Debugging broken overlay/lighting

- Break instance overlay/light back into 2 layout elements
- Write light directly as an int
- Make light a short backed float element
- Clamp overlay coords in common.frag to avoid explosions
- Explosions: integer vertex attributes sometimes blow up to massive
  sizes, greater than Short.MAX_VALUE which should not be possible.
- Reorganize some texture/uniform binding code

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

@@ -4,9 +4,9 @@ import java.util.List;
 
 import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.api.layout.FloatRepr;
+import com.jozufozu.flywheel.api.layout.IntegerRepr;
 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.engine.LayoutAttributes;
 import com.jozufozu.flywheel.backend.gl.array.VertexAttribute;
@@ -19,7 +19,7 @@ public final class InternalVertex {
 			.vector("position", FloatRepr.FLOAT, 3)
 			.vector("color", FloatRepr.NORMALIZED_UNSIGNED_BYTE, 4)
 			.vector("tex", FloatRepr.FLOAT, 2)
-			.vector("overlay_light", UnsignedIntegerRepr.UNSIGNED_SHORT, 4)
+			.vector("overlay_light", IntegerRepr.SHORT, 4)
 			.vector("normal", FloatRepr.NORMALIZED_BYTE, 3)
 			.build();
 

src/main/java/com/jozufozu/flywheel/backend/engine/MeshPool.java

@@ -207,12 +207,13 @@ public class MeshPool {
 		}
 
 		public void setup(GlVertexArray vao) {
-			if (boundTo.add(vao)) {
+            if (!boundTo.add(vao)) {
+                return;
+            }
             MeshPool.this.indexPool.bind(vao);
             vao.bindVertexBuffer(0, MeshPool.this.vbo.handle(), byteIndex, InternalVertex.STRIDE);
             vao.bindAttributes(0, 0, InternalVertex.ATTRIBUTES);
         }
-		}
 
 		public void acquire() {
 			referenceCount++;

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

@@ -64,6 +64,7 @@ public class InstancingEngine extends AbstractEngine {
 		}
 
 		try (var state = GlStateTracker.getRestoreState()) {
+			Uniforms.bindForDraw();
 			render(drawSet);
 		}
 	}
@@ -104,7 +105,6 @@ public class InstancingEngine extends AbstractEngine {
 			var program = programs.get(shader.instanceType(), context.contextShader());
 			program.bind();
 
-			Uniforms.bindForDraw();
 			uploadMaterialUniform(program, material);
 
 			context.prepare(material, program, textures);

src/main/java/com/jozufozu/flywheel/backend/engine/textures/TextureBinder.java

@@ -48,14 +48,15 @@ public class TextureBinder {
 
 	public static void bindLightAndOverlay() {
 		var gameRenderer = Minecraft.getInstance().gameRenderer;
-		gameRenderer.overlayTexture()
-				.setupOverlayColor();
-		gameRenderer.lightTexture()
-				.turnOnLightLayer();
 
 		GlTextureUnit.T1.makeActive();
+		gameRenderer.overlayTexture()
+				.setupOverlayColor();
 		RenderSystem.bindTexture(RenderSystem.getShaderTexture(1));
+
 		GlTextureUnit.T2.makeActive();
+		gameRenderer.lightTexture()
+				.turnOnLightLayer();
 		RenderSystem.bindTexture(RenderSystem.getShaderTexture(2));
 	}
 

