Layout down to rest

- Remove BufferLayout and associated classes.
- Replace InternalVertex with new Layout.
- Calculate InternalVertex stuff as static final fields.
- Elements track their own byte size.
  - The byte size of an element type is unchanged.
  - The byte size of an element is 4-aligned.
- Layout byte size now accounts for alignment.
- Generated packed fields are now always prefixed with an underscore.

src/main/java/com/jozufozu/flywheel/api/layout/Layout.java

@@ -24,5 +24,7 @@ public interface Layout {
 		ElementType type();
 
 		int offset();
+
+		int byteSize();
 	}
 }

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

@@ -1,24 +1,33 @@
 package com.jozufozu.flywheel.backend;
 
+import java.util.List;
+
 import com.jozufozu.flywheel.Flywheel;
+import com.jozufozu.flywheel.api.layout.FloatRepr;
+import com.jozufozu.flywheel.api.layout.Layout;
+import com.jozufozu.flywheel.api.layout.LayoutBuilder;
+import com.jozufozu.flywheel.api.layout.UnsignedIntegerRepr;
 import com.jozufozu.flywheel.api.vertex.VertexView;
-import com.jozufozu.flywheel.backend.gl.layout.BufferLayout;
-import com.jozufozu.flywheel.backend.gl.layout.CommonItems;
+import com.jozufozu.flywheel.backend.engine.LayoutAttributes;
+import com.jozufozu.flywheel.backend.gl.array.VertexAttribute;
 import com.jozufozu.flywheel.lib.vertex.FullVertexView;
 
 import net.minecraft.resources.ResourceLocation;
 
 public final class InternalVertex {
-	public static final BufferLayout LAYOUT = BufferLayout.builder()
-			.addItem(CommonItems.VEC3, "position")
-			.addItem(CommonItems.UNORM_4x8, "color")
-			.addItem(CommonItems.VEC2, "tex")
-			.addItem(CommonItems.LIGHT_COORD, "overlay")
-			.addItem(CommonItems.LIGHT_COORD, "light")
-			.addItem(CommonItems.NORM_3x8, "normal")
-			.withPadding(1)
+	public static final Layout LAYOUT = LayoutBuilder.create()
+			.vector("position", FloatRepr.FLOAT, 3)
+			.vector("color", FloatRepr.NORMALIZED_UNSIGNED_BYTE, 4)
+			.vector("tex", FloatRepr.FLOAT, 2)
+			.vector("overlay", UnsignedIntegerRepr.UNSIGNED_SHORT, 2)
+			.vector("light", UnsignedIntegerRepr.UNSIGNED_SHORT, 2)
+			.vector("normal", FloatRepr.NORMALIZED_BYTE, 3)
 			.build();
 
+	public static final List<VertexAttribute> ATTRIBUTES = LayoutAttributes.attributes(LAYOUT);
+	public static final int ATTRIBUTE_COUNT = ATTRIBUTES.size();
+	public static final int STRIDE = LAYOUT.byteSize();
+
 	public static final ResourceLocation LAYOUT_SHADER = Flywheel.rl("internal/vertex_input.vert");
 
 	private InternalVertex() {

src/main/java/com/jozufozu/flywheel/backend/compile/PipelineCompiler.java

@@ -21,7 +21,7 @@ public class PipelineCompiler {
 								.withResource(pipeline.vertexApiImpl())
 								.withResource(InternalVertex.LAYOUT_SHADER)
 								.withComponent(key -> pipeline.assembler()
-										.assemble(new Pipeline.InstanceAssemblerContext(InternalVertex.LAYOUT.getAttributeCount(), key.instanceType())))
+										.assemble(new Pipeline.InstanceAssemblerContext(InternalVertex.ATTRIBUTE_COUNT, key.instanceType())))
 								.withComponents(vertexComponents)
 								.withResource(key -> key.instanceType()
 										.vertexShader())

src/main/java/com/jozufozu/flywheel/backend/compile/component/IndirectComponent.java

