Fix visual artifacts with contraptions while using opfine.

I think the buffers from the shadow pass were bleeding into the color pass.

src/main/java/com/jozufozu/flywheel/backend/Backend.java

@@ -1,10 +1,6 @@
 package com.jozufozu.flywheel.backend;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 import javax.annotation.Nullable;
 
@@ -55,7 +51,7 @@ public class Backend {
 	 * (Meshlet, MDI, GL31 Draw Instanced are planned), this will name which one is in use.
 	 */
 	public String getBackendDescriptor() {
-		return engine.getProperName();
+		return engine == null ? "" : engine.getProperName();
 	}
 
 	public FlwEngine getEngine() {

src/main/java/com/jozufozu/flywheel/backend/OptifineHandler.java

@@ -4,7 +4,11 @@ import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
+import java.lang.reflect.Field;
 import java.util.Optional;
+import java.util.function.BooleanSupplier;
+
+import com.jozufozu.flywheel.util.Lazy;
 
 import net.minecraft.client.Minecraft;
 
@@ -15,6 +19,23 @@ public class OptifineHandler {
 	private static Package optifine;
 	private static OptifineHandler handler;
 
+	private static final Lazy<BooleanSupplier> isShadowPass = Lazy.of(() -> {
+		try {
+			Class<?> ofShaders = Class.forName("net.optifine.shaders.Shaders");
+			Field field = ofShaders.getDeclaredField("isShadowPass");
+			field.setAccessible(true);
+			return () -> {
+				try {
+					return field.getBoolean(null);
+				} catch (IllegalAccessException ignored) {
+					return false;
+				}
+			};
+		} catch (Exception ignored) {
+			return () -> false;
+		}
+	});
+
 	public final boolean usingShaders;
 
 	public OptifineHandler(boolean usingShaders) {
@@ -40,6 +61,10 @@ public class OptifineHandler {
 				.orElse(false);
 	}
 
+	public static boolean isShadowPass() {
+		return isShadowPass.get().getAsBoolean();
+	}
+
 	public static void init() {
 		optifine = Package.getPackage(OPTIFINE_ROOT_PACKAGE);
 

src/main/java/com/jozufozu/flywheel/backend/instancing/InstanceWorld.java

@@ -90,12 +90,12 @@ public class InstanceWorld {
 	 * </p>
 	 */
 	public void beginFrame(BeginFrameEvent event) {
-		engine.beginFrame(event.getInfo());
+		engine.beginFrame(event.getCamera());
 
 		taskEngine.syncPoint();
 
-		blockEntityInstanceManager.beginFrame(taskEngine, event.getInfo());
-		entityInstanceManager.beginFrame(taskEngine, event.getInfo());
+		blockEntityInstanceManager.beginFrame(taskEngine, event.getCamera());
+		entityInstanceManager.beginFrame(taskEngine, event.getCamera());
 	}
 
 	/**

src/main/java/com/jozufozu/flywheel/core/LastActiveCamera.java

@@ -0,0 +1,16 @@
+package com.jozufozu.flywheel.core;
+
+import net.minecraft.client.Camera;
+
+public class LastActiveCamera {
+
+	private static Camera camera;
+
+	public static void _setActiveCamera(Camera camera) {
+		LastActiveCamera.camera = camera;
+	}
+
+	public static Camera getActiveCamera() {
+		return camera;
+	}
+}

src/main/java/com/jozufozu/flywheel/event/BeginFrameEvent.java

@@ -8,28 +8,28 @@ import net.minecraftforge.eventbus.api.Event;
 
 public class BeginFrameEvent extends Event {
 	private final ClientLevel world;
-	private final Camera info;
-	private final Frustum clippingHelper;
+	private final Camera camera;
+	private final Frustum frustum;
 
-	public BeginFrameEvent(ClientLevel world, Camera info, Frustum clippingHelper) {
+	public BeginFrameEvent(ClientLevel world, Camera camera, Frustum frustum) {
 		this.world = world;
-		this.info = info;
-		this.clippingHelper = clippingHelper;
+		this.camera = camera;
+		this.frustum = frustum;
 	}
 
 	public ClientLevel getWorld() {
 		return world;
 	}
 
-	public Camera getInfo() {
-		return info;
+	public Camera getCamera() {
+		return camera;
 	}
 
