Shader sanity

- Drastically lower shader boilerplate for instance materials
 - Somewhat lower boilerplate for contexts
 - VertexTypes are responsible for shader headers
 - Better shader compiler errors (at least on nvidia)
 - Simplify template classes
 - Begin work on lazy shader compilation

src/main/java/com/jozufozu/flywheel/api/shader/FlexibleShader.java

@@ -0,0 +1,15 @@
+package com.jozufozu.flywheel.api.shader;
+
+import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
+
+/**
+ * Represents a vertex format agnostic shader.
+ */
+public interface FlexibleShader<P extends GlProgram> {
+
+	/**
+	 * Get a version of this shader that accepts the given VertexType as input.
+	 */
+	P get(VertexType type);
+}

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

@@ -39,4 +39,6 @@ public interface VertexType {
 	default int byteOffset(int vertexIndex) {
 		return getStride() * vertexIndex;
 	}
+
+	String writeShaderHeader();
 }

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

@@ -115,7 +115,7 @@ public class Backend {
 
 		enabled = switch (engine) {
 			case OFF -> false;
-			case BATCHING -> !usingShaders;
+			case BATCHING -> true;
 			case INSTANCING -> !usingShaders && compat.instancedArraysSupported();
 		};
 	}

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

@@ -1,19 +1,19 @@
 package com.jozufozu.flywheel.backend;
 
-import java.util.function.Supplier;
-
+import com.jozufozu.flywheel.api.shader.FlexibleShader;
+import com.jozufozu.flywheel.api.vertex.VertexType;
 import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
 
 import net.minecraft.resources.ResourceLocation;
 
 public interface ShaderContext<P extends GlProgram> {
 
-	default P getProgram(ResourceLocation loc) {
+	default P getProgram(ResourceLocation loc, VertexType inputType) {
 		return this.getProgramSupplier(loc)
-				.get();
+				.get(inputType);
 	}
 
-	Supplier<P> getProgramSupplier(ResourceLocation loc);
+	FlexibleShader<P> getProgramSupplier(ResourceLocation loc);
 
 	/**
 	 * Load all programs associated with this context. This might be just one, if the context is very specialized.

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() {
-		return this.displayName;
+	public String getTypeName() {
+		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();
-			offset += spec.getSize();
+			startIndex += spec.attributeCount();
+			offset += spec.size();
 		}
 	}
 

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

@@ -1,10 +1,16 @@
 package com.jozufozu.flywheel.backend.gl.shader;
 
+import java.util.List;
+
 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.backend.pipeline.ShaderCompiler;
+import com.jozufozu.flywheel.backend.source.ShaderLoadingException;
+import com.jozufozu.flywheel.backend.source.error.ErrorBuilder;
+import com.jozufozu.flywheel.backend.source.error.ErrorReporter;
 
 import net.minecraft.resources.ResourceLocation;
 
@@ -13,8 +19,8 @@ public class GlShader extends GlObject {
 	public final ResourceLocation name;
 	public final ShaderType type;
 
-	public GlShader(ResourceLocation name, ShaderType type, CharSequence source) {
-		this.name = name;
+	public GlShader(ShaderCompiler env, ShaderType type, String source) {
+		name = env.name;
 		this.type = type;
 		int handle = GL20.glCreateShader(type.glEnum);
 
@@ -24,13 +30,31 @@ public class GlShader extends GlObject {
 		String log = GL20.glGetShaderInfoLog(handle);
 
 		if (!log.isEmpty()) {
-			Backend.log.error("Shader compilation log for " + name + ": " + log);
-			Backend.log.error(source);
+			List<String> lines = log.lines()
+					.toList();
+
+			boolean needsSourceDump = false;
+
+			StringBuilder errors = new StringBuilder();
+			for (String line : lines) {
+				ErrorBuilder builder = env.parseCompilerError(line);
+
+				if (builder != null) {
+					errors.append(builder.build());
+				} else {
+					errors.append(line).append('\n');
+					needsSourceDump = true;
+				}
+			}
+			Backend.log.error("Errors compiling '" + name + "': \n" + errors);
+			if (needsSourceDump) {
+				// TODO: generated code gets its own "file"
+				ErrorReporter.printLines(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);

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 Cache<Object, GPUInstancer<D>> models;
+	protected final ModelAllocator allocator;
+	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;
-
-		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();
+		this.allocator = allocator;
 	}
 
 	/**
@@ -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.get(key, () -> new GPUInstancer<>(type, modelSupplier.get(), allocator));
-		} catch (ExecutionException e) {
-			throw new RuntimeException("error creating instancer", e);
-		}
+		return models.computeIfAbsent(key, $ -> {
+			GPUInstancer<D> instancer = new GPUInstancer<>(type, modelSupplier.get(), allocator);
+			uninitialized.add(instancer);
+			return instancer;
+		});
 	}
 
 	public boolean nothingToRender() {
-		return models.size() > 0 && models.asMap()
-				.values()
+		return models.size() > 0 && models.values()
 				.stream()
 				.allMatch(GPUInstancer::isEmpty);
 	}
 
 	public void delete() {
-		models.invalidateAll();
-		if (allocator instanceof ModelPool pool) pool.delete();
+		models.values().forEach(GPUInstancer::delete);
+		models.clear();
 	}
 
 	/**
 	 * Clear all instance data without freeing resources.
 	 */
 	public void clear() {
-		models.asMap()
-				.values()
+		models.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 +7,11 @@ 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.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.shader.WorldProgram;
 import com.jozufozu.flywheel.util.Textures;
 import com.mojang.math.Matrix4f;
@@ -27,17 +30,23 @@ 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.getInstance().compat.onAMDWindows()) {
+			this.allocator = ImmediateAllocator.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.");
 		}
@@ -51,25 +60,25 @@ public class InstancedMaterialGroup<P extends WorldProgram> implements MaterialG
 	}
 
 	protected void renderAll(Matrix4f viewProjection, double camX, double camY, double camZ) {
+		// 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()
-					.values();
-
-			// 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();
+			P program = owner.context.getProgram(entry.getKey()
+					.getProgramSpec(), Formats.POS_TEX_NORMAL);
 
 			program.bind();
 			program.uploadViewProjection(viewProjection);
@@ -77,7 +86,7 @@ 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

