // TODO: Should this return peripherals on the current computer?
-        return Collections.emptyMap();
-    }
-
-    @Nullable
-    @Override
-    public IPeripheral getAvailablePeripheral( @Nonnull String name )
-    {
-        return null;
-    }
 }

src/main/java/dan200/computercraft/core/filesystem/ComboMount.java

@@ -10,6 +10,7 @@ import dan200.computercraft.api.filesystem.IMount;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
@@ -115,7 +116,8 @@ public class ComboMount implements IMount
 
     @Nonnull
     @Override
-    public ReadableByteChannel openForRead( @Nonnull String path ) throws IOException
+    @Deprecated
+    public InputStream openForRead( @Nonnull String path ) throws IOException
     {
         for( int i = m_parts.length - 1; i >= 0; --i )
         {
@@ -128,6 +130,21 @@ public class ComboMount implements IMount
         throw new FileOperationException( path, "No such file" );
     }
 
+    @Nonnull
+    @Override
+    public ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
+    {
+        for( int i = m_parts.length - 1; i >= 0; --i )
+        {
+            IMount part = m_parts[i];
+            if( part.exists( path ) && !part.isDirectory( path ) )
+            {
+                return part.openChannelForRead( path );
+            }
+        }
+        throw new FileOperationException( path, "No such file" );
+    }
+
     @Nonnull
     @Override
     public BasicFileAttributes getAttributes( @Nonnull String path ) throws IOException

src/main/java/dan200/computercraft/core/filesystem/EmptyMount.java

@@ -10,6 +10,7 @@ import dan200.computercraft.api.filesystem.IMount;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.util.List;
 
@@ -40,7 +41,16 @@ public class EmptyMount implements IMount
 
     @Nonnull
     @Override
-    public ReadableByteChannel openForRead( @Nonnull String path ) throws IOException
+    @Deprecated
+    public InputStream openForRead( @Nonnull String path ) throws IOException
+    {
+        throw new FileOperationException( path, "No such file" );
+    }
+
+    @Nonnull
+    @Override
+    @Deprecated
+    public ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
     {
         throw new FileOperationException( path, "No such file" );
     }

src/main/java/dan200/computercraft/core/filesystem/FileMount.java

@@ -11,8 +11,7 @@ import dan200.computercraft.api.filesystem.FileOperationException;
 import dan200.computercraft.api.filesystem.IWritableMount;
 
 import javax.annotation.Nonnull;
-import java.io.File;
-import java.io.IOException;
+import java.io.*;
 import java.nio.ByteBuffer;
 import java.nio.channels.*;
 import java.nio.file.*;
@@ -201,7 +200,21 @@ public class FileMount implements IWritableMount
 
     @Nonnull
     @Override
-    public ReadableByteChannel openForRead( @Nonnull String path ) throws IOException
+    @Deprecated
+    public InputStream openForRead( @Nonnull String path ) throws IOException
+    {
+        if( created() )
+        {
+            File file = getRealPath( path );
+            if( file.exists() && !file.isDirectory() ) return new FileInputStream( file );
+        }
+
+        throw new FileOperationException( path, "No such file" );
+    }
+
+    @Nonnull
+    @Override
+    public ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
     {
         if( created() )
         {
@@ -300,7 +313,23 @@ public class FileMount implements IWritableMount
 
     @Nonnull
     @Override
-    public WritableByteChannel openForWrite( @Nonnull String path ) throws IOException
+    @Deprecated
+    public OutputStream openForWrite( @Nonnull String path ) throws IOException
+    {
+        return Channels.newOutputStream( openChannelForWrite( path ) );
+    }
+
+    @Nonnull
+    @Override
+    @Deprecated
+    public OutputStream openForAppend( @Nonnull String path ) throws IOException
+    {
+        return Channels.newOutputStream( openChannelForAppend( path ) );
+    }
+
+    @Nonnull
+    @Override
+    public WritableByteChannel openChannelForWrite( @Nonnull String path ) throws IOException
     {
         create();
         File file = getRealPath( path );
@@ -321,7 +350,7 @@ public class FileMount implements IWritableMount
 
     @Nonnull
     @Override
-    public WritableByteChannel openForAppend( @Nonnull String path ) throws IOException
+    public WritableByteChannel openChannelForAppend( @Nonnull String path ) throws IOException
     {
         if( !created() )
         {

src/main/java/dan200/computercraft/core/filesystem/FileSystem.java

@@ -366,8 +366,7 @@ public class FileSystem
             Reference<?> ref;
             while( (ref = m_openFileQueue.poll()) != null )
             {
-                Closeable file = m_openFiles.remove( ref );
-                if( file != null ) IoUtil.closeQuietly( file );
+                IoUtil.closeQuietly( m_openFiles.remove( ref ) );
             }
         }
     }

src/main/java/dan200/computercraft/core/filesystem/FileSystemWrapperMount.java

@@ -9,6 +9,9 @@ import dan200.computercraft.api.filesystem.IFileSystem;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.channels.Channels;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
 import java.util.Collections;
@@ -52,7 +55,7 @@ public class FileSystemWrapperMount implements IFileSystem
 
     @Nonnull
     @Override
-    public ReadableByteChannel openForRead( @Nonnull String path ) throws IOException
+    public ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
     {
         try
         {
@@ -67,7 +70,7 @@ public class FileSystemWrapperMount implements IFileSystem
 
     @Nonnull
     @Override
-    public WritableByteChannel openForWrite( @Nonnull String path ) throws IOException
+    public WritableByteChannel openChannelForWrite( @Nonnull String path ) throws IOException
     {
         try
         {
@@ -81,7 +84,7 @@ public class FileSystemWrapperMount implements IFileSystem
 
     @Nonnull
     @Override
-    public WritableByteChannel openForAppend( @Nonnull String path ) throws IOException
+    public WritableByteChannel openChannelForAppend( @Nonnull String path ) throws IOException
     {
         try
         {
@@ -93,6 +96,30 @@ public class FileSystemWrapperMount implements IFileSystem
         }
     }
 