-	public Frustum getClippingHelper() {
-		return clippingHelper;
+	public Frustum getFrustum() {
+		return frustum;
 	}
 
 	public Vec3 getCameraPos() {
-		return info.getPosition();
+		return camera.getPosition();
 	}
 }

src/main/java/com/jozufozu/flywheel/mixin/CameraMixin.java

@@ -0,0 +1,21 @@
+package com.jozufozu.flywheel.mixin;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.jozufozu.flywheel.core.LastActiveCamera;
+
+import net.minecraft.client.Camera;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.BlockGetter;
+
+@Mixin(Camera.class)
+public class CameraMixin {
+
+	@Inject(method = "setup", at = @At("TAIL"))
+	private void setup(BlockGetter level, Entity entity, boolean is3rdPerson, boolean isMirrored, float pt, CallbackInfo ci) {
+		LastActiveCamera._setActiveCamera((Camera)(Object) this);
+	}
+}

src/main/java/com/jozufozu/flywheel/mixin/FrustumMixin.java

@@ -0,0 +1,25 @@
+package com.jozufozu.flywheel.mixin;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.jozufozu.flywheel.backend.OptifineHandler;
+import com.jozufozu.flywheel.core.LastActiveCamera;
+import com.jozufozu.flywheel.event.BeginFrameEvent;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.culling.Frustum;
+import net.minecraftforge.common.MinecraftForge;
+
+@Mixin(Frustum.class)
+public class FrustumMixin {
+
+	@Inject(method = "prepare", at = @At("TAIL"))
+	private void onPrepare(double x, double y, double z, CallbackInfo ci) {
+		if (OptifineHandler.isShadowPass()) {
+			MinecraftForge.EVENT_BUS.post(new BeginFrameEvent(Minecraft.getInstance().level, LastActiveCamera.getActiveCamera(), (Frustum) (Object) this));
+		}
+	}
+}

src/main/java/com/jozufozu/flywheel/mixin/LevelRendererMixin.java

@@ -33,7 +33,7 @@ import net.minecraftforge.common.MinecraftForge;
 
 @OnlyIn(Dist.CLIENT)
 @Mixin(LevelRenderer.class)
-public class RenderHooksMixin {
+public class LevelRendererMixin {
 
 	@Shadow
 	private ClientLevel level;
@@ -52,7 +52,7 @@ public class RenderHooksMixin {
 	 * layer-correct custom rendering. RenderWorldLast is not refined enough for rendering world objects.
 	 * This should probably be a forge event.
 	 */
-	@Inject(at = @At("TAIL"), method = "renderChunkLayer")
+	@Inject(at = @At(value = "INVOKE", target = "Lnet/minecraft/client/renderer/ShaderInstance;clear()V"), method = "renderChunkLayer")
 	private void renderLayer(RenderType type, PoseStack stack, double camX, double camY, double camZ, Matrix4f p_172999_, CallbackInfo ci) {
 
 		RenderBuffers renderBuffers = this.renderBuffers;

src/main/resources/flywheel.mixins.json

@@ -1,34 +1,36 @@
 {
-    "required": true,
-    "minVersion": "0.8",
-    "package": "com.jozufozu.flywheel.mixin",
-    "compatibilityLevel": "JAVA_17",
-    "refmap": "flywheel.refmap.json",
-    "client": [
-        "BlockEntityTypeMixin",
-        "BufferBuilderMixin",
-        "BufferUploaderAccessor",
-        "CancelEntityRenderMixin",
-        "ChunkRebuildHooksMixin",
-        "EntityTypeMixin",
-        "FixFabulousDepthMixin",
-        "InstanceAddMixin",
-        "InstanceRemoveMixin",
-        "LevelRendererAccessor",
-        "PausedPartialTickAccessor",
-        "RenderHooksMixin",
-        "RenderTexturesMixin",
-        "ShaderCloseMixin",
-        "ShaderInstanceAccessor",
-        "atlas.AtlasDataMixin",
-        "atlas.SheetDataAccessor",
-        "light.LightUpdateMixin",
-        "light.NetworkLightUpdateMixin",
-        "matrix.Matrix3fMixin",
-        "matrix.Matrix4fMixin",
-        "matrix.PoseStackMixin"
-    ],
-    "injectors": {
-        "defaultRequire": 1
-    }
+  "required": true,
+  "minVersion": "0.8",
+  "package": "com.jozufozu.flywheel.mixin",
+  "compatibilityLevel": "JAVA_17",
+  "refmap": "flywheel.refmap.json",
+  "client": [
+    "BlockEntityTypeMixin",
+    "BufferBuilderMixin",
+    "BufferUploaderAccessor",
+    "CameraMixin",
+    "CancelEntityRenderMixin",
+    "ChunkRebuildHooksMixin",
+    "EntityTypeMixin",
+    "FixFabulousDepthMixin",
+    "FrustumMixin",
+    "InstanceAddMixin",
+    "InstanceRemoveMixin",
+    "LevelRendererAccessor",
+    "LevelRendererMixin",
+    "PausedPartialTickAccessor",
+    "RenderTexturesMixin",
+    "ShaderCloseMixin",
+    "ShaderInstanceAccessor",
+    "atlas.AtlasDataMixin",
+    "atlas.SheetDataAccessor",
+    "light.LightUpdateMixin",
+    "light.NetworkLightUpdateMixin",
+    "matrix.Matrix3fMixin",
+    "matrix.Matrix4fMixin",
+    "matrix.PoseStackMixin"
+  ],
+  "injectors": {
+    "defaultRequire": 1
+  }
 }