Crumbling grumbling

- Fix crumbling on indirect
- Directly use the baseInstance as instance index without indirection
- #define base instance and draw id variables to simplify usage
- Fix null pointer looking up culling group
- Add method to map an instancer's local instance index to a global
  index in the page file

common/src/backend/java/dev/engine_room/flywheel/backend/engine/indirect/IndirectBuffers.java

@@ -113,7 +113,7 @@ public class IndirectBuffers {
 	 * Bind all buffers except the draw command buffer.
 	 */
 	public void bindForCrumbling() {
-		multiBind(3, 3);
+		multiBind(1, 4);
 	}
 
 	private void multiBind(int base, int count) {

common/src/backend/java/dev/engine_room/flywheel/backend/engine/indirect/IndirectDraw.java

@@ -89,7 +89,7 @@ public class IndirectDraw {
 		MemoryUtil.memPutInt(ptr + 4, 1); // instanceCount - only drawing one instance
 		MemoryUtil.memPutInt(ptr + 8, mesh.firstIndex()); // firstIndex
 		MemoryUtil.memPutInt(ptr + 12, mesh.baseVertex()); // baseVertex
-		MemoryUtil.memPutInt(ptr + 16, instancer.baseInstance() + instanceIndex); // baseInstance
+		MemoryUtil.memPutInt(ptr + 16, instancer.local2GlobalInstanceIndex(instanceIndex)); // baseInstance
 
 		MemoryUtil.memPutInt(ptr + 20, instancer.modelIndex()); // modelIndex
 

common/src/backend/java/dev/engine_room/flywheel/backend/engine/indirect/IndirectDrawManager.java

@@ -21,6 +21,7 @@ import dev.engine_room.flywheel.backend.compile.ContextShader;
 import dev.engine_room.flywheel.backend.compile.IndirectPrograms;
 import dev.engine_room.flywheel.backend.engine.CommonCrumbling;
 import dev.engine_room.flywheel.backend.engine.DrawManager;
+import dev.engine_room.flywheel.backend.engine.GroupKey;
 import dev.engine_room.flywheel.backend.engine.InstancerKey;
 import dev.engine_room.flywheel.backend.engine.LightStorage;
 import dev.engine_room.flywheel.backend.engine.MaterialRenderState;
@@ -204,15 +205,21 @@ public class IndirectDrawManager extends DrawManager<IndirectInstancer<?>> {
 			// Scratch memory for writing draw commands.
 			var block = MemoryBlock.malloc(IndirectBuffers.DRAW_COMMAND_STRIDE);
 
+			// Set up the crumbling program buffers. Nothing changes here between draws.
 			GlBufferType.DRAW_INDIRECT_BUFFER.bind(crumblingDrawBuffer.handle());
 			glBindBufferRange(GL_SHADER_STORAGE_BUFFER, BufferBindings.DRAW, crumblingDrawBuffer.handle(), 0, IndirectBuffers.DRAW_COMMAND_STRIDE);
 
 			for (var groupEntry : byType.entrySet()) {
 				var byProgress = groupEntry.getValue();
 
-				// Set up the crumbling program buffers. Nothing changes here between draws.
-				cullingGroups.get(groupEntry.getKey())
-						.bindWithContextShader(ContextShader.CRUMBLING);
+				GroupKey<?> groupKey = groupEntry.getKey();
+				IndirectCullingGroup<?> cullingGroup = cullingGroups.get(groupKey.instanceType());
+
+				if (cullingGroup == null) {
+					continue;
+				}
+
+				cullingGroup.bindWithContextShader(ContextShader.CRUMBLING);
 
 				for (var progressEntry : byProgress.int2ObjectEntrySet()) {
 					Samplers.CRUMBLING.makeActive();

common/src/backend/java/dev/engine_room/flywheel/backend/engine/indirect/IndirectInstancer.java

@@ -144,4 +144,8 @@ public class IndirectInstancer<I extends Instance> extends AbstractInstancer<I>
 	public int baseInstance() {
 		return baseInstance;
 	}
+
+	public int local2GlobalInstanceIndex(int instanceIndex) {
+		return mapping.objectIndex2GlobalIndex(instanceIndex);
+	}
 }

common/src/backend/java/dev/engine_room/flywheel/backend/engine/indirect/ObjectStorage.java

@@ -216,5 +216,9 @@ public class ObjectStorage extends AbstractArena {
 
 			pages = Arrays.copyOf(pages, neededPages);
 		}
+
+		public int objectIndex2GlobalIndex(int objectIndex) {
+			return (pages[objectIndex2PageIndex(objectIndex)] << LOG_2_PAGE_SIZE) + (objectIndex & PAGE_MASK);
+		}
 	}
 }

common/src/backend/resources/assets/flywheel/flywheel/internal/indirect/main.vert

@@ -23,12 +23,16 @@ uniform uint _flw_baseDraw;
 
 flat out uvec3 _flw_packedMaterial;
 
-void main() {
 #if __VERSION__ < 460
-    uint drawIndex = gl_DrawIDARB + _flw_baseDraw;
+#define flw_baseInstance gl_BaseInstanceARB
+#define flw_drawId gl_DrawIDARB
 #else
-    uint drawIndex = gl_DrawID + _flw_baseDraw;
+#define flw_baseInstance gl_BaseInstance
+#define flw_drawId gl_DrawID
 #endif
+
+void main() {
+    uint drawIndex = flw_drawId + _flw_baseDraw;
     MeshDrawCommand draw = _flw_drawCommands[drawIndex];
 
     _flw_uberMaterialVertexIndex = draw.materialVertexIndex;
@@ -42,11 +46,12 @@ void main() {
     //    _flw_normalMatrix = mat3(1.);
     #endif
 
-    #if __VERSION__ < 460
-    uint instanceIndex = _flw_instanceIndices[gl_BaseInstanceARB + gl_InstanceID];
-#else
-    uint instanceIndex = _flw_instanceIndices[gl_BaseInstance + gl_InstanceID];
-#endif
+    #ifdef _FLW_CRUMBLING
+    uint instanceIndex = flw_baseInstance;
+    #else
+    uint instanceIndex = _flw_instanceIndices[flw_baseInstance + gl_InstanceID];
+    #endif
+
     FlwInstance instance = _flw_unpackInstance(instanceIndex);
 
     _flw_main(instance, instanceIndex);