Merge branch '1.18/shader-sanity' into 1.18/dev

src/main/java/com/jozufozu/flywheel/FlywheelClient.java

@@ -1,13 +1,16 @@
 package com.jozufozu.flywheel;
 
 import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.OptifineHandler;
 import com.jozufozu.flywheel.core.Contexts;
-import com.jozufozu.flywheel.core.Materials;
 import com.jozufozu.flywheel.core.PartialModel;
 import com.jozufozu.flywheel.core.StitchedSprite;
+import com.jozufozu.flywheel.core.compile.ProgramCompiler;
+import com.jozufozu.flywheel.event.ReloadRenderersEvent;
 import com.jozufozu.flywheel.mixin.PausedPartialTickAccessor;
 import com.jozufozu.flywheel.vanilla.VanillaInstances;
 
+import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.eventbus.api.IEventBus;
 import net.minecraftforge.fml.CrashReportCallables;
 import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
@@ -15,20 +18,21 @@ import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
 public class FlywheelClient {
 
 	public static void clientInit() {
-		CrashReportCallables.registerCrashCallable("Flywheel Backend", () ->
+		CrashReportCallables.registerCrashCallable("Flywheel Backend", Backend::getBackendDescriptor);
-				Backend.getInstance().getBackendDescriptor());
 
+		OptifineHandler.init();
 		Backend.init();
 		IEventBus modEventBus = FMLJavaModLoadingContext.get()
 				.getModEventBus();
 
 		modEventBus.addListener(Contexts::flwInit);
-		modEventBus.addListener(Materials::flwInit);
 		modEventBus.addListener(PartialModel::onModelRegistry);
 		modEventBus.addListener(PartialModel::onModelBake);
 		modEventBus.addListener(StitchedSprite::onTextureStitchPre);
 		modEventBus.addListener(StitchedSprite::onTextureStitchPost);
 
+		MinecraftForge.EVENT_BUS.<ReloadRenderersEvent>addListener(ProgramCompiler::invalidateAll);
+
 		VanillaInstances.init();
 
 		// https://github.com/Jozufozu/Flywheel/issues/69

src/main/java/com/jozufozu/flywheel/api/vertex/VertexType.java

@@ -32,6 +32,8 @@ public interface VertexType {
 	 */
 	VertexList createReader(ByteBuffer buffer, int vertexCount);
 
+	String getShaderHeader();
+
 	default int getStride() {
 		return getLayout().getStride();
 	}

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

@@ -1,25 +1,15 @@
 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 javax.annotation.Nullable;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.lwjgl.opengl.GL;
-import org.lwjgl.opengl.GLCapabilities;
 
 import com.jozufozu.flywheel.api.FlywheelWorld;
-import com.jozufozu.flywheel.api.InstanceData;
-import com.jozufozu.flywheel.api.struct.StructType;
 import com.jozufozu.flywheel.backend.gl.versioned.GlCompat;
 import com.jozufozu.flywheel.config.FlwConfig;
 import com.jozufozu.flywheel.config.FlwEngine;
-import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
+import com.jozufozu.flywheel.core.shader.ProgramSpec;
 
 import net.minecraft.client.Minecraft;
 import net.minecraft.resources.ResourceLocation;
@@ -29,101 +19,39 @@ import net.minecraft.world.level.LevelAccessor;
 public class Backend {
 	public static final Logger LOGGER = LogManager.getLogger(Backend.class);
 
-	protected static final Backend INSTANCE = new Backend();
+	private static FlwEngine engine;
-	public static Backend getInstance() {
-		return INSTANCE;
-	}
 
-	private FlwEngine engine;
+	public static GlCompat compat;
 
-	public GLCapabilities capabilities;
+	private static final Loader loader = new Loader();
-	public GlCompat compat;
-
-	public final Loader loader;
-	private final List<ShaderContext<?>> contexts = new ArrayList<>();
-	private final Map<ResourceLocation, StructType<?>> materialRegistry = new HashMap<>();
-	private final Map<ResourceLocation, ProgramSpec> programSpecRegistry = new HashMap<>();
-
-	protected Backend() {
-		loader = new Loader(this);
-
-		OptifineHandler.init();
-	}
 
 	/**
 	 * Get a string describing the Flywheel backend. When there are eventually multiple backends
 	 * (Meshlet, MDI, GL31 Draw Instanced are planned), this will name which one is in use.
 	 */
-	public String getBackendDescriptor() {
+	public static String getBackendDescriptor() {
 		return engine == null ? "" : engine.getProperName();
 	}
 
-	public FlwEngine getEngine() {
+	public static FlwEngine getEngine() {
 		return engine;
 	}
 
-	/**
+	@Nullable
-	 * Register a shader program.
+	public static ProgramSpec getSpec(ResourceLocation name) {
-	 */
+		return loader.get(name);
-	public ProgramSpec register(ProgramSpec spec) {
-		ResourceLocation name = spec.name;
-		if (programSpecRegistry.containsKey(name)) {
-			throw new IllegalStateException("Program spec '" + name + "' already registered.");
-		}
-		programSpecRegistry.put(name, spec);
-		return spec;
 	}
 
-	/**
+	public static void refresh() {
-	 * Register a shader context.
-	 */
-	public <C extends ShaderContext<?>> C register(C spec) {
-		contexts.add(spec);
-		return spec;
-	}
-
-	/**
-	 * Register an instancing material.
-	 */
-	public <D extends InstanceData> StructType<D> register(ResourceLocation name, StructType<D> spec) {
-		if (materialRegistry.containsKey(name)) {
-			throw new IllegalStateException("Material spec '" + name + "' already registered.");
-		}
-		materialRegistry.put(name, spec);
-
-		LOGGER.debug("registered material '" + name + "' with instance size " + spec.getLayout().getStride());
-
-		return spec;
-	}
-
-	public ProgramSpec getSpec(ResourceLocation name) {
-		return programSpecRegistry.get(name);
-	}
-
-	public void refresh() {
 		OptifineHandler.refresh();
 
-		capabilities = GL.createCapabilities();
+		compat = new GlCompat();
-
-		compat = new GlCompat(capabilities);
 
 		engine = chooseEngine(compat);
 	}
 
-	public Collection<StructType<?>> allMaterials() {
-		return materialRegistry.values();
-	}
-
-	public Collection<ProgramSpec> allPrograms() {
-		return programSpecRegistry.values();
-	}
-
-	public Collection<ShaderContext<?>> allContexts() {
-		return contexts;
-	}
-
 	public static boolean isOn() {
-		return getInstance().engine != FlwEngine.OFF;
+		return engine != FlwEngine.OFF;
 	}
 
 	public static boolean canUseInstancing(@Nullable Level world) {
@@ -151,20 +79,6 @@ public class Backend {
 		RenderWork.enqueue(Minecraft.getInstance().levelRenderer::allChanged);
 	}
 
-	/**
-	 * INTERNAL USE ONLY
-	 */
-	void _clearContexts() {
-		GameStateRegistry.clear();
-		programSpecRegistry.clear();
-		contexts.forEach(ShaderContext::delete);
-		contexts.clear();
-		materialRegistry.clear();
-	}
-
-	public static void init() {
-	}
-
 	private static FlwEngine chooseEngine(GlCompat compat) {
 		FlwEngine preferredChoice = FlwConfig.get()
 				.getEngine();
@@ -178,4 +92,12 @@ public class Backend {
 
 		return canUseEngine ? preferredChoice : FlwEngine.OFF;
 	}
+
+	public static void init() {
+		// noop
+	}
+
+	private Backend() {
+		throw new UnsupportedOperationException("Backend is a static class!");
+	}
 }

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

@@ -1,35 +0,0 @@
-package com.jozufozu.flywheel.backend;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import com.jozufozu.flywheel.core.shader.gamestate.GameStateProvider;
-
-import net.minecraft.resources.ResourceLocation;
-
-public class GameStateRegistry {
-
-	private static final Map<ResourceLocation, GameStateProvider> registeredStateProviders = new HashMap<>();
-
-	static void clear() {
-		registeredStateProviders.clear();
-	}
-
-	public static GameStateProvider getStateProvider(ResourceLocation location) {
-		GameStateProvider out = registeredStateProviders.get(location);
-
-		if (out == null) {
-			throw new IllegalArgumentException("State provider '" + location + "' does not exist.");
-		}
-
-		return out;
-	}
-
-	public static void register(GameStateProvider context) {
-		if (registeredStateProviders.containsKey(context.getID())) {
-			throw new IllegalStateException("Duplicate game state provider: " + context.getID());
-		}
-
-		registeredStateProviders.put(context.getID(), context);
-	}
-}

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

@@ -1,16 +1,20 @@
 package com.jozufozu.flywheel.backend;
 
 import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.annotation.Nullable;
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonElement;
 import com.jozufozu.flywheel.backend.instancing.InstancedRenderDispatcher;
-import com.jozufozu.flywheel.backend.source.Resolver;
+import com.jozufozu.flywheel.core.GameStateRegistry;
-import com.jozufozu.flywheel.backend.source.ShaderLoadingException;
-import com.jozufozu.flywheel.backend.source.ShaderSources;
 import com.jozufozu.flywheel.core.crumbling.CrumblingRenderer;
-import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
+import com.jozufozu.flywheel.core.shader.ProgramSpec;
+import com.jozufozu.flywheel.core.source.Resolver;
+import com.jozufozu.flywheel.core.source.ShaderSources;
 import com.jozufozu.flywheel.event.GatherContextEvent;
 import com.jozufozu.flywheel.util.ResourceUtil;
 import com.jozufozu.flywheel.util.StringUtil;
@@ -38,14 +42,11 @@ public class Loader implements ResourceManagerReloadListener {
 	public static final String PROGRAM_DIR = "flywheel/programs/";
 	private static final Gson GSON = new GsonBuilder().create();
 
-	private final Backend backend;
+	private final Map<ResourceLocation, ProgramSpec> programSpecRegistry = new HashMap<>();
-	private boolean shouldCrash;
 
 	private boolean firstLoad = true;
 
-	public Loader(Backend backend) {
+	Loader() {
-		this.backend = backend;
-
 		// Can be null when running datagenerators due to the unfortunate time we call this
 		Minecraft minecraft = Minecraft.getInstance();
 		if (minecraft != null) {
@@ -56,36 +57,28 @@ public class Loader implements ResourceManagerReloadListener {
 		}
 	}
 
-	public void notifyError() {
+	@Nullable
-		shouldCrash = true;
+	public ProgramSpec get(ResourceLocation name) {
+		return programSpecRegistry.get(name);
 	}
 
 	@Override
 	public void onResourceManagerReload(ResourceManager manager) {
-		backend.refresh();
+		Backend.refresh();
 
-		shouldCrash = false;
+		GameStateRegistry._clear();
-		backend._clearContexts();
 
 		Resolver.INSTANCE.invalidate();
 		ModLoader.get()
-				.postEvent(new GatherContextEvent(backend, firstLoad));
+				.postEvent(new GatherContextEvent(firstLoad));
 
 		ShaderSources sources = new ShaderSources(manager);
 
 		loadProgramSpecs(manager);
 
-		Resolver.INSTANCE.resolve(sources);
+		Resolver.INSTANCE.run(sources);
 
-		for (ShaderContext<?> context : backend.allContexts()) {
+		Backend.LOGGER.info("Loaded all shader sources.");
-			context.load();
-		}
-
-		if (shouldCrash) {
-			throw new ShaderLoadingException("Could not load all shaders, see log for details");
-		}
-
-		Backend.LOGGER.info("Loaded all shader programs.");
 
 		ClientLevel world = Minecraft.getInstance().level;
 		if (Backend.canUseInstancing(world)) {
@@ -116,10 +109,21 @@ public class Loader implements ResourceManagerReloadListener {
 
 				spec.setName(specName);
 
-				backend.register(spec);
+				register(spec);
 			} catch (Exception e) {
 				Backend.LOGGER.error(e);
 			}
 		}
 	}
+
+	/**
+	 * Register a shader program.
+	 */
+	private void register(ProgramSpec spec) {
+		ResourceLocation name = spec.name;
+		if (programSpecRegistry.containsKey(name)) {
+			throw new IllegalStateException("Program spec '" + name + "' already registered.");
+		}
+		programSpecRegistry.put(name, spec);
+	}
 }

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

@@ -38,7 +38,7 @@ public enum RenderLayer {
 	;
 
 	@Nullable
-	public static RenderLayer fromRenderType(RenderType type) {
+	public static RenderLayer getPrimaryLayer(RenderType type) {
 		if (type == RenderType.solid()) {
 			return SOLID;
 		} else if (type == RenderType.cutoutMipped()) {
@@ -49,4 +49,17 @@ public enum RenderLayer {
 
 		return null;
 	}
+
+	@Nullable
+	public static RenderLayer getLayer(RenderType type) {
+		if (type == RenderType.solid()) {
+			return SOLID;
+		} else if (type == RenderType.cutoutMipped() || type == RenderType.cutout()) {
+			return CUTOUT;
+		} else if (type == RenderType.translucent()) {
+			return TRANSPARENT;
+		}
+
+		return null;
+	}
 }

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

@@ -1,24 +0,0 @@
-package com.jozufozu.flywheel.backend;
-
-import java.util.function.Supplier;
-
-import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
-
-import net.minecraft.resources.ResourceLocation;
-
-public interface ShaderContext<P extends GlProgram> {
-
-	default P getProgram(ResourceLocation loc) {
-		return this.getProgramSupplier(loc)
-				.get();
-	}
-
-	Supplier<P> getProgramSupplier(ResourceLocation loc);
-
-	/**
-	 * Load all programs associated with this context. This might be just one, if the context is very specialized.
-	 */
-	void load();
-
-	void delete();
-}

src/main/java/com/jozufozu/flywheel/backend/gl/GlNumericType.java

@@ -26,15 +26,15 @@ public enum GlNumericType {
 
 	private static final GlNumericType[] VALUES = values();
 	private static final Map<String, GlNumericType> NAME_LOOKUP = Arrays.stream(VALUES)
-			.collect(Collectors.toMap(GlNumericType::getDisplayName, type -> type));
+			.collect(Collectors.toMap(GlNumericType::getTypeName, type -> type));
 
 	private final int byteWidth;
-	private final String displayName;
+	private final String typeName;
 	private final int glEnum;
 
 	GlNumericType(int bytes, String name, int glEnum) {
 		this.byteWidth = bytes;
-		this.displayName = name;
+		this.typeName = name;
 		this.glEnum = glEnum;
 	}
 
@@ -42,8 +42,8 @@ public enum GlNumericType {
 		return this.byteWidth;
 	}
 
-	public String getDisplayName() {
+	public String getTypeName() {
-		return this.displayName;
+		return this.typeName;
 	}
 
 	public int getGlEnum() {
@@ -64,4 +64,9 @@ public enum GlNumericType {
 	public static GlNumericType byName(String name) {
 		return name == null ? null : NAME_LOOKUP.get(name.toLowerCase(Locale.ROOT));
 	}
+
+	@Override
+	public String toString() {
+		return typeName;
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/gl/GlVertexArray.java

@@ -39,8 +39,8 @@ public class GlVertexArray extends GlObject {
 		int offset = 0;
 		for (LayoutItem spec : type.getLayoutItems()) {
 			spec.vertexAttribPointer(type.getStride(), startIndex, offset);
-			startIndex += spec.getAttributeCount();
+			startIndex += spec.attributeCount();
-			offset += spec.getSize();
+			offset += spec.size();
 		}
 	}
 

src/main/java/com/jozufozu/flywheel/backend/gl/buffer/GlBuffer.java

@@ -21,7 +21,7 @@ public abstract class GlBuffer extends GlObject {
 	 * @return A buffer that will be persistent if the driver supports it.
 	 */
 	public static GlBuffer requestPersistent(GlBufferType type) {
-		if (Backend.getInstance().compat.bufferStorageSupported()) {
+		if (Backend.compat.bufferStorageSupported()) {
 			return new PersistentGlBuffer(type);
 		} else {
 			return new MappedGlBuffer(type);

src/main/java/com/jozufozu/flywheel/backend/gl/buffer/PersistentGlBuffer.java

@@ -46,7 +46,7 @@ public class PersistentGlBuffer extends GlBuffer implements Mappable {
 
 		fence.clear();
 
-		Backend.getInstance().compat.bufferStorage.bufferStorage(type, size, flags);
+		Backend.compat.bufferStorage.bufferStorage(type, size, flags);
 
 		ByteBuffer byteBuffer = GL30.glMapBufferRange(type.glEnum, 0, size, flags);
 

src/main/java/com/jozufozu/flywheel/backend/gl/shader/GlProgram.java

@@ -7,6 +7,8 @@ import static org.lwjgl.opengl.GL20.glUniformMatrix4fv;
 
 import java.nio.FloatBuffer;
 
+import javax.annotation.Nonnull;
+
 import org.lwjgl.system.MemoryStack;
 
 import com.jozufozu.flywheel.backend.Backend;
@@ -83,4 +85,13 @@ public abstract class GlProgram extends GlObject {
 	public String toString() {
 		return "program " + name;
 	}
+
+	/**
+	 * A factory interface to create a {@link GlProgram}.
+	 */
+	public interface Factory<P extends GlProgram> {
+
+		@Nonnull
+		P create(ResourceLocation name, int handle);
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/gl/shader/GlShader.java

@@ -2,9 +2,9 @@ package com.jozufozu.flywheel.backend.gl.shader;
 
 import org.lwjgl.opengl.GL20;
 
-import com.jozufozu.flywheel.backend.Backend;
 import com.jozufozu.flywheel.backend.gl.GlObject;
 import com.jozufozu.flywheel.backend.gl.versioned.GlCompat;
+import com.jozufozu.flywheel.core.source.ShaderLoadingException;
 
 import net.minecraft.resources.ResourceLocation;
 
@@ -13,7 +13,7 @@ public class GlShader extends GlObject {
 	public final ResourceLocation name;
 	public final ShaderType type;
 
-	public GlShader(ResourceLocation name, ShaderType type, CharSequence source) {
+	public GlShader(ResourceLocation name, ShaderType type, String source) {
 		this.name = name;
 		this.type = type;
 		int handle = GL20.glCreateShader(type.glEnum);
@@ -23,14 +23,12 @@ public class GlShader extends GlObject {
 
 		String log = GL20.glGetShaderInfoLog(handle);
 
-		if (!log.isEmpty()) {
+//		if (!log.isEmpty()) {
-			Backend.LOGGER.error("Shader compilation log for " + name + ": " + log);
+//			env.printShaderInfoLog(source, log, this.name);
-			Backend.LOGGER.error(source);
+//		}
-		}
-		//Backend.log.debug(shader.printSource());
 
 		if (GL20.glGetShaderi(handle, GL20.GL_COMPILE_STATUS) != GL20.GL_TRUE) {
-			throw new RuntimeException("Could not compile " + name + ". See log for details.");
+			throw new ShaderLoadingException("Could not compile " + name + ". See log for details.");
 		}
 
 		setHandle(handle);
@@ -40,4 +38,5 @@ public class GlShader extends GlObject {
 	protected void deleteInternal(int handle) {
 		GL20.glDeleteShader(handle);
 	}
+
 }

src/main/java/com/jozufozu/flywheel/backend/gl/shader/ShaderType.java

@@ -16,4 +16,8 @@ public enum ShaderType {
 		this.define = define;
 		this.glEnum = glEnum;
 	}
+
+	public String getDefineStatement() {
+		return "#define " + define + "\n";
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/gl/versioned/GlCompat.java

@@ -4,6 +4,7 @@ import java.nio.ByteBuffer;
 import java.util.Arrays;
 
 import org.lwjgl.PointerBuffer;
+import org.lwjgl.opengl.GL;
 import org.lwjgl.opengl.GL20C;
 import org.lwjgl.opengl.GLCapabilities;
 import org.lwjgl.system.MemoryStack;
@@ -23,11 +24,11 @@ public class GlCompat {
 	public final BufferStorage bufferStorage;
 	public final boolean amd;
 
-	public GlCompat(GLCapabilities caps) {
+	public GlCompat() {
+		GLCapabilities caps = GL.createCapabilities();
 		instancedArrays = getLatest(InstancedArrays.class, caps);
 		bufferStorage = getLatest(BufferStorage.class, caps);
 
-
 		if (Util.getPlatform() == Util.OS.WINDOWS) {
 			String vendor = GL20C.glGetString(GL20C.GL_VENDOR);
 			// vendor string I got was "ATI Technologies Inc."