+    @Nonnull
+    @Override
+    @Deprecated
+    public InputStream openForRead( @Nonnull String path ) throws IOException
+    {
+        return Channels.newInputStream( openChannelForRead( path ) );
+    }
+
+    @Nonnull
+    @Override
+    @Deprecated
+    public OutputStream openForWrite( @Nonnull String path ) throws IOException
+    {
+        return Channels.newOutputStream( openChannelForWrite( path ) );
+    }
+
+    @Nonnull
+    @Override
+    @Deprecated
+    public OutputStream openForAppend( @Nonnull String path ) throws IOException
+    {
+        return Channels.newOutputStream( openChannelForAppend( path ) );
+    }
+
     @Override
     public long getRemainingSpace() throws IOException
     {

src/main/java/dan200/computercraft/core/filesystem/JarMount.java

@@ -184,7 +184,15 @@ public class JarMount implements IMount
 
     @Nonnull
     @Override
-    public ReadableByteChannel openForRead( @Nonnull String path ) throws IOException
+    @Deprecated
+    public InputStream openForRead( @Nonnull String path ) throws IOException
+    {
+        return Channels.newInputStream( openChannelForRead( path ) );
+    }
+
+    @Nonnull
+    @Override
+    public ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
     {
         FileEntry file = get( path );
         if( file != null && !file.isDirectory() )

src/main/java/dan200/computercraft/core/filesystem/MountWrapper.java

@@ -20,11 +20,11 @@ import java.util.OptionalLong;
 
 class MountWrapper
 {
-    private final String label;
-    private final String location;
+    private String label;
+    private String location;
 
-    private final IMount mount;
-    private final IWritableMount writableMount;
+    private IMount mount;
+    private IWritableMount writableMount;
 
     MountWrapper( String label, String location, IMount mount )
     {
@@ -36,9 +36,7 @@ class MountWrapper
 
     MountWrapper( String label, String location, IWritableMount mount )
     {
-        this.label = label;
-        this.location = location;
-        this.mount = mount;
+        this( label, location, (IMount) mount );
         writableMount = mount;
     }
 
@@ -156,7 +154,7 @@ class MountWrapper
         {
             if( mount.exists( path ) && !mount.isDirectory( path ) )
             {
-                return mount.openForRead( path );
+                return mount.openChannelForRead( path );
             }
             else
             {
@@ -234,7 +232,7 @@ class MountWrapper
                         writableMount.makeDirectory( dir );
                     }
                 }
-                return writableMount.openForWrite( path );
+                return writableMount.openChannelForWrite( path );
             }
         }
         catch( AccessDeniedException e )
@@ -264,7 +262,7 @@ class MountWrapper
                         writableMount.makeDirectory( dir );
                     }
                 }
-                return writableMount.openForWrite( path );
+                return writableMount.openChannelForWrite( path );
             }
             else if( mount.isDirectory( path ) )
             {
@@ -272,7 +270,7 @@ class MountWrapper
             }
             else
             {
-                return writableMount.openForAppend( path );
+                return writableMount.openChannelForAppend( path );
             }
         }
         catch( AccessDeniedException e )

src/main/java/dan200/computercraft/core/filesystem/ResourceMount.java

@@ -223,7 +223,15 @@ public final class ResourceMount implements IMount
 
     @Nonnull
     @Override
-    public ReadableByteChannel openForRead( @Nonnull String path ) throws IOException
+    @Deprecated
+    public InputStream openForRead( @Nonnull String path ) throws IOException
+    {
+        return Channels.newInputStream( openChannelForRead( path ) );
+    }
+
+    @Nonnull
+    @Override
+    public ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
     {
         FileEntry file = get( path );
         if( file != null && !file.isDirectory() )

src/main/java/dan200/computercraft/core/filesystem/SubMount.java

@@ -9,6 +9,7 @@ import dan200.computercraft.api.filesystem.IMount;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.List;
@@ -50,11 +51,19 @@ public class SubMount implements IMount
 
     @Nonnull
     @Override
-    public ReadableByteChannel openForRead( @Nonnull String path ) throws IOException
+    @Deprecated
+    public InputStream openForRead( @Nonnull String path ) throws IOException
     {
         return parent.openForRead( getFullPath( path ) );
     }
 
+    @Nonnull
+    @Override
+    public ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
+    {
+        return parent.openChannelForRead( getFullPath( path ) );
+    }
+
     @Nonnull
     @Override
     public BasicFileAttributes getAttributes( @Nonnull String path ) throws IOException

src/main/java/dan200/computercraft/core/terminal/Terminal.java

@@ -5,18 +5,20 @@
  */
 package dan200.computercraft.core.terminal;
 
+import dan200.computercraft.shared.util.Colour;
 import dan200.computercraft.shared.util.Palette;
 import net.minecraft.nbt.CompoundNBT;
+import net.minecraft.network.PacketBuffer;
 
 public class Terminal
 {
     private static final String base16 = "0123456789abcdef";
 
-    private int m_cursorX;
-    private int m_cursorY;
-    private boolean m_cursorBlink;
-    private int m_cursorColour;
-    private int m_cursorBackgroundColour;
+    private int m_cursorX = 0;
+    private int m_cursorY = 0;
+    private boolean m_cursorBlink = false;
+    private int m_cursorColour = 0;
+    private int m_cursorBackgroundColour = 15;
 
     private int m_width;
     private int m_height;
@@ -25,9 +27,9 @@ public class Terminal
     private TextBuffer[] m_textColour;
     private TextBuffer[] m_backgroundColour;
 
-    private final Palette m_palette;
+    private final Palette m_palette = new Palette();
 
-    private boolean m_changed;
+    private boolean m_changed = false;
     private final Runnable onChanged;
 
     public Terminal( int width, int height )
@@ -41,9 +43,6 @@ public class Terminal
         m_height = height;
         onChanged = changedCallback;
 
-        m_cursorColour = 0;
-        m_cursorBackgroundColour = 15;
-
         m_text = new TextBuffer[m_height];
         m_textColour = new TextBuffer[m_height];
         m_backgroundColour = new TextBuffer[m_height];
@@ -53,14 +52,6 @@ public class Terminal
             m_textColour[i] = new TextBuffer( base16.charAt( m_cursorColour ), m_width );
             m_backgroundColour[i] = new TextBuffer( base16.charAt( m_cursorBackgroundColour ), m_width );
         }
-
-        m_cursorX = 0;
-        m_cursorY = 0;
-        m_cursorBlink = false;
-
-        m_changed = false;
-
-        m_palette = new Palette();
     }
 
     public synchronized void reset()
@@ -312,6 +303,19 @@ public class Terminal
         return null;
     }
 
+    /**
+     * Determine whether this terminal has changed.
+     *
+     * @return If this terminal is dirty.
+     * @deprecated All {@code *Changed()} methods are deprecated: one should pass in a callback
+     * instead.
+     */
+    @Deprecated
+    public final boolean getChanged()
+    {
+        return m_changed;
+    }
+
     public final void setChanged()
     {
         m_changed = true;
@@ -323,6 +327,62 @@ public class Terminal
         m_changed = false;
     }
 