@@ -3,17 +3,17 @@ 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;
 
 import com.jozufozu.flywheel.api.MaterialGroup;
-import com.jozufozu.flywheel.backend.instancing.TaskEngine;
+import com.jozufozu.flywheel.api.shader.FlexibleShader;
 import com.jozufozu.flywheel.backend.RenderLayer;
 import com.jozufozu.flywheel.backend.gl.GlVertexArray;
 import com.jozufozu.flywheel.backend.gl.buffer.GlBufferType;
 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.shader.WorldProgram;
 import com.jozufozu.flywheel.event.RenderLayerEvent;
@@ -126,7 +126,7 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 		}
 	}
 
-	public Supplier<P> getProgram(ResourceLocation name) {
+	public FlexibleShader<P> getProgram(ResourceLocation name) {
 		return context.getProgramSupplier(name);
 	}
 

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/InstancingTemplateData.java

@@ -3,15 +3,17 @@ package com.jozufozu.flywheel.backend.pipeline;
 import java.util.Optional;
 
 import com.google.common.collect.ImmutableList;
+import com.jozufozu.flywheel.api.vertex.VertexType;
 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.StructField;
 import com.jozufozu.flywheel.backend.source.parse.Variable;
 import com.jozufozu.flywheel.backend.source.span.Span;
 
-public class InstancingProgramMetaData {
+public class InstancingTemplateData implements TemplateData {
 
 	public final SourceFile file;
 	public final ShaderFunction vertexMain;
@@ -20,10 +22,9 @@ public class InstancingProgramMetaData {
 	public final Span vertexName;
 	public final Span instanceName;
 	public final ShaderStruct interpolant;
-	public final ShaderStruct vertex;
 	public final ShaderStruct instance;
 
-	public InstancingProgramMetaData(SourceFile file) {
+	public InstancingTemplateData(SourceFile file) {
 		this.file = file;
 
 		Optional<ShaderFunction> vertexFunc = file.findFunction("vertex");
@@ -54,20 +55,25 @@ public class InstancingProgramMetaData {
 			throw new ShaderLoadingException();
 		}
 
-		interpolantName = vertexMain.getType();
-		vertexName = vertexParams.get(0)
-				.typeName();
-		instanceName = vertexParams.get(1)
-				.typeName();
+		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();
+		}
+
+		interpolantName = parameters.get(0).type;
+		instanceName = vertexParams.get(1).type;
 
 		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");
 		}
@@ -76,12 +82,74 @@ public class InstancingProgramMetaData {
 			ErrorReporter.generateMissingStruct(file, instanceName, "struct not defined");
 		}
 
-		if (maybeVertex.isEmpty() || maybeInterpolant.isEmpty() || maybeInstance.isEmpty()) {
+		if (maybeInterpolant.isEmpty() || maybeInstance.isEmpty()) {
 			throw new ShaderLoadingException();
 		}
 
 		interpolant = maybeInterpolant.get();
-		vertex = maybeVertex.get();
 		instance = maybeInstance.get();
 	}
+
+	public void vertexFooter(StringBuilder template, ShaderCompiler shader) {
+		ImmutableList<StructField> fields = instance.getFields();
+		VertexType vertexType = shader.vertexType;
+
+		int attributeBinding = vertexType.getLayout()
+				.getAttributeCount();
+
+		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 += ShaderInput.from(field).attribCount;
+		}
+		Template.prefixFields(template, interpolant, "out", "v2f_");
+
+		template.append(String.format("""
+						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,
+				Template.assignFields(instance, "i.", "a_i_")
+		));
+	}
+
+	public void fragmentFooter(StringBuilder template, ShaderCompiler shader) {
+		Template.prefixFields(template, interpolant, "in", "v2f_");
+
+		template.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")
+		));
+	}
 }

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

@@ -0,0 +1,33 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.jozufozu.flywheel.api.shader.FlexibleShader;
+import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.core.shader.ContextAwareProgram;
+import com.jozufozu.flywheel.core.shader.WorldProgram;
+import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
+
+public class LazyCompiler<P extends WorldProgram> implements FlexibleShader<P> {
+
+	private final ShaderPipeline<P> pipeline;
+	private final ProgramSpec spec;
+
+	private final Map<VertexType, ContextAwareProgram<P>> cache = new HashMap<>();
+
+	public LazyCompiler(ShaderPipeline<P> pipeline, ProgramSpec spec) {
+
+		this.pipeline = pipeline;
+		this.spec = spec;
+	}
+
+	public void delete() {
+		cache.values().forEach(ContextAwareProgram::delete);
+	}
+
+	@Override
+	public P get(VertexType type) {
+		return cache.computeIfAbsent(type, t -> pipeline.compile(spec, t)).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/OneShotTemplateData.java

@@ -3,6 +3,7 @@ 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;
@@ -10,17 +11,15 @@ 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 class OneShotTemplateData implements TemplateData {
 
 	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) {
+	public OneShotTemplateData(SourceFile file) {
 		this.file = file;
 
 		Optional<ShaderFunction> maybeVertexMain = file.findFunction("vertex");
@@ -55,24 +54,67 @@ public class OneShotProgramMetaData {
 			throw new RuntimeException();
 		}
 
-		interpolantName = vertexMain.getType();
-		vertexName = vertexParameters.get(0)
-				.typeName();
+		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();
+		}
+
+		interpolantName = fragmentMain.getParameters().get(0).type;
 
