Make the shader mod system a little more flexible

Mostly for multi-loader support, but also /technically/ makes it easier
to support multiple loaders in the future.

projects/common-api/src/main/java/dan200/computercraft/impl/Services.java

@@ -8,8 +8,6 @@
 import org.jetbrains.annotations.ApiStatus;
 
 import javax.annotation.Nullable;
-import java.util.ArrayList;
-import java.util.List;
 import java.util.ServiceLoader;
 import java.util.stream.Collectors;
 
@@ -32,17 +30,15 @@ private Services() {
      * @throws IllegalStateException When the service cannot be loaded.
      */
     public static <T> T load(Class<T> klass) {
-        List<T> services = new ArrayList<>(1);
-        for (var provider : ServiceLoader.load(klass)) services.add(provider);
-        switch (services.size()) {
-            case 1:
-                return services.get(0);
-            case 0:
-                throw new IllegalStateException("Cannot find service for " + klass.getName());
-            default:
-                var serviceTypes = services.stream().map(x -> x.getClass().getName()).collect(Collectors.joining(", "));
+        var services = ServiceLoader.load(klass).stream().toList();
+        return switch (services.size()) {
+            case 1 -> services.get(0).get();
+            case 0 -> throw new IllegalStateException("Cannot find service for " + klass.getName());
+            default -> {
+                var serviceTypes = services.stream().map(x -> x.type().getName()).collect(Collectors.joining(", "));
                 throw new IllegalStateException("Multiple services for " + klass.getName() + ": " + serviceTypes);
-        }
+            }
+        };
     }
 
     /**

src/main/java/dan200/computercraft/client/integration/IrisShaderMod.java

@@ -3,8 +3,9 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.shared.integration;
+package dan200.computercraft.client.integration;
 
+import com.google.auto.service.AutoService;
 import com.mojang.blaze3d.vertex.VertexFormat;
 import dan200.computercraft.client.render.RenderTypes;
 import dan200.computercraft.client.render.text.DirectFixedWidthFontRenderer;
@@ -13,28 +14,20 @@
 import net.minecraftforge.fml.ModList;
 
 import java.nio.ByteBuffer;
+import java.util.Optional;
 import java.util.function.IntFunction;
 
-public class ShaderMod {
-    public static final ShaderMod INSTANCE
-        = ModList.get().isLoaded("oculus") ? new IrisImpl()
-        : new ShaderMod();
-
-    public boolean isShaderMod() {
-        return Optifine.isLoaded();
+/**
+ * A {@link ShaderMod} for Oculus (the Forge Iris port).
+ */
+@AutoService(ShaderMod.Provider.class)
+public class IrisShaderMod implements ShaderMod.Provider {
+    @Override
+    public Optional<ShaderMod> get() {
+        return ModList.get().isLoaded("oculus") ? Optional.of(new Impl()) : Optional.empty();
     }
 
-    public boolean isRenderingShadowPass() {
-        return false;
-    }
-
-    public DirectFixedWidthFontRenderer.QuadEmitter getQuadEmitter(int vertexCount, IntFunction<ByteBuffer> makeBuffer) {
-        return new DirectFixedWidthFontRenderer.ByteBufferEmitter(
-            makeBuffer.apply(RenderTypes.TERMINAL.format().getVertexSize() * vertexCount * 4)
-        );
-    }
-
-    private static final class IrisImpl extends ShaderMod {
+    private static final class Impl extends ShaderMod {
         @Override
         public boolean isRenderingShadowPass() {
             return IrisApi.getInstance().isRenderingShadowPass();

src/main/java/dan200/computercraft/client/integration/Optifine.java

@@ -3,7 +3,7 @@
  * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.shared.integration;
+package dan200.computercraft.client.integration;
 
 /**
  * Detect whether Optifine is installed.