@@ -113,13 +113,14 @@ public class IndirectComponent implements SourceComponent {
 		// FIXME: I don't think we're unpacking signed byte/short values correctly
 		// FIXME: we definitely don't consider endianness. this all assumes little endian which works on my machine.
 		var type = element.type();
+		var name = "_" + element.name();
 
 		if (type instanceof ScalarElementType scalar) {
-			return unpackScalar(element.name(), packed, scalar);
+			return unpackScalar(name, packed, scalar);
 		} else if (type instanceof VectorElementType vector) {
-			return unpackVector(element.name(), packed, vector);
+			return unpackVector(name, packed, vector);
 		} else if (type instanceof MatrixElementType matrix) {
-			return unpackMatrix(element.name(), packed, matrix);
+			return unpackMatrix(name, packed, matrix);
 		}
 
 		throw new IllegalArgumentException("Unknown type " + type);
@@ -217,7 +218,7 @@ public class IndirectComponent implements SourceComponent {
 	private static GlslExpr unpack(String fieldName, GlslStruct packed, int size, String backingType, String outType, Function<GlslExpr, GlslExpr> perElement) {
 		List<GlslExpr> args = new ArrayList<>();
 		for (int i = 0; i < size; i++) {
-			var name = "_" + fieldName + "_" + i;
+			var name = fieldName + "_" + i;
 			packed.addField(backingType, name);
 			args.add(UNPACKING_VARIABLE.access(name)
 					.transform(perElement));
@@ -258,7 +259,7 @@ public class IndirectComponent implements SourceComponent {
 		for (int i = 0; i < size; i++) {
 			int unpackField = i / 2;
 			int bitPos = (i % 2) * 16;
-			var name = "_" + fieldName + "_" + unpackField;
+			var name = fieldName + "_" + unpackField;
 			if (bitPos == 0) {
 				// First time we're seeing this field, add it to the struct.
 				packed.addField("uint", name);

src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectMeshPool.java

@@ -37,8 +37,8 @@ public class IndirectMeshPool {
 		vertexArray = GlVertexArray.create();
 
 		vertexArray.setElementBuffer(ebo.handle());
-		vertexArray.bindVertexBuffer(0, vbo.handle(), 0, InternalVertex.LAYOUT.getStride());
-		vertexArray.bindAttributes(0, 0, InternalVertex.LAYOUT.attributes());
+		vertexArray.bindVertexBuffer(0, vbo.handle(), 0, InternalVertex.STRIDE);
+		vertexArray.bindAttributes(0, 0, InternalVertex.ATTRIBUTES);
 	}
 
 	/**
@@ -151,7 +151,7 @@ public class IndirectMeshPool {
 		private BufferedMesh(Mesh mesh) {
 			this.mesh = mesh;
 			vertexCount = mesh.vertexCount();
-			byteSize = vertexCount * InternalVertex.LAYOUT.getStride();
+			byteSize = vertexCount * InternalVertex.STRIDE;
 		}
 
 		public int vertexCount() {

src/main/java/com/jozufozu/flywheel/backend/engine/instancing/DrawCall.java

@@ -36,7 +36,7 @@ public class DrawCall {
 			return;
 		}
 
-		instancer.bindIfNeeded(vao, InternalVertex.LAYOUT.getAttributeCount());
+		instancer.bindIfNeeded(vao, InternalVertex.ATTRIBUTE_COUNT);
 		mesh.setup(vao);
 
 		vao.bindForDraw();
@@ -58,7 +58,7 @@ public class DrawCall {
 
 		var vao = lazyScratchVao();
 
-		instancer.bindRaw(vao, InternalVertex.LAYOUT.getAttributeCount(), impl.index);
+		instancer.bindRaw(vao, InternalVertex.ATTRIBUTE_COUNT, impl.index);
 		mesh.setup(vao);
 
 		vao.bindForDraw();

src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancedMeshPool.java

@@ -36,7 +36,7 @@ public class InstancedMeshPool {
 	 */
 	public InstancedMeshPool() {
 		vertexView = InternalVertex.createVertexView();
-		int stride = InternalVertex.LAYOUT.getStride();
+		int stride = InternalVertex.STRIDE;
 		vbo = new GlBuffer();
 		vbo.growthFunction(l -> Math.max(l + stride * 128L, (long) (l * 1.6)));
 	}
@@ -149,7 +149,7 @@ public class InstancedMeshPool {
 		private BufferedMesh(Mesh mesh, long byteIndex, EboCache eboCache) {
 			this.mesh = mesh;
 			vertexCount = mesh.vertexCount();
-			byteSize = vertexCount * InternalVertex.LAYOUT.getStride();
+			byteSize = vertexCount * InternalVertex.STRIDE;
 			this.byteIndex = byteIndex;
 			this.ebo = eboCache.get(mesh.indexSequence(), mesh.indexCount());
 		}
@@ -182,8 +182,8 @@ public class InstancedMeshPool {
 
