1  #version 450 core
 2  
 3  #extension GL_EXT_scalar_block_layout : require
 4  #extension GL_EXT_shader_8bit_storage : require
 5  
 6  layout (local_size_x = 16, local_size_y = 1, local_size_z = 1) in;
 7  
 8  layout (std430, set = 0, binding = 0) uniform index_buffer_pattern
 9  {
10      int ibp_pattern[8];
11      int ibp_primitive_vertices;
12      int ibp_primitive_vertices_out;
13      int ibp_index_size;
14      int ibp_index_size_out;
15      int ibp_base_index;
16      int ibp_index_stride;
17      int src_offset;
18      int total_primitives;
19  };
20  
21  layout (std430, set = 1, binding = 1) buffer in_s
22  {
23      uint8_t[] in_data;
24  };
25  
26  layout (std430, set = 1, binding = 2) buffer out_s
27  {
28      uint8_t[] out_data;
29  };
30  
31  void main()
32  {
33      int primitiveIndex = int(gl_GlobalInvocationID.x);
34      if (primitiveIndex >= total_primitives)
35      {
36          return;
37      }
38  
39      int inOffset = primitiveIndex * ibp_index_stride;
40      int outOffset = primitiveIndex * ibp_primitive_vertices_out;
41  
42      for (int i = 0; i < ibp_primitive_vertices_out; i++)
43      {
44          int j;
45          int io = max(0, inOffset + ibp_base_index + ibp_pattern[i]) * ibp_index_size;
46          int oo = (outOffset + i) * ibp_index_size_out;
47  
48          for (j = 0; j < ibp_index_size; j++)
49          {
50              out_data[oo + j] = in_data[src_offset + io + j];
51          }
52  
53          for (; j < ibp_index_size_out; j++)
54          {
55              out_data[oo + j] = uint8_t(0);
56          }
57      }
58  }