 		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())
+		if (maybeInterpolant.isEmpty()) {
 			ErrorReporter.generateMissingStruct(file, interpolantName, "struct not defined");
 
-		if (maybeVertex.isEmpty() || maybeInterpolant.isEmpty()) {
 			throw new RuntimeException();
 		}
 
 		interpolant = maybeInterpolant.get();
-		vertex = maybeVertex.get();
+	}
+
+    public void vertexFooter(StringBuilder template, ShaderCompiler file) {
+		Template.prefixFields(template, interpolant, "out", "v2f_");
+
+		template.append("""
+						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
+						}
+						""");
+    }
+
+	public void fragmentFooter(StringBuilder template, ShaderCompiler file) {
+		Template.prefixFields(template, interpolant, "in", "v2f_");
+
+		template.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")
+		));
 	}
 }

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

@@ -3,7 +3,6 @@ package com.jozufozu.flywheel.backend.pipeline;
 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;
@@ -13,44 +12,33 @@ import java.util.List;
 
 import com.jozufozu.flywheel.backend.Backend;
 import com.jozufozu.flywheel.backend.gl.shader.GlShader;
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
+import com.jozufozu.flywheel.core.shader.ExtensibleGlProgram;
+import com.jozufozu.flywheel.core.shader.WorldProgram;
 
 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 ProtoProgram(WorldShader parent) {
-		this.parent = parent;
+	public ProgramAssembler(ResourceLocation name) {
+		this.name = name;
 		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() {
-
-		parent.template.getShaderInputs(parent.mainFile)
-				.forEach(this::addAttribute);
-
+	public ProgramAssembler link() {
 		glLinkProgram(this.program);
 
 		String log = glGetProgramInfoLog(this.program);
 
 		if (!log.isEmpty()) {
-			Backend.log.debug("Program link log for " + parent.name + ": " + log);
+			Backend.log.debug("Program link log for " + name + ": " + log);
 		}
 
 		int result = glGetProgrami(this.program, GL_LINK_STATUS);
@@ -62,19 +50,18 @@ 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) {
-		glBindAttribLocation(this.program, attributeIndex, shaderInput.name);
-		attributeIndex += shaderInput.attribCount;
+	public <P extends WorldProgram> P build(ExtensibleGlProgram.Factory<P> factory) {
+		return factory.create(name, program);
 	}
-
 }

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

@@ -0,0 +1,145 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.annotation.Nullable;
+
+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.backend.source.FileResolution;
+import com.jozufozu.flywheel.backend.source.SourceFile;
+import com.jozufozu.flywheel.backend.source.error.ErrorBuilder;
+import com.jozufozu.flywheel.backend.source.span.Span;
+import com.jozufozu.flywheel.core.shader.ExtensibleGlProgram;
+import com.jozufozu.flywheel.core.shader.WorldProgram;
+import com.jozufozu.flywheel.core.shader.spec.ProgramState;
+
+import net.minecraft.resources.ResourceLocation;
+
+public class ShaderCompiler {
+
+	public final ResourceLocation name;
+	public final Template<?> template;
+	private final FileResolution header;
+
+	@Nullable
+	private ProgramState variant;
+
+	public final VertexType vertexType;
+
+	public SourceFile mainFile;
+
+	public ShaderCompiler(ResourceLocation name, SourceFile mainSource, Template<?> template, FileResolution header, VertexType vertexType) {
+		this.name = name;
+		this.template = template;
+		this.header = header;
+		this.mainFile = mainSource;
+		this.vertexType = vertexType;
+	}
+
+	public ShaderCompiler setMainSource(SourceFile file) {
+		if (mainFile == file) return this;
+
+		mainFile = file;
+
+		return this;
+	}
+
+	public GlShader compile(ShaderType type) {
+
+		StringBuilder finalSource = new StringBuilder();
+
+		finalSource.append("#version ")
+				.append(template.getVersion())
+				.append('\n')
+				.append("#extension GL_ARB_explicit_attrib_location : enable\n")
+				.append("#extension GL_ARB_conservative_depth : enable\n")
+				.append("#define ")
+				.append(type.define) // special case shader type declaration
+				.append('\n');
+
+		ProgramState variant = getVariant();
+		if (variant != null) {
+			for (String def : variant.defines()) {
+				finalSource.append("#define ")
+						.append(def)
+						.append('\n');
+			}
+		}
+
+		if (type == ShaderType.VERTEX) {
+			finalSource.append("""
+					struct Vertex {
+					    vec3 pos;
+					    vec4 color;
+					    vec2 texCoords;
+					    vec2 light;
+					    vec3 normal;
+					};
+					""");
+			finalSource.append(vertexType.writeShaderHeader());
+		}
+
+		files.clear();
+		if (header.getFile() != null) {
+			header.getFile().generateFinalSource(this, finalSource);
+		}
+		mainFile.generateFinalSource(this, finalSource);
+
+		template.getMetadata(mainFile).generateFooter(finalSource, type, this);
+
+		return new GlShader(this, type, finalSource.toString());
+	}
+
+	@Nullable
+	public ProgramState getVariant() {
+		return variant;
+	}
+
+	public void setVariant(@Nullable ProgramState variant) {
+		this.variant = variant;
+	}
+
+	private final List<SourceFile> files = new ArrayList<>();
+
+	public int allocateFile(SourceFile sourceFile) {
+		int i = files.indexOf(sourceFile);
+		if (i != -1) {
+			return i;
+		}
+
+		int size = files.size();
+		files.add(sourceFile);
+		return size;
+	}
+
+	public Span getLineSpan(int fileId, int lineNo) {
+		SourceFile file = files.get(fileId);
+
+		return file.getLineSpanNoWhitespace(lineNo);
+	}
+
+	@Nullable
+	public ErrorBuilder parseCompilerError(String line) {
+		try {
+			ErrorBuilder error = ErrorBuilder.fromLogLine(this, line);
+			if (error != null) {
+				return error;
+			}
+		} catch (Exception ignored) {
+		}
+
+		return null;
+	}
+
+	public <P extends WorldProgram> P compile(ExtensibleGlProgram.Factory<P> worldShaderPipeline) {
+		return new ProgramAssembler(this.name)
+				.attachShader(compile(ShaderType.VERTEX))
+				.attachShader(compile(ShaderType.FRAGMENT))
+				.link()
+				.deleteLinkedShaders()
+				.build(worldShaderPipeline);
+	}
+}