+    public synchronized void write( PacketBuffer buffer )
+    {
+        buffer.writeInt( m_cursorX );
+        buffer.writeInt( m_cursorY );
+        buffer.writeBoolean( m_cursorBlink );
+        buffer.writeByte( m_cursorBackgroundColour << 4 | m_cursorColour );
+
+        for( int y = 0; y < m_height; y++ )
+        {
+            TextBuffer text = m_text[y];
+            TextBuffer textColour = m_textColour[y];
+            TextBuffer backColour = m_backgroundColour[y];
+
+            for( int x = 0; x < m_width; x++ )
+            {
+                buffer.writeByte( text.charAt( x ) & 0xFF );
+                buffer.writeByte( getColour(
+                    backColour.charAt( x ), Colour.Black ) << 4 |
+                    getColour( textColour.charAt( x ), Colour.White )
+                );
+            }
+        }
+
+        m_palette.write( buffer );
+    }
+
+    public synchronized void read( PacketBuffer buffer )
+    {
+        m_cursorX = buffer.readInt();
+        m_cursorY = buffer.readInt();
+        m_cursorBlink = buffer.readBoolean();
+
+        byte cursorColour = buffer.readByte();
+        m_cursorBackgroundColour = (cursorColour >> 4) & 0xF;
+        m_cursorColour = cursorColour & 0xF;
+
+        for( int y = 0; y < m_height; y++ )
+        {
+            TextBuffer text = m_text[y];
+            TextBuffer textColour = m_textColour[y];
+            TextBuffer backColour = m_backgroundColour[y];
+
+            for( int x = 0; x < m_width; x++ )
+            {
+                text.setChar( x, (char) (buffer.readByte() & 0xFF) );
+
+                byte colour = buffer.readByte();
+                backColour.setChar( x, base16.charAt( (colour >> 4) & 0xF ) );
+                textColour.setChar( x, base16.charAt( colour & 0xF ) );
+            }
+        }
+
+        m_palette.read( buffer );
+        setChanged();
+    }
+
     public synchronized CompoundNBT writeToNBT( CompoundNBT nbt )
     {
         nbt.putInt( "term_cursorX", m_cursorX );
@@ -336,10 +396,8 @@ public class Terminal
             nbt.putString( "term_textColour_" + n, m_textColour[n].toString() );
             nbt.putString( "term_textBgColour_" + n, m_backgroundColour[n].toString() );
         }
-        if( m_palette != null )
-        {
-            m_palette.writeToNBT( nbt );
-        }
+
+        m_palette.writeToNBT( nbt );
         return nbt;
     }
 
@@ -369,10 +427,15 @@ public class Terminal
                 m_backgroundColour[n].write( nbt.getString( "term_textBgColour_" + n ) );
             }
         }
-        if( m_palette != null )
-        {
-            m_palette.readFromNBT( nbt );
-        }
+
+        m_palette.readFromNBT( nbt );
         setChanged();
     }
+
+    public static int getColour( char c, Colour def )
+    {
+        if( c >= '0' && c <= '9' ) return c - '0';
+        if( c >= 'a' && c <= 'f' ) return c - 'a' + 10;
+        return 15 - def.ordinal();
+    }
 }

src/main/java/dan200/computercraft/data/LootTableProvider.java

@@ -14,10 +14,9 @@ import net.minecraft.data.DataGenerator;
 import net.minecraft.data.DirectoryCache;
 import net.minecraft.data.IDataProvider;
 import net.minecraft.util.ResourceLocation;
-import net.minecraft.world.storage.loot.LootParameterSets;
 import net.minecraft.world.storage.loot.LootTable;
 import net.minecraft.world.storage.loot.LootTableManager;
-import net.minecraft.world.storage.loot.ValidationTracker;
+import net.minecraft.world.storage.loot.ValidationResults;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
@@ -43,17 +42,17 @@ public abstract class LootTableProvider implements IDataProvider
     @Override
     public void act( @Nonnull DirectoryCache cache )
     {
-        Map<ResourceLocation, LootTable> tables = new HashMap<>();
-        ValidationTracker validation = new ValidationTracker( LootParameterSets.GENERIC, x -> null, tables::get );
 
+        ValidationResults validation = new ValidationResults();
+        Map<ResourceLocation, LootTable> tables = new HashMap<>();
         registerLoot( ( id, table ) -> {
-            if( tables.containsKey( id ) ) validation.func_227530_a_( "Duplicate loot tables for " + id );
+            if( tables.containsKey( id ) ) validation.addProblem( "Duplicate loot tables for " + id );
             tables.put( id, table );
         } );
 
-        tables.forEach( ( key, value ) -> LootTableManager.func_227508_a_( validation, key, value ) );
+        tables.forEach( ( key, value ) -> LootTableManager.func_215302_a( validation, key, value, tables::get ) );
 
-        Multimap<String, String> problems = validation.func_227527_a_();
+        Multimap<String, String> problems = validation.getProblems();
         if( !problems.isEmpty() )
         {
             problems.forEach( ( child, problem ) ->

src/main/java/dan200/computercraft/data/LootTables.java

@@ -8,6 +8,7 @@ package dan200.computercraft.data;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.data.BlockNamedEntityLootCondition;
+import dan200.computercraft.shared.data.HasComputerIdLootCondition;
 import dan200.computercraft.shared.data.PlayerCreativeLootCondition;
 import net.minecraft.block.Block;
 import net.minecraft.data.DataGenerator;
@@ -67,6 +68,7 @@ public class LootTables extends LootTableProvider
                 .addEntry( DynamicLootEntry.func_216162_a( new ResourceLocation( ComputerCraft.MOD_ID, "computer" ) ) )
                 .acceptCondition( Alternative.builder(
                     BlockNamedEntityLootCondition.builder(),
+                    HasComputerIdLootCondition.builder(),
                     PlayerCreativeLootCondition.builder().inverted()
                 ) )
             ).build() );

src/main/java/dan200/computercraft/shared/Config.java

@@ -6,28 +6,27 @@
 package dan200.computercraft.shared;
 
 import com.electronwill.nightconfig.core.CommentedConfig;
-import com.electronwill.nightconfig.core.UnmodifiableConfig;
 import com.electronwill.nightconfig.core.file.CommentedFileConfig;
 import com.google.common.base.CaseFormat;
 import com.google.common.base.Converter;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.turtle.event.TurtleAction;
-import dan200.computercraft.core.apis.http.AddressRule;
+import dan200.computercraft.core.apis.AddressPredicate;
 import dan200.computercraft.core.apis.http.websocket.Websocket;
+import dan200.computercraft.shared.peripheral.monitor.MonitorRenderer;
 import net.minecraftforge.common.ForgeConfigSpec;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.ModLoadingContext;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.config.ModConfig;
 
