1  #version 450 core
 2  
 3  layout (std140, binding = 0) uniform sample_counts_log2_in
 4  {
 5      ivec4 sample_counts_log2;
 6  };
 7  
 8  layout (set = 2, binding = 0) uniform sampler2D src;
 9  
10  void main()
11  {
12      int deltaX = sample_counts_log2.x - sample_counts_log2.z;
13      int deltaY = sample_counts_log2.y - sample_counts_log2.w;
14      int samplesInXLog2 = sample_counts_log2.z;
15      int samplesInYLog2 = sample_counts_log2.w;
16      int samplesInX = 1 << samplesInXLog2;
17      int samplesInY = 1 << samplesInYLog2;
18  
19      int sampleIndex = gl_SampleID;
20  
21      int inX = (int(gl_FragCoord.x) << sample_counts_log2.x) | ((sampleIndex & (samplesInX - 1)) << deltaX);
22      int inY = (int(gl_FragCoord.y) << sample_counts_log2.y) | ((sampleIndex >> samplesInXLog2) << deltaY);
23  
24      gl_FragDepth = texelFetch(src, ivec2(inX, inY), 0).r;
25  }