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

@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.backend.pipeline;
 
+import com.jozufozu.flywheel.api.vertex.VertexType;
 import com.jozufozu.flywheel.core.shader.ContextAwareProgram;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
 import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
@@ -10,6 +11,6 @@ import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
  */
 public interface ShaderPipeline<P extends WorldProgram> {
 
-	ContextAwareProgram<P> compile(ProgramSpec spec);
+	ContextAwareProgram<P> compile(ProgramSpec spec, VertexType vertexType);
 
 }

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

@@ -1,13 +1,11 @@
 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;
@@ -21,37 +19,25 @@ import com.jozufozu.flywheel.backend.source.parse.StructField;
  * </p>
  * @param <D> Holds metadata, generates errors.
  */
-public abstract class Template<D> {
+public class Template<D extends TemplateData> {
 
 	private final Map<SourceFile, D> metadata = new HashMap<>();
 
 	private final Function<SourceFile, D> reader;
+	private final GLSLVersion glslVersion;
 
-	protected Template(Function<SourceFile, D> reader) {
+	public Template(GLSLVersion glslVersion, Function<SourceFile, D> reader) {
 		this.reader = reader;
+		this.glslVersion = glslVersion;
 	}
 
-	/**
-	 * 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;
+		return glslVersion;
 	}
 
 	public static void prefixFields(StringBuilder builder, ShaderStruct struct, String qualifier, String prefix) {
@@ -68,9 +54,11 @@ public abstract class Template<D> {
 		}
 	}
 
-	public static void assignFields(StringBuilder builder, ShaderStruct struct, String prefix1, String prefix2) {
+	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)
@@ -79,5 +67,7 @@ public abstract class Template<D> {
 					.append(field.name)
 					.append(";\n");
 		}
+
+		return builder;
 	}
 }

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

@@ -0,0 +1,23 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
+
+public interface TemplateData {
+	void vertexFooter(StringBuilder builder, ShaderCompiler file);
+	void fragmentFooter(StringBuilder builder, ShaderCompiler file);
+
+	/**
+	 * Generate the necessary glue code here.
+	 *
+	 * @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.
+	 */
+	default void generateFooter(StringBuilder builder, ShaderType type, ShaderCompiler file) {
+		if (type == ShaderType.VERTEX) {
+			vertexFooter(builder, file);
+		} else if (type == ShaderType.FRAGMENT) {
+			fragmentFooter(builder, file);
+		}
+	}
+}

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

@@ -1,10 +1,6 @@
 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.api.vertex.VertexType;
 import com.jozufozu.flywheel.backend.source.FileResolution;
 import com.jozufozu.flywheel.backend.source.SourceFile;
 import com.jozufozu.flywheel.core.shader.ContextAwareProgram;
@@ -14,8 +10,6 @@ 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;
@@ -29,38 +23,18 @@ public class WorldShaderPipeline<P extends WorldProgram> implements ShaderPipeli
 		this.header = header;
 	}
 
-	public ContextAwareProgram<P> compile(ProgramSpec spec) {
+	public ContextAwareProgram<P> compile(ProgramSpec spec, VertexType vertexType) {
 
 		SourceFile file = spec.getSource().getFile();
 
-		return compile(spec.name, file, spec.getStates());
-	}
+		ShaderCompiler shader = new ShaderCompiler(spec.name, file, template, header, vertexType);
 
-	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));
+		GameStateProgram.Builder<P> builder = GameStateProgram.builder(shader.compile(this.factory));
+		for (ProgramState variant : spec.getStates()) {
+			shader.setVariant(variant);
+			builder.withVariant(variant.context(), shader.compile(this.factory));
 		}
 
 		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/FileResolution.java

@@ -62,16 +62,15 @@ public class FileResolution {
 	 *     Called after all files are loaded. If we can't find the file here, it doesn't exist.
 	 * </p>
 	 */
-	void resolve(ISourceHolder sources) {
+	void resolve(SourceFinder sources) {
+		file = sources.findSource(fileLoc);
 
-		try {
-			file = sources.findSource(fileLoc);
-		} catch (RuntimeException error) {
+		if (file == null) {
 			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 (Span span : foundSpans) {
 				builder.pointAtFile(span.getSourceFile())
-						.pointAt(span, 2);
+						.pointAt(span, 1);
 			}
 			Backend.log.error(builder.build());
 		}

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

@@ -28,7 +28,7 @@ public class Resolver {
 	/**
 	 * Try and resolve all referenced source files, printing errors if any aren't found.
 	 */
-	public void resolve(ISourceHolder sources) {
+	public void resolve(SourceFinder sources) {
 		for (FileResolution resolution : resolutions.values()) {
 			resolution.resolve(sources);
 		}

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

@@ -1,22 +1,11 @@
 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/ShaderSources.java

@@ -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;
@@ -17,7 +19,7 @@ import net.minecraft.server.packs.resources.ResourceManager;
 /**
  * The main object for loading and parsing source files.
  */
-public class ShaderSources implements ISourceHolder {
+public class ShaderSources implements SourceFinder {
 	public static final String SHADER_DIR = "flywheel/shaders/";
 	public static final ArrayList<String> EXTENSIONS = Lists.newArrayList(".vert", ".vsh", ".frag", ".fsh", ".glsl");
 