-import javax.annotation.Nullable;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-import java.util.Objects;
 import java.util.concurrent.TimeUnit;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
+import static dan200.computercraft.ComputerCraft.DEFAULT_HTTP_BLACKLIST;
+import static dan200.computercraft.ComputerCraft.DEFAULT_HTTP_WHITELIST;
 import static net.minecraftforge.common.ForgeConfigSpec.Builder;
 import static net.minecraftforge.common.ForgeConfigSpec.ConfigValue;
 
@@ -52,7 +51,8 @@ public final class Config
 
     private static final ConfigValue<Boolean> httpEnabled;
     private static final ConfigValue<Boolean> httpWebsocketEnabled;
-    private static final ConfigValue<List<? extends UnmodifiableConfig>> httpRules;
+    private static final ConfigValue<List<? extends String>> httpWhitelist;
+    private static final ConfigValue<List<? extends String>> httpBlacklist;
 
     private static final ConfigValue<Integer> httpTimeout;
     private static final ConfigValue<Integer> httpMaxRequests;
@@ -67,6 +67,7 @@ public final class Config
     private static final ConfigValue<Integer> modemRangeDuringStorm;
     private static final ConfigValue<Integer> modemHighAltitudeRangeDuringStorm;
     private static final ConfigValue<Integer> maxNotesPerTick;
+    private static final ConfigValue<Integer> monitorBandwidth;
 
     private static final ConfigValue<Boolean> turtlesNeedFuel;
     private static final ConfigValue<Integer> turtleFuelLimit;
@@ -75,7 +76,10 @@ public final class Config
     private static final ConfigValue<Boolean> turtlesCanPush;
     private static final ConfigValue<List<? extends String>> turtleDisabledActions;
 
-    private static final ForgeConfigSpec spec;
+    private static final ConfigValue<MonitorRenderer> monitorRenderer;
+
+    private static final ForgeConfigSpec commonSpec;
+    private static final ForgeConfigSpec clientSpec;
 
     private Config() {}
 
@@ -152,25 +156,25 @@ public final class Config
             builder.push( "http" );
 
             httpEnabled = builder
-                .comment( "Enable the \"http\" API on Computers (see \"rules\" for more fine grained control than this)." )
-                .define( "enabled", ComputerCraft.httpEnabled );
+                .comment( "Enable the \"http\" API on Computers (see \"http_whitelist\" and \"http_blacklist\" for more " +
+                    "fine grained control than this)" )
+                .define( "enabled", ComputerCraft.http_enable );
 
             httpWebsocketEnabled = builder
                 .comment( "Enable use of http websockets. This requires the \"http_enable\" option to also be true." )
-                .define( "websocket_enabled", ComputerCraft.httpWebsocketEnabled );
+                .define( "websocket_enabled", ComputerCraft.http_websocket_enable );
 
-            httpRules = builder
-                .comment( "A list of rules which control which domains or IPs are allowed through the \"http\" API on computers.\n" +
-                    "Each rule is an item with a 'host' to match against, and an action. " +
-                    "The host may be a domain name (\"pastebin.com\"),\n" +
-                    "wildcard (\"*.pastebin.com\") or CIDR notation (\"127.0.0.0/8\"). 'action' maybe 'allow' or 'block'. If no rules" +
-                    "match, the domain will be blocked." )
-                .defineList( "rules",
-                    Stream.concat(
-                        Stream.of( ComputerCraft.DEFAULT_HTTP_DENY ).map( x -> makeRule( x, "deny" ) ),
-                        Stream.of( ComputerCraft.DEFAULT_HTTP_ALLOW ).map( x -> makeRule( x, "allow" ) )
-                    ).collect( Collectors.toList() ),
-                    x -> x instanceof UnmodifiableConfig && parseRule( (UnmodifiableConfig) x ) != null );
+            httpWhitelist = builder
+                .comment( "A list of wildcards for domains or IP ranges that can be accessed through the \"http\" API on Computers.\n" +
+                    "Set this to \"*\" to access to the entire internet. Example: \"*.pastebin.com\" will restrict access to just subdomains of pastebin.com.\n" +
+                    "You can use domain names (\"pastebin.com\"), wilcards (\"*.pastebin.com\") or CIDR notation (\"127.0.0.0/8\")." )
+                .defineList( "whitelist", Arrays.asList( DEFAULT_HTTP_WHITELIST ), x -> true );
+
+            httpBlacklist = builder
+                .comment( "A list of wildcards for domains or IP ranges that cannot be accessed through the \"http\" API on Computers.\n" +
+                    "If this is empty then all whitelisted domains will be accessible. Example: \"*.github.com\" will block access to all subdomains of github.com.\n" +
+                    "You can use domain names (\"pastebin.com\"), wilcards (\"*.pastebin.com\") or CIDR notation (\"127.0.0.0/8\")." )
+                .defineList( "blacklist", Arrays.asList( DEFAULT_HTTP_BLACKLIST ), x -> true );
 
             httpTimeout = builder
                 .comment( "The period of time (in milliseconds) to wait before a HTTP request times out. Set to 0 for unlimited." )
@@ -227,6 +231,16 @@ public final class Config
                 .comment( "Maximum amount of notes a speaker can play at once" )
                 .defineInRange( "max_notes_per_tick", ComputerCraft.maxNotesPerTick, 1, Integer.MAX_VALUE );
 
+            monitorBandwidth = builder
+                .comment( "The limit to how much monitor data can be sent *per tick*. Note:\n" +
+                    " - Bandwidth is measured before compression, so the data sent to the client is smaller.\n" +
+                    " - This ignores the number of players a packet is sent to. Updating a monitor for one player consumes " +
+                    "the same bandwidth limit as sending to 20.\n" +
+                    " - A full sized monitor sends ~25kb of data. So the default (1MB) allows for ~40 monitors to be updated " +
+                    "in a single tick. \n" +
+                    "Set to 0 to disable." )
+                .defineInRange( "monitor_bandwidth", (int) ComputerCraft.monitorBandwidth, 0, Integer.MAX_VALUE );
+
             builder.pop();
         }
 
@@ -261,12 +275,20 @@ public final class Config
             builder.pop();
         }
 
-        spec = builder.build();
+        commonSpec = builder.build();
+
+        Builder clientBuilder = new Builder();
+        monitorRenderer = clientBuilder
+            .comment( "The renderer to use for monitors. Generally this should be kept at \"best\" - if " +
+                "monitors have performance issues, you may wish to experiment with alternative renderers." )
+            .defineEnum( "monitor_renderer", MonitorRenderer.BEST );
+        clientSpec = clientBuilder.build();
     }
 
     public static void load()
     {
-        ModLoadingContext.get().registerConfig( ModConfig.Type.COMMON, spec );
+        ModLoadingContext.get().registerConfig( ModConfig.Type.COMMON, commonSpec );
+        ModLoadingContext.get().registerConfig( ModConfig.Type.CLIENT, clientSpec );
     }
 
     public static void sync()
@@ -287,10 +309,10 @@ public final class Config
         ComputerCraft.maxMainComputerTime = TimeUnit.MILLISECONDS.toNanos( maxMainComputerTime.get() );
 