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

@@ -39,8 +39,7 @@ public class InstanceWorld {
 		this.taskEngine = new ParallelTaskEngine("Flywheel " + world.dimension().location());
 		this.taskEngine.startWorkers();
 
-		FlwEngine engine = Backend.getInstance()
+		FlwEngine engine = Backend.getEngine();
-				.getEngine();
 
 		switch (engine) {
 		case INSTANCING -> {

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

@@ -151,11 +151,17 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 
 			final StructWriter<D> writer = instancedType.getWriter(mapped);
 
+			boolean sequential = true;
 			for (int i = 0; i < size; i++) {
 				final D element = data.get(i);
 				if (element.checkDirtyAndClear()) {
-					writer.seek(i);
+					if (!sequential) {
+						writer.seek(i);
+					}
 					writer.write(element);
+					sequential = true;
+				} else {
+					sequential = false;
 				}
 			}
 		} catch (Exception e) {
@@ -192,7 +198,7 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 		vao.bindAttributes(attributeBaseIndex, instanceFormat);
 
 		for (int i = 0; i < instanceFormat.getAttributeCount(); i++) {
-			Backend.getInstance().compat.instancedArrays.vertexAttribDivisor(attributeBaseIndex + i, 1);
+			Backend.compat.instancedArrays.vertexAttribDivisor(attributeBaseIndex + i, 1);
 		}
 	}
 }

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

@@ -1,20 +1,17 @@
 package com.jozufozu.flywheel.backend.instancing.instancing;
 
-import java.util.concurrent.ExecutionException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.function.Supplier;
 
-import com.google.common.cache.Cache;
-import com.google.common.cache.CacheBuilder;
 import com.jozufozu.flywheel.api.InstanceData;
 import com.jozufozu.flywheel.api.Instancer;
 import com.jozufozu.flywheel.api.Material;
 import com.jozufozu.flywheel.api.struct.Instanced;
-import com.jozufozu.flywheel.backend.Backend;
-import com.jozufozu.flywheel.backend.RenderWork;
-import com.jozufozu.flywheel.backend.model.ImmediateAllocator;
 import com.jozufozu.flywheel.backend.model.ModelAllocator;
-import com.jozufozu.flywheel.backend.model.ModelPool;
-import com.jozufozu.flywheel.core.Formats;
 import com.jozufozu.flywheel.core.model.Model;
 
 /**
@@ -23,24 +20,14 @@ import com.jozufozu.flywheel.core.model.Model;
  */
 public class InstancedMaterial<D extends InstanceData> implements Material<D> {
 
-	final ModelAllocator allocator;
+	protected final ModelAllocator allocator;
-	protected final Cache<Object, GPUInstancer<D>> models;
+	protected final Map<Object, GPUInstancer<D>> models = new HashMap<>();
 	protected final Instanced<D> type;
+	protected final List<GPUInstancer<D>> uninitialized = new ArrayList<>();
 
-	public InstancedMaterial(Instanced<D> type) {
+	public InstancedMaterial(Instanced<D> type, ModelAllocator allocator) {
 		this.type = type;
-
+		this.allocator = allocator;
-		if (Backend.getInstance().compat.onAMDWindows()) {
-			allocator = ImmediateAllocator.INSTANCE;
-		} else {
-			allocator = new ModelPool(Formats.POS_TEX_NORMAL, 64);
-		}
-		this.models = CacheBuilder.newBuilder()
-				.removalListener(notification -> {
-					GPUInstancer<?> instancer = (GPUInstancer<?>) notification.getValue();
-					RenderWork.enqueue(instancer::delete);
-				})
-				.build();
 	}
 
 	/**
@@ -52,32 +39,33 @@ public class InstancedMaterial<D extends InstanceData> implements Material<D> {
 	 */
 	@Override
 	public Instancer<D> model(Object key, Supplier<Model> modelSupplier) {
-		try {
+		return models.computeIfAbsent(key, $ -> {
-			return models.get(key, () -> new GPUInstancer<>(type, modelSupplier.get(), allocator));
+			GPUInstancer<D> instancer = new GPUInstancer<>(type, modelSupplier.get(), allocator);
-		} catch (ExecutionException e) {
+			uninitialized.add(instancer);
-			throw new RuntimeException("error creating instancer", e);
+			return instancer;
-		}
+		});
 	}
 
 	public boolean nothingToRender() {
-		return models.size() > 0 && models.asMap()
+		return models.size() > 0 && models.values()
-				.values()
 				.stream()
 				.allMatch(GPUInstancer::isEmpty);
 	}
 
 	public void delete() {
-		models.invalidateAll();
+		models.values().forEach(GPUInstancer::delete);
-		if (allocator instanceof ModelPool pool) pool.delete();
+		models.clear();
 	}
 
 	/**
 	 * Clear all instance data without freeing resources.
 	 */
 	public void clear() {
-		models.asMap()
+		models.values()
-				.values()
 				.forEach(GPUInstancer::clear);
 	}
 
+	public Collection<GPUInstancer<D>> getAllInstancers() {
+		return models.values();
+	}
 }

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

@@ -1,6 +1,5 @@
 package com.jozufozu.flywheel.backend.instancing.instancing;
 
-import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -8,7 +7,13 @@ import com.jozufozu.flywheel.api.InstanceData;
 import com.jozufozu.flywheel.api.MaterialGroup;
 import com.jozufozu.flywheel.api.struct.Instanced;
 import com.jozufozu.flywheel.api.struct.StructType;
+import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.RenderLayer;
+import com.jozufozu.flywheel.backend.model.FallbackAllocator;
+import com.jozufozu.flywheel.backend.model.ModelAllocator;
 import com.jozufozu.flywheel.backend.model.ModelPool;
+import com.jozufozu.flywheel.core.Formats;
+import com.jozufozu.flywheel.core.compile.ProgramContext;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
 import com.jozufozu.flywheel.util.Textures;
 import com.mojang.math.Matrix4f;
@@ -27,49 +32,55 @@ public class InstancedMaterialGroup<P extends WorldProgram> implements MaterialG
 	protected final RenderType type;
 
 	private final Map<Instanced<? extends InstanceData>, InstancedMaterial<?>> materials = new HashMap<>();
+	private final ModelAllocator allocator;
 
 	public InstancedMaterialGroup(InstancingEngine<P> owner, RenderType type) {
 		this.owner = owner;
 		this.type = type;
+		if (Backend.compat.onAMDWindows()) {
+			this.allocator = FallbackAllocator.INSTANCE;
+		} else {
+			this.allocator = new ModelPool(Formats.POS_TEX_NORMAL, 2048);
+		}
 	}
 
 	@SuppressWarnings("unchecked")
 	@Override
 	public <D extends InstanceData> InstancedMaterial<D> material(StructType<D> type) {
 		if (type instanceof Instanced<D> instanced) {
-			return (InstancedMaterial<D>) materials.computeIfAbsent(instanced, InstancedMaterial::new);
+			return (InstancedMaterial<D>) materials.computeIfAbsent(instanced, t -> new InstancedMaterial<>(t, allocator));
 		} else {
 			throw new ClassCastException("Cannot use type '" + type + "' with GPU instancing.");
 		}
 	}
 
-	public void render(Matrix4f viewProjection, double camX, double camY, double camZ) {
+	public void render(Matrix4f viewProjection, double camX, double camY, double camZ, RenderLayer layer) {
 		type.setupRenderState();
 		Textures.bindActiveTextures();
-		renderAll(viewProjection, camX, camY, camZ);
+		renderAll(viewProjection, camX, camY, camZ, layer);
 		type.clearRenderState();
 	}
 
-	protected void renderAll(Matrix4f viewProjection, double camX, double camY, double camZ) {
+	protected void renderAll(Matrix4f viewProjection, double camX, double camY, double camZ, RenderLayer layer) {
+		// initialize all uninitialized instancers...
+		for (InstancedMaterial<?> material : materials.values()) {
+			for (GPUInstancer<?> instancer : material.uninitialized) {
+				instancer.init();
+			}
+			material.uninitialized.clear();
+		}
+
+		if (allocator instanceof ModelPool pool) {
+			// ...and then flush the model arena in case anything was marked for upload
+			pool.flush();
+		}
+
 		for (Map.Entry<Instanced<? extends InstanceData>, InstancedMaterial<?>> entry : materials.entrySet()) {
 			InstancedMaterial<?> material = entry.getValue();
 			if (material.nothingToRender()) continue;
 
-			Collection<? extends GPUInstancer<?>> instancers = material.models.asMap()
+			P program = owner.context.getProgram(ProgramContext.create(entry.getKey()
-					.values();
+					.getProgramSpec(), Formats.POS_TEX_NORMAL, layer));
-
-			// initialize all uninitialized instancers...
-			for (GPUInstancer<?> gpuInstancer : instancers) {
-				gpuInstancer.init();
-			}
-
-			if (material.allocator instanceof ModelPool pool) {
-				// ...and then flush the model arena in case anything was marked for upload
-				pool.flush();
-			}
-
-			P program = owner.getProgram(entry.getKey()
-					.getProgramSpec()).get();
 
 			program.bind();
 			program.uploadViewProjection(viewProjection);
@@ -77,7 +88,7 @@ public class InstancedMaterialGroup<P extends WorldProgram> implements MaterialG
 
 			setup(program);
 
-			for (GPUInstancer<?> instancer : instancers) {
+			for (GPUInstancer<?> instancer : material.getAllInstancers()) {
 				instancer.render();
 			}
 		}

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

@@ -3,7 +3,6 @@ package com.jozufozu.flywheel.backend.instancing.instancing;
 import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.function.Supplier;
 import java.util.stream.Stream;
 
 import javax.annotation.Nullable;
@@ -12,7 +11,7 @@ import com.jozufozu.flywheel.api.MaterialGroup;
 import com.jozufozu.flywheel.backend.RenderLayer;
 import com.jozufozu.flywheel.backend.instancing.Engine;
 import com.jozufozu.flywheel.backend.instancing.TaskEngine;
-import com.jozufozu.flywheel.core.WorldContext;
+import com.jozufozu.flywheel.core.compile.ProgramCompiler;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
 import com.jozufozu.flywheel.event.RenderLayerEvent;
 import com.jozufozu.flywheel.util.WeakHashSet;
@@ -22,7 +21,6 @@ import net.minecraft.client.Camera;
 import net.minecraft.client.renderer.RenderType;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Vec3i;
-import net.minecraft.resources.ResourceLocation;
 import net.minecraft.util.Mth;
 
 public class InstancingEngine<P extends WorldProgram> implements Engine {
@@ -31,7 +29,7 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 
 	protected BlockPos originCoordinate = BlockPos.ZERO;
 
-	protected final WorldContext<P> context;
+	protected final ProgramCompiler<P> context;
 	protected final GroupFactory<P> groupFactory;
 	protected final boolean ignoreOriginCoordinate;
 
@@ -39,15 +37,11 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 
 	private final WeakHashSet<OriginShiftListener> listeners;
 
-	public InstancingEngine(WorldContext<P> context, TaskEngine taskEngine) {
+	public static <P extends WorldProgram> Builder<P> builder(ProgramCompiler<P> context) {
-		this(context, InstancedMaterialGroup::new, false);
-	}
-
-	public static <P extends WorldProgram> Builder<P> builder(WorldContext<P> context) {
 		return new Builder<>(context);
 	}
 
-	public InstancingEngine(WorldContext<P> context, GroupFactory<P> groupFactory, boolean ignoreOriginCoordinate) {
+	public InstancingEngine(ProgramCompiler<P> context, GroupFactory<P> groupFactory, boolean ignoreOriginCoordinate) {
 		this.context = context;
 		this.ignoreOriginCoordinate = ignoreOriginCoordinate;
 
@@ -95,7 +89,7 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 			viewProjection = event.viewProjection;
 		}
 
-		getGroupsToRender(event.getLayer()).forEach(group -> group.render(viewProjection, camX, camY, camZ));
+		getGroupsToRender(event.getLayer()).forEach(group -> group.render(viewProjection, camX, camY, camZ, event.getLayer()));
 	}
 
 	private Stream<InstancedMaterialGroup<P>> getGroupsToRender(@Nullable RenderLayer layer) {
@@ -120,10 +114,6 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 		}
 	}
 
-	public Supplier<P> getProgram(ResourceLocation name) {
-		return context.getProgramSupplier(name);
-	}
-
 	@Override
 	public Vec3i getOriginCoordinate() {
 		return originCoordinate;
@@ -171,11 +161,11 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 	}
 
 	public static class Builder<P extends WorldProgram> {
-		protected final WorldContext<P> context;
+		protected final ProgramCompiler<P> context;
 		protected GroupFactory<P> groupFactory = InstancedMaterialGroup::new;
 		protected boolean ignoreOriginCoordinate;
 
-		public Builder(WorldContext<P> context) {
+		public Builder(ProgramCompiler<P> context) {
 			this.context = context;
 		}
 

src/main/java/com/jozufozu/flywheel/backend/model/FallbackAllocator.java

@@ -2,9 +2,8 @@ package com.jozufozu.flywheel.backend.model;
 
 import com.jozufozu.flywheel.core.model.Model;
 
-public class ImmediateAllocator implements ModelAllocator {
+public enum FallbackAllocator implements ModelAllocator {
-
+	INSTANCE;
-	public static final ImmediateAllocator INSTANCE = new ImmediateAllocator();
 
 	@Override
 	public BufferedModel alloc(Model model, Callback allocationCallback) {

src/main/java/com/jozufozu/flywheel/backend/pipeline/InstancingProgramMetaData.java

@@ -1,87 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.Optional;
-
-import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.source.ShaderLoadingException;
-import com.jozufozu.flywheel.backend.source.SourceFile;
-import com.jozufozu.flywheel.backend.source.error.ErrorReporter;
-import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
-import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.source.parse.Variable;
-import com.jozufozu.flywheel.backend.source.span.Span;
-
-public class InstancingProgramMetaData {
-
-	public final SourceFile file;
-	public final ShaderFunction vertexMain;
-	public final ShaderFunction fragmentMain;
-	public final Span interpolantName;
-	public final Span vertexName;
-	public final Span instanceName;
-	public final ShaderStruct interpolant;
-	public final ShaderStruct vertex;
-	public final ShaderStruct instance;
-
-	public InstancingProgramMetaData(SourceFile file) {
-		this.file = file;
-
-		Optional<ShaderFunction> vertexFunc = file.findFunction("vertex");
-		Optional<ShaderFunction> fragmentFunc = file.findFunction("fragment");
-
-		if (fragmentFunc.isEmpty()) {
-			ErrorReporter.generateMissingFunction(file, "fragment", "\"fragment\" function not defined");
-		}
-		if (vertexFunc.isEmpty()) {
-			ErrorReporter.generateFileError(file, "could not find \"vertex\" function");
-		}
-
-		if (fragmentFunc.isEmpty() || vertexFunc.isEmpty()) {
-			throw new ShaderLoadingException();
-		}
-
-		fragmentMain = fragmentFunc.get();
-		vertexMain = vertexFunc.get();
-		ImmutableList<Variable> parameters = fragmentMain.getParameters();
-		ImmutableList<Variable> vertexParams = vertexMain.getParameters();
-
-		if (parameters.size() != 1) {
-			ErrorReporter.generateSpanError(fragmentMain.getArgs(), "instancing requires fragment function to have 1 argument");
-		}
-
-		if (vertexParams.size() != 2) {
-			ErrorReporter.generateSpanError(vertexMain.getArgs(), "instancing requires vertex function to have 2 arguments");
-			throw new ShaderLoadingException();
-		}
-
-		interpolantName = vertexMain.getType();
-		vertexName = vertexParams.get(0)
-				.typeName();
-		instanceName = vertexParams.get(1)
-				.typeName();
-
-		Optional<ShaderStruct> maybeInterpolant = file.findStruct(interpolantName);
-		Optional<ShaderStruct> maybeVertex = file.findStruct(vertexName);
-		Optional<ShaderStruct> maybeInstance = file.findStruct(instanceName);
-
-		if (maybeVertex.isEmpty()) {
-			ErrorReporter.generateMissingStruct(file, vertexName, "struct not defined");
-		}
-
-		if (maybeInterpolant.isEmpty()) {
-			ErrorReporter.generateMissingStruct(file, interpolantName, "struct not defined");
-		}
-
-		if (maybeInstance.isEmpty()) {
-			ErrorReporter.generateMissingStruct(file, instanceName, "struct not defined");
-		}
-
-		if (maybeVertex.isEmpty() || maybeInterpolant.isEmpty() || maybeInstance.isEmpty()) {
-			throw new ShaderLoadingException();
-		}
-
-		interpolant = maybeInterpolant.get();
-		vertex = maybeVertex.get();
-		instance = maybeInstance.get();
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/InstancingTemplate.java