@@ -51,13 +53,9 @@ public class ShaderSources implements ISourceHolder {
 	}
 
 	@Override
+	@Nullable
 	public SourceFile findSource(ResourceLocation name) {
-		SourceFile source = shaderSources.get(name);
 
-		if (source == null) {
-			throw new ShaderLoadingException(String.format("shader '%s' does not exist", name));
-		}
-
-		return source;
+		return shaderSources.get(name);
 	}
 }

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

@@ -10,6 +10,7 @@ import java.util.regex.Pattern;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.jozufozu.flywheel.backend.pipeline.ShaderCompiler;
 import com.jozufozu.flywheel.backend.source.parse.Import;
 import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
 import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
@@ -74,6 +75,23 @@ 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.
 	 *
@@ -120,18 +138,25 @@ public class SourceFile {
 		return "#use " + '"' + name + '"';
 	}
 
-	public CharSequence generateFinalSource() {
+	public CharSequence generateFinalSource(ShaderCompiler env) {
 		StringBuilder builder = new StringBuilder();
-		generateFinalSource(builder);
+		generateFinalSource(env, builder);
 		return builder;
 	}
 
-	public void generateFinalSource(StringBuilder source) {
+	public void generateFinalSource(ShaderCompiler env, StringBuilder source) {
 		for (Import include : imports) {
 			SourceFile file = include.getFile();
 
-			if (file != null) file.generateFinalSource(source);
+			if (file != null) file.generateFinalSource(env, source);
 		}
+
+		int i = env.allocateFile(this);
+		source.append("#line ")
+				.append(0)
+				.append(' ')
+				.append(i)
+				.append('\n');
 		source.append(elided);
 	}
 

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

@@ -1,12 +1,15 @@
 package com.jozufozu.flywheel.backend.source;
 
+import javax.annotation.Nullable;
+
 import net.minecraft.resources.ResourceLocation;
 
 /**
  * A minimal source file lookup function.
  */
 @FunctionalInterface
-public interface ISourceHolder {
+public interface SourceFinder {
 
+	@Nullable
 	SourceFile findSource(ResourceLocation name);
 }

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

@@ -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/backend/source/error/ErrorBuilder.java

@@ -2,9 +2,12 @@ package com.jozufozu.flywheel.backend.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.backend.pipeline.ShaderCompiler;
 import com.jozufozu.flywheel.backend.source.SourceFile;
 import com.jozufozu.flywheel.backend.source.SourceLines;
 import com.jozufozu.flywheel.backend.source.error.lines.ErrorLine;
@@ -12,27 +15,60 @@ 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.error.lines.TextLine;
 import com.jozufozu.flywheel.backend.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<>();
 
-	private final Level level;
+	public ErrorBuilder() {
 
-	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);
+		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(Level.WARN, msg);
+		return new ErrorBuilder()
+				.header(ErrorLevel.WARN, msg);
+	}
+
+	@Nullable
+	public static ErrorBuilder fromLogLine(ShaderCompiler 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) {
@@ -42,14 +78,14 @@ public class ErrorBuilder {
 
 	public ErrorBuilder hintIncludeFor(@Nullable Span span, CharSequence msg) {
 		if (span == null) return this;
+		SourceFile sourceFile = span.getSourceFile();
 
-		String builder = "add " + span.getSourceFile()
-				.importStatement() + ' ' + msg;
+		String builder = "add " + sourceFile.importStatement() + ' ' + msg + "\n defined here:";
 
-		lines.add(new HeaderLine("hint", builder));
+		header(ErrorLevel.HINT, builder);
 
-		return this.pointAtFile(span.getSourceFile())
-				.pointAt(span, 1);
+		return this.pointAtFile(sourceFile)
+				.pointAt(span, 0);
 	}
 
 	public ErrorBuilder pointAt(Span span, int ctxLines) {

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

@@ -1,13 +1,14 @@
 package com.jozufozu.flywheel.backend.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/backend/source/error/ErrorReporter.java

@@ -1,12 +1,15 @@
 package com.jozufozu.flywheel.backend.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.backend.source.parse.ShaderFunction;
 import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
 import com.jozufozu.flywheel.backend.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.log.error(error.build());
@@ -64,4 +67,29 @@ public class ErrorReporter {
 
 		Backend.log.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/backend/source/error/lines/ErrorLine.java

@@ -14,6 +14,10 @@ public interface ErrorLine {
 		return left() + divider() + right();
 	}
 
-	String left();
-	String right();
+	default String left() {
+		return "";
+	}
+	default String right() {
+		return "";
+	}
 }

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

@@ -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;
-	}
 }

src/main/java/com/jozufozu/flywheel/backend/source/error/lines/TextLine.java

@@ -0,0 +1,9 @@
+package com.jozufozu.flywheel.backend.source.error.lines;
+
+public record TextLine(String msg) implements ErrorLine {
+
+	@Override
+	public String build() {
+		return msg;
+	}
+}

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

@@ -9,7 +9,7 @@ import com.jozufozu.flywheel.backend.source.span.Span;
 
 public class ShaderFunction extends AbstractShaderElement {
 
-	public static final Pattern argument = Pattern.compile("(\\w+)\\s+(\\w+)");
+	public static final Pattern argument = Pattern.compile("(?:(inout|in|out) )?(\\w+)\\s+(\\w+)");
 	public static final Pattern assignment = Pattern.compile("(\\w+)\\s*=");
 
 	private final Span type;
@@ -66,10 +66,11 @@ public class ShaderFunction extends AbstractShaderElement {
 
 		while (arguments.find()) {
 			Span self = Span.fromMatcher(args, arguments);
-			Span type = Span.fromMatcher(args, arguments, 1);
-			Span name = Span.fromMatcher(args, arguments, 2);
+			Span qualifier = Span.fromMatcher(args, arguments, 1);
+			Span type = Span.fromMatcher(args, arguments, 2);
+			Span name = Span.fromMatcher(args, arguments, 3);
 