 		public void setup(GlVertexArray vao) {
 			if (boundTo.add(vao)) {
-				vao.bindVertexBuffer(0, InstancedMeshPool.this.vbo.handle(), byteIndex, InternalVertex.LAYOUT.getStride());
-				vao.bindAttributes(0, 0, InternalVertex.LAYOUT.attributes());
+				vao.bindVertexBuffer(0, InstancedMeshPool.this.vbo.handle(), byteIndex, InternalVertex.STRIDE);
+				vao.bindAttributes(0, 0, InternalVertex.ATTRIBUTES);
 				vao.setElementBuffer(ebo);
 			}
 		}

src/main/java/com/jozufozu/flywheel/backend/gl/layout/BufferLayout.java

@@ -1,85 +0,0 @@
-package com.jozufozu.flywheel.backend.gl.layout;
-
-import java.util.List;
-
-import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.gl.array.VertexAttribute;
-
-/**
- * Classic Vertex Format with a clever name.
- *
- * <p>
- *     Used for vertices and instances. Describes the layout of a datatype in a buffer object.
- * </p>
- *
- * @see com.jozufozu.flywheel.api.instance.InstanceType
- */
-public class BufferLayout {
-
-	public final List<LayoutItem> layoutItems;
-	public final List<VertexAttribute> attributes;
-
-	private final int stride;
-
-	public BufferLayout(List<LayoutItem> layoutItems, int padding) {
-		this.layoutItems = ImmutableList.copyOf(layoutItems);
-
-		ImmutableList.Builder<VertexAttribute> attributes = ImmutableList.builder();
-
-		for (var item : this.layoutItems) {
-			item.type()
-					.provideAttributes(attributes::add);
-		}
-
-		this.attributes = attributes.build();
-		this.stride = calculateStride(this.attributes) + padding;
-	}
-
-	public List<VertexAttribute> attributes() {
-		return attributes;
-	}
-
-	public int getAttributeCount() {
-		return attributes.size();
-	}
-
-	public int getStride() {
-		return stride;
-	}
-
-	public static Builder builder() {
-		return new Builder();
-	}
-
-	private static int calculateStride(List<VertexAttribute> layoutItems) {
-		int stride = 0;
-		for (var spec : layoutItems) {
-			stride += spec.byteWidth();
-		}
-		return stride;
-	}
-
-	public static class Builder {
-		private final ImmutableList.Builder<LayoutItem> allItems;
-		private int padding;
-
-		public Builder() {
-			allItems = ImmutableList.builder();
-		}
-
-		public Builder addItem(InputType type, String name) {
-			allItems.add(new LayoutItem(type, name));
-			return this;
-		}
-
-		public Builder withPadding(int padding) {
-			this.padding = padding;
-			return this;
-		}
-
-		public BufferLayout build() {
-			return new BufferLayout(allItems.build(), padding);
-		}
-	}
-
-}