@@ -1,78 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.source.SourceFile;
-
-public class InstancingTemplate extends Template<InstancingProgramMetaData> {
-
-	public static final InstancingTemplate INSTANCE = new InstancingTemplate();
-
-	public InstancingTemplate() {
-		super(InstancingProgramMetaData::new);
-	}
-
-	@Override
-	public void generateTemplateSource(StringBuilder builder, ShaderType type, SourceFile file) {
-		if (type == ShaderType.VERTEX) {
-			vertexFooter(builder, file);
-		} else if (type == ShaderType.FRAGMENT) {
-			fragmentFooter(builder, file);
-		}
-	}
-
-	@Override
-	public Collection<ShaderInput> getShaderInputs(SourceFile file) {
-		InstancingProgramMetaData data = getMetadata(file);
-
-		List<ShaderInput> inputs = new ArrayList<>(ShaderInput.fromStruct(data.vertex, "a_v_"));
-		inputs.addAll(ShaderInput.fromStruct(data.instance, "a_i_"));
-
-		return inputs;
-	}
-
-	public void vertexFooter(StringBuilder template, SourceFile file) {
-		InstancingProgramMetaData data = getMetadata(file);
-
-		Template.prefixFields(template, data.vertex, "in", "a_v_");
-		Template.prefixFields(template, data.instance, "in", "a_i_");
-		Template.prefixFields(template, data.interpolant, "out", "v2f_");
-
-		template.append("void main() {\n");
-		template.append(data.vertexName)
-				.append(" v;\n");
-		Template.assignFields(template, data.vertex, "v.", "a_v_");
-
-		template.append(data.instanceName)
-				.append(" i;\n");
-		Template.assignFields(template, data.instance, "i.", "a_i_");
-
-		template.append(data.interpolantName)
-				.append(" o = ")
-				.append(data.vertexMain.call("v", "i"))
-				.append(";\n");
-
-		Template.assignFields(template, data.interpolant, "v2f_", "o.");
-
-		template.append('}');
-	}
-
-	public void fragmentFooter(StringBuilder template, SourceFile file) {
-		InstancingProgramMetaData data = getMetadata(file);
-
-		Template.prefixFields(template, data.interpolant, "in", "v2f_");
-
-		template.append("void main() {\n");
-		template.append(data.interpolantName)
-				.append(" o;\n");
-		Template.assignFields(template, data.interpolant, "o.", "v2f_");
-
-		template.append(data.fragmentMain.call("o"))
-				.append(";\n");
-
-		template.append('}');
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/OneShotProgramMetaData.java

@@ -1,78 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.Optional;
-
-import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.source.SourceFile;
-import com.jozufozu.flywheel.backend.source.error.ErrorReporter;
-import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
-import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.source.parse.Variable;
-import com.jozufozu.flywheel.backend.source.span.Span;
-
-public class OneShotProgramMetaData {
-
-	public final SourceFile file;
-	public final ShaderFunction vertexMain;
-	public final Span interpolantName;
-	public final Span vertexName;
-	public final ShaderStruct interpolant;
-	public final ShaderStruct vertex;
-	public final ShaderFunction fragmentMain;
-
-	public OneShotProgramMetaData(SourceFile file) {
-		this.file = file;
-
-		Optional<ShaderFunction> maybeVertexMain = file.findFunction("vertex");
-		Optional<ShaderFunction> maybeFragmentMain = file.findFunction("fragment");
-
-		if (maybeVertexMain.isEmpty()) {
-			ErrorReporter.generateFileError(file, "could not find \"vertex\" function");
-		}
-
-		if (maybeFragmentMain.isEmpty()) {
-			ErrorReporter.generateMissingFunction(file, "fragment", "\"fragment\" function not defined");
-		}
-
-		if (maybeVertexMain.isEmpty() || maybeFragmentMain.isEmpty()) {
-			throw new RuntimeException();
-		}
-
-		vertexMain = maybeVertexMain.get();
-		fragmentMain = maybeFragmentMain.get();
-		ImmutableList<Variable> fragmentParameters = fragmentMain.getParameters();
-		ImmutableList<Variable> vertexParameters = vertexMain.getParameters();
-
-		if (vertexParameters.size() != 1) {
-			ErrorReporter.generateSpanError(vertexMain.getArgs(), "a basic model requires vertex function to have one argument");
-		}
-
-		if (fragmentParameters.size() != 1) {
-			ErrorReporter.generateSpanError(fragmentMain.getArgs(), "fragment function must have exactly one argument");
-		}
-
-		if (vertexParameters.size() != 1 || fragmentParameters.size() != 1) {
-			throw new RuntimeException();
-		}
-
-		interpolantName = vertexMain.getType();
-		vertexName = vertexParameters.get(0)
-				.typeName();
-
-		Optional<ShaderStruct> maybeInterpolant = file.findStruct(interpolantName);
-		Optional<ShaderStruct> maybeVertex = file.findStruct(vertexName);
-
-		if (maybeVertex.isEmpty())
-			ErrorReporter.generateMissingStruct(file, vertexName, "struct not defined");
-
-		if (maybeInterpolant.isEmpty())
-			ErrorReporter.generateMissingStruct(file, interpolantName, "struct not defined");
-
-		if (maybeVertex.isEmpty() || maybeInterpolant.isEmpty()) {
-			throw new RuntimeException();
-		}
-
-		interpolant = maybeInterpolant.get();
-		vertex = maybeVertex.get();
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/OneShotTemplate.java

@@ -1,68 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.Collection;
-
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.source.SourceFile;
-
-public class OneShotTemplate extends Template<OneShotProgramMetaData> {
-
-	public static final OneShotTemplate INSTANCE = new OneShotTemplate();
-
-	public OneShotTemplate() {
-		super(OneShotProgramMetaData::new);
-	}
-
-	@Override
-	public void generateTemplateSource(StringBuilder builder, ShaderType type, SourceFile file) {
-		if (type == ShaderType.VERTEX) {
-			vertexFooter(builder, file);
-		} else if (type == ShaderType.FRAGMENT) {
-			fragmentFooter(builder, file);
-		}
-	}
-
-	@Override
-	public Collection<ShaderInput> getShaderInputs(SourceFile file) {
-		OneShotProgramMetaData data = getMetadata(file);
-
-		return ShaderInput.fromStruct(data.vertex, "a_v_");
-	}
-
-	public void vertexFooter(StringBuilder template, SourceFile file) {
-		OneShotProgramMetaData data = getMetadata(file);
-
-		Template.prefixFields(template, data.vertex, "in", "a_v_");
-		Template.prefixFields(template, data.interpolant, "out", "v2f_");
-
-		template.append("void main() {\n");
-		template.append(data.vertexName)
-				.append(" v;\n");
-		Template.assignFields(template, data.vertex, "v.", "a_v_");
-
-		template.append(data.interpolantName)
-				.append(" o = ")
-				.append(data.vertexMain.call("v"))
-				.append(";\n");
-
-		Template.assignFields(template, data.interpolant, "v2f_", "o.");
-
-		template.append('}');
-	}
-
-	public void fragmentFooter(StringBuilder template, SourceFile file) {
-		OneShotProgramMetaData data = getMetadata(file);
-
-		Template.prefixFields(template, data.interpolant, "in", "v2f_");
-
-		template.append("void main() {\n");
-		template.append(data.interpolant.name)
-				.append(" o;\n");
-		Template.assignFields(template, data.interpolant, "o.", "v2f_");
-
-		template.append(data.fragmentMain.call("o"))
-				.append(";\n");
-
-		template.append('}');
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/Shader.java

@@ -1,6 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-public class Shader {
-
-
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/ShaderInput.java

@@ -1,38 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.Collection;
-import java.util.stream.Collectors;
-
-import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.source.parse.StructField;
-
-/**
- * A single input to a shader.
- */
-public class ShaderInput {
-	public final CharSequence name;
-	public final int attribCount;
-
-	public ShaderInput(CharSequence name, int attribCount) {
-		this.name = name;
-		this.attribCount = attribCount;
-	}
-
-	public ShaderInput withPrefix(CharSequence prefix) {
-		return new ShaderInput(prefix.toString() + name, attribCount);
-	}
-
-	public static Collection<ShaderInput> fromStruct(ShaderStruct struct, String prefix) {
-		return struct.getFields()
-				.stream()
-				.map(ShaderInput::from)
-				.map(a -> a.withPrefix(prefix))
-				.collect(Collectors.toList());
-	}
-
-	public static ShaderInput from(StructField field) {
-		int attributeCount = TypeHelper.getAttributeCount(field.type);
-
-		return new ShaderInput(field.name, attributeCount);
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/ShaderPipeline.java

@@ -1,15 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import com.jozufozu.flywheel.core.shader.ContextAwareProgram;
-import com.jozufozu.flywheel.core.shader.WorldProgram;
-import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
-
-/**
- * The main interface for compiling usable shaders from program specs.
- * @param <P> the type of the program that this pipeline compiles.
- */
-public interface ShaderPipeline<P extends WorldProgram> {
-
-	ContextAwareProgram<P> compile(ProgramSpec spec);
-
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/Template.java

@@ -1,83 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.function.Function;
-
-import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.gl.GLSLVersion;
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.source.SourceFile;
-import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.source.parse.StructField;
-
-/**
- * A class that generates glsl glue code given a SourceFile.
- *
- * <p>
- *     Shader files are written somewhat abstractly. Subclasses of Template handle those abstractions, using SourceFile
- *     metadata to generate shader code that OpenGL can use to call into our shader programs.
- * </p>
- * @param <D> Holds metadata, generates errors.
- */
-public abstract class Template<D> {
-
-	private final Map<SourceFile, D> metadata = new HashMap<>();
-
-	private final Function<SourceFile, D> reader;
-
-	protected Template(Function<SourceFile, D> reader) {
-		this.reader = reader;
-	}
-
-	/**
-	 * Generate the necessary glue code here.
-	 *
-	 * <p>
-	 *     See {@link InstancingTemplate} and {@link OneShotTemplate} for examples.
-	 * </p>
-	 * @param builder The builder to generate the source into.
-	 * @param type The shader stage glue code is needed for.
-	 * @param file The SourceFile with user written code.
-	 */
-	public abstract void generateTemplateSource(StringBuilder builder, ShaderType type, SourceFile file);
-
-	public abstract Collection<ShaderInput> getShaderInputs(SourceFile file);
-
-	public D getMetadata(SourceFile file) {
-		// lazily read files, cache results
-		return metadata.computeIfAbsent(file, reader);
-	}
-
-	public GLSLVersion getVersion() {
-		return GLSLVersion.V150;
-	}
-
-	public static void prefixFields(StringBuilder builder, ShaderStruct struct, String qualifier, String prefix) {
-		ImmutableList<StructField> fields = struct.getFields();
-
-		for (StructField field : fields) {
-			builder.append(qualifier)
-					.append(' ')
-					.append(field.type)
-					.append(' ')
-					.append(prefix)
-					.append(field.name)
-					.append(";\n");
-		}
-	}
-
-	public static void assignFields(StringBuilder builder, ShaderStruct struct, String prefix1, String prefix2) {
-		ImmutableList<StructField> fields = struct.getFields();
-
-		for (StructField field : fields) {
-			builder.append(prefix1)
-					.append(field.name)
-					.append(" = ")
-					.append(prefix2)
-					.append(field.name)
-					.append(";\n");
-		}
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/WorldShader.java

@@ -1,77 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.List;
-import java.util.Optional;
-
-import com.jozufozu.flywheel.backend.gl.shader.GlShader;
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.source.FileResolution;
-import com.jozufozu.flywheel.backend.source.SourceFile;
-
-import net.minecraft.resources.ResourceLocation;
-
-public class WorldShader {
-
-	public final ResourceLocation name;
-	public final Template<?> template;
-	public final CharSequence header;
-
-	public SourceFile mainFile;
-
-	private CharSequence source;
-	private StringBuilder defines;
-
-	public WorldShader(ResourceLocation name, Template<?> template, FileResolution header) {
-		this.name = name;
-		this.template = template;
-		this.header = Optional.ofNullable(header.getFile())
-				.map(SourceFile::generateFinalSource)
-				.orElse("");
-	}
-
-	public WorldShader setDefines(List<String> defs) {
-		defines = new StringBuilder();
-
-		for (String def : defs) {
-			defines.append("#define ")
-					.append(def)
-					.append('\n');
-		}
-		return this;
-	}
-
-	public WorldShader setMainSource(SourceFile file) {
-		if (mainFile == file) return this;
-
-		mainFile = file;
-		source = file.generateFinalSource();
-
-		return this;
-	}
-
-	public GlShader compile(ShaderType type) {
-
-		StringBuilder finalSource = new StringBuilder();
-
-		finalSource.append("#version ")
-				.append(template.getVersion())
-				.append('\n')
-				.append("#extension GL_ARB_conservative_depth : enable\n")
-				.append("#define ")
-				.append(type.define) // special case shader type declaration
-				.append('\n')
-				.append(defines != null ? defines : "")
-				.append(header)
-				.append('\n')
-				.append(source)
-				.append('\n');
-
-		template.generateTemplateSource(finalSource, type, mainFile);
-
-		return new GlShader(name, type, finalSource);
-	}
-
-	public ProtoProgram createProgram() {
-		return new ProtoProgram(this);
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/WorldShaderPipeline.java

@@ -1,66 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.List;
-
-import javax.annotation.Nullable;
-
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.source.FileResolution;
-import com.jozufozu.flywheel.backend.source.SourceFile;
-import com.jozufozu.flywheel.core.shader.ContextAwareProgram;
-import com.jozufozu.flywheel.core.shader.ExtensibleGlProgram;
-import com.jozufozu.flywheel.core.shader.GameStateProgram;
-import com.jozufozu.flywheel.core.shader.WorldProgram;
-import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
-import com.jozufozu.flywheel.core.shader.spec.ProgramState;
-
-import net.minecraft.resources.ResourceLocation;
-
-public class WorldShaderPipeline<P extends WorldProgram> implements ShaderPipeline<P> {
-
-	private final ExtensibleGlProgram.Factory<P> factory;
-
-	private final Template<?> template;
-	private final FileResolution header;
-
-	public WorldShaderPipeline(ExtensibleGlProgram.Factory<P> factory, Template<?> template, FileResolution header) {
-		this.factory = factory;
-		this.template = template;
-		this.header = header;
-	}
-
-	public ContextAwareProgram<P> compile(ProgramSpec spec) {
-
-		SourceFile file = spec.getSource().getFile();
-
-		return compile(spec.name, file, spec.getStates());
-	}
-
-	public ContextAwareProgram<P> compile(ResourceLocation name, SourceFile file, List<ProgramState> variants) {
-		WorldShader shader = new WorldShader(name, template, header)
-				.setMainSource(file);
-
-		GameStateProgram.Builder<P> builder = GameStateProgram.builder(compile(shader, null));
-
-		for (ProgramState variant : variants) {
-			builder.withVariant(variant.context(), compile(shader, variant));
-		}
-
-		return builder.build();
-	}
-
-	private P compile(WorldShader shader, @Nullable ProgramState variant) {
-
-		if (variant != null) {
-			shader.setDefines(variant.defines());
-		}
-
-		ProtoProgram program = shader.createProgram()
-				.compilePart(ShaderType.VERTEX)
-				.compilePart(ShaderType.FRAGMENT)
-				.link()
-				.deleteLinkedShaders();
-
-		return factory.create(shader.name, program.program);
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/source/Resolver.java

@@ -1,47 +0,0 @@
-package com.jozufozu.flywheel.backend.source;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import net.minecraft.resources.ResourceLocation;
-
-/**
- * Manages deferred file resolution.
- *
- * <p>
- *     Interns all referenced files in all sources, duplicating the final lookups and allowing for more dev-friendly
- *     error reporting.
- * </p><p>
- *     See {@link FileResolution} for more information.
- * </p>
- */
-public class Resolver {
-
-	public static final Resolver INSTANCE = new Resolver();
-
-	private final Map<ResourceLocation, FileResolution> resolutions = new HashMap<>();
-
-	public FileResolution findShader(ResourceLocation fileLoc) {
-		return resolutions.computeIfAbsent(fileLoc, FileResolution::new);
-	}
-
-	/**
-	 * Try and resolve all referenced source files, printing errors if any aren't found.
-	 */
-	public void resolve(SourceFinder sources) {
-		for (FileResolution resolution : resolutions.values()) {
-			resolution.resolve(sources);
-		}
-	}
-
-	/**
-	 * Invalidates all FileResolutions.
-	 *
-	 * <p>
-	 *     Called on resource reload.
-	 * </p>
-	 */
-	public void invalidate() {
-		resolutions.values().forEach(FileResolution::invalidate);
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/source/ShaderLoadingException.java

@@ -1,22 +0,0 @@
-package com.jozufozu.flywheel.backend.source;
-
-public class ShaderLoadingException extends RuntimeException {
-	public ShaderLoadingException() {
-	}
-
-	public ShaderLoadingException(String message) {
-		super(message);
-	}
-
-	public ShaderLoadingException(String message, Throwable cause) {
-		super(message, cause);
-	}
-
-	public ShaderLoadingException(Throwable cause) {
-		super(cause);
-	}
-
-	public ShaderLoadingException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
-		super(message, cause, enableSuppression, writableStackTrace);
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/source/error/ErrorBuilder.java

@@ -1,104 +0,0 @@
-package com.jozufozu.flywheel.backend.source.error;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import javax.annotation.Nullable;
-
-import com.jozufozu.flywheel.backend.source.SourceFile;
-import com.jozufozu.flywheel.backend.source.SourceLines;
-import com.jozufozu.flywheel.backend.source.error.lines.ErrorLine;
-import com.jozufozu.flywheel.backend.source.error.lines.FileLine;
-import com.jozufozu.flywheel.backend.source.error.lines.HeaderLine;
-import com.jozufozu.flywheel.backend.source.error.lines.SourceLine;
-import com.jozufozu.flywheel.backend.source.error.lines.SpanHighlightLine;
-import com.jozufozu.flywheel.backend.source.span.Span;
-import com.jozufozu.flywheel.util.FlwUtil;
-
-public class ErrorBuilder {
-
-	private final List<ErrorLine> lines = new ArrayList<>();
-
-	private final Level level;
-
-	public ErrorBuilder(Level level, CharSequence msg) {
-		this.level = level;
-
-		lines.add(new HeaderLine(level.toString(), msg));
-	}
-
-	public static ErrorBuilder error(CharSequence msg) {
-		return new ErrorBuilder(Level.ERROR, msg);
-	}
-
-	public static ErrorBuilder warn(CharSequence msg) {
-		return new ErrorBuilder(Level.WARN, msg);
-	}
-
-	public ErrorBuilder pointAtFile(SourceFile file) {
-		lines.add(new FileLine(file.name.toString()));
-		return this;
-	}
-
-	public ErrorBuilder hintIncludeFor(@Nullable Span span, CharSequence msg) {
-		if (span == null) return this;
-
-		String builder = "add " + span.getSourceFile()
-				.importStatement() + ' ' + msg;
-
-		lines.add(new HeaderLine("hint", builder));
-
-		return this.pointAtFile(span.getSourceFile())
-				.pointAt(span, 1);
-	}
-
-	public ErrorBuilder pointAt(Span span, int ctxLines) {
-
-		if (span.lines() == 1) {
-			SourceLines lines = span.getSourceFile().lines;
-
-			int spanLine = span.firstLine();
-
-			int firstLine = Math.max(0, spanLine - ctxLines);
-			int lastLine = Math.min(lines.getLineCount(), spanLine + ctxLines);
-
-            int firstCol = span.getStart()
-                    .col();
-            int lastCol = span.getEnd()
-                    .col();
-
-			for (int i = firstLine; i <= lastLine; i++) {
-				CharSequence line = lines.getLine(i);
-
-				this.lines.add(SourceLine.numbered(i + 1, line.toString()));
-
-				if (i == spanLine) {
-					this.lines.add(new SpanHighlightLine(firstCol, lastCol));
-				}
-			}
-		}
-
-		return this;
-	}
-
-	public CharSequence build() {
-
-		int maxLength = -1;
-		for (ErrorLine line : lines) {
-			int length = line.neededMargin();
-
-			if (length > maxLength) maxLength = length;
-		}
-
-		StringBuilder builder = new StringBuilder();
-		for (ErrorLine line : lines) {
-			int length = line.neededMargin();
-
-			builder.append(FlwUtil.repeatChar(' ', maxLength - length))
-					.append(line.build())
-					.append('\n');
-		}
-
-		return builder;
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/source/parse/Variable.java

