Rasterized occlusion culling

src/main/resources/assets/voxelmon/shaders/lod/gl46/bindings.glsl

@@ -50,17 +50,21 @@ layout(binding = 3, std430) readonly restrict buffer SectionBuffer {
     SectionMeta sectionData[];
 };
 
-layout(binding = 4, std430) readonly restrict buffer StateBuffer {
-    State stateData[];
-};
-
-layout(binding = 5, std430) readonly restrict buffer BiomeBuffer {
-    Biome biomeData[];
-};
-
 #ifndef VISIBILITY_ACCESS
 #define VISIBILITY_ACCESS readonly
 #endif
-layout(binding = 6, std430) VISIBILITY_ACCESS restrict buffer VisibilityBuffer {
+layout(binding = 4, std430) VISIBILITY_ACCESS restrict buffer VisibilityBuffer {
     uint visibilityData[];
 };
+
+layout(binding = 5, std430) readonly restrict buffer StateBuffer {
+    State stateData[];
+};
+
+layout(binding = 6, std430) readonly restrict buffer BiomeBuffer {
+    Biome biomeData[];
+};
+
+layout(binding = 7, std430) readonly restrict buffer LightingBuffer {
+    vec4 lightData[];
+};

src/main/resources/assets/voxelmon/shaders/lod/gl46/cmdgen.comp

@@ -34,12 +34,20 @@ void main() {
     uint detail = extractDetail(meta);
     ivec3 ipos = extractPosition(meta);
 
-    //TODO: fixme; i dont think this is correct
     vec3 cornerPos = vec3(((ipos<<detail)-baseSectionPos)<<5)-cameraSubPos;
 
 
     bool shouldRender = testFrustum(frustum, cornerPos, cornerPos+vec3(1<<(detail+5)));
 
+    //Check the occlusion data from last frame
+    if (visibilityData[gl_GlobalInvocationID.x] != frameId - 1) {
+        shouldRender = false;
+    }
+    //Clear the occlusion data (not strictly? needed? i think???)
+    //visibilityData[gl_GlobalInvocationID.x] = 0;
+
+    //TODO: need to make it check that only if it was also in the frustum last frame does it apply the visibilityData check!
+
     //This prevents overflow of the relative position encoder
     if (shouldRender) {
         shouldRender = !any(lessThan(ivec3(254), abs(ipos-(baseSectionPos>>detail))));

src/main/resources/assets/voxelmon/shaders/lod/gl46/cull/raster.frag

@@ -4,7 +4,9 @@
 #import <voxelmon:lod/gl46/bindings.glsl>
 flat in uint id;
 flat in uint value;
+//out vec4 colour;
 
 void main() {
     visibilityData[id] = value;
+    //colour = vec4(float(id&7)/7, float((id>>3)&7)/7, float((id>>6)&7)/7, 1);
 }

src/main/resources/assets/voxelmon/shaders/lod/gl46/cull/raster.vert

@@ -8,18 +8,20 @@ flat out uint id;
 flat out uint value;
 
 void main() {
-    SectionMeta section = sectionData[gl_VertexID>>3];
+    uint sid = gl_InstanceID;
+
+    SectionMeta section = sectionData[sid];
 
     uint detail = extractDetail(section);
     ivec3 ipos = extractPosition(section);
 
     //Transform ipos with respect to the vertex corner
-    ipos += ivec3(gl_VertexID&1, (gl_VertexID>>1)&1, (gl_VertexID>>2)&1);
+    ipos += ivec3(gl_VertexID&1, (gl_VertexID>>2)&1, (gl_VertexID>>1)&1);
 
     vec3 cornerPos = vec3(((ipos<<detail)-baseSectionPos)<<5);
     gl_Position = MVP * vec4(cornerPos,1);
 
     //Write to this id
-    id = gl_VertexID>>3;
+    id = sid;
     value = frameId;
 }