src/main/java/com/jozufozu/flywheel/backend/gl/layout/CommonItems.java

@@ -1,134 +0,0 @@
-package com.jozufozu.flywheel.backend.gl.layout;
-
-import com.jozufozu.flywheel.backend.gl.GlNumericType;
-import com.jozufozu.flywheel.backend.gl.array.VertexAttribute;
-import com.jozufozu.flywheel.backend.glsl.generate.FnSignature;
-import com.jozufozu.flywheel.backend.glsl.generate.GlslExpr;
-
-public final class CommonItems {
-	private static final String VEC2_TYPE = "vec2";
-	private static final String VEC3_TYPE = "vec3";
-	private static final String VEC4_TYPE = "vec4";
-	private static final String VEC2F_TYPE = "Vec2F";
-	private static final String VEC3F_TYPE = "Vec3F";
-	private static final String VEC4F_TYPE = "Vec4F";
-	private static final String IVEC2_TYPE = "ivec2";
-	private static final String FLOAT_TYPE = "float";
-	private static final String UINT_TYPE = "uint";
-	private static final String LIGHT_COORD_TYPE = "uint";
-
-	public static final VecInput LIGHT_COORD = VecInput.builder()
-			.vertexAttribute(new VertexAttribute.Int(GlNumericType.USHORT, 2))
-			.typeName(IVEC2_TYPE)
-			.packedTypeName(LIGHT_COORD_TYPE)
-			.unpackingFunction(expr -> expr.callFunction("unpackLightCoord"))
-			.declaration(builder -> builder.function()
-					.signature(FnSignature.create()
-							.name("unpackLightCoord")
-							.returnType(IVEC2_TYPE)
-							.arg("uint", "light")
-							.build())
-					.body(block -> block.raw("return ivec2(light & 0xFFFFu, (light >> 16) & 0xFFFFu);")))
-			.build();
-
-	public static final VecInput FLOAT = VecInput.builder()
-			.vertexAttribute(new VertexAttribute.Float(GlNumericType.FLOAT, 1, false))
-			.typeName(FLOAT_TYPE)
-			.packedTypeName(FLOAT_TYPE)
-			.build();
-	public static final VecInput NORM_3x8 = VecInput.builder()
-			.vertexAttribute(new VertexAttribute.Float(GlNumericType.BYTE, 3, true))
-			.typeName(VEC3_TYPE)
-			.packedTypeName(UINT_TYPE)
-			.unpackingFunction(expr -> expr.callFunction("unpackSnorm4x8")
-					.swizzle("xyz"))
-			.build();
-	public static final VecInput UNORM_4x8 = VecInput.builder()
-			.vertexAttribute(new VertexAttribute.Float(GlNumericType.UBYTE, 4, true))
-			.typeName(VEC4_TYPE)
-			.packedTypeName(UINT_TYPE)
-			.unpackingFunction(expr -> expr.callFunction("unpackUnorm4x8"))
-			.build();
-	public static final VecInput UNORM_3x8 = VecInput.builder()
-			.vertexAttribute(new VertexAttribute.Float(GlNumericType.UBYTE, 3, true))
-			.typeName(VEC3_TYPE)
-			.packedTypeName(UINT_TYPE)
-			.unpackingFunction(expr -> expr.callFunction("unpackUnorm4x8")
-					.swizzle("xyz"))
-			.build();
-	public static final VecInput VEC4 = VecInput.builder()
-			.vertexAttribute(new VertexAttribute.Float(GlNumericType.FLOAT, 4, false))
-			.typeName(VEC4_TYPE)
-			.packedTypeName(VEC4F_TYPE)
-			.unpackingFunction(expr -> expr.callFunction("unpackVec4F"))
-			.declaration(builder -> {
-				builder.struct()
-						.setName(VEC4F_TYPE)
-						.addField(FLOAT_TYPE, "x")
-						.addField(FLOAT_TYPE, "y")
-						.addField(FLOAT_TYPE, "z")
-						.addField(FLOAT_TYPE, "w");
-				builder.function()
-						.signature(FnSignature.create()
-								.name("unpackVec4F")
-								.returnType(VEC4_TYPE)
-								.arg(VEC4F_TYPE, "v")
-								.build())
-						.body(block -> {
-							var v = GlslExpr.variable("v");
-							block.ret(GlslExpr.call("vec4", v.access("x"), v.access("y"), v.access("z"), v.access("w")));
-						});
-			})
-			.build();
-	public static final VecInput VEC3 = VecInput.builder()
-			.vertexAttribute(new VertexAttribute.Float(GlNumericType.FLOAT, 3, false))
-			.typeName(VEC3_TYPE)
-			.packedTypeName(VEC3F_TYPE)
-			.unpackingFunction(expr -> expr.callFunction("unpackVec3F"))
-			.declaration(builder -> {
-				builder.struct()
-						.setName(VEC3F_TYPE)
-						.addField(FLOAT_TYPE, "x")
-						.addField(FLOAT_TYPE, "y")
-						.addField(FLOAT_TYPE, "z");
-				builder.function()
-						.signature(FnSignature.create()
-								.name("unpackVec3F")
-								.returnType(VEC3_TYPE)
-								.arg(VEC3F_TYPE, "v")
-								.build())
-						.body(block -> {
-							var v = GlslExpr.variable("v");
-							block.ret(GlslExpr.call("vec3", v.access("x"), v.access("y"), v.access("z")));
-						});
-			})
-			.build();
-	public static final VecInput VEC2 = VecInput.builder()
-			.vertexAttribute(new VertexAttribute.Float(GlNumericType.FLOAT, 2, false))
-			.typeName(VEC2_TYPE)
-			.packedTypeName(VEC2F_TYPE)
-			.unpackingFunction(expr -> expr.callFunction("unpackVec2F"))
-			.declaration(builder -> {
-				builder.struct()
-						.setName(VEC2F_TYPE)
-						.addField(FLOAT_TYPE, "x")
-						.addField(FLOAT_TYPE, "y");
-				builder.function()
-						.signature(FnSignature.create()
-								.name("unpackVec2F")
-								.returnType(VEC2_TYPE)
-								.arg(VEC2F_TYPE, "v")
-								.build())
-						.body(block -> {
-							var v = GlslExpr.variable("v");
-							block.ret(GlslExpr.call("vec2", v.access("x"), v.access("y")));
-						});
-			})
-			.build();
-
-	public static final MatInput MAT3 = new MatInput(3, 3, "mat3", "Mat3F", "unpackMat3F");
-	public static final MatInput MAT4 = new MatInput(4, 4, "mat4", "Mat4F", "unpackMat4F");
-
-	private CommonItems() {
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/gl/layout/InputType.java