@@ -1,28 +0,0 @@
-package com.jozufozu.flywheel.backend.source.parse;
-
-import com.jozufozu.flywheel.backend.source.span.Span;
-
-public class Variable extends AbstractShaderElement {
-
-	private final Span type;
-	private final Span name;
-
-	public Variable(Span self, Span type, Span name) {
-		super(self);
-		this.type = type;
-		this.name = name;
-	}
-
-	public Span typeName() {
-		return type;
-	}
-
-	public Span getName() {
-		return name;
-	}
-
-	@Override
-	public String toString() {
-		return type + " " + name;
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/struct/BufferWriter.java

@@ -33,6 +33,6 @@ public abstract class BufferWriter<S> implements StructWriter<S> {
 
 	@Override
 	public void seek(int pos) {
-			backingBuffer.position(pos * stride);
+		backingBuffer.position(pos * stride);
 	}
 }

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

@@ -1,16 +1,12 @@
 package com.jozufozu.flywheel.core;
 
 import com.jozufozu.flywheel.Flywheel;
-import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.core.compile.ProgramCompiler;
-import com.jozufozu.flywheel.backend.GameStateRegistry;
-import com.jozufozu.flywheel.backend.pipeline.InstancingTemplate;
-import com.jozufozu.flywheel.backend.pipeline.ShaderPipeline;
-import com.jozufozu.flywheel.backend.pipeline.WorldShaderPipeline;
-import com.jozufozu.flywheel.backend.source.FileResolution;
-import com.jozufozu.flywheel.backend.source.Resolver;
 import com.jozufozu.flywheel.core.crumbling.CrumblingProgram;
+import com.jozufozu.flywheel.core.shader.NormalDebugStateProvider;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
-import com.jozufozu.flywheel.core.shader.gamestate.NormalDebugStateProvider;
+import com.jozufozu.flywheel.core.source.FileResolution;
+import com.jozufozu.flywheel.core.source.Resolver;
 import com.jozufozu.flywheel.event.GatherContextEvent;
 import com.jozufozu.flywheel.util.ResourceUtil;
 
@@ -21,22 +17,17 @@ import net.minecraftforge.api.distmarker.OnlyIn;
 @OnlyIn(Dist.CLIENT)
 public class Contexts {
 
-	public static WorldContext<WorldProgram> WORLD;
+	public static ProgramCompiler<WorldProgram> WORLD;
-	public static WorldContext<CrumblingProgram> CRUMBLING;
+	public static ProgramCompiler<CrumblingProgram> CRUMBLING;
 
 	public static void flwInit(GatherContextEvent event) {
-		Backend backend = event.getBackend();
-
 		GameStateRegistry.register(NormalDebugStateProvider.INSTANCE);
 
-        FileResolution crumblingBuiltins = Resolver.INSTANCE.findShader(ResourceUtil.subPath(Names.CRUMBLING, ".glsl"));
+		FileResolution worldBuiltins = Resolver.INSTANCE.get(ResourceUtil.subPath(Names.WORLD, ".glsl"));
-        FileResolution worldBuiltins = Resolver.INSTANCE.findShader(ResourceUtil.subPath(Names.WORLD, ".glsl"));
+		FileResolution crumblingBuiltins = Resolver.INSTANCE.get(ResourceUtil.subPath(Names.CRUMBLING, ".glsl"));
 
-		ShaderPipeline<CrumblingProgram> crumblingPipeline = new WorldShaderPipeline<>(CrumblingProgram::new, InstancingTemplate.INSTANCE, crumblingBuiltins);
+		WORLD = ProgramCompiler.create(Templates.INSTANCING, WorldProgram::new, worldBuiltins);
-		ShaderPipeline<WorldProgram> worldPipeline = new WorldShaderPipeline<>(WorldProgram::new, InstancingTemplate.INSTANCE, worldBuiltins);
+		CRUMBLING = ProgramCompiler.create(Templates.INSTANCING, CrumblingProgram::new, crumblingBuiltins);
-
-		CRUMBLING = backend.register(WorldContext.builder(backend, Names.CRUMBLING).build(crumblingPipeline));
-		WORLD = backend.register(WorldContext.builder(backend, Names.WORLD).build(worldPipeline));
 	}
 
 	public static class Names {

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

@@ -0,0 +1,58 @@
+package com.jozufozu.flywheel.core;
+
+import java.util.ArrayList;
+import java.util.BitSet;
+import java.util.List;
+
+import com.jozufozu.flywheel.core.shader.GameStateProvider;
+import com.jozufozu.flywheel.core.shader.ShaderConstants;
+import com.jozufozu.flywheel.core.shader.StateSnapshot;
+
+public class GameStateRegistry {
+
+	private static final List<GameStateProvider> PROVIDERS = new ArrayList<>();
+
+	/**
+	 * Registers a game state provider.
+	 * @param provider The provider to register.
+	 */
+	public static void register(GameStateProvider provider) {
+		PROVIDERS.add(provider);
+	}
+
+	/**
+	 * Takes a snapshot of the current game state, storing it in a bit set.
+	 * @return An object that represents the current game state.
+	 */
+	public static StateSnapshot takeSnapshot() {
+		BitSet bitSet = new BitSet(PROVIDERS.size());
+
+		for (int i = 0, listSize = PROVIDERS.size(); i < listSize; i++) {
+			if (PROVIDERS.get(i).isTrue()) {
+				bitSet.set(i);
+			}
+		}
+		return new StateSnapshot(bitSet);
+	}
+
+	/**
+	 * Based on the given snapshot, gathers shader constants to be injected during shader compilation.
+	 * @param snapshot The snapshot to use.
+	 * @return A list of shader constants.
+	 */
+	public static ShaderConstants getShaderConstants(StateSnapshot snapshot) {
+		BitSet ctx = snapshot.ctx();
+		ShaderConstants shaderConstants = new ShaderConstants();
+
+		for (int i = 0, listSize = PROVIDERS.size(); i < listSize; i++) {
+			if (ctx.get(i)) {
+				PROVIDERS.get(i).alterConstants(shaderConstants);
+			}
+		}
+		return shaderConstants;
+	}
+
+	public static void _clear() {
+		PROVIDERS.clear();
+	}
+}

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

@@ -2,12 +2,10 @@ package com.jozufozu.flywheel.core;
 
 import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.api.struct.StructType;
-import com.jozufozu.flywheel.backend.Backend;
 import com.jozufozu.flywheel.core.materials.model.ModelData;
 import com.jozufozu.flywheel.core.materials.model.ModelType;
 import com.jozufozu.flywheel.core.materials.oriented.OrientedData;
 import com.jozufozu.flywheel.core.materials.oriented.OrientedType;
-import com.jozufozu.flywheel.event.GatherContextEvent;
 
 import net.minecraft.resources.ResourceLocation;
 import net.minecraftforge.api.distmarker.Dist;
@@ -19,14 +17,9 @@ public class Materials {
 	public static final StructType<OrientedData> ORIENTED = new OrientedType();
 	public static final StructType<ModelData> TRANSFORMED = new ModelType();
 
-	public static void flwInit(GatherContextEvent event) {
-		Backend backend = event.getBackend();
-		backend.register(Names.ORIENTED, ORIENTED);
-		backend.register(Names.MODEL, TRANSFORMED);
-	}
-
 	public static class Names {
 		public static final ResourceLocation MODEL = Flywheel.rl("model");
 		public static final ResourceLocation ORIENTED = Flywheel.rl("oriented");
+		public static final ResourceLocation PASSTHRU = Flywheel.rl("passthru");
 	}
 }

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

@@ -0,0 +1,14 @@
+package com.jozufozu.flywheel.core;
+
+import com.jozufozu.flywheel.backend.gl.GLSLVersion;
+import com.jozufozu.flywheel.core.compile.FragmentTemplateData;
+import com.jozufozu.flywheel.core.compile.InstancingTemplateData;
+import com.jozufozu.flywheel.core.compile.OneShotTemplateData;
+import com.jozufozu.flywheel.core.compile.Template;
+
+public class Templates {
+
+	public static final Template<InstancingTemplateData> INSTANCING = new Template<>(GLSLVersion.V330, InstancingTemplateData::new);
+	public static final Template<OneShotTemplateData> ONE_SHOT = new Template<>(GLSLVersion.V150, OneShotTemplateData::new);
+	public static final Template<FragmentTemplateData> FRAGMENT = new Template<>(GLSLVersion.V150, FragmentTemplateData::new);
+}

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

@@ -1,99 +0,0 @@
-package com.jozufozu.flywheel.core;
-
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Objects;
-import java.util.function.Supplier;
-import java.util.stream.Stream;
-
-import com.jozufozu.flywheel.api.struct.Instanced;
-import com.jozufozu.flywheel.backend.Backend;
-import com.jozufozu.flywheel.backend.ShaderContext;
-import com.jozufozu.flywheel.backend.pipeline.ShaderPipeline;
-import com.jozufozu.flywheel.core.shader.ContextAwareProgram;
-import com.jozufozu.flywheel.core.shader.WorldProgram;
-import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
-
-import net.minecraft.resources.ResourceLocation;
-
-public class WorldContext<P extends WorldProgram> implements ShaderContext<P> {
-	public final Backend backend;
-	protected final Map<ResourceLocation, ContextAwareProgram<P>> programs = new HashMap<>();
-	protected final ResourceLocation name;
-	protected final Supplier<Stream<ResourceLocation>> specStream;
-
-	public final ShaderPipeline<P> pipeline;
-
-	public WorldContext(Backend backend, ResourceLocation name, Supplier<Stream<ResourceLocation>> specStream, ShaderPipeline<P> pipeline) {
-		this.backend = backend;
-		this.name = name;
-		this.specStream = specStream;
-		this.pipeline = pipeline;
-	}
-
-	@Override
-	public void load() {
-
-		Backend.LOGGER.info("Loading context '{}'", name);
-
-		specStream.get()
-				.map(backend::getSpec)
-				.forEach(this::loadSpec);
-	}
-
-	private void loadSpec(ProgramSpec spec) {
-
-		try {
-			programs.put(spec.name, pipeline.compile(spec));
-
-			Backend.LOGGER.debug("Loaded program {}", spec.name);
-		} catch (Exception e) {
-			Backend.LOGGER.error("Error loading program {}", spec.name);
-			Backend.LOGGER.error("", e);
-			backend.loader.notifyError();
-		}
-	}
-
-	@Override
-	public Supplier<P> getProgramSupplier(ResourceLocation spec) {
-		return programs.get(spec);
-	}
-
-	@Override
-	public void delete() {
-		programs.values()
-				.forEach(ContextAwareProgram::delete);
-		programs.clear();
-	}
-
-	public static Builder builder(Backend backend, ResourceLocation name) {
-		return new Builder(backend, name);
-	}
-
-	public static class Builder {
-		private final Backend backend;
-		private final ResourceLocation name;
-		private Supplier<Stream<ResourceLocation>> specStream;
-
-		public Builder(Backend backend, ResourceLocation name) {
-			this.backend = backend;
-			this.name = name;
-		}
-
-		public Builder setSpecStream(Supplier<Stream<ResourceLocation>> specStream) {
-			this.specStream = specStream;
-			return this;
-		}
-
-		public <P extends WorldProgram> WorldContext<P> build(ShaderPipeline<P> pipeline) {
-			if (specStream == null) {
-				specStream = () -> backend.allMaterials()
-						.stream()
-						.map(t -> t instanceof Instanced<?> i ? i : null)
-						.filter(Objects::nonNull)
-						.map(Instanced::getProgramSpec);
-			}
-			return new WorldContext<>(backend, name, specStream, pipeline);
-		}
-	}
-}

src/main/java/com/jozufozu/flywheel/core/compile/CompileUtil.java

@@ -1,13 +1,25 @@
-package com.jozufozu.flywheel.backend.pipeline;
+package com.jozufozu.flywheel.core.compile;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-public class TypeHelper {
+import com.jozufozu.flywheel.backend.gl.GLSLVersion;
+import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
+
+public class CompileUtil {
 
 	public static final Pattern vecType = Pattern.compile("^[biud]?vec([234])$");
 	public static final Pattern matType = Pattern.compile("^mat([234])(?:x([234]))?$");
 
+	protected static String generateHeader(GLSLVersion version, ShaderType type) {
+		return "#version "
+				+ version
+				+ '\n'
+				+ "#extension GL_ARB_explicit_attrib_location : enable\n"
+				+ "#extension GL_ARB_conservative_depth : enable\n"
+				+ type.getDefineStatement();
+	}
+
 	public static int getElementCount(String type) {
 		Matcher vec = vecType.matcher(type);
 		if (vec.find()) return Integer.parseInt(vec.group(1));

src/main/java/com/jozufozu/flywheel/core/compile/FragmentCompiler.java

@@ -0,0 +1,102 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.Objects;
+
+import com.jozufozu.flywheel.backend.gl.shader.GlShader;
+import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
+import com.jozufozu.flywheel.core.shader.ShaderConstants;
+import com.jozufozu.flywheel.core.shader.StateSnapshot;
+import com.jozufozu.flywheel.core.source.FileIndexImpl;
+import com.jozufozu.flywheel.core.source.FileResolution;
+import com.jozufozu.flywheel.core.source.SourceFile;
+
+public class FragmentCompiler extends Memoizer<FragmentCompiler.Context, GlShader> {
+	private final FileResolution header;
+	private final Template<FragmentTemplateData> fragment;
+
+	public FragmentCompiler(Template<FragmentTemplateData> fragment, FileResolution header) {
+		this.header = header;
+		this.fragment = fragment;
+	}
+
+	@Override
+	protected GlShader _create(Context key) {
+		SourceFile fragmentFile = key.file;
+		FragmentTemplateData appliedTemplate = fragment.apply(fragmentFile);
+
+		StringBuilder builder = new StringBuilder();
+
+		builder.append(CompileUtil.generateHeader(fragment.getVersion(), ShaderType.FRAGMENT));
+
+		key.getShaderConstants().writeInto(builder);
+
+		FileIndexImpl index = new FileIndexImpl();
+
+		header.getFile().generateFinalSource(index, builder);
+		fragmentFile.generateFinalSource(index, builder);
+
+		builder.append(appliedTemplate.generateFooter());
+
+		return new GlShader(fragmentFile.name, ShaderType.FRAGMENT, builder.toString());
+	}
+
+	@Override
+	protected void _destroy(GlShader value) {
+		value.delete();
+	}
+
+	/**
+	 * Represents the conditions under which a shader is compiled.
+	 */
+	public static final class Context {
+		/**
+		 * The file to compile.
+		 */
+		private final SourceFile file;
+
+		/**
+		 * The shader constants to apply.
+		 */
+		private final StateSnapshot ctx;
+
+		/**
+		 * Alpha threshold below which fragments are discarded.
+		 */
+		private final float alphaDiscard;
+
+		public Context(SourceFile file, StateSnapshot ctx, float alphaDiscard) {
+			this.file = file;
+			this.ctx = ctx;
+			this.alphaDiscard = alphaDiscard;
+		}
+
+		public ShaderConstants getShaderConstants() {
+			ShaderConstants shaderConstants = ctx.getShaderConstants();
+
+			if (alphaDiscard > 0) {
+				shaderConstants.define("ALPHA_DISCARD", alphaDiscard);
+			}
+
+			return shaderConstants;
+		}
+
+		@Override
+		public boolean equals(Object obj) {
+			if (obj == this) return true;
+			if (obj == null || obj.getClass() != this.getClass()) return false;
+			var that = (Context) obj;
+			return this.file == that.file && Objects.equals(this.ctx, that.ctx) && Float.floatToIntBits(this.alphaDiscard) == Float.floatToIntBits(that.alphaDiscard);
+		}
+
+		@Override
+		public int hashCode() {
+			return Objects.hash(file, ctx, alphaDiscard);
+		}
+
+		@Override
+		public String toString() {
+			return "Context[" + "file=" + file + ", " + "ctx=" + ctx + ", " + "alphaDiscard=" + alphaDiscard + ']';
+		}
+
+	}
+}

src/main/java/com/jozufozu/flywheel/core/compile/FragmentData.java

@@ -0,0 +1,8 @@
+package com.jozufozu.flywheel.core.compile;
+
+public interface FragmentData {
+	/**
+	 * Generate the necessary glue code here.
+	 */
+	String generateFooter();
+}

