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 sampler2DMS srcMS;
 9  
10  void main()
11  {
12      uvec2 coords = uvec2(gl_FragCoord.xy);
13  
14      int deltaX = sample_counts_log2.x - sample_counts_log2.z;
15      int deltaY = sample_counts_log2.y - sample_counts_log2.w;
16      int samplesInXLog2 = sample_counts_log2.z;
17      int samplesInYLog2 = sample_counts_log2.w;
18      int samplesInX = 1 << samplesInXLog2;
19      int samplesInY = 1 << samplesInYLog2;
20      int sampleIdx = ((int(coords.x) >> deltaX) & (samplesInX - 1)) | (((int(coords.y) >> deltaY) & (samplesInY - 1)) << samplesInXLog2);
21  
22      samplesInXLog2 = sample_counts_log2.x;
23      samplesInYLog2 = sample_counts_log2.y;
24  
25      ivec2 shiftedCoords = ivec2(int(coords.x) >> samplesInXLog2, int(coords.y) >> samplesInYLog2);
26  
27      gl_FragDepth = texelFetch(srcMS, shiftedCoords, sampleIdx).r;
28  }