src/main/java/dan200/computercraft/client/integration/ShaderMod.java

@@ -0,0 +1,67 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2022. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.client.integration;
+
+import dan200.computercraft.client.render.RenderTypes;
+import dan200.computercraft.client.render.text.DirectFixedWidthFontRenderer;
+import dan200.computercraft.client.util.DirectVertexBuffer;
+
+import java.nio.ByteBuffer;
+import java.util.Optional;
+import java.util.ServiceLoader;
+import java.util.function.IntFunction;
+
+/**
+ * Find the currently loaded shader mod (if present) and provides utilities for interacting with it.
+ */
+public class ShaderMod {
+    public static ShaderMod get() {
+        return Storage.INSTANCE;
+    }
+
+    /**
+     * Determine if shaders may be used in the current session.
+     *
+     * @return Whether a shader mod is loaded.
+     */
+    public boolean isShaderMod() {
+        return Optifine.isLoaded();
+    }
+
+    /**
+     * Check whether we're currently rendering shadows. Rendering may fall back to a faster but less detailed pass.
+     *
+     * @return Whether we're rendering shadows.
+     */
+    public boolean isRenderingShadowPass() {
+        return false;
+    }
+
+    /**
+     * Get an appropriate quad emitter for use with {@link DirectVertexBuffer} and {@link DirectFixedWidthFontRenderer} .
+     *
+     * @param vertexCount The number of vertices.
+     * @param makeBuffer  A function to allocate a temporary buffer.
+     * @return The quad emitter.
+     */
+    public DirectFixedWidthFontRenderer.QuadEmitter getQuadEmitter(int vertexCount, IntFunction<ByteBuffer> makeBuffer) {
+        return new DirectFixedWidthFontRenderer.ByteBufferEmitter(
+            makeBuffer.apply(RenderTypes.TERMINAL.format().getVertexSize() * vertexCount * 4)
+        );
+    }
+
+    public interface Provider {
+        Optional<ShaderMod> get();
+    }
+
+    private static class Storage {
+        static final ShaderMod INSTANCE = ServiceLoader.load(Provider.class)
+            .stream()
+            .flatMap(x -> x.get().get().stream())
+            .findFirst()
+            .orElseGet(ShaderMod::new);
+    }
+}

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

@@ -16,6 +16,7 @@
 import com.mojang.math.Matrix4f;
 import com.mojang.math.Vector3f;
 import dan200.computercraft.client.FrameInfo;
+import dan200.computercraft.client.integration.ShaderMod;
 import dan200.computercraft.client.render.monitor.MonitorRenderState;
 import dan200.computercraft.client.render.text.DirectFixedWidthFontRenderer;
 import dan200.computercraft.client.render.text.FixedWidthFontRenderer;
@@ -23,7 +24,6 @@
 import dan200.computercraft.client.util.DirectVertexBuffer;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.config.Config;
-import dan200.computercraft.shared.integration.ShaderMod;
 import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
 import dan200.computercraft.shared.peripheral.monitor.MonitorRenderer;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
@@ -112,7 +112,7 @@ public void render(TileMonitor monitor, float partialTicks, PoseStack transform,
 
         // Draw the contents
         var terminal = originTerminal.getTerminal();
-        if (terminal != null && !ShaderMod.INSTANCE.isRenderingShadowPass()) {
+        if (terminal != null && !ShaderMod.get().isRenderingShadowPass()) {
             // Draw a terminal
             int width = terminal.getWidth(), height = terminal.getHeight();
             int pixelWidth = width * FONT_WIDTH, pixelHeight = height * FONT_HEIGHT;
@@ -233,7 +233,7 @@ private static void renderTerminal(
     }
 
     private static void renderToBuffer(DirectVertexBuffer vbo, int size, Consumer<DirectFixedWidthFontRenderer.QuadEmitter> draw) {
-        var sink = ShaderMod.INSTANCE.getQuadEmitter(size, TileEntityMonitorRenderer::getBuffer);
+        var sink = ShaderMod.get().getQuadEmitter(size, TileEntityMonitorRenderer::getBuffer);
         var buffer = sink.buffer();
 
         draw.accept(sink);
@@ -279,8 +279,8 @@ private static MonitorRenderer bestRenderer() {
             return MonitorRenderer.VBO;
         }
 
-        if (ShaderMod.INSTANCE.isShaderMod()) {
-            LOG.warn("Optifine is loaded, assuming shaders are being used. Falling back to VBO monitor renderer.");
+        if (ShaderMod.get().isShaderMod()) {
+            LOG.warn("A shader mod is loaded, assuming shaders are being used. Falling back to VBO monitor renderer.");
             return MonitorRenderer.VBO;
         }
 

src/main/java/dan200/computercraft/shared/peripheral/monitor/TileMonitor.java

@@ -519,6 +519,7 @@ private void eachComputer(Consumer<IComputerAccess> fun) {
     }
 
     public IPeripheral peripheral() {
+        createServerMonitor();
         if (peripheral != null) return peripheral;
         return peripheral = new MonitorPeripheral(this);
     }