         // HTTP
-        ComputerCraft.httpEnabled = httpEnabled.get();
-        ComputerCraft.httpWebsocketEnabled = httpWebsocketEnabled.get();
-        ComputerCraft.httpRules = Collections.unmodifiableList( httpRules.get().stream()
-            .map( Config::parseRule ).filter( Objects::nonNull ).collect( Collectors.toList() ) );
+        ComputerCraft.http_enable = httpEnabled.get();
+        ComputerCraft.http_websocket_enable = httpWebsocketEnabled.get();
+        ComputerCraft.http_whitelist = new AddressPredicate( httpWhitelist.get() );
+        ComputerCraft.http_blacklist = new AddressPredicate( httpBlacklist.get() );
 
         ComputerCraft.httpTimeout = httpTimeout.get();
         ComputerCraft.httpMaxRequests = httpMaxRequests.get();
@@ -306,6 +328,7 @@ public final class Config
         ComputerCraft.modem_highAltitudeRange = modemHighAltitudeRange.get();
         ComputerCraft.modem_rangeDuringStorm = modemRangeDuringStorm.get();
         ComputerCraft.modem_highAltitudeRangeDuringStorm = modemHighAltitudeRangeDuringStorm.get();
+        ComputerCraft.monitorBandwidth = monitorBandwidth.get();
 
         // Turtles
         ComputerCraft.turtlesNeedFuel = turtlesNeedFuel.get();
@@ -316,6 +339,9 @@ public final class Config
 
         ComputerCraft.turtleDisabledActions.clear();
         for( String value : turtleDisabledActions.get() ) ComputerCraft.turtleDisabledActions.add( getAction( value ) );
+
+        // Client
+        ComputerCraft.monitorRenderer = monitorRenderer.get();
     }
 
     @SubscribeEvent
@@ -325,7 +351,7 @@ public final class Config
     }
 
     @SubscribeEvent
-    public static void sync( ModConfig.Reloading event )
+    public static void sync( ModConfig.ConfigReloading event )
     {
         // Ensure file configs are reloaded. Forge should probably do this, so worth checking in the future.
         CommentedConfig config = event.getConfig().getConfigData();
@@ -347,28 +373,4 @@ public final class Config
             return null;
         }
     }
-
-    private static UnmodifiableConfig makeRule( String host, String action )
-    {
-        com.electronwill.nightconfig.core.Config config = com.electronwill.nightconfig.core.Config.inMemory();
-        config.add( "host", host );
-        config.add( "action", action );
-        return config;
-    }
-
-    @Nullable
-    private static AddressRule parseRule( UnmodifiableConfig builder )
-    {
-        Object hostObj = builder.get( "host" );
-        Object actionObj = builder.get( "action" );
-        if( !(hostObj instanceof String) || !(actionObj instanceof String) ) return null;
-
-        String host = (String) hostObj, action = (String) actionObj;
-        for( AddressRule.Action candiate : AddressRule.Action.values() )
-        {
-            if( candiate.name().equalsIgnoreCase( action ) ) return AddressRule.parse( host, candiate );
-        }
-
-        return null;
-    }
 }

src/main/java/dan200/computercraft/shared/Registry.java

@@ -84,17 +84,17 @@ public final class Registry
         // Computers
         ComputerCraft.Blocks.computerNormal = new BlockComputer(
             Block.Properties.create( Material.ROCK ).hardnessAndResistance( 2.0f ),
-            ComputerFamily.NORMAL, TileComputer.FACTORY_NORMAL
+            ComputerFamily.Normal, TileComputer.FACTORY_NORMAL
         );
 
         ComputerCraft.Blocks.computerAdvanced = new BlockComputer(
             Block.Properties.create( Material.ROCK ).hardnessAndResistance( 2.0f ),
-            ComputerFamily.ADVANCED, TileComputer.FACTORY_ADVANCED
+            ComputerFamily.Advanced, TileComputer.FACTORY_ADVANCED
         );
 
         ComputerCraft.Blocks.computerCommand = new BlockComputer(
             Block.Properties.create( Material.ROCK ).hardnessAndResistance( -1, 6000000.0F ),
-            ComputerFamily.COMMAND, TileCommandComputer.FACTORY
+            ComputerFamily.Command, TileCommandComputer.FACTORY
         );
 
         registry.registerAll(
@@ -106,12 +106,12 @@ public final class Registry
         // Turtles
         ComputerCraft.Blocks.turtleNormal = new BlockTurtle(
             Block.Properties.create( Material.ROCK ).hardnessAndResistance( 2.5f ),
-            ComputerFamily.NORMAL, TileTurtle.FACTORY_NORMAL
+            ComputerFamily.Normal, TileTurtle.FACTORY_NORMAL
         );
 
         ComputerCraft.Blocks.turtleAdvanced = new BlockTurtle(
             Block.Properties.create( Material.ROCK ).hardnessAndResistance( 2.5f ),
-            ComputerFamily.ADVANCED, TileTurtle.FACTORY_ADVANCED
+            ComputerFamily.Advanced, TileTurtle.FACTORY_ADVANCED
         );
 
         registry.registerAll(
@@ -234,8 +234,8 @@ public final class Registry
         );
 
         // Pocket computer
-        ComputerCraft.Items.pocketComputerNormal = new ItemPocketComputer( defaultItem().maxStackSize( 1 ), ComputerFamily.NORMAL );
-        ComputerCraft.Items.pocketComputerAdvanced = new ItemPocketComputer( defaultItem().maxStackSize( 1 ), ComputerFamily.ADVANCED );
+        ComputerCraft.Items.pocketComputerNormal = new ItemPocketComputer( defaultItem().maxStackSize( 1 ), ComputerFamily.Normal );
+        ComputerCraft.Items.pocketComputerAdvanced = new ItemPocketComputer( defaultItem().maxStackSize( 1 ), ComputerFamily.Advanced );
 
         registry.registerAll(
             ComputerCraft.Items.pocketComputerNormal.setRegistryName( new ResourceLocation( ComputerCraft.MOD_ID, "pocket_computer_normal" ) ),

src/main/java/dan200/computercraft/shared/command/CommandComputerCraft.java

@@ -205,7 +205,7 @@ public final class CommandComputerCraft
                     int queued = 0;
                     for( ServerComputer computer : computers )
                     {
-                        if( computer.getFamily() == ComputerFamily.COMMAND && computer.isOn() )
+                        if( computer.getFamily() == ComputerFamily.Command && computer.isOn() )
                         {
                             computer.queueEvent( "computer_command", rest );
                             queued++;

src/main/java/dan200/computercraft/shared/common/BlockGeneric.java

@@ -11,14 +11,12 @@ import net.minecraft.block.BlockState;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.tileentity.TileEntityType;
-import net.minecraft.util.ActionResultType;
 import net.minecraft.util.Hand;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.BlockRayTraceResult;
 import net.minecraft.world.IBlockReader;
 import net.minecraft.world.IWorldReader;
 import net.minecraft.world.World;
-import net.minecraft.world.server.ServerWorld;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -47,13 +45,12 @@ public abstract class BlockGeneric extends Block
         if( tile instanceof TileGeneric ) ((TileGeneric) tile).destroy();
     }
 