-			builder.add(new Variable(self, type, name));
+			builder.add(new Variable(self, qualifier, type, name));
 		}
 
 		return builder.build();
@@ -79,7 +80,7 @@ public class ShaderFunction extends AbstractShaderElement {
 	public String toString() {
 
 		String p = parameters.stream()
-				.map(Variable::typeName)
+				.map(variable -> variable.type)
 				.map(Span::get)
 				.collect(Collectors.joining(","));
 

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

@@ -4,25 +4,41 @@ import com.jozufozu.flywheel.backend.source.span.Span;
 
 public class Variable extends AbstractShaderElement {
 
-	private final Span type;
-	private final Span name;
+	public final Span qualifierSpan;
+	public final Span type;
+	public final Span name;
+	public final Qualifier qualifier;
 
-	public Variable(Span self, Span type, Span name) {
+	public Variable(Span self, Span qualifier, Span type, Span name) {
 		super(self);
+		this.qualifierSpan = qualifier;
 		this.type = type;
 		this.name = name;
-	}
-
-	public Span typeName() {
-		return type;
-	}
-
-	public Span getName() {
-		return name;
+		this.qualifier = Qualifier.fromSpan(qualifierSpan);
 	}
 
 	@Override
 	public String toString() {
 		return type + " " + name;
 	}
+
+	public enum Qualifier {
+		NONE,
+		IN,
+		OUT,
+		INOUT,
+		ERROR;
+
+		public static Qualifier fromSpan(Span s) {
+			String span = s.toString();
+
+			return switch (span) {
+				case "" -> NONE;
+				case "in" -> IN;
+				case "inout" -> INOUT;
+				case "out" -> OUT;
+				default -> ERROR;
+			};
+		}
+	}
 }

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

@@ -3,7 +3,6 @@ package com.jozufozu.flywheel.core;
 import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.backend.Backend;
 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;
@@ -32,8 +31,8 @@ public class Contexts {
         FileResolution crumblingBuiltins = Resolver.INSTANCE.findShader(ResourceUtil.subPath(Names.CRUMBLING, ".glsl"));
         FileResolution worldBuiltins = Resolver.INSTANCE.findShader(ResourceUtil.subPath(Names.WORLD, ".glsl"));
 
-		ShaderPipeline<CrumblingProgram> crumblingPipeline = new WorldShaderPipeline<>(CrumblingProgram::new, InstancingTemplate.INSTANCE, crumblingBuiltins);
-		ShaderPipeline<WorldProgram> worldPipeline = new WorldShaderPipeline<>(WorldProgram::new, InstancingTemplate.INSTANCE, worldBuiltins);
+		ShaderPipeline<CrumblingProgram> crumblingPipeline = new WorldShaderPipeline<>(CrumblingProgram::new, Templates.INSTANCING, crumblingBuiltins);
+		ShaderPipeline<WorldProgram> worldPipeline = new WorldShaderPipeline<>(WorldProgram::new, Templates.INSTANCING, worldBuiltins);
 
 		CRUMBLING = backend.register(WorldContext.builder(backend, Names.CRUMBLING).build(crumblingPipeline));
 		WORLD = backend.register(WorldContext.builder(backend, Names.WORLD).build(worldPipeline));

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

@@ -0,0 +1,12 @@
+package com.jozufozu.flywheel.core;
+
+import com.jozufozu.flywheel.backend.gl.GLSLVersion;
+import com.jozufozu.flywheel.backend.pipeline.InstancingTemplateData;
+import com.jozufozu.flywheel.backend.pipeline.OneShotTemplateData;
+import com.jozufozu.flywheel.backend.pipeline.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);
+}

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

@@ -6,11 +6,13 @@ import java.util.Objects;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 
+import com.jozufozu.flywheel.api.shader.FlexibleShader;
 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.LazyCompiler;
 import com.jozufozu.flywheel.backend.pipeline.ShaderPipeline;
-import com.jozufozu.flywheel.core.shader.ContextAwareProgram;
+import com.jozufozu.flywheel.backend.source.ShaderLoadingException;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
 import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
 
@@ -18,7 +20,7 @@ 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 Map<ResourceLocation, LazyCompiler<P>> programs = new HashMap<>();
 	protected final ResourceLocation name;
 	protected final Supplier<Stream<ResourceLocation>> specStream;
 
@@ -44,25 +46,27 @@ public class WorldContext<P extends WorldProgram> implements ShaderContext<P> {
 	private void loadSpec(ProgramSpec spec) {
 
 		try {
-			programs.put(spec.name, pipeline.compile(spec));
+			programs.put(spec.name, new LazyCompiler<>(pipeline, spec));
 
 			Backend.log.debug("Loaded program {}", spec.name);
 		} catch (Exception e) {
 			Backend.log.error("Error loading program {}", spec.name);
-			Backend.log.error("", e);
+			if (!(e instanceof ShaderLoadingException)) {
+				Backend.log.error("", e);
+			}
 			backend.loader.notifyError();
 		}
 	}
 
 	@Override
-	public Supplier<P> getProgramSupplier(ResourceLocation spec) {
+	public FlexibleShader<P> getProgramSupplier(ResourceLocation spec) {
 		return programs.get(spec);
 	}
 
 	@Override
 	public void delete() {
 		programs.values()
-				.forEach(ContextAwareProgram::delete);
+				.forEach(LazyCompiler::delete);
 		programs.clear();
 	}
 