src/main/java/com/jozufozu/flywheel/core/compile/FragmentTemplateData.java

@@ -0,0 +1,88 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.Optional;
+
+import com.google.common.collect.ImmutableList;
+import com.jozufozu.flywheel.core.source.SourceFile;
+import com.jozufozu.flywheel.core.source.error.ErrorReporter;
+import com.jozufozu.flywheel.core.source.parse.ShaderFunction;
+import com.jozufozu.flywheel.core.source.parse.ShaderStruct;
+import com.jozufozu.flywheel.core.source.parse.StructField;
+import com.jozufozu.flywheel.core.source.parse.Variable;
+import com.jozufozu.flywheel.core.source.span.Span;
+
+public class FragmentTemplateData implements FragmentData {
+	public final SourceFile file;
+	public final Span interpolantName;
+	public final ShaderStruct interpolant;
+	public final ShaderFunction fragmentMain;
+
+	public FragmentTemplateData(SourceFile file) {
+		this.file = file;
+
+		Optional<ShaderFunction> maybeFragmentMain = file.findFunction("fragment");
+
+		if (maybeFragmentMain.isEmpty()) {
+			ErrorReporter.generateMissingFunction(file, "fragment", "\"fragment\" function not defined");
+			throw new RuntimeException();
+		}
+
+		fragmentMain = maybeFragmentMain.get();
+		ImmutableList<Variable> fragmentParameters = fragmentMain.getParameters();
+
+
+		if (fragmentParameters.size() != 1) {
+			ErrorReporter.generateSpanError(fragmentMain.getArgs(), "fragment function must have exactly one argument");
+			throw new RuntimeException();
+		}
+
+		interpolantName = fragmentMain.getParameters().get(0).type;
+
+		Optional<ShaderStruct> maybeInterpolant = file.findStruct(interpolantName);
+
+		if (maybeInterpolant.isEmpty()) {
+			ErrorReporter.generateMissingStruct(file, interpolantName, "struct not defined");
+
+			throw new RuntimeException();
+		}
+
+		interpolant = maybeInterpolant.get();
+	}
+
+	@Override
+	public String generateFooter() {
+		StringBuilder builder = new StringBuilder();
+		prefixFields(builder, interpolant, "in", "v2f_");
+
+		builder.append(String.format("""
+				void main() {
+				    Fragment o;
+					o.color = v2f_color;
+					o.texCoords = v2f_texCoords;
+					o.light = v2f_light;
+					o.diffuse = v2f_diffuse;
+
+				    vec4 color = %s;
+				    FLWFinalizeColor(color);
+				}
+				""",
+				fragmentMain.call("o")
+		));
+
+		return builder.toString();
+	}
+
+	public static void prefixFields(StringBuilder builder, ShaderStruct struct, String qualifier, String prefix) {
+		ImmutableList<StructField> fields = struct.getFields();
+
+		for (StructField field : fields) {
+			builder.append(qualifier)
+					.append(' ')
+					.append(field.type)
+					.append(' ')
+					.append(prefix)
+					.append(field.name)
+					.append(";\n");
+		}
+	}
+}

src/main/java/com/jozufozu/flywheel/core/compile/InstancingTemplateData.java

@@ -0,0 +1,135 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.Optional;
+
+import com.google.common.collect.ImmutableList;
+import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.core.source.FileIndex;
+import com.jozufozu.flywheel.core.source.ShaderLoadingException;
+import com.jozufozu.flywheel.core.source.SourceFile;
+import com.jozufozu.flywheel.core.source.error.ErrorReporter;
+import com.jozufozu.flywheel.core.source.parse.ShaderFunction;
+import com.jozufozu.flywheel.core.source.parse.ShaderStruct;
+import com.jozufozu.flywheel.core.source.parse.StructField;
+import com.jozufozu.flywheel.core.source.parse.Variable;
+import com.jozufozu.flywheel.core.source.span.Span;
+
+public class InstancingTemplateData implements VertexData {
+
+	public final SourceFile file;
+	public final ShaderFunction vertexMain;
+	public final Span vertexName;
+	public final Span instanceName;
+	public final ShaderStruct instance;
+
+	public InstancingTemplateData(SourceFile file) {
+		this.file = file;
+
+		Optional<ShaderFunction> vertexFunc = file.findFunction("vertex");
+
+		if (vertexFunc.isEmpty()) {
+			ErrorReporter.generateFileError(file, "could not find \"vertex\" function");
+			throw new ShaderLoadingException();
+		}
+
+		vertexMain = vertexFunc.get();
+		ImmutableList<Variable> vertexParams = vertexMain.getParameters();
+
+		if (vertexParams.size() != 2) {
+			ErrorReporter.generateSpanError(vertexMain.getArgs(), "instancing requires vertex function to have 2 arguments");
+			throw new ShaderLoadingException();
+		}
+
+		Variable vertexParam = vertexParams.get(0);
+		vertexName = vertexParam.type;
+
+		boolean namedVertex = vertexParam.type
+				.toString()
+				.equals("Vertex");
+
+
+		if (!(namedVertex && vertexParam.qualifier == Variable.Qualifier.INOUT)) {
+			ErrorReporter.generateSpanError(vertexParam.qualifierSpan, "first parameter must be inout Vertex");
+			throw new ShaderLoadingException();
+		}
+
+		instanceName = vertexParams.get(1).type;
+
+		Optional<ShaderStruct> maybeInstance = file.findStruct(instanceName);
+
+		if (maybeInstance.isEmpty()) {
+			ErrorReporter.generateMissingStruct(file, instanceName, "struct not defined");
+			throw new ShaderLoadingException();
+		}
+
+		instance = maybeInstance.get();
+	}
+
+	@Override
+	public String generateFooter(FileIndex shader, VertexType vertexType) {
+		ImmutableList<StructField> fields = instance.getFields();
+
+		int attributeBinding = vertexType.getLayout()
+				.getAttributeCount();
+
+		StringBuilder template = new StringBuilder();
+
+		for (StructField field : fields) {
+			template.append("layout(location = ")
+					.append(attributeBinding)
+					.append(") in")
+					.append(' ')
+					.append(field.type)
+					.append(' ')
+					.append("a_i_")
+					.append(field.name)
+					.append(";\n");
+			attributeBinding += CompileUtil.getAttributeCount(field.type);
+		}
+		template.append(String.format("""
+						out vec4 v2f_color;
+						out vec2 v2f_texCoords;
+						out vec2 v2f_light;
+						out float v2f_diffuse;
+
+						void main() {
+						    Vertex v = FLWCreateVertex();
+						    %s i;
+						    %s
+						    vertex(v, i);
+						    gl_Position = FLWVertex(v);
+						    v.normal = normalize(v.normal);
+
+						    v2f_color = v.color;
+						    v2f_texCoords = v.texCoords;
+						    v2f_light = v.light;
+						    v2f_diffuse = diffuse(v.normal);
+						    #if defined(DEBUG_NORMAL)
+						    v2f_color = vec4(v.normal, 1.);
+						    #endif
+						}
+						""",
+				instanceName,
+				assignFields(instance, "i.", "a_i_")
+		));
+
+		return template.toString();
+	}
+
+	public static StringBuilder assignFields(ShaderStruct struct, String prefix1, String prefix2) {
+		ImmutableList<StructField> fields = struct.getFields();
+
+		StringBuilder builder = new StringBuilder();
+
+		for (StructField field : fields) {
+			builder.append(prefix1)
+					.append(field.name)
+					.append(" = ")
+					.append(prefix2)
+					.append(field.name)
+					.append(";\n");
+		}
+
+		return builder;
+	}
+}

src/main/java/com/jozufozu/flywheel/core/compile/Memoizer.java

@@ -0,0 +1,22 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public abstract class Memoizer<K, V> {
+
+	private final Map<K, V> map = new HashMap<>();
+
+	public V get(K key) {
+		return map.computeIfAbsent(key, this::_create);
+	}
+
+	public void invalidate() {
+		map.values().forEach(this::_destroy);
+		map.clear();
+	}
+
+	protected abstract V _create(K key);
+
+	protected abstract void _destroy(V value);
+}

src/main/java/com/jozufozu/flywheel/core/compile/OneShotTemplateData.java

@@ -0,0 +1,73 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.Optional;
+
+import com.google.common.collect.ImmutableList;
+import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.core.source.FileIndex;
+import com.jozufozu.flywheel.core.source.ShaderLoadingException;
+import com.jozufozu.flywheel.core.source.SourceFile;
+import com.jozufozu.flywheel.core.source.error.ErrorReporter;
+import com.jozufozu.flywheel.core.source.parse.ShaderFunction;
+import com.jozufozu.flywheel.core.source.parse.Variable;
+
+public class OneShotTemplateData implements VertexData {
+
+	public final SourceFile file;
+	public final ShaderFunction vertexMain;
+
+	public OneShotTemplateData(SourceFile file) {
+		this.file = file;
+
+		Optional<ShaderFunction> maybeVertexMain = file.findFunction("vertex");
+
+		if (maybeVertexMain.isEmpty()) {
+			ErrorReporter.generateFileError(file, "could not find \"vertex\" function");
+			throw new RuntimeException();
+		}
+
+		vertexMain = maybeVertexMain.get();
+		ImmutableList<Variable> vertexParameters = vertexMain.getParameters();
+
+		if (vertexParameters.size() != 1) {
+			ErrorReporter.generateSpanError(vertexMain.getArgs(), "a basic model requires vertex function to have one argument");
+			throw new RuntimeException();
+		}
+
+		Variable vertexParam = vertexMain.getParameters().get(0);
+
+		boolean namedVertex = vertexParam.type
+				.toString()
+				.equals("Vertex");
+
+		if (!(namedVertex && vertexParam.qualifier == Variable.Qualifier.INOUT)) {
+			ErrorReporter.generateSpanError(vertexParam.qualifierSpan, "first parameter must be inout Vertex");
+			throw new ShaderLoadingException();
+		}
+	}
+
+	@Override
+    public String generateFooter(FileIndex file, VertexType vertexType) {
+		return """
+				out vec4 v2f_color;
+				out vec2 v2f_texCoords;
+				out vec2 v2f_light;
+				out float v2f_diffuse;
+
+				void main() {
+					Vertex v = FLWCreateVertex();
+					vertex(v);
+					gl_Position = FLWVertex(v);
+					v.normal = normalize(v.normal);
+
+					v2f_color = v.color;
+					v2f_texCoords = v.texCoords;
+					v2f_light = v.light;
+					v2f_diffuse = diffuse(v.normal);
+					#if defined(DEBUG_NORMAL)
+					v2f_color = vec4(v.normal, 1.);
+					#endif
+				}
+				""";
+    }
+}

src/main/java/com/jozufozu/flywheel/core/compile/ProgramAssembler.java

@@ -1,9 +1,8 @@
-package com.jozufozu.flywheel.backend.pipeline;
+package com.jozufozu.flywheel.core.compile;
 
 import static org.lwjgl.opengl.GL11.GL_TRUE;
 import static org.lwjgl.opengl.GL20.GL_LINK_STATUS;
 import static org.lwjgl.opengl.GL20.glAttachShader;
-import static org.lwjgl.opengl.GL20.glBindAttribLocation;
 import static org.lwjgl.opengl.GL20.glCreateProgram;
 import static org.lwjgl.opengl.GL20.glGetProgramInfoLog;
 import static org.lwjgl.opengl.GL20.glGetProgrami;
@@ -12,45 +11,33 @@ import static org.lwjgl.opengl.GL20.glLinkProgram;
 import java.util.List;
 
 import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
 import com.jozufozu.flywheel.backend.gl.shader.GlShader;
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
 
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+import net.minecraft.resources.ResourceLocation;
 
-public class ProtoProgram {
+public class ProgramAssembler {
 	public final int program;
-	public final WorldShader parent;
+	private final ResourceLocation name;
 
-	private int attributeIndex;
+	private final List<GlShader> shaders = new ObjectArrayList<>();
 
-	private final List<GlShader> shaders;
+	public ProgramAssembler(ResourceLocation name) {
-
+		this.name = name;
-	public ProtoProgram(WorldShader parent) {
-		this.parent = parent;
 		this.program = glCreateProgram();
-		shaders = new ObjectArrayList<>();
-	}
-
-	public ProtoProgram compilePart(ShaderType type) {
-		GlShader shader = parent.compile(type);
-		attachShader(shader);
-		return this;
 	}
 
 	/**
 	 * Links the attached shaders to this program.
 	 */
-	public ProtoProgram link() {
+	public ProgramAssembler link() {
-
-		parent.template.getShaderInputs(parent.mainFile)
-				.forEach(this::addAttribute);
-
 		glLinkProgram(this.program);
 
 		String log = glGetProgramInfoLog(this.program);
 
 		if (!log.isEmpty()) {
-			Backend.LOGGER.debug("Program link log for " + parent.name + ": " + log);
+			Backend.LOGGER.debug("Program link log for " + name + ": " + log);
 		}
 
 		int result = glGetProgrami(this.program, GL_LINK_STATUS);
@@ -62,19 +49,18 @@ public class ProtoProgram {
 		return this;
 	}
 
-	public ProtoProgram deleteLinkedShaders() {
+	public ProgramAssembler deleteLinkedShaders() {
 		shaders.forEach(GlShader::delete);
 		return this;
 	}
 
-	private void attachShader(GlShader glShader) {
+	public ProgramAssembler attachShader(GlShader glShader) {
 		shaders.add(glShader);
 		glAttachShader(this.program, glShader.handle());
+		return this;
 	}
 
-	private void addAttribute(ShaderInput shaderInput) {
+	public <P extends GlProgram> P build(GlProgram.Factory<P> factory) {
-		glBindAttribLocation(this.program, attributeIndex, shaderInput.name);
+		return factory.create(name, program);
-		attributeIndex += shaderInput.attribCount;
 	}
-
 }

src/main/java/com/jozufozu/flywheel/core/compile/ProgramCompiler.java

@@ -0,0 +1,80 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
+import com.jozufozu.flywheel.core.Templates;
+import com.jozufozu.flywheel.core.source.FileResolution;
+import com.jozufozu.flywheel.event.ReloadRenderersEvent;
+
+/**
+ * A caching compiler.
+ *
+ * <p>
+ *     This class is responsible for compiling programs on the fly. An instance of this class will keep a cache of
+ *     compiled programs, and will only compile a program if it is not already in the cache.
+ * </p>
+ */
+public class ProgramCompiler<P extends GlProgram> extends Memoizer<ProgramContext, P> {
+
+	private static final List<ProgramCompiler<?>> ALL_COMPILERS = new ArrayList<>();
+
+	private final GlProgram.Factory<P> factory;
+	private final VertexCompiler vertexCompiler;
+	private final FragmentCompiler fragmentCompiler;
+
+	public ProgramCompiler(GlProgram.Factory<P> factory, VertexCompiler vertexCompiler, FragmentCompiler fragmentCompiler) {
+		this.factory = factory;
+		this.vertexCompiler = vertexCompiler;
+		this.fragmentCompiler = fragmentCompiler;
+
+		ALL_COMPILERS.add(this);
+	}
+
+	/**
+	 * Creates a program compiler using this template.
+	 * @param template The vertex template to use.
+	 * @param factory A factory to add meaning to compiled programs.
+	 * @param header The header file to use for the program.
+	 * @param <P> The type of program to compile.
+	 * @return A program compiler.
+	 */
+	public static <T extends VertexData, P extends GlProgram> ProgramCompiler<P> create(Template<T> template, GlProgram.Factory<P> factory, FileResolution header) {
+		return new ProgramCompiler<>(factory, new VertexCompiler(template, header), new FragmentCompiler(Templates.FRAGMENT, header));
+	}
+
+	/**
+	 * Get or compile a spec to the given vertex type, accounting for all game state conditions specified by the spec.
+	 *
+	 * @param ctx The context of compilation.
+	 * @return A compiled GlProgram.
+	 */
+	public P getProgram(ProgramContext ctx) {
+		return super.get(ctx);
+	}
+
+	public void invalidate() {
+		super.invalidate();
+		vertexCompiler.invalidate();
+		fragmentCompiler.invalidate();
+	}
+
+	@Override
+	protected P _create(ProgramContext ctx) {
+		return new ProgramAssembler(ctx.spec.name)
+				.attachShader(vertexCompiler.get(new VertexCompiler.Context(ctx.spec.getVertexFile(), ctx.ctx, ctx.vertexType)))
+				.attachShader(fragmentCompiler.get(new FragmentCompiler.Context(ctx.spec.getFragmentFile(), ctx.ctx, ctx.alphaDiscard)))
+				.link()
+				.build(this.factory);
+	}
+
+	@Override
+	protected void _destroy(P value) {
+		value.delete();
+	}
+
+	public static void invalidateAll(ReloadRenderersEvent event) {
+		ALL_COMPILERS.forEach(ProgramCompiler::invalidate);
+	}
+}

src/main/java/com/jozufozu/flywheel/core/compile/ProgramContext.java

@@ -0,0 +1,83 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.Objects;
+
+import javax.annotation.Nullable;
+
+import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.RenderLayer;
+import com.jozufozu.flywheel.core.GameStateRegistry;
+import com.jozufozu.flywheel.core.shader.ProgramSpec;
+import com.jozufozu.flywheel.core.shader.StateSnapshot;
+
+import net.minecraft.resources.ResourceLocation;
+
+/**
+ * Represents the entire context of a program's usage.
+ */
+public final class ProgramContext {
+	/**
+	 * Creates a compilation context for the given program, vertex type and render layer.
+	 *
+	 * @param programName The name of the program to use.
+	 * @param vertexType  The vertex type to use.
+	 * @param layer       If cutout, the alpha discard threshold is 0.1, otherwise 0.
+	 * @return A compilation context.
+	 */
+	public static ProgramContext create(ResourceLocation programName, VertexType vertexType, @Nullable RenderLayer layer) {
+		ProgramSpec spec = Backend.getSpec(programName);
+
+		if (spec == null) {
+			throw new NullPointerException("Cannot compile shader because '" + programName + "' is not recognized.");
+		}
+
+		return new ProgramContext(spec, getAlphaDiscard(layer), vertexType, GameStateRegistry.takeSnapshot());
+	}
+
+	/**
+	 * Gets the alpha discard threshold for the given render layer.
+	 *
+	 * @param layer The render layer to get the alpha discard threshold for.
+	 * @return The alpha discard threshold.
+	 */
+	public static float getAlphaDiscard(@Nullable RenderLayer layer) {
+		return layer == RenderLayer.CUTOUT ? 0.1f : 0f;
+	}
+
+	public final ProgramSpec spec;
+	public final float alphaDiscard;
+	public final VertexType vertexType;
+	public final StateSnapshot ctx;
+
+	/**
+	 * @param spec			The program to use.
+	 * @param alphaDiscard 	Alpha threshold below which pixels are discarded.
+	 * @param vertexType   	The vertexType the program should be adapted for.
+	 * @param ctx          	A snapshot of the game state.
+	 */
+	public ProgramContext(ProgramSpec spec, float alphaDiscard, VertexType vertexType, StateSnapshot ctx) {
+		this.spec = spec;
+		this.alphaDiscard = alphaDiscard;
+		this.vertexType = vertexType;
+		this.ctx = ctx;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) return true;
+		if (o == null || getClass() != o.getClass()) return false;
+		var that = (ProgramContext) o;
+		return spec == that.spec && vertexType == that.vertexType && ctx.equals(that.ctx) && Float.floatToIntBits(alphaDiscard) == Float.floatToIntBits(that.alphaDiscard);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(spec, alphaDiscard, vertexType, ctx);
+	}
+
+	@Override
+	public String toString() {
+		return "ProgramContext{" + "spec=" + spec + ", alphaDiscard=" + alphaDiscard + ", vertexType=" + vertexType + ", ctx=" + ctx + '}';
+	}
+}