src/main/java/com/jozufozu/flywheel/lib/instance/InstanceTypes.java

@@ -14,7 +14,8 @@ public final class InstanceTypes {
 	public static final InstanceType<TransformedInstance> TRANSFORMED = SimpleInstanceType.builder(TransformedInstance::new)
 			.layout(LayoutBuilder.create()
 					.vector("color", FloatRepr.NORMALIZED_UNSIGNED_BYTE, 4)
-					.vector("overlay_light", IntegerRepr.SHORT, 4)
+					.vector("overlay", IntegerRepr.SHORT, 2)
+					.vector("light", FloatRepr.UNSIGNED_SHORT, 2)
 					.matrix("pose", FloatRepr.FLOAT, 4)
 					.matrix("normal", FloatRepr.FLOAT, 3)
 					.build())
@@ -24,8 +25,7 @@ public final class InstanceTypes {
 				MemoryUtil.memPutByte(ptr + 2, instance.b);
 				MemoryUtil.memPutByte(ptr + 3, instance.a);
 				MemoryUtil.memPutInt(ptr + 4, instance.overlay);
-				MemoryUtil.memPutShort(ptr + 8, instance.blockLight);
+				MemoryUtil.memPutInt(ptr + 8, (int) instance.blockLight | (int) instance.skyLight << 16);
-				MemoryUtil.memPutShort(ptr + 10, instance.skyLight);
 				MatrixMath.writeUnsafe(instance.model, ptr + 12);
 				MatrixMath.writeUnsafe(instance.normal, ptr + 76);
 			})
@@ -36,7 +36,8 @@ public final class InstanceTypes {
 	public static final InstanceType<OrientedInstance> ORIENTED = SimpleInstanceType.builder(OrientedInstance::new)
 			.layout(LayoutBuilder.create()
 					.vector("color", FloatRepr.NORMALIZED_UNSIGNED_BYTE, 4)
-					.vector("overlay_light", IntegerRepr.SHORT, 4)
+					.vector("overlay", IntegerRepr.SHORT, 2)
+					.vector("light", FloatRepr.UNSIGNED_SHORT, 2)
 					.vector("position", FloatRepr.FLOAT, 3)
 					.vector("pivot", FloatRepr.FLOAT, 3)
 					.vector("rotation", FloatRepr.FLOAT, 4)
@@ -47,8 +48,7 @@ public final class InstanceTypes {
 				MemoryUtil.memPutByte(ptr + 2, instance.b);
 				MemoryUtil.memPutByte(ptr + 3, instance.a);
 				MemoryUtil.memPutInt(ptr + 4, instance.overlay);
-				MemoryUtil.memPutShort(ptr + 8, instance.blockLight);
+				MemoryUtil.memPutInt(ptr + 8, (int) instance.blockLight | (int) instance.skyLight << 16);
-				MemoryUtil.memPutShort(ptr + 10, instance.skyLight);
 				MemoryUtil.memPutFloat(ptr + 12, instance.posX);
 				MemoryUtil.memPutFloat(ptr + 16, instance.posY);
 				MemoryUtil.memPutFloat(ptr + 20, instance.posZ);

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

@@ -4,6 +4,6 @@ void flw_instanceVertex(in FlwInstance i) {
     flw_vertexPos = vec4(rotateByQuaternion(flw_vertexPos.xyz - i.pivot, i.rotation) + i.pivot + i.position, 1.0);
     flw_vertexNormal = rotateByQuaternion(flw_vertexNormal, i.rotation);
     flw_vertexColor = i.color;
-    flw_vertexOverlay = i.overlay_light.xy;
+    flw_vertexOverlay = i.overlay;
-    flw_vertexLight = i.overlay_light.zw / 15.0;
+    flw_vertexLight = i.light / 15.;
 }

src/main/resources/assets/flywheel/flywheel/instance/transformed.vert

@@ -2,6 +2,6 @@ void flw_instanceVertex(in FlwInstance i) {
     flw_vertexPos = i.pose * flw_vertexPos;
     flw_vertexNormal = i.normal * flw_vertexNormal;
     flw_vertexColor = i.color;
-    flw_vertexOverlay = i.overlay_light.xy;
+    flw_vertexOverlay = i.overlay;
-    flw_vertexLight = i.overlay_light.zw / 15.0;
+    flw_vertexLight = i.light / 15.;
 }

src/main/resources/assets/flywheel/flywheel/internal/common.frag

@@ -37,7 +37,14 @@ void _flw_main() {
     }
 
     if (flw_material.useOverlay) {
-        vec4 overlayColor = texelFetch(_flw_overlayTex, flw_fragOverlay, 0);
+        // Need to clamp the overlay texture coords to sane coordinates because integer vertex attributes explode on
+        // some drivers for some draw calls.
+        // This can be removed once instancing uses sampler buffers, though
+        // we may need a solution for the internal vertex format. Perhaps
+        // pass as floats and convert to integers in the shader?
+        ivec2 actualCoord = clamp(flw_fragOverlay, ivec2(3), ivec2(10));
+
+        vec4 overlayColor = texelFetch(_flw_overlayTex, actualCoord, 0);
         color.rgb = mix(overlayColor.rgb, color.rgb, overlayColor.a);
     }