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();
-			stride += spec.getSize();
+			numAttributes += spec.attributeCount();
+			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/vertex/BlockVertex.java

@@ -4,8 +4,8 @@ import java.nio.ByteBuffer;
 
 import com.jozufozu.flywheel.api.vertex.VertexList;
 import com.jozufozu.flywheel.api.vertex.VertexType;
-import com.jozufozu.flywheel.core.layout.CommonItems;
 import com.jozufozu.flywheel.core.layout.BufferLayout;
+import com.jozufozu.flywheel.core.layout.CommonItems;
 import com.mojang.blaze3d.vertex.BufferBuilder;
 import com.mojang.blaze3d.vertex.DefaultVertexFormat;
 import com.mojang.datafixers.util.Pair;
@@ -36,6 +36,27 @@ public class BlockVertex implements VertexType {
 		return new BlockVertexListUnsafe(buffer, vertexCount);
 	}
 
+	@Override
+	public String writeShaderHeader() {
+		return """
+layout (location = 0) in vec3 _flw_v_pos;
+layout (location = 1) in vec4 _flw_v_color;
+layout (location = 2) in vec2 _flw_v_texCoords;
+layout (location = 3) in vec2 _flw_v_light;
+layout (location = 4) in vec3 _flw_v_normal;
+
+Vertex FLWCreateVertex() {
+	Vertex v;
+	v.pos = _flw_v_pos;
+	v.color = _flw_v_color;
+	v.texCoords = _flw_v_texCoords;
+	v.light = _flw_v_light;
+	v.normal = _flw_v_normal;
+	return v;
+}
+				""";
+	}
+
 	public VertexList createReader(BufferBuilder bufferBuilder) {
 		// TODO: try to avoid virtual model rendering
 		Pair<BufferBuilder.DrawState, ByteBuffer> pair = bufferBuilder.popNextBuffer();

src/main/java/com/jozufozu/flywheel/core/vertex/PosTexNormalVertex.java

@@ -3,8 +3,8 @@ package com.jozufozu.flywheel.core.vertex;
 import java.nio.ByteBuffer;
 
 import com.jozufozu.flywheel.api.vertex.VertexType;
-import com.jozufozu.flywheel.core.layout.CommonItems;
 import com.jozufozu.flywheel.core.layout.BufferLayout;
+import com.jozufozu.flywheel.core.layout.CommonItems;
 
 public class PosTexNormalVertex implements VertexType {
 
@@ -26,4 +26,23 @@ public class PosTexNormalVertex implements VertexType {
 	public PosTexNormalVertexListUnsafe createReader(ByteBuffer buffer, int vertexCount) {
 		return new PosTexNormalVertexListUnsafe(buffer, vertexCount);
 	}
+
+	@Override
+	public String writeShaderHeader() {
+		return """
+layout (location = 0) in vec3 _flw_v_pos;
+layout (location = 1) in vec2 _flw_v_texCoords;
+layout (location = 2) in vec3 _flw_v_normal;
+
+Vertex FLWCreateVertex() {
+	Vertex v;
+	v.pos = _flw_v_pos;
+	v.color = vec4(1.);
+	v.texCoords = _flw_v_texCoords;
+	v.light = vec2(0.);
+	v.normal = _flw_v_normal;
+	return v;
+}
+				""";
+	}
 }

src/main/resources/assets/flywheel/flywheel/shaders/block.frag

@@ -1,5 +1,5 @@
 
-struct BlockFrag {
+struct Fragment {
     vec2 texCoords;
     vec4 color;
     float diffuse;
@@ -7,11 +7,9 @@ struct BlockFrag {
 };
 
 #if defined(FRAGMENT_SHADER)
-void fragment(BlockFrag r) {
+vec4 fragment(Fragment r) {
     vec4 tex = FLWBlockTexture(r.texCoords);
 
-    vec4 color = vec4(tex.rgb * FLWLight(r.light).rgb * r.diffuse, tex.a) * r.color;
-
-    FLWFinalizeColor(color);
+    return vec4(tex.rgb * FLWLight(r.light).rgb * r.diffuse, tex.a) * r.color;
 }
 #endif

src/main/resources/assets/flywheel/flywheel/shaders/context/crumbling.glsl

@@ -1,4 +1,5 @@
 #use "flywheel:context/fog.glsl"
+#use "flywheel:core/diffuse.glsl"
 
 uniform float uTime;
 uniform mat4 uViewProjection;
@@ -11,17 +12,11 @@ uniform sampler2D uCrumbling;
 
 uniform vec2 uWindowSize;
 
-void FLWFinalizeNormal(inout vec3 normal) {
-    // noop
-}
-
 #if defined(VERTEX_SHADER)
-void FLWFinalizeWorldPos(inout vec4 worldPos) {
-    #if defined(USE_FOG)
-    FragDistance = cylindrical_distance(worldPos.xyz, uCameraPos);
-    #endif
+vec4 FLWVertex(inout Vertex v) {
+    FragDistance = cylindrical_distance(v.pos, uCameraPos);
 
-    gl_Position = uViewProjection * worldPos;
+    return uViewProjection * vec4(v.pos, 1.);
 }
 
 #elif defined(FRAGMENT_SHADER)

src/main/resources/assets/flywheel/flywheel/shaders/context/world.glsl

@@ -1,4 +1,5 @@
 #use "flywheel:context/fog.glsl"
+#use "flywheel:core/diffuse.glsl"
 
 uniform float uTime;
 uniform mat4 uViewProjection;
@@ -10,15 +11,12 @@ uniform sampler2D uLightMap;
 
 uniform vec2 uWindowSize;
 
-void FLWFinalizeNormal(inout vec3 normal) {
-    // noop
-}
-
 #if defined(VERTEX_SHADER)
-void FLWFinalizeWorldPos(inout vec4 worldPos) {
-    FragDistance = cylindrical_distance(worldPos.xyz, uCameraPos);
 