src/main/java/com/jozufozu/flywheel/core/compile/Template.java

@@ -0,0 +1,52 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.function.Function;
+
+import com.jozufozu.flywheel.backend.gl.GLSLVersion;
+import com.jozufozu.flywheel.core.source.SourceFile;
+
+/**
+ * A class that generates glsl glue code given a SourceFile.
+ *
+ * <p>
+ *     Shader files are written somewhat abstractly. Subclasses of Template handle those abstractions, using SourceFile
+ *     metadata to generate shader code that OpenGL can use to call into our shader programs.
+ * </p>
+ */
+public class Template<T> extends Memoizer<SourceFile, T> {
+
+	private final Function<SourceFile, T> reader;
+	private final GLSLVersion glslVersion;
+
+	public Template(GLSLVersion glslVersion, Function<SourceFile, T> reader) {
+		this.reader = reader;
+		this.glslVersion = glslVersion;
+	}
+
+	/**
+	 * Verify that the given SourceFile is valid for this Template and return the metadata.
+	 * @param file The SourceFile to apply this Template to.
+	 * @return The applied template metadata.
+	 */
+	public T apply(SourceFile file) {
+		// lazily read files, cache results
+		return super.get(file);
+	}
+
+	/**
+	 * @return The GLSL version this template requires.
+	 */
+	public GLSLVersion getVersion() {
+		return glslVersion;
+	}
+
+	@Override
+	protected T _create(SourceFile key) {
+		return reader.apply(key);
+	}
+
+	@Override
+	protected void _destroy(T value) {
+		// noop
+	}
+}

src/main/java/com/jozufozu/flywheel/core/compile/VertexCompiler.java

@@ -0,0 +1,93 @@
+package com.jozufozu.flywheel.core.compile;
+
+import java.util.Objects;
+
+import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.backend.gl.shader.GlShader;
+import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
+import com.jozufozu.flywheel.core.shader.StateSnapshot;
+import com.jozufozu.flywheel.core.source.FileIndexImpl;
+import com.jozufozu.flywheel.core.source.FileResolution;
+import com.jozufozu.flywheel.core.source.SourceFile;
+
+public class VertexCompiler extends Memoizer<VertexCompiler.Context, GlShader> {
+	private final Template<? extends VertexData> template;
+	private final FileResolution header;
+
+	public VertexCompiler(Template<? extends VertexData> template, FileResolution header) {
+		this.template = template;
+		this.header = header;
+	}
+
+	@Override
+	protected GlShader _create(Context key) {
+		StringBuilder finalSource = new StringBuilder();
+
+		finalSource.append(CompileUtil.generateHeader(template.getVersion(), ShaderType.VERTEX));
+
+		key.ctx.getShaderConstants().writeInto(finalSource);
+
+		finalSource.append("""
+				struct Vertex {
+					vec3 pos;
+					vec4 color;
+					vec2 texCoords;
+					vec2 light;
+					vec3 normal;
+				};
+				""");
+		finalSource.append(key.vertexType.getShaderHeader());
+
+		FileIndexImpl index = new FileIndexImpl();
+
+		header.getFile().generateFinalSource(index, finalSource);
+
+		key.file.generateFinalSource(index, finalSource);
+
+		VertexData appliedTemplate = template.apply(key.file);
+		finalSource.append(appliedTemplate.generateFooter(index, key.vertexType));
+
+		return new GlShader(key.file.name, ShaderType.VERTEX, finalSource.toString());
+	}
+
+	@Override
+	protected void _destroy(GlShader value) {
+		value.delete();
+	}
+
+	public static class Context {
+		/**
+		 * The file to compile.
+		 */
+		private final SourceFile file;
+
+		/**
+		 * The shader constants to apply.
+		 */
+		private final StateSnapshot ctx;
+
+		/**
+		 * The vertex type to use.
+		 */
+		private final VertexType vertexType;
+
+		public Context(SourceFile file, StateSnapshot ctx, VertexType vertexType) {
+			this.file = file;
+			this.ctx = ctx;
+			this.vertexType = vertexType;
+		}
+
+		@Override
+		public boolean equals(Object o) {
+			if (this == o) return true;
+			if (o == null || getClass() != o.getClass()) return false;
+			var that = (Context) o;
+			return file == that.file && vertexType == that.vertexType && ctx.equals(that.ctx);
+		}
+
+		@Override
+		public int hashCode() {
+			return Objects.hash(file, ctx, vertexType);
+		}
+	}
+}

src/main/java/com/jozufozu/flywheel/core/compile/VertexData.java

@@ -0,0 +1,12 @@
+package com.jozufozu.flywheel.core.compile;
+
+import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.core.source.FileIndex;
+
+public interface VertexData {
+	/**
+	 * Generate the necessary glue code here.
+	 * @param file The SourceFile with user written code.
+	 */
+	String generateFooter(FileIndex file, VertexType vertexType);
+}

src/main/java/com/jozufozu/flywheel/core/compile/package-info.java

@@ -1,5 +1,5 @@
 @ParametersAreNonnullByDefault @MethodsReturnNonnullByDefault
-package com.jozufozu.flywheel.backend.source;
+package com.jozufozu.flywheel.core.compile;
 
 import javax.annotation.ParametersAreNonnullByDefault;
 

src/main/java/com/jozufozu/flywheel/core/crumbling/CrumblingGroup.java

@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.core.crumbling;
 
+import com.jozufozu.flywheel.backend.RenderLayer;
 import com.jozufozu.flywheel.backend.instancing.instancing.InstancedMaterialGroup;
 import com.jozufozu.flywheel.backend.instancing.instancing.InstancingEngine;
 import com.jozufozu.flywheel.util.Textures;
@@ -18,7 +19,7 @@ public class CrumblingGroup<P extends CrumblingProgram> extends InstancedMateria
 	}
 
 	@Override
-	public void render(Matrix4f viewProjection, double camX, double camY, double camZ) {
+	public void render(Matrix4f viewProjection, double camX, double camY, double camZ, RenderLayer layer) {
 		type.setupRenderState();
 
 		int renderTex = RenderSystem.getShaderTexture(0);
@@ -35,7 +36,7 @@ public class CrumblingGroup<P extends CrumblingProgram> extends InstancedMateria
 		RenderSystem.setShaderTexture(4, breakingTex);
 
 		Textures.bindActiveTextures();
-		renderAll(viewProjection, camX, camY, camZ);
+		renderAll(viewProjection, camX, camY, camZ, layer);
 
 		CrumblingRenderer._currentLayer.clearRenderState();
 	}

src/main/java/com/jozufozu/flywheel/core/layout/BufferLayout.java

@@ -27,8 +27,8 @@ public class BufferLayout {
 
 		int numAttributes = 0, stride = 0;
 		for (LayoutItem spec : allAttributes) {
-			numAttributes += spec.getAttributeCount();
+			numAttributes += spec.attributeCount();
-			stride += spec.getSize();
+			stride += spec.size();
 		}
 		this.numAttributes = numAttributes;
 		this.stride = stride;

src/main/java/com/jozufozu/flywheel/core/layout/CommonItems.java

@@ -19,6 +19,6 @@ public class CommonItems {
 	public static final PrimitiveItem LIGHT_SHORT = new PrimitiveItem(GlNumericType.USHORT, 2, true);
 
 	public static final PrimitiveItem NORMALIZED_BYTE = new PrimitiveItem(GlNumericType.BYTE, 1, true);
-	public static final LayoutItem PADDING_BYTE = new PaddingItem(1);
+	public static final LayoutItem PADDING_BYTE = new Padding(1);
 
 }

src/main/java/com/jozufozu/flywheel/core/layout/LayoutItem.java

@@ -4,7 +4,7 @@ public interface LayoutItem {
 
 	void vertexAttribPointer(int stride, int index, int offset);
 
-	int getSize();
+	int size();
 
-	int getAttributeCount();
+	int attributeCount();
 }

src/main/java/com/jozufozu/flywheel/core/layout/MatrixItems.java

@@ -26,12 +26,13 @@ public enum MatrixItems implements LayoutItem {
 	}
 
 	@Override
-	public int getSize() {
+	public int size() {
 		return GlNumericType.FLOAT.getByteWidth() * rows * cols;
 	}
 
 	@Override
-	public int getAttributeCount() {
+	public int attributeCount() {
 		return rows;
 	}
+
 }

src/main/java/com/jozufozu/flywheel/core/layout/Padding.java

@@ -1,6 +1,6 @@
 package com.jozufozu.flywheel.core.layout;
 
-record PaddingItem(int bytes) implements LayoutItem {
+record Padding(int bytes) implements LayoutItem {
 
 	@Override
 	public void vertexAttribPointer(int stride, int index, int offset) {
@@ -8,12 +8,13 @@ record PaddingItem(int bytes) implements LayoutItem {
 	}
 
 	@Override
-	public int getSize() {
+	public int size() {
 		return bytes;
 	}
 
 	@Override
-	public int getAttributeCount() {
+	public int attributeCount() {
 		return 0;
 	}
+
 }

src/main/java/com/jozufozu/flywheel/core/layout/PrimitiveItem.java

@@ -30,12 +30,13 @@ public class PrimitiveItem implements LayoutItem {
 	}
 
 	@Override
-	public int getSize() {
+	public int size() {
 		return size;
 	}
 
 	@Override
-	public int getAttributeCount() {
+	public int attributeCount() {
 		return attributeCount;
 	}
+
 }

src/main/java/com/jozufozu/flywheel/core/materials/BasicData.java

@@ -1,6 +1,7 @@
 package com.jozufozu.flywheel.core.materials;
 
 import com.jozufozu.flywheel.api.InstanceData;
+import com.jozufozu.flywheel.util.Color;
 
 import net.minecraft.client.renderer.LightTexture;
 
@@ -33,6 +34,15 @@ public abstract class BasicData extends InstanceData implements FlatLit<BasicDat
 		return LightTexture.pack(this.blockLight, this.skyLight);
 	}
 
+	public BasicData setColor(Color color) {
+		this.r = (byte) color.getRed();
+		this.g = (byte) color.getGreen();
+		this.b = (byte) color.getBlue();
+		this.a = (byte) color.getAlpha();
+		markDirty();
+		return this;
+	}
+
 	public BasicData setColor(int color) {
 		return setColor(color, false);
 	}

src/main/java/com/jozufozu/flywheel/core/shader/ContextAwareProgram.java

@@ -1,26 +0,0 @@
-package com.jozufozu.flywheel.core.shader;
-
-import java.util.function.Supplier;
-
-import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
-
-/**
- * Encapsulates any number of shader programs for use in similar contexts.
- * Allows the implementor to choose which shader program to use based on arbitrary state.
- *
- * @param <P>
- */
-public interface ContextAwareProgram<P extends GlProgram> extends Supplier<P> {
-
-	/**
-	 * Get the shader program most suited for the current game state.
-	 *
-	 * @return The one true program.
-	 */
-	P get();
-
-	/**
-	 * Delete all shader programs encapsulated by your implementation.
-	 */
-	void delete();
-}

src/main/java/com/jozufozu/flywheel/core/shader/ExtensibleGlProgram.java

@@ -1,64 +0,0 @@
-package com.jozufozu.flywheel.core.shader;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import javax.annotation.Nonnull;
-
-import com.jozufozu.flywheel.backend.ShaderContext;
-import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
-import com.jozufozu.flywheel.core.shader.extension.ExtensionInstance;
-
-import net.minecraft.resources.ResourceLocation;
-
-/**
- * A shader program that be arbitrarily "extended". This class can take in any number of program extensions, and
- * will initialize them and then call their {@link ExtensionInstance#bind() bind} function every subsequent time this
- * program is bound. An "extension" is something that interacts with the shader program in a way that is invisible to
- * the caller using the program. This is used by some programs to implement the different fog modes. Other uses might
- * include binding extra textures to allow for blocks to have normal maps, for example. As the extensions are
- * per-program, this also allows for same extra specialization within a
- * {@link ShaderContext ShaderContext}.
- */
-public class ExtensibleGlProgram extends GlProgram {
-
-	protected final List<ExtensionInstance> extensions = new ArrayList<>();
-
-	public ExtensibleGlProgram(ResourceLocation name, int handle) {
-		super(name, handle);
-	}
-
-	@Override
-	public void bind() {
-		super.bind();
-
-		extensions.forEach(ExtensionInstance::bind);
-	}
-
-	@Override
-	public String toString() {
-		StringBuilder builder = new StringBuilder();
-		builder.append("program ")
-				.append(name)
-				.append('[');
-
-		for (ExtensionInstance extension : extensions) {
-			builder.append(extension)
-					.append('+');
-		}
-
-		builder.append(']');
-
-		return builder.toString();
-	}
-
-	/**
-	 * A factory interface to create {@link GlProgram}s parameterized by a list of extensions. This doesn't necessarily
-	 * have to return an {@link ExtensibleGlProgram} if implementors want more flexibility for whatever reason.
-	 */
-	public interface Factory<P extends GlProgram> {
-
-		@Nonnull
-		P create(ResourceLocation name, int handle);
-	}
-}

src/main/java/com/jozufozu/flywheel/core/shader/GameStateProgram.java

@@ -1,62 +0,0 @@
-package com.jozufozu.flywheel.core.shader;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
-import com.jozufozu.flywheel.core.shader.spec.GameStateCondition;
-import com.jozufozu.flywheel.util.Pair;
-
-public class GameStateProgram<P extends GlProgram> implements ContextAwareProgram<P> {
-
-	private final List<Pair<GameStateCondition, P>> variants;
-	private final P fallback;
-
-	protected GameStateProgram(List<Pair<GameStateCondition, P>> variants, P fallback) {
-		this.variants = variants;
-		this.fallback = fallback;
-	}
-
-	@Override
-	public P get() {
-		for (Pair<GameStateCondition, P> variant : variants) {
-            if (variant.first()
-					.isMet()) return variant.second();
-		}
-
-		return fallback;
-	}
-
-	@Override
-	public void delete() {
-		for (Pair<GameStateCondition, P> variant : variants) {
-			variant.second()
-					.delete();
-		}
-
-		fallback.delete();
-	}
-
-	public static <P extends GlProgram> Builder<P> builder(P fallback) {
-		return new Builder<>(fallback);
-	}
-
-	public static class Builder<P extends GlProgram> {
-		private final P fallback;
-		private final List<Pair<GameStateCondition, P>> variants = new ArrayList<>();
-
-		public Builder(P fallback) {
-			this.fallback = fallback;
-		}
-
-		public Builder<P> withVariant(GameStateCondition condition, P program) {
-			variants.add(Pair.of(condition, program));
-			return this;
-		}
-
-		public ContextAwareProgram<P> build() {
-			return new GameStateProgram<>(ImmutableList.copyOf(variants), fallback);
-		}
-	}
-}

src/main/java/com/jozufozu/flywheel/core/shader/GameStateProvider.java

@@ -0,0 +1,19 @@
+package com.jozufozu.flywheel.core.shader;
+
+/**
+ * An object that provides a view of the current game state for shader compilation.
+ */
+public interface GameStateProvider {
+
+	/**
+	 * Get the status of this game state provider.
+	 * @return Returning {@code true} will cause #alterConstants to be called before compiling a shader.
+	 */
+	boolean isTrue();
+
+	/**
+	 * Alter the constants for shader compilation.
+	 * @param constants The shader constants.
+	 */
+	void alterConstants(ShaderConstants constants);
+}

src/main/java/com/jozufozu/flywheel/core/shader/NormalDebugStateProvider.java

@@ -0,0 +1,18 @@
+package com.jozufozu.flywheel.core.shader;
+
+import com.jozufozu.flywheel.config.FlwConfig;
+
+public enum NormalDebugStateProvider implements GameStateProvider {
+	INSTANCE;
+
+	@Override
+	public boolean isTrue() {
+		return FlwConfig.get()
+				.debugNormals();
+	}
+
+	@Override
+	public void alterConstants(ShaderConstants constants) {
+		constants.define("DEBUG_NORMAL");
+	}
+}

src/main/java/com/jozufozu/flywheel/core/shader/ProgramSpec.java

@@ -1,11 +1,8 @@
-package com.jozufozu.flywheel.core.shader.spec;
+package com.jozufozu.flywheel.core.shader;
 
-import java.util.Collections;
+import com.jozufozu.flywheel.core.source.FileResolution;
-import java.util.List;
+import com.jozufozu.flywheel.core.source.Resolver;
-
+import com.jozufozu.flywheel.core.source.SourceFile;
-import com.jozufozu.flywheel.backend.source.FileResolution;
-import com.jozufozu.flywheel.backend.source.Resolver;
-import com.jozufozu.flywheel.backend.source.SourceFile;
 import com.mojang.serialization.Codec;
 import com.mojang.serialization.codecs.RecordCodecBuilder;
 
@@ -26,39 +23,46 @@ import net.minecraft.resources.ResourceLocation;
  */
 public class ProgramSpec {
 
-	// TODO: Block model style inheritance?
 	public static final Codec<ProgramSpec> CODEC = RecordCodecBuilder.create(instance -> instance.group(
-			ResourceLocation.CODEC.fieldOf("source")
+			ResourceLocation.CODEC.fieldOf("vertex")
 					.forGetter(ProgramSpec::getSourceLoc),
-			ProgramState.CODEC.listOf()
+				ResourceLocation.CODEC.fieldOf("fragment")
-					.optionalFieldOf("states", Collections.emptyList())
+					.forGetter(ProgramSpec::getFragmentLoc))
-					.forGetter(ProgramSpec::getStates))
 			.apply(instance, ProgramSpec::new));
 
 	public ResourceLocation name;
-	public final FileResolution source;
+	public final FileResolution vertex;
+	public final FileResolution fragment;
 
-	public final List<ProgramState> states;
+	public ProgramSpec(ResourceLocation vertex, ResourceLocation fragment) {
-
+		this.vertex = Resolver.INSTANCE.get(vertex);
-	public ProgramSpec(ResourceLocation source, List<ProgramState> states) {
+		this.fragment = Resolver.INSTANCE.get(fragment);
-		this.source = Resolver.INSTANCE.findShader(source);
-		this.states = states;
 	}
 
 	public void setName(ResourceLocation name) {
 		this.name = name;
+		this.vertex.addSpec(name);
+		this.fragment.addSpec(name);
 	}
 
 	public ResourceLocation getSourceLoc() {
-		return source.getFileLoc();
+		return vertex.getFileLoc();
 	}
 
-	public FileResolution getSource() {
+	public ResourceLocation getFragmentLoc() {
-		return source;
+		return fragment.getFileLoc();
 	}
 
-	public List<ProgramState> getStates() {
+	public SourceFile getVertexFile() {
-		return states;
+		return vertex.getFile();
 	}
 