-    @Nonnull
     @Override
     @Deprecated
-    public final ActionResultType onBlockActivated( BlockState state, World world, BlockPos pos, PlayerEntity player, Hand hand, BlockRayTraceResult hit )
+    public final boolean onBlockActivated( BlockState state, World world, BlockPos pos, PlayerEntity player, Hand hand, BlockRayTraceResult hit )
     {
         TileEntity tile = world.getTileEntity( pos );
-        return tile instanceof TileGeneric ? ((TileGeneric) tile).onActivate( player, hand, hit ) : ActionResultType.PASS;
+        return tile instanceof TileGeneric && ((TileGeneric) tile).onActivate( player, hand, hit );
     }
 
     @Override
@@ -73,7 +70,7 @@ public abstract class BlockGeneric extends Block
 
     @Override
     @Deprecated
-    public void tick( BlockState state, ServerWorld world, BlockPos pos, Random rand )
+    public void tick( BlockState state, World world, BlockPos pos, Random rand )
     {
         TileEntity te = world.getTileEntity( pos );
         if( te instanceof TileGeneric ) ((TileGeneric) te).blockTick();

src/main/java/dan200/computercraft/shared/common/ClientTerminal.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.common;
 
 import dan200.computercraft.core.terminal.Terminal;
-import net.minecraft.nbt.CompoundNBT;
+import dan200.computercraft.shared.network.client.TerminalState;
 
 public class ClientTerminal implements ITerminal
 {
@@ -46,14 +46,13 @@ public class ClientTerminal implements ITerminal
         return m_colour;
     }
 
-    public void readDescription( CompoundNBT nbt )
+    public void read( TerminalState state )
     {
-        m_colour = nbt.getBoolean( "colour" );
-        if( nbt.contains( "terminal" ) )
+        m_colour = state.colour;
+        if( state.hasTerminal() )
         {
-            CompoundNBT terminal = nbt.getCompound( "terminal" );
-            resizeTerminal( terminal.getInt( "term_width" ), terminal.getInt( "term_height" ) );
-            m_terminal.readFromNBT( terminal );
+            resizeTerminal( state.width, state.height );
+            state.apply( m_terminal );
         }
         else
         {

src/main/java/dan200/computercraft/shared/common/ServerTerminal.java

@@ -6,7 +6,7 @@
 package dan200.computercraft.shared.common;
 
 import dan200.computercraft.core.terminal.Terminal;
-import net.minecraft.nbt.CompoundNBT;
+import dan200.computercraft.shared.network.client.TerminalState;
 
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -69,8 +69,6 @@ public class ServerTerminal implements ITerminal
         return m_terminalChangedLastFrame;
     }
 
-    // ITerminal implementation
-
     @Override
     public Terminal getTerminal()
     {
@@ -83,18 +81,8 @@ public class ServerTerminal implements ITerminal
         return m_colour;
     }
 
-    // Networking stuff
-
-    public void writeDescription( CompoundNBT nbt )
+    public TerminalState write()
     {
-        nbt.putBoolean( "colour", m_colour );
-        if( m_terminal != null )
-        {
-            CompoundNBT terminal = new CompoundNBT();
-            terminal.putInt( "term_width", m_terminal.getWidth() );
-            terminal.putInt( "term_height", m_terminal.getHeight() );
-            m_terminal.writeToNBT( terminal );
-            nbt.put( "terminal", terminal );
-        }
+        return new TerminalState( m_colour, m_terminal );
     }
 }

src/main/java/dan200/computercraft/shared/common/TileGeneric.java

@@ -12,7 +12,6 @@ import net.minecraft.network.NetworkManager;
 import net.minecraft.network.play.server.SUpdateTileEntityPacket;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.tileentity.TileEntityType;
-import net.minecraft.util.ActionResultType;
 import net.minecraft.util.Hand;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.BlockRayTraceResult;
@@ -38,10 +37,9 @@ public abstract class TileGeneric extends TileEntity
         getWorld().notifyBlockUpdate( pos, state, state, 3 );
     }
 
-    @Nonnull
-    public ActionResultType onActivate( PlayerEntity player, Hand hand, BlockRayTraceResult hit )
+    public boolean onActivate( PlayerEntity player, Hand hand, BlockRayTraceResult hit )
     {
-        return ActionResultType.PASS;
+        return false;
     }
 
     public void onNeighbourChange( @Nonnull BlockPos neighbour )

src/main/java/dan200/computercraft/shared/computer/blocks/TileCommandComputer.java

@@ -32,7 +32,7 @@ public class TileCommandComputer extends TileComputer
 {
     public static final NamedTileEntityType<TileCommandComputer> FACTORY = NamedTileEntityType.create(
         new ResourceLocation( ComputerCraft.MOD_ID, "command_computer" ),
-        f -> new TileCommandComputer( ComputerFamily.COMMAND, f )
+        f -> new TileCommandComputer( ComputerFamily.Command, f )
     );
 
     public class CommandReceiver implements ICommandSource
@@ -120,6 +120,11 @@ public class TileCommandComputer extends TileComputer
 