-    gl_Position = uViewProjection * worldPos;
+vec4 FLWVertex(inout Vertex v) {
+    FragDistance = cylindrical_distance(v.pos, uCameraPos);
+
+    return uViewProjection * vec4(v.pos, 1.);
 }
 
 #elif defined(FRAGMENT_SHADER)

src/main/resources/assets/flywheel/flywheel/shaders/data/modelvertex.glsl

@@ -1,5 +0,0 @@
-struct Vertex {
-    vec3 pos;
-    vec2 texCoords;
-    vec3 normal;
-};

src/main/resources/assets/flywheel/flywheel/shaders/model.vert

@@ -1,7 +1,7 @@
-#use "flywheel:core/diffuse.glsl"
-#use "flywheel:data/modelvertex.glsl"
 #use "flywheel:block.frag"
 
+#if defined(VERTEX_SHADER)
+
 struct Instance {
     vec2 light;
     vec4 color;
@@ -9,26 +9,10 @@ struct Instance {
     mat3 normalMat;
 };
 
-#if defined(VERTEX_SHADER)
-BlockFrag vertex(Vertex v, Instance i) {
-    vec4 worldPos = i.transform * vec4(v.pos, 1.);
-
-    vec3 norm = i.normalMat * v.normal;
-
-    FLWFinalizeWorldPos(worldPos);
-    FLWFinalizeNormal(norm);
-
-    norm = normalize(norm);
-
-    BlockFrag b;
-    b.diffuse = diffuse(norm);
-    b.texCoords = v.texCoords;
-    b.light = i.light;
-    #if defined(DEBUG_NORMAL)
-    b.color = vec4(norm, 1.);
-    #else
-    b.color = i.color;
-    #endif
-    return b;
+void vertex(inout Vertex v, Instance i) {
+    v.pos = (i.transform * vec4(v.pos, 1.)).xyz;
+    v.normal = i.normalMat * v.normal;
+    v.color = i.color;
+    v.light = i.light;
 }
 #endif

src/main/resources/assets/flywheel/flywheel/shaders/oriented.vert

@@ -1,9 +1,8 @@
-#use "flywheel:core/quaternion.glsl"
-#use "flywheel:core/diffuse.glsl"
-
-#use "flywheel:data/modelvertex.glsl"
 #use "flywheel:block.frag"
 
+#if defined(VERTEX_SHADER)
+#use "flywheel:core/quaternion.glsl"
+
 struct Oriented {
     vec2 light;
     vec4 color;
@@ -12,24 +11,10 @@ struct Oriented {
     vec4 rotation;
 };
 
-#if defined(VERTEX_SHADER)
-BlockFrag vertex(Vertex v, Oriented o) {
-    vec4 worldPos = vec4(rotateVertexByQuat(v.pos - o.pivot, o.rotation) + o.pivot + o.pos, 1.);
-
-    vec3 norm = rotateVertexByQuat(v.normal, o.rotation);
-
-    FLWFinalizeWorldPos(worldPos);
-    FLWFinalizeNormal(norm);
-
-    BlockFrag b;
-    b.diffuse = diffuse(norm);
-    b.texCoords = v.texCoords;
-    b.light = o.light;
-    #if defined(DEBUG_NORMAL)
-    b.color = vec4(norm, 1.);
-    #else
-    b.color = o.color;
-    #endif
-    return b;
+void vertex(inout Vertex v, Oriented o) {
+    v.pos = rotateVertexByQuat(v.pos - o.pivot, o.rotation) + o.pivot + o.pos;
+    v.normal = rotateVertexByQuat(v.normal, o.rotation);
+    v.color = o.color;
+    v.light = o.light;
 }
 #endif

src/main/resources/assets/flywheel/flywheel/shaders/smooth_oriented.glsl

@@ -1,53 +0,0 @@
-#use "flywheel:core/matutils.glsl"
-#use "flywheel:core/quaternion.glsl"
-#use "flywheel:core/diffuse.glsl"
-
-struct Oriented {
-// each vec 4 is 2 light coords packed <lo y, hi y>
-//               x   z
-    vec4 lightA;// lo, lo
-    vec4 lightB;// hi, lo
-    vec4 lightC;// hi, hi
-    vec4 lightD;// lo, hi
-
-    vec3 loCorner;
-    vec3 size;
-
-    vec4 color;
-    vec3 pos;
-    vec3 pivot;
-    vec4 rotation;
-};
-
-#use "flywheel:data/modelvertex.glsl"
-#use "flywheel:block.frag"
-
-BlockFrag vertex(Vertex v, Oriented o) {
-    vec4 worldPos = vec4(rotateVertexByQuat(v.pos - o.pivot, o.rotation) + o.pivot + o.pos, 1.);
-
-    vec3 norm = rotateVertexByQuat(v.normal, o.rotation);
-
-    FLWFinalizeWorldPos(worldPos);
-    FLWFinalizeNormal(norm);
-
-    // manual trilinear interpolation
-    vec3 lightPos = (worldPos.xyz - o.loCorner) / o.size;
-
-    vec4 lightLoZ = mix(lightA, lightB, lightPos.x);// lo z
-    vec4 lightHiZ = mix(lightD, lightC, lightPos.x);// hi z
-
-    vec4 lightE = mix(lightLoZ, lightHiZ, lightPos.z);// <lo y, hi y>
-
-    vec2 lightCoord = mix(lightE.xy, lightE.zw, lightPos.y);
-
-    BlockFrag b;
-    b.diffuse = diffuse(norm);
-    b.texCoords = v.texCoords;
-    b.light = lightCoord;
-    #if defined(DEBUG_NORMAL)
-    b.color = vec4(norm, 1.);
-    #else
-    b.color = o.color;
-    #endif
-    return b;
-}