+	public SourceFile getFragmentFile() {
+		return fragment.getFile();
+	}
+
+	@Override
+	public String toString() {
+		return name.toString();
+	}
 }

src/main/java/com/jozufozu/flywheel/core/shader/ShaderConstants.java

@@ -0,0 +1,55 @@
+package com.jozufozu.flywheel.core.shader;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A class for manipulating a list of {@code #define} directives.
+ *
+ * <p>Based loosely on code by jellysquid3.
+ */
+public class ShaderConstants {
+
+	private final Map<String, String> definitions = new HashMap<>();
+
+	public ShaderConstants define(String def) {
+		definitions.put(def, "");
+		return this;
+	}
+
+	public ShaderConstants define(String def, String value) {
+		definitions.put(def, value);
+		return this;
+	}
+
+	public ShaderConstants define(String def, float value) {
+		definitions.put(def, Float.toString(value));
+		return this;
+	}
+
+	public ShaderConstants defineAll(List<String> defines) {
+		for (String def : defines) {
+			definitions.put(def, "");
+		}
+		return this;
+	}
+
+	public String build() {
+		final StringBuilder acc = new StringBuilder();
+		writeInto(acc);
+		return acc.toString();
+	}
+
+	public void writeInto(final StringBuilder acc) {
+		for (Map.Entry<String, String> e : definitions.entrySet()) {
+			acc.append("#define ")
+					.append(e.getKey());
+			if (e.getValue().length() > 0) {
+				acc.append(' ')
+						.append(e.getValue());
+			}
+			acc.append('\n');
+		}
+	}
+}

src/main/java/com/jozufozu/flywheel/core/shader/StateSnapshot.java

@@ -0,0 +1,13 @@
+package com.jozufozu.flywheel.core.shader;
+
+import java.util.BitSet;
+
+import com.jozufozu.flywheel.core.GameStateRegistry;
+
+public record StateSnapshot(BitSet ctx) {
+	// TODO: is this needed?
+
+	public ShaderConstants getShaderConstants() {
+		return GameStateRegistry.getShaderConstants(this);
+	}
+}

src/main/java/com/jozufozu/flywheel/core/shader/WorldFog.java

@@ -1,16 +1,11 @@
-package com.jozufozu.flywheel.core.shader.extension;
+package com.jozufozu.flywheel.core.shader;
 
 import org.lwjgl.opengl.GL20;
 
-import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
 import com.mojang.blaze3d.systems.RenderSystem;
 
-import net.minecraft.resources.ResourceLocation;
+public class WorldFog {
-
-public class WorldFog implements ExtensionInstance {
-
-	public static final ResourceLocation NAME = Flywheel.rl("fog");
 
 	private final int uFogColor;
 	private final int uFogRange;
@@ -20,14 +15,8 @@ public class WorldFog implements ExtensionInstance {
 		this.uFogRange = program.getUniformLocation("uFogRange");
 	}
 
-	@Override
 	public void bind() {
 		GL20.glUniform2f(uFogRange, RenderSystem.getShaderFogStart(), RenderSystem.getShaderFogEnd());
 		GL20.glUniform4fv(uFogColor, RenderSystem.getShaderFogColor());
 	}
-
-	@Override
-	public ResourceLocation name() {
-		return NAME;
-	}
 }

src/main/java/com/jozufozu/flywheel/core/shader/WorldProgram.java

@@ -4,7 +4,7 @@ import static org.lwjgl.opengl.GL20.glUniform1f;
 import static org.lwjgl.opengl.GL20.glUniform2f;
 import static org.lwjgl.opengl.GL20.glUniform3f;
 
-import com.jozufozu.flywheel.core.shader.extension.WorldFog;
+import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
 import com.jozufozu.flywheel.util.AnimationTickHolder;
 import com.mojang.blaze3d.platform.Window;
 import com.mojang.math.Matrix4f;
@@ -12,11 +12,12 @@ import com.mojang.math.Matrix4f;
 import net.minecraft.client.Minecraft;
 import net.minecraft.resources.ResourceLocation;
 
-public class WorldProgram extends ExtensibleGlProgram {
+public class WorldProgram extends GlProgram {
 	protected final int uTime = getUniformLocation("uTime");
 	protected final int uViewProjection = getUniformLocation("uViewProjection");
 	protected final int uCameraPos = getUniformLocation("uCameraPos");
 	protected final int uWindowSize = getUniformLocation("uWindowSize");
+	private final WorldFog fog;
 
 	protected int uBlockAtlas;
 	protected int uLightMap;
@@ -24,7 +25,7 @@ public class WorldProgram extends ExtensibleGlProgram {
 	public WorldProgram(ResourceLocation name, int handle) {
 		super(name, handle);
 
-		this.extensions.add(new WorldFog(this));
+		fog = new WorldFog(this);
 
 		super.bind();
 		registerSamplers();
@@ -67,7 +68,7 @@ public class WorldProgram extends ExtensibleGlProgram {
 	@Override
 	public void bind() {
 		super.bind();
-
+		fog.bind();
 		uploadWindowSize();
 		uploadTime(AnimationTickHolder.getRenderTime());
 	}

src/main/java/com/jozufozu/flywheel/core/shader/extension/ExtensionInstance.java

@@ -1,13 +0,0 @@
-package com.jozufozu.flywheel.core.shader.extension;
-
-import net.minecraft.resources.ResourceLocation;
-
-public interface ExtensionInstance {
-
-	/**
-	 * Bind the extra program state. It is recommended to grab the state information from global variables.
-	 */
-	void bind();
-
-	ResourceLocation name();
-}

src/main/java/com/jozufozu/flywheel/core/shader/extension/UnitExtensionInstance.java

@@ -1,24 +0,0 @@
-package com.jozufozu.flywheel.core.shader.extension;
-
-import com.jozufozu.flywheel.Flywheel;
-import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
-
-import net.minecraft.resources.ResourceLocation;
-
-public class UnitExtensionInstance implements ExtensionInstance {
-
-	public static final ResourceLocation NAME = Flywheel.rl("unit");
-
-	public UnitExtensionInstance(GlProgram program) {
-	}
-
-	@Override
-	public void bind() {
-
-	}
-
-	@Override
-	public ResourceLocation name() {
-		return NAME;
-	}
-}

src/main/java/com/jozufozu/flywheel/core/shader/gamestate/GameStateProvider.java

@@ -1,15 +0,0 @@
-package com.jozufozu.flywheel.core.shader.gamestate;
-
-import com.jozufozu.flywheel.backend.GameStateRegistry;
-import com.mojang.serialization.Codec;
-
-import net.minecraft.resources.ResourceLocation;
-
-public interface GameStateProvider {
-
-	Codec<GameStateProvider> CODEC = ResourceLocation.CODEC.xmap(GameStateRegistry::getStateProvider, GameStateProvider::getID);
-
-	ResourceLocation getID();
-
-	Object getValue();
-}

src/main/java/com/jozufozu/flywheel/core/shader/gamestate/NormalDebugStateProvider.java

@@ -1,28 +0,0 @@
-package com.jozufozu.flywheel.core.shader.gamestate;
-
-import com.jozufozu.flywheel.Flywheel;
-import com.jozufozu.flywheel.config.FlwConfig;
-import com.jozufozu.flywheel.core.shader.spec.BooleanStateProvider;
-
-import net.minecraft.resources.ResourceLocation;
-
-public class NormalDebugStateProvider implements BooleanStateProvider {
-
-	public static final NormalDebugStateProvider INSTANCE = new NormalDebugStateProvider();
-	public static final ResourceLocation NAME = Flywheel.rl("normal_debug");
-
-	protected NormalDebugStateProvider() {
-
-	}
-
-	@Override
-	public boolean isTrue() {
-		return FlwConfig.get()
-				.debugNormals();
-	}
-
-	@Override
-	public ResourceLocation getID() {
-		return NAME;
-	}
-}

src/main/java/com/jozufozu/flywheel/core/shader/package-info.java

@@ -1,5 +1,5 @@
 @ParametersAreNonnullByDefault @MethodsReturnNonnullByDefault
-package com.jozufozu.flywheel.backend.pipeline;
+package com.jozufozu.flywheel.core.shader;
 
 import javax.annotation.ParametersAreNonnullByDefault;
 

src/main/java/com/jozufozu/flywheel/core/shader/spec/BooleanGameStateCondition.java

@@ -1,37 +0,0 @@
-package com.jozufozu.flywheel.core.shader.spec;
-
-import com.jozufozu.flywheel.core.shader.gamestate.GameStateProvider;
-import com.mojang.serialization.Codec;
-
-import net.minecraft.resources.ResourceLocation;
-
-public class BooleanGameStateCondition implements GameStateCondition {
-
-	public static final Codec<BooleanGameStateCondition> BOOLEAN_SUGAR = GameStateProvider.CODEC.xmap(gameContext -> {
-		if (gameContext instanceof BooleanStateProvider) {
-			return new BooleanGameStateCondition(((BooleanStateProvider) gameContext));
-		}
-
-		return null;
-	}, GameStateCondition::getStateProvider);
-	protected final BooleanStateProvider context;
-
-	public BooleanGameStateCondition(BooleanStateProvider context) {
-		this.context = context;
-	}
-
-	@Override
-	public ResourceLocation getID() {
-		return context.getID();
-	}
-
-	@Override
-	public GameStateProvider getStateProvider() {
-		return context;
-	}
-
-	@Override
-	public boolean isMet() {
-		return context.isTrue();
-	}
-}

src/main/java/com/jozufozu/flywheel/core/shader/spec/BooleanStateProvider.java

@@ -1,13 +0,0 @@
-package com.jozufozu.flywheel.core.shader.spec;
-
-import com.jozufozu.flywheel.core.shader.gamestate.GameStateProvider;
-
-public interface BooleanStateProvider extends GameStateProvider {
-
-	boolean isTrue();
-
-	@Override
-	default Boolean getValue() {
-		return isTrue();
-	}
-}

src/main/java/com/jozufozu/flywheel/core/shader/spec/GameStateCondition.java

@@ -1,14 +0,0 @@
-package com.jozufozu.flywheel.core.shader.spec;
-
-import com.jozufozu.flywheel.core.shader.gamestate.GameStateProvider;
-
-import net.minecraft.resources.ResourceLocation;
-
-public interface GameStateCondition {
-
-	ResourceLocation getID();
-
-	GameStateProvider getStateProvider();
-
-	boolean isMet();
-}

src/main/java/com/jozufozu/flywheel/core/shader/spec/ProgramState.java

@@ -1,33 +0,0 @@
-package com.jozufozu.flywheel.core.shader.spec;
-
-import java.util.Collections;
-import java.util.List;
-
-import com.jozufozu.flywheel.util.CodecUtil;
-import com.mojang.datafixers.util.Either;
-import com.mojang.serialization.Codec;
-import com.mojang.serialization.DataResult;
-import com.mojang.serialization.codecs.RecordCodecBuilder;
-
-public record ProgramState(GameStateCondition context, List<String> defines) {
-
-	// TODO: Use Codec.dispatch
-	private static final Codec<GameStateCondition> WHEN = Codec.either(BooleanGameStateCondition.BOOLEAN_SUGAR, SpecificValueCondition.CODEC)
-			.flatXmap(either -> either.map(DataResult::success, DataResult::success), any -> {
-				if (any instanceof BooleanGameStateCondition) {
-					return DataResult.success(Either.left((BooleanGameStateCondition) any));
-				}
-
-				if (any instanceof SpecificValueCondition) {
-					return DataResult.success(Either.right((SpecificValueCondition) any));
-				}
-
-				return DataResult.error("unknown context condition");
-			});
-
-	public static final Codec<ProgramState> CODEC = RecordCodecBuilder.create(state -> state.group(WHEN.fieldOf("when")
-					.forGetter(ProgramState::context), CodecUtil.oneOrMore(Codec.STRING)
-					.optionalFieldOf("define", Collections.emptyList())
-					.forGetter(ProgramState::defines))
-			.apply(state, ProgramState::new));
-}

src/main/java/com/jozufozu/flywheel/core/shader/spec/SpecificValueCondition.java

@@ -1,43 +0,0 @@
-package com.jozufozu.flywheel.core.shader.spec;
-
-import com.jozufozu.flywheel.core.shader.gamestate.GameStateProvider;
-import com.mojang.serialization.Codec;
-import com.mojang.serialization.codecs.RecordCodecBuilder;
-
-import net.minecraft.resources.ResourceLocation;
-
-public class SpecificValueCondition implements GameStateCondition {
-
-	public static final Codec<SpecificValueCondition> CODEC = RecordCodecBuilder.create(condition -> condition.group(GameStateProvider.CODEC.fieldOf("provider")
-					.forGetter(SpecificValueCondition::getStateProvider), Codec.STRING.fieldOf("value")
-					.forGetter(SpecificValueCondition::getValue))
-			.apply(condition, SpecificValueCondition::new));
-
-	private final String required;
-	private final GameStateProvider context;
-
-	public SpecificValueCondition(GameStateProvider context, String required) {
-		this.required = required;
-		this.context = context;
-	}
-
-	@Override
-	public ResourceLocation getID() {
-		return context.getID();
-	}
-
-	public String getValue() {
-		return required;
-	}
-
-	@Override
-	public GameStateProvider getStateProvider() {
-		return context;
-	}
-
-	@Override
-	public boolean isMet() {
-		return required.equals(context.getValue()
-									   .toString());
-	}
-}

src/main/java/com/jozufozu/flywheel/core/source/FileIndex.java

@@ -0,0 +1,19 @@
+package com.jozufozu.flywheel.core.source;
+
+import com.jozufozu.flywheel.core.source.span.Span;
+
+public interface FileIndex {
+	/**
+	 * Returns an arbitrary file ID for use this compilation context, or generates one if missing.
+	 *
+	 * @param sourceFile The file to retrieve the ID for.
+	 * @return A file ID unique to the given sourceFile.
+	 */
+	int getFileID(SourceFile sourceFile);
+
+	SourceFile getFile(int fileID);
+
+	default Span getLineSpan(int fileId, int lineNo) {
+		return getFile(fileId).getLineSpanNoWhitespace(lineNo);
+	}
+}

src/main/java/com/jozufozu/flywheel/core/source/FileIndexImpl.java

@@ -0,0 +1,76 @@
+package com.jozufozu.flywheel.core.source;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.annotation.Nullable;
+
+import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.core.source.error.ErrorBuilder;
+import com.jozufozu.flywheel.core.source.error.ErrorReporter;
+
+import net.minecraft.resources.ResourceLocation;
+
+public class FileIndexImpl implements FileIndex {
+	public final List<SourceFile> files = new ArrayList<>();
+
+	/**
+	 * Returns an arbitrary file ID for use this compilation context, or generates one if missing.
+	 * @param sourceFile The file to retrieve the ID for.
+	 * @return A file ID unique to the given sourceFile.
+	 */
+	@Override
+	public int getFileID(SourceFile sourceFile) {
+		int i = files.indexOf(sourceFile);
+		if (i != -1) {
+			return i;
+		}
+
+		int size = files.size();
+		files.add(sourceFile);
+		return size;
+	}
+
+	@Override
+	public SourceFile getFile(int fileId) {
+		return files.get(fileId);
+	}
+
+
+	public void printShaderInfoLog(String source, String log, ResourceLocation name) {
+		List<String> lines = log.lines()
+				.toList();
+
+		boolean needsSourceDump = false;
+
+		StringBuilder errors = new StringBuilder();
+		for (String line : lines) {
+			ErrorBuilder builder = parseCompilerError(line);
+
+			if (builder != null) {
+				errors.append(builder.build());
+			} else {
+				errors.append(line).append('\n');
+				needsSourceDump = true;
+			}
+		}
+		Backend.LOGGER.error("Errors compiling '" + name + "': \n" + errors);
+		if (needsSourceDump) {
+			// TODO: generated code gets its own "file"
+			ErrorReporter.printLines(source);
+		}
+	}
+
+	@Nullable
+	private ErrorBuilder parseCompilerError(String line) {
+		try {
+			ErrorBuilder error = ErrorBuilder.fromLogLine(this, line);
+			if (error != null) {
+				return error;
+			}
+		} catch (Exception ignored) {
+		}
+
+		return null;
+	}
+}

src/main/java/com/jozufozu/flywheel/core/source/FileResolution.java

@@ -1,13 +1,12 @@
-package com.jozufozu.flywheel.backend.source;
+package com.jozufozu.flywheel.core.source;
 
 import java.util.ArrayList;
 import java.util.List;
-
+import java.util.function.Consumer;
-import javax.annotation.Nullable;
 
 import com.jozufozu.flywheel.backend.Backend;
-import com.jozufozu.flywheel.backend.source.error.ErrorBuilder;
+import com.jozufozu.flywheel.core.source.error.ErrorBuilder;
-import com.jozufozu.flywheel.backend.source.span.Span;
+import com.jozufozu.flywheel.core.source.span.Span;
 
 import net.minecraft.resources.ResourceLocation;
 
@@ -23,13 +22,13 @@ import net.minecraft.resources.ResourceLocation;
 public class FileResolution {
 
 	/**
-	 * Spans that have references that resolved to this.
+	 * Extra info about where this resolution is required. Includes ProgramSpecs and shader Spans.
 	 */
-	private final List<Span> foundSpans = new ArrayList<>();
+	private final List<Consumer<ErrorBuilder>> extraCrashInfoProviders = new ArrayList<>();
 	private final ResourceLocation fileLoc;
 	private SourceFile file;
 
-	public FileResolution(ResourceLocation fileLoc) {
+	FileResolution(ResourceLocation fileLoc) {
 		this.fileLoc = fileLoc;
 	}
 
@@ -37,7 +36,10 @@ public class FileResolution {
 		return fileLoc;
 	}
 
-	@Nullable
+	/**
+	 * Non-null if this file is resolved because there would have been a crash otherwise.
+	 * @return The file that this resolution resolves to.
+	 */
 	public SourceFile getFile() {
 		return file;
 	}
@@ -51,34 +53,44 @@ public class FileResolution {
 	 * @param span A span where this file is referenced.
 	 */
 	public FileResolution addSpan(Span span) {
-		foundSpans.add(span);
+		extraCrashInfoProviders.add(builder -> builder.pointAtFile(span.getSourceFile())
+				.pointAt(span, 1));
 		return this;
 	}
 
+	public void addSpec(ResourceLocation name) {
+		extraCrashInfoProviders.add(builder -> builder.extra("needed by spec: " + name + ".json"));
+	}
+
 	/**
 	 * Check to see if this file actually resolves to something.
 	 *
 	 * <p>
 	 *     Called after all files are loaded. If we can't find the file here, it doesn't exist.
 	 * </p>
+	 *
+	 * @return True if this file is resolved.
 	 */
-	void resolve(SourceFinder sources) {
+	boolean resolve(SourceFinder sources) {
+		file = sources.findSource(fileLoc);
 