     @Override
     public boolean isUsable( PlayerEntity player, boolean ignoreRange )
+    {
+        return isUsable( player ) && super.isUsable( player, ignoreRange );
+    }
+
+    public static boolean isUsable( PlayerEntity player )
     {
         MinecraftServer server = player.getServer();
         if( server == null || !server.isCommandBlockEnabled() )
@@ -127,14 +132,12 @@ public class TileCommandComputer extends TileComputer
             player.sendStatusMessage( new TranslationTextComponent( "advMode.notEnabled" ), true );
             return false;
         }
-        else if( !player.canUseCommandBlock() )
+        else if( ComputerCraft.commandRequireCreative ? !player.canUseCommandBlock() : !server.getPlayerList().canSendCommands( player.getGameProfile() ) )
         {
             player.sendStatusMessage( new TranslationTextComponent( "advMode.notAllowed" ), true );
             return false;
         }
-        else
-        {
-            return super.isUsable( player, ignoreRange );
-        }
+
+        return true;
     }
 }

src/main/java/dan200/computercraft/shared/computer/blocks/TileComputer.java

@@ -27,12 +27,12 @@ public class TileComputer extends TileComputerBase
 {
     public static final NamedTileEntityType<TileComputer> FACTORY_NORMAL = NamedTileEntityType.create(
         new ResourceLocation( ComputerCraft.MOD_ID, "computer_normal" ),
-        f -> new TileComputer( ComputerFamily.NORMAL, f )
+        f -> new TileComputer( ComputerFamily.Normal, f )
     );
 
     public static final NamedTileEntityType<TileComputer> FACTORY_ADVANCED = NamedTileEntityType.create(
         new ResourceLocation( ComputerCraft.MOD_ID, "computer_advanced" ),
-        f -> new TileComputer( ComputerFamily.ADVANCED, f )
+        f -> new TileComputer( ComputerFamily.Advanced, f )
     );
 
     private ComputerProxy m_proxy;

src/main/java/dan200/computercraft/shared/computer/blocks/TileComputerBase.java

@@ -30,7 +30,6 @@ import net.minecraft.item.Items;
 import net.minecraft.nbt.CompoundNBT;
 import net.minecraft.tileentity.ITickableTileEntity;
 import net.minecraft.tileentity.TileEntityType;
-import net.minecraft.util.ActionResultType;
 import net.minecraft.util.Direction;
 import net.minecraft.util.Hand;
 import net.minecraft.util.INameable;
@@ -103,9 +102,8 @@ public abstract class TileComputerBase extends TileGeneric implements IComputerT
         return false;
     }
 
-    @Nonnull
     @Override
-    public ActionResultType onActivate( PlayerEntity player, Hand hand, BlockRayTraceResult hit )
+    public boolean onActivate( PlayerEntity player, Hand hand, BlockRayTraceResult hit )
     {
         ItemStack currentItem = player.getHeldItem( hand );
         if( !currentItem.isEmpty() && currentItem.getItem() == Items.NAME_TAG && canNameWithTag( player ) && currentItem.hasDisplayName() )
@@ -116,9 +114,9 @@ public abstract class TileComputerBase extends TileGeneric implements IComputerT
                 setLabel( currentItem.getDisplayName().getString() );
                 currentItem.shrink( 1 );
             }
-            return ActionResultType.SUCCESS;
+            return true;
         }
-        else if( !player.isCrouching() )
+        else if( !player.isSneaking() )
         {
             // Regular right click to activate computer
             if( !getWorld().isRemote && isUsable( player, false ) )
@@ -126,9 +124,9 @@ public abstract class TileComputerBase extends TileGeneric implements IComputerT
                 createServerComputer().turnOn();
                 new ComputerContainerData( createServerComputer() ).open( player, this );
             }
-            return ActionResultType.SUCCESS;
+            return true;
         }
-        return ActionResultType.PASS;
+        return false;
     }
 
     @Override
@@ -279,7 +277,7 @@ public abstract class TileComputerBase extends TileGeneric implements IComputerT
             if( offset.equals( neighbour ) )
             {
                 updateSideInput( computer, dir, offset );
-                break;
+                return;
             }
         }
 

src/main/java/dan200/computercraft/shared/computer/core/ComputerFamily.java

@@ -7,7 +7,7 @@ package dan200.computercraft.shared.computer.core;
 
 public enum ComputerFamily
 {
-    NORMAL,
-    ADVANCED,
-    COMMAND
+    Normal,
+    Advanced,
+    Command
 }

src/main/java/dan200/computercraft/shared/computer/core/ComputerState.java

@@ -35,4 +35,3 @@ public enum ComputerState implements IStringSerializable
         return name;
     }
 }
-

src/main/java/dan200/computercraft/shared/computer/core/ServerComputer.java

@@ -50,7 +50,7 @@ public class ServerComputer extends ServerTerminal implements IComputer, IComput
 
     public ServerComputer( World world, int computerID, String label, int instanceID, ComputerFamily family, int terminalWidth, int terminalHeight )
     {
-        super( family != ComputerFamily.NORMAL, terminalWidth, terminalHeight );
+        super( family != ComputerFamily.Normal, terminalWidth, terminalHeight );
         m_instanceID = instanceID;
 
         m_world = world;
@@ -154,9 +154,7 @@ public class ServerComputer extends ServerTerminal implements IComputer, IComput
 
     protected NetworkMessage createTerminalPacket()
     {
-        CompoundNBT tagCompound = new CompoundNBT();
-        writeDescription( tagCompound );
-        return new ComputerTerminalClientMessage( getInstanceID(), tagCompound );
+        return new ComputerTerminalClientMessage( getInstanceID(), write() );
     }
 
     public void broadcastState( boolean force )

src/main/java/dan200/computercraft/shared/computer/inventory/ContainerViewComputer.java

@@ -6,6 +6,7 @@
 package dan200.computercraft.shared.computer.inventory;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.shared.computer.blocks.TileCommandComputer;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.IContainerComputer;
 import dan200.computercraft.shared.computer.core.ServerComputer;
@@ -14,8 +15,6 @@ import dan200.computercraft.shared.network.container.ViewComputerContainerData;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.entity.player.PlayerInventory;
 import net.minecraft.inventory.container.ContainerType;
-import net.minecraft.server.MinecraftServer;
-import net.minecraft.util.text.TranslationTextComponent;
 
 import javax.annotation.Nonnull;
 
@@ -48,18 +47,9 @@ public class ContainerViewComputer extends ContainerComputerBase implements ICon
         }
 
         // If we're a command computer then ensure we're in creative
-        if( computer.getFamily() == ComputerFamily.COMMAND )
+        if( computer.getFamily() == ComputerFamily.Command && !TileCommandComputer.isUsable( player ) )
         {
-            MinecraftServer server = player.getServer();
-            if( server == null || !server.isCommandBlockEnabled() )
-            {
-                return false;
-            }
-            else if( !player.canUseCommandBlock() )
-            {
-                player.sendStatusMessage( new TranslationTextComponent( "advMode.notAllowed" ), false );
-                return false;
-            }
+            return false;
         }
 
         return true;

src/main/java/dan200/computercraft/shared/computer/items/ComputerItemFactory.java