@@ -1,22 +0,0 @@
-package com.jozufozu.flywheel.backend.gl.layout;
-
-import java.util.function.Consumer;
-
-import com.jozufozu.flywheel.backend.gl.array.VertexAttribute;
-import com.jozufozu.flywheel.backend.glsl.generate.GlslBuilder;
-import com.jozufozu.flywheel.backend.glsl.generate.GlslExpr;
-
-public interface InputType {
-
-	void provideAttributes(Consumer<VertexAttribute> consumer);
-
-	String typeName();
-
-	String packedTypeName();
-
-	int attributeCount();
-
-	GlslExpr unpack(GlslExpr packed);
-
-	void declare(GlslBuilder builder);
-}

src/main/java/com/jozufozu/flywheel/backend/gl/layout/LayoutItem.java

@@ -1,5 +0,0 @@
-package com.jozufozu.flywheel.backend.gl.layout;
-
-public record LayoutItem(InputType type, String name) {
-
-}

src/main/java/com/jozufozu/flywheel/backend/gl/layout/MatInput.java

@@ -1,64 +0,0 @@
-package com.jozufozu.flywheel.backend.gl.layout;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.function.Consumer;
-
-import com.jozufozu.flywheel.backend.gl.GlNumericType;
-import com.jozufozu.flywheel.backend.gl.array.VertexAttribute;
-import com.jozufozu.flywheel.backend.glsl.generate.FnSignature;
-import com.jozufozu.flywheel.backend.glsl.generate.GlslBuilder;
-import com.jozufozu.flywheel.backend.glsl.generate.GlslExpr;
-
-public record MatInput(int rows, int cols, String typeName, String packedTypeName,
-					   String unpackingFunction) implements InputType {
-
-	@Override
-	public void provideAttributes(Consumer<VertexAttribute> consumer) {
-		for (int i = 0; i < rows; i++) {
-			consumer.accept(new VertexAttribute.Float(GlNumericType.FLOAT, cols, false));
-		}
-	}
-
-	@Override
-	public int attributeCount() {
-		return rows;
-	}
-
-	@Override
-	public GlslExpr unpack(GlslExpr packed) {
-		return packed.callFunction(unpackingFunction);
-	}
-
-	@Override
-	public void declare(GlslBuilder builder) {
-
-		var s = builder.struct();
-		s.setName(packedTypeName);
-
-		for (int c = 0; c < cols; c++) {
-			for (int r = 0; r < rows; r++) {
-				s.addField("float", "m" + c + r);
-			}
-		}
-
-		builder.function()
-				.signature(FnSignature.create()
-						.name(unpackingFunction)
-						.returnType(typeName)
-						.arg(packedTypeName, "p")
-						.build())
-				.body(block -> {
-					List<GlslExpr> args = new ArrayList<>();
-					var p = GlslExpr.variable("p");
-
-					for (int c = 0; c < cols; c++) {
-						for (int r = 0; r < rows; r++) {
-							args.add(p.access("m" + c + r));
-						}
-					}
-
-					block.ret(GlslExpr.call(typeName, args));
-				});
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/gl/layout/VecInput.java