-		try {
+		if (file == null) {
-			file = sources.findSource(fileLoc);
-		} catch (RuntimeException error) {
 			ErrorBuilder builder = ErrorBuilder.error(String.format("could not find source for file %s", fileLoc));
-			// print the location of all places where this file was referenced
+			for (Consumer<ErrorBuilder> consumer : extraCrashInfoProviders) {
-			for (Span span : foundSpans) {
+				consumer.accept(builder);
-				builder.pointAtFile(span.getSourceFile())
-						.pointAt(span, 2);
 			}
 			Backend.LOGGER.error(builder.build());
+
+			return false;
 		}
+
+		// Let the GC do its thing
+		extraCrashInfoProviders.clear();
+		return true;
 	}
 
 	void invalidate() {
-		foundSpans.clear();
+		extraCrashInfoProviders.clear();
 		file = null;
 	}
 }

src/main/java/com/jozufozu/flywheel/core/source/Index.java

@@ -1,12 +1,12 @@
-package com.jozufozu.flywheel.backend.source;
+package com.jozufozu.flywheel.core.source;
 
 import java.util.Collection;
 import java.util.Map;
 
 import com.google.common.collect.Multimap;
 import com.google.common.collect.MultimapBuilder;
-import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
+import com.jozufozu.flywheel.core.source.parse.ShaderFunction;
-import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
+import com.jozufozu.flywheel.core.source.parse.ShaderStruct;
 
 import net.minecraft.resources.ResourceLocation;
 

src/main/java/com/jozufozu/flywheel/core/source/Resolver.java

@@ -0,0 +1,70 @@
+package com.jozufozu.flywheel.core.source;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import net.minecraft.resources.ResourceLocation;
+
+/**
+ * Manages deferred file resolution.
+ *
+ * <p>
+ *     Interns all file names in shader sources and program specs, deduplicating the final lookups and allowing for more
+ *     dev-friendly error reporting.
+ * </p>
+ *
+ * @see FileResolution
+ */
+public class Resolver {
+
+	public static final Resolver INSTANCE = new Resolver();
+
+	private final Map<ResourceLocation, FileResolution> resolutions = new HashMap<>();
+	private boolean hasRun = false;
+
+	public FileResolution get(ResourceLocation file) {
+		if (!hasRun) {
+			return resolutions.computeIfAbsent(file, FileResolution::new);
+		} else {
+			// Lock the map after resolution has run.
+			FileResolution fileResolution = resolutions.get(file);
+
+			// ...so crash immediately if the file isn't found.
+			if (fileResolution == null) {
+				throw new RuntimeException("could not find source for file: " + file);
+			}
+
+			return fileResolution;
+		}
+	}
+
+	/**
+	 * Try and resolve all referenced source files, printing errors if any aren't found.
+	 */
+	public void run(SourceFinder sources) {
+		boolean needsCrash = false;
+		for (FileResolution resolution : resolutions.values()) {
+			if (!resolution.resolve(sources)) {
+				needsCrash = true;
+			}
+		}
+
+		if (needsCrash) {
+			throw new ShaderLoadingException("Failed to resolve all source files, see log for details");
+		}
+
+		hasRun = true;
+	}
+
+	/**
+	 * Invalidates all FileResolutions.
+	 *
+	 * <p>
+	 *     Called on resource reload.
+	 * </p>
+	 */
+	public void invalidate() {
+		resolutions.values().forEach(FileResolution::invalidate);
+		hasRun = false;
+	}
+}

src/main/java/com/jozufozu/flywheel/core/source/ShaderLoadingException.java

@@ -0,0 +1,11 @@
+package com.jozufozu.flywheel.core.source;
+
+public class ShaderLoadingException extends RuntimeException {
+
+	public ShaderLoadingException() {
+	}
+
+	public ShaderLoadingException(String message) {
+		super(message);
+	}
+}

src/main/java/com/jozufozu/flywheel/core/source/ShaderSources.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.source;
+package com.jozufozu.flywheel.core.source;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -6,6 +6,8 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 
+import javax.annotation.Nullable;
+
 import com.google.common.collect.Lists;
 import com.jozufozu.flywheel.util.ResourceUtil;
 import com.jozufozu.flywheel.util.StringUtil;
@@ -51,13 +53,9 @@ public class ShaderSources implements SourceFinder {
 	}
 
 	@Override
+	@Nullable
 	public SourceFile findSource(ResourceLocation name) {
-		SourceFile source = shaderSources.get(name);
 
-		if (source == null) {
+		return shaderSources.get(name);
-			throw new ShaderLoadingException(String.format("shader '%s' does not exist", name));
-		}
-
-		return source;
 	}
 }

src/main/java/com/jozufozu/flywheel/core/source/SourceFile.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.source;
+package com.jozufozu.flywheel.core.source;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -10,12 +10,12 @@ import java.util.regex.Pattern;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import com.jozufozu.flywheel.backend.source.parse.Import;
+import com.jozufozu.flywheel.core.source.parse.Import;
-import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
+import com.jozufozu.flywheel.core.source.parse.ShaderFunction;
-import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
+import com.jozufozu.flywheel.core.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.source.span.ErrorSpan;
+import com.jozufozu.flywheel.core.source.span.ErrorSpan;
-import com.jozufozu.flywheel.backend.source.span.Span;
+import com.jozufozu.flywheel.core.source.span.Span;
-import com.jozufozu.flywheel.backend.source.span.StringSpan;
+import com.jozufozu.flywheel.core.source.span.StringSpan;
 
 import net.minecraft.resources.ResourceLocation;
 
@@ -74,6 +74,23 @@ public class SourceFile {
 		this.elided = elideSource(source, elisions).toString();
 	}
 
+	public Span getLineSpan(int line) {
+		int begin = lines.getLineStart(line);
+		int end = begin + lines.getLine(line).length();
+		return new StringSpan(this, lines.getCharPos(begin), lines.getCharPos(end));
+	}
+
+	public Span getLineSpanNoWhitespace(int line) {
+		int begin = lines.getLineStart(line);
+		int end = begin + lines.getLine(line).length();
+
+		while (begin < end && Character.isWhitespace(source.charAt(begin))) {
+			begin++;
+		}
+
+		return new StringSpan(this, lines.getCharPos(begin), lines.getCharPos(end));
+	}
+
 	/**
 	 * Search this file and recursively search all imports to find a struct definition matching the given name.
 	 *
@@ -120,30 +137,23 @@ public class SourceFile {
 		return "#use " + '"' + name + '"';
 	}
 
-	public CharSequence generateFinalSource() {
+	public void generateFinalSource(FileIndex env, StringBuilder source) {
-		StringBuilder builder = new StringBuilder();
-		generateFinalSource(builder);
-		return builder;
-	}
-
-	public void generateFinalSource(StringBuilder source) {
 		for (Import include : imports) {
 			SourceFile file = include.getFile();
 
-			if (file != null) file.generateFinalSource(source);
+			if (file != null) file.generateFinalSource(env, source);
 		}
+
+		source.append("#line ")
+				.append(0)
+				.append(' ')
+				.append(env.getFileID(this))
+				.append('\n');
 		source.append(elided);
 	}
 
 	public String printSource() {
-		StringBuilder builder = new StringBuilder();
+		return "Source for shader '" + name + "':\n" + lines.printLinesWithNumbers();
-
-		builder.append("Source for shader '")
-				.append(name)
-				.append("':\n")
-				.append(lines.printLinesWithNumbers());
-
-		return builder.toString();
 	}
 
 	private static CharSequence elideSource(String source, List<Span> elisions) {
@@ -257,4 +267,8 @@ public class SourceFile {
 		return -1;
 	}
 
+	@Override
+	public String toString() {
+		return name.toString();
+	}
 }

src/main/java/com/jozufozu/flywheel/core/source/SourceFinder.java

@@ -1,4 +1,6 @@
-package com.jozufozu.flywheel.backend.source;
+package com.jozufozu.flywheel.core.source;
+
+import javax.annotation.Nullable;
 
 import net.minecraft.resources.ResourceLocation;
 
@@ -8,5 +10,6 @@ import net.minecraft.resources.ResourceLocation;
 @FunctionalInterface
 public interface SourceFinder {
 
+	@Nullable
 	SourceFile findSource(ResourceLocation name);
 }

src/main/java/com/jozufozu/flywheel/core/source/SourceLines.java

@@ -1,10 +1,10 @@
-package com.jozufozu.flywheel.backend.source;
+package com.jozufozu.flywheel.core.source;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.source.span.CharPos;
+import com.jozufozu.flywheel.core.source.span.CharPos;
 import com.jozufozu.flywheel.util.StringUtil;
 
 import it.unimi.dsi.fastutil.ints.IntArrayList;
@@ -29,6 +29,48 @@ public class SourceLines {
 		this.lines = getLines(source, lineStarts);
 	}
 
+	public int getLineCount() {
+		return lines.size();
+	}
+
+	public String getLine(int lineNo) {
+		return lines.get(lineNo);
+	}
+
+	public int getLineStart(int lineNo) {
+
+		return lineStarts.getInt(lineNo);
+	}
+
+	public CharPos getCharPos(int charPos) {
+		int lineNo = 0;
+		for (; lineNo < lineStarts.size(); lineNo++) {
+			int ls = lineStarts.getInt(lineNo);
+
+			if (charPos < ls) {
+				break;
+			}
+		}
+
+		lineNo -= 1;
+
+		int lineStart = lineStarts.getInt(lineNo);
+
+		return new CharPos(charPos, lineNo, charPos - lineStart);
+	}
+
+	public String printLinesWithNumbers() {
+		StringBuilder builder = new StringBuilder();
+
+		for (int i = 0, linesSize = lines.size(); i < linesSize; i++) {
+			builder.append(String.format("%1$4s: ", i + 1))
+					.append(lines.get(i))
+					.append('\n');
+		}
+
+		return builder.toString();
+	}
+
 	/**
 	 * Scan the source for line breaks, recording the position of the first character of each line.
 	 * @param source
@@ -57,41 +99,4 @@ public class SourceLines {
 
 		return builder.build();
 	}
-
-	public CharPos getCharPos(int charPos) {
-		int lineNo = 0;
-		for (; lineNo < lineStarts.size(); lineNo++) {
-			int ls = lineStarts.getInt(lineNo);
-
-			if (charPos < ls) {
-				break;
-			}
-		}
-
-		lineNo -= 1;
-
-		int lineStart = lineStarts.getInt(lineNo);
-
-		return new CharPos(charPos, lineNo, charPos - lineStart);
-	}
-
-	public int getLineCount() {
-		return lines.size();
-	}
-
-	public String getLine(int lineNo) {
-		return lines.get(lineNo);
-	}
-
-	public String printLinesWithNumbers() {
-		StringBuilder builder = new StringBuilder();
-
-		for (int i = 0, linesSize = lines.size(); i < linesSize; i++) {
-			builder.append(String.format("%1$4s: ", i + 1))
-					.append(lines.get(i))
-					.append('\n');
-		}
-
-		return builder.toString();
-	}
 }

src/main/java/com/jozufozu/flywheel/core/source/error/ErrorBuilder.java

@@ -0,0 +1,141 @@
+package com.jozufozu.flywheel.core.source.error;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import javax.annotation.Nullable;
+
+import com.jozufozu.flywheel.core.source.FileIndex;
+import com.jozufozu.flywheel.core.source.SourceFile;
+import com.jozufozu.flywheel.core.source.SourceLines;
+import com.jozufozu.flywheel.core.source.error.lines.ErrorLine;
+import com.jozufozu.flywheel.core.source.error.lines.FileLine;
+import com.jozufozu.flywheel.core.source.error.lines.HeaderLine;
+import com.jozufozu.flywheel.core.source.error.lines.SourceLine;
+import com.jozufozu.flywheel.core.source.error.lines.SpanHighlightLine;
+import com.jozufozu.flywheel.core.source.error.lines.TextLine;
+import com.jozufozu.flywheel.core.source.span.Span;
+import com.jozufozu.flywheel.util.FlwUtil;
+
+public class ErrorBuilder {
+
+	private static final Pattern ERROR_LINE = Pattern.compile("(\\d+)\\((\\d+)\\) : (.*)");
+
+	private final List<ErrorLine> lines = new ArrayList<>();
+
+	public ErrorBuilder() {
+
+	}
+
+	public static ErrorBuilder error(CharSequence msg) {
+		return new ErrorBuilder()
+				.header(ErrorLevel.ERROR, msg);
+	}
+
+	public static ErrorBuilder compError(CharSequence msg) {
+		return new ErrorBuilder()
+				.extra(msg);
+	}
+
+	public static ErrorBuilder warn(CharSequence msg) {
+		return new ErrorBuilder()
+				.header(ErrorLevel.WARN, msg);
+	}
+
+	@Nullable
+	public static ErrorBuilder fromLogLine(FileIndex env, String s) {
+		Matcher matcher = ERROR_LINE.matcher(s);
+
+		if (matcher.find()) {
+			String fileId = matcher.group(1);
+			String lineNo = matcher.group(2);
+			String msg = matcher.group(3);
+			Span span = env.getLineSpan(Integer.parseInt(fileId), Integer.parseInt(lineNo));
+			return ErrorBuilder.compError(msg)
+					.pointAtFile(span.getSourceFile())
+					.pointAt(span, 1);
+		} else {
+			return null;
+		}
+	}
+
+	public ErrorBuilder header(ErrorLevel level, CharSequence msg) {
+		lines.add(new HeaderLine(level.toString(), msg));
+		return this;
+	}
+
+	public ErrorBuilder extra(CharSequence msg) {
+		lines.add(new TextLine(msg.toString()));
+		return this;
+	}
+
+	public ErrorBuilder pointAtFile(SourceFile file) {
+		lines.add(new FileLine(file.name.toString()));
+		return this;
+	}
+
+	public ErrorBuilder hintIncludeFor(@Nullable Span span, CharSequence msg) {
+		if (span == null) return this;
+		SourceFile sourceFile = span.getSourceFile();
+
+		String builder = "add " + sourceFile.importStatement() + ' ' + msg + "\n defined here:";
+
+		header(ErrorLevel.HINT, builder);
+
+		return this.pointAtFile(sourceFile)
+				.pointAt(span, 0);
+	}
+
+	public ErrorBuilder pointAt(Span span, int ctxLines) {
+
+		if (span.lines() == 1) {
+			SourceLines lines = span.getSourceFile().lines;
+
+			int spanLine = span.firstLine();
+
+			int firstLine = Math.max(0, spanLine - ctxLines);
+			int lastLine = Math.min(lines.getLineCount(), spanLine + ctxLines);
+
+            int firstCol = span.getStart()
+                    .col();
+            int lastCol = span.getEnd()
+                    .col();
+
+			for (int i = firstLine; i <= lastLine; i++) {
+				CharSequence line = lines.getLine(i);
+
+				this.lines.add(SourceLine.numbered(i + 1, line.toString()));
+
+				if (i == spanLine) {
+					this.lines.add(new SpanHighlightLine(firstCol, lastCol));
+				}
+			}
+		}
+
+		return this;
+	}
+
+	public CharSequence build() {
+
+		int maxLength = -1;
+		for (ErrorLine line : lines) {
+			int length = line.neededMargin();
+
+			if (length > maxLength) maxLength = length;
+		}
+
+		StringBuilder builder = new StringBuilder();
+		builder.append('\n');
+		for (ErrorLine line : lines) {
+			int length = line.neededMargin();
+
+			builder.append(FlwUtil.repeatChar(' ', maxLength - length))
+					.append(line.build())
+					.append('\n');
+		}
+
+		return builder;
+	}
+}

src/main/java/com/jozufozu/flywheel/core/source/error/ErrorLevel.java

@@ -1,13 +1,14 @@
-package com.jozufozu.flywheel.backend.source.error;
+package com.jozufozu.flywheel.core.source.error;
 
-public enum Level {
+public enum ErrorLevel {
 	WARN("warn"),
 	ERROR("error"),
+	HINT("hint"),
 	;
 
 	private final String error;
 
-	Level(String error) {
+	ErrorLevel(String error) {
 		this.error = error;
 	}
 

src/main/java/com/jozufozu/flywheel/core/source/error/ErrorReporter.java

@@ -1,12 +1,15 @@
-package com.jozufozu.flywheel.backend.source.error;
+package com.jozufozu.flywheel.core.source.error;
 
+import java.util.List;
 import java.util.Optional;
 
+import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.backend.Backend;
-import com.jozufozu.flywheel.backend.source.SourceFile;
+import com.jozufozu.flywheel.core.source.SourceFile;
-import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
+import com.jozufozu.flywheel.core.source.parse.ShaderFunction;
-import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
+import com.jozufozu.flywheel.core.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.source.span.Span;
+import com.jozufozu.flywheel.core.source.span.Span;
+import com.jozufozu.flywheel.util.FlwUtil;
 
 public class ErrorReporter {
 
@@ -42,7 +45,7 @@ public class ErrorReporter {
 
 		ErrorBuilder error = ErrorBuilder.error(msg)
 				.pointAtFile(file)
-				.pointAt(vertexName, 2)
+				.pointAt(vertexName, 1)
 				.hintIncludeFor(span.orElse(null), hint);
 
 		Backend.LOGGER.error(error.build());
@@ -64,4 +67,29 @@ public class ErrorReporter {
 
 		Backend.LOGGER.error(error.build());
 	}
+
+	public static void printLines(CharSequence source) {
+		String string = source.toString();
+
+		List<String> lines = string.lines()
+				.toList();
+
+		int size = lines.size();
+
+		int maxWidth = FlwUtil.numDigits(size) + 1;
+
+		StringBuilder builder = new StringBuilder().append('\n');
+
+		for (int i = 0; i < size; i++) {
+
+			builder.append(i)
+					.append(FlwUtil.repeatChar(' ', maxWidth - FlwUtil.numDigits(i)))
+					.append("| ")
+					.append(lines.get(i))
+					.append('\n');
+		}
+
+		Flywheel.LOGGER.error(builder.toString());
+	}
+
 }

src/main/java/com/jozufozu/flywheel/core/source/error/lines/Divider.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.source.error.lines;
+package com.jozufozu.flywheel.core.source.error.lines;
 
 public enum Divider {
 	BAR(" | "),

src/main/java/com/jozufozu/flywheel/core/source/error/lines/ErrorLine.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.source.error.lines;
+package com.jozufozu.flywheel.core.source.error.lines;
 
 public interface ErrorLine {
 
@@ -14,6 +14,10 @@ public interface ErrorLine {
 		return left() + divider() + right();
 	}
 
-	String left();
+	default String left() {
-	String right();
+		return "";
+	}
+	default String right() {
+		return "";
+	}
 }

src/main/java/com/jozufozu/flywheel/core/source/error/lines/FileLine.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.source.error.lines;
+package com.jozufozu.flywheel.core.source.error.lines;
 
 public record FileLine(String fileName) implements ErrorLine {
 

src/main/java/com/jozufozu/flywheel/core/source/error/lines/HeaderLine.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.source.error.lines;
+package com.jozufozu.flywheel.core.source.error.lines;
 
 public record HeaderLine(String level, CharSequence message) implements ErrorLine {
 
@@ -11,14 +11,4 @@ public record HeaderLine(String level, CharSequence message) implements ErrorLin
 	public String build() {
 		return level + ": " + message;
 	}
-
-	@Override
-	public String left() {
-		return null;
-	}
-
-	@Override
-	public String right() {
-		return null;
-	}
 }