@@ -19,9 +19,7 @@ public final class ComputerItemFactory
     @Nonnull
     public static ItemStack create( TileComputer tile )
     {
-        String label = tile.getLabel();
-        int id = label != null ? tile.getComputerID() : -1;
-        return create( id, label, tile.getFamily() );
+        return create( tile.getComputerID(), tile.getLabel(), tile.getFamily() );
     }
 
     @Nonnull
@@ -29,11 +27,11 @@ public final class ComputerItemFactory
     {
         switch( family )
         {
-            case NORMAL:
+            case Normal:
                 return ComputerCraft.Items.computerNormal.create( id, label );
-            case ADVANCED:
+            case Advanced:
                 return ComputerCraft.Items.computerAdvanced.create( id, label );
-            case COMMAND:
+            case Command:
                 return ComputerCraft.Items.computerCommand.create( id, label );
             default:
                 return ItemStack.EMPTY;

src/main/java/dan200/computercraft/shared/computer/items/ItemComputerBase.java

@@ -37,7 +37,7 @@ public abstract class ItemComputerBase extends BlockItem implements IComputerIte
     @Override
     public void addInformation( @Nonnull ItemStack stack, @Nullable World world, @Nonnull List<ITextComponent> list, @Nonnull ITooltipFlag options )
     {
-        if( options.isAdvanced() )
+        if( options.isAdvanced() || getLabel( stack ) == null )
         {
             int id = getComputerID( stack );
             if( id >= 0 )
@@ -80,7 +80,7 @@ public abstract class ItemComputerBase extends BlockItem implements IComputerIte
     public IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )
     {
         ComputerFamily family = getFamily();
-        if( family != ComputerFamily.COMMAND )
+        if( family != ComputerFamily.Command )
         {
             int id = getComputerID( stack );
             if( id >= 0 )

src/main/java/dan200/computercraft/shared/data/HasComputerIdLootCondition.java

@@ -0,0 +1,48 @@
+/*
+ * 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.shared.data;
+
+import dan200.computercraft.shared.computer.blocks.IComputerTile;
+import net.minecraft.tileentity.TileEntity;
+import net.minecraft.world.storage.loot.LootContext;
+import net.minecraft.world.storage.loot.LootParameter;
+import net.minecraft.world.storage.loot.LootParameters;
+import net.minecraft.world.storage.loot.conditions.ILootCondition;
+
+import javax.annotation.Nonnull;
+import java.util.Collections;
+import java.util.Set;
+
+/**
+ * A loot condition which checks if the tile entity has has a non-0 ID.
+ */
+public final class HasComputerIdLootCondition implements ILootCondition
+{
+    public static final HasComputerIdLootCondition INSTANCE = new HasComputerIdLootCondition();
+
+    private HasComputerIdLootCondition()
+    {
+    }
+
+    @Override
+    public boolean test( LootContext lootContext )
+    {
+        TileEntity tile = lootContext.get( LootParameters.BLOCK_ENTITY );
+        return tile instanceof IComputerTile && ((IComputerTile) tile).getComputerID() >= 0;
+    }
+
+    @Nonnull
+    @Override
+    public Set<LootParameter<?>> getRequiredParameters()
+    {
+        return Collections.singleton( LootParameters.BLOCK_ENTITY );
+    }
+
+    public static IBuilder builder()
+    {
+        return () -> INSTANCE;
+    }
+}

src/main/java/dan200/computercraft/shared/integration/jei/JEIComputerCraft.java

@@ -116,8 +116,8 @@ public class JEIComputerCraft implements IModPlugin
         StringBuilder name = new StringBuilder();
 
         // Add left and right upgrades to the identifier
-        ITurtleUpgrade left = turtle.getUpgrade( stack, TurtleSide.LEFT );
-        ITurtleUpgrade right = turtle.getUpgrade( stack, TurtleSide.RIGHT );
+        ITurtleUpgrade left = turtle.getUpgrade( stack, TurtleSide.Left );
+        ITurtleUpgrade right = turtle.getUpgrade( stack, TurtleSide.Right );
         if( left != null ) name.append( left.getUpgradeID() );
         if( left != null && right != null ) name.append( '|' );
         if( right != null ) name.append( right.getUpgradeID() );

src/main/java/dan200/computercraft/shared/integration/jei/RecipeResolver.java

@@ -37,7 +37,7 @@ import static net.minecraft.util.NonNullList.from;
 
 class RecipeResolver implements IRecipeManagerPlugin
 {
-    static final ComputerFamily[] MAIN_FAMILIES = new ComputerFamily[] { ComputerFamily.NORMAL, ComputerFamily.ADVANCED };
+    static final ComputerFamily[] MAIN_FAMILIES = new ComputerFamily[] { ComputerFamily.Normal, ComputerFamily.Advanced };
 
     private final Map<Item, List<UpgradeInfo>> upgradeItemLookup = new HashMap<>();
     private final List<UpgradeInfo> pocketUpgrades = new ArrayList<>();
@@ -150,8 +150,8 @@ class RecipeResolver implements IRecipeManagerPlugin
         {
             // Suggest possible upgrades which can be applied to this turtle
             ITurtleItem item = (ITurtleItem) stack.getItem();
-            ITurtleUpgrade left = item.getUpgrade( stack, TurtleSide.LEFT );
-            ITurtleUpgrade right = item.getUpgrade( stack, TurtleSide.RIGHT );
+            ITurtleUpgrade left = item.getUpgrade( stack, TurtleSide.Left );
+            ITurtleUpgrade right = item.getUpgrade( stack, TurtleSide.Right );
             if( left != null && right != null ) return Collections.emptyList();
 
             List<Shaped> recipes = new ArrayList<>();
@@ -231,8 +231,8 @@ class RecipeResolver implements IRecipeManagerPlugin
             ITurtleItem item = (ITurtleItem) stack.getItem();
             List<Shaped> recipes = new ArrayList<>( 0 );
 
-            ITurtleUpgrade left = item.getUpgrade( stack, TurtleSide.LEFT );
-            ITurtleUpgrade right = item.getUpgrade( stack, TurtleSide.RIGHT );
+            ITurtleUpgrade left = item.getUpgrade( stack, TurtleSide.Left );
+            ITurtleUpgrade right = item.getUpgrade( stack, TurtleSide.Right );
 
             // The turtle is facing towards us, so upgrades on the left are actually crafted on the right.
             if( left != null )

src/main/java/dan200/computercraft/shared/media/items/ItemDisk.java

@@ -126,6 +126,6 @@ public class ItemDisk extends Item implements IMedia, IColouredItem
     public int getColour( @Nonnull ItemStack stack )
     {
         int colour = IColouredItem.getColourBasic( stack );
-        return colour == -1 ? Colour.WHITE.getHex() : colour;
+        return colour == -1 ? Colour.White.getHex() : colour;
     }
 }