@@ -1,96 +0,0 @@
-package com.jozufozu.flywheel.backend.gl.layout;
-
-import java.util.function.Consumer;
-import java.util.function.Function;
-
-import com.jozufozu.flywheel.backend.gl.array.VertexAttribute;
-import com.jozufozu.flywheel.backend.glsl.generate.GlslBuilder;
-import com.jozufozu.flywheel.backend.glsl.generate.GlslExpr;
-
-public class VecInput implements InputType {
-	private final VertexAttribute attribute;
-	private final String typeName;
-	private final String packedTypeName;
-	private final Function<GlslExpr, GlslExpr> unpackingFunction;
-	private final Consumer<GlslBuilder> declaration;
-
-	public VecInput(VertexAttribute attribute, String typeName, String packedTypeName, Function<GlslExpr, GlslExpr> unpackingFunction, Consumer<GlslBuilder> declaration) {
-		this.attribute = attribute;
-		this.typeName = typeName;
-		this.packedTypeName = packedTypeName;
-		this.unpackingFunction = unpackingFunction;
-		this.declaration = declaration;
-	}
-
-	@Override
-	public void provideAttributes(Consumer<VertexAttribute> consumer) {
-		consumer.accept(attribute);
-	}
-
-	@Override
-	public String typeName() {
-		return typeName;
-	}
-
-	@Override
-	public String packedTypeName() {
-		return packedTypeName;
-	}
-
-	@Override
-	public int attributeCount() {
-		return 1;
-	}
-
-	public static Builder builder() {
-		return new Builder();
-	}
-
-	@Override
-	public GlslExpr unpack(GlslExpr packed) {
-		return unpackingFunction.apply(packed);
-	}
-
-	@Override
-	public void declare(GlslBuilder builder) {
-		declaration.accept(builder);
-	}
-
-	public static class Builder {
-		private VertexAttribute attribute;
-		private String typeName;
-		private String packedTypeName;
-		private Function<GlslExpr, GlslExpr> unpackingFunction = Function.identity();
-		private Consumer<GlslBuilder> declaration = $ -> {
-		};
-
-		public Builder vertexAttribute(VertexAttribute attribute) {
-			this.attribute = attribute;
-			return this;
-		}
-
-		public Builder typeName(String typeName) {
-			this.typeName = typeName;
-			return this;
-		}
-
-		public Builder packedTypeName(String packedTypeName) {
-			this.packedTypeName = packedTypeName;
-			return this;
-		}
-
-		public Builder unpackingFunction(Function<GlslExpr, GlslExpr> f) {
-			this.unpackingFunction = f;
-			return this;
-		}
-
-		public Builder declaration(Consumer<GlslBuilder> declaration) {
-			this.declaration = declaration;
-			return this;
-		}
-
-		public VecInput build() {
-			return new VecInput(attribute, typeName, packedTypeName, unpackingFunction, declaration);
-		}
-	}
-}

src/main/java/com/jozufozu/flywheel/impl/layout/LayoutBuilderImpl.java

@@ -126,7 +126,7 @@ public class LayoutBuilderImpl implements LayoutBuilder {
 	}
 
 	private LayoutBuilder element(String name, ElementType type) {
-		elements.add(new ElementImpl(name, type, offset));
+		elements.add(new ElementImpl(name, type, offset, MoreMath.align4(type.byteSize())));
 		offset += type.byteSize();
 		offset = MoreMath.align4(offset);
 		return this;
@@ -173,7 +173,7 @@ public class LayoutBuilderImpl implements LayoutBuilder {
 			}
 		}
 
-		return new LayoutImpl(List.copyOf(elements));
+		return new LayoutImpl(List.copyOf(elements), offset);
 	}
 
 	private static boolean isValidNameCharacter(char c) {

src/main/java/com/jozufozu/flywheel/impl/layout/LayoutImpl.java

@@ -18,14 +18,12 @@ final class LayoutImpl implements Layout {
 	private final Map<String, Element> map;
 	private final int byteSize;
 
-	LayoutImpl(@Unmodifiable List<Element> elements) {
+	LayoutImpl(@Unmodifiable List<Element> elements, int byteSize) {
 		this.elements = elements;
 
 		Object2ObjectOpenHashMap<String, Element> map = new Object2ObjectOpenHashMap<>();
-		int byteSize = 0;
 		for (Element element : this.elements) {
 			map.put(element.name(), element);
-			byteSize += element.type().byteSize();
 		}
 		map.trim();
 
@@ -73,6 +71,6 @@ final class LayoutImpl implements Layout {
 		return elements.equals(other.elements);
 	}
 
-	record ElementImpl(String name, ElementType type, int offset) implements Element {
+	record ElementImpl(String name, ElementType type, int offset, int byteSize) implements Element {
 	}
 }