91 lines
2.3 KiB
Plaintext
91 lines
2.3 KiB
Plaintext
#version 450 core
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/**
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Maximum number of lights per cluster
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*/
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#define MAX_LIGHTS_PER_CLUSTER 100
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/**
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The number of "threads" to run
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*/
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#define CULL_LOCAL_SIZE 128
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/**
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Bind points for different SSBOs
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*/
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#define CLUSTER_SSBO_BIND_POINT 1
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#define POINT_LIGHT_SSBO_BIND_POINT 2
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#define DIRECT_LIGHT_SSBO_BIND_POINT 3
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layout(local_size_x = CULL_LOCAL_SIZE, local_size_y = 1, local_size_z = 1) in;
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struct PointLight {
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vec4 position;
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vec4 color;
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float constant;
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float linear;
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float quadratic;
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float radius;
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};
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struct Cluster {
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vec4 minPoint;
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vec4 maxPoint;
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uint count;
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uint lightIndices[MAX_LIGHTS_PER_CLUSTER];
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};
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layout(std430, binding = CLUSTER_SSBO_BIND_POINT) restrict buffer clusterSSBO {
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Cluster clusters[];
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};
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layout(std430, binding = POINT_LIGHT_SSBO_BIND_POINT) restrict buffer lightSSBO {
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PointLight pointLight[];
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};
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uniform mat4 viewMatrix;
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/**
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* Number of lights in the scene
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*/
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uniform int lightCount;
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bool testSphereAABB(uint i, Cluster c);
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// each invocation of main() is a thread processing a cluster
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void main() {
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uint index = gl_WorkGroupID.x * CULL_LOCAL_SIZE + gl_LocalInvocationID.x;
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Cluster cluster = clusters[index];
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// we need to reset count because culling runs every frame.
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// otherwise it would accumulate.
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cluster.count = 0;
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for (uint i = 0; i < lightCount; ++i){
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if (testSphereAABB(i, cluster) && cluster.count < MAX_LIGHTS_PER_CLUSTER){
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cluster.lightIndices[cluster.count] = i;
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cluster.count++;
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}
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}
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clusters[index] = cluster;
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}
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bool sphereAABBIntersection(vec3 center, float radius, vec3 aabbMin, vec3 aabbMax) {
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// closest point on the AABB to the sphere center
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vec3 closestPoint = clamp(center, aabbMin, aabbMax);
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// squared distance between the sphere center and closest point
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float distanceSquared = dot(closestPoint - center, closestPoint - center);
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return distanceSquared <= radius * radius;
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}
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// this just unpacks data for sphereAABBIntersection
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bool testSphereAABB(uint i, Cluster cluster) {
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vec3 center = vec3(viewMatrix * pointLight[i].position);
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float radius = pointLight[i].radius;
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vec3 aabbMin = cluster.minPoint.xyz;
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vec3 aabbMax = cluster.maxPoint.xyz;
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return sphereAABBIntersection(center, radius, aabbMin, aabbMax);
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} |