| static const uint GROUP_DIM = 8; // 2 ^ (out_mip_count - 1) |
| |
| Texture2D tex : register(t0); |
| SamplerState samp : register(s0); |
| |
| cbuffer ConstantBuffer : register(b0) |
| { |
| uint2 mip1Size; |
| uint sampleLevel; |
| uint totalMips; |
| } |
| |
| RWTexture2D<float4> mip1 : register(u0); |
| RWTexture2D<float4> mip2 : register(u1); |
| RWTexture2D<float4> mip3 : register(u2); |
| RWTexture2D<float4> mip4 : register(u3); |
| |
| groupshared float4 groupColor[GROUP_DIM][GROUP_DIM]; |
| |
| [numthreads(GROUP_DIM, GROUP_DIM, 1)] |
| void CS_Generate4MipMaps(uint3 localId: SV_GroupThreadId, uint3 globalId: SV_DispatchThreadID) |
| { |
| const float2 coord = float2(1.0f / float(mip1Size.x), 1.0f / float(mip1Size.y)) * (globalId.xy + 0.5); |
| float4 c = tex.SampleLevel(samp, coord, sampleLevel); |
| |
| mip1[globalId.xy] = c; |
| groupColor[localId.y][localId.x] = c; |
| |
| if (sampleLevel + 1 >= totalMips) |
| return; |
| |
| GroupMemoryBarrierWithGroupSync(); |
| |
| if ((localId.x & 1) == 0 && (localId.y & 1) == 0) { |
| c = (c + groupColor[localId.y][localId.x + 1] + groupColor[localId.y + 1][localId.x] + groupColor[localId.y + 1][localId.x + 1]) / 4.0; |
| mip2[globalId.xy / 2] = c; |
| groupColor[localId.y][localId.x] = c; |
| } |
| |
| if (sampleLevel + 2 >= totalMips) |
| return; |
| |
| GroupMemoryBarrierWithGroupSync(); |
| |
| if ((localId.x & 3) == 0 && (localId.y & 3) == 0) { |
| c = (c + groupColor[localId.y][localId.x + 2] + groupColor[localId.y + 2][localId.x] + groupColor[localId.y + 2][localId.x + 2]) / 4.0; |
| mip3[globalId.xy / 4] = c; |
| groupColor[localId.y][localId.x] = c; |
| } |
| |
| if (sampleLevel + 3 >= totalMips) |
| return; |
| |
| GroupMemoryBarrierWithGroupSync(); |
| |
| if ((localId.x & 7) == 0 && (localId.y & 7) == 0) { |
| c = (c + groupColor[localId.y][localId.x + 3] + groupColor[localId.y + 3][localId.x] + groupColor[localId.y + 3][localId.x + 3]) / 4.0; |
| mip4[globalId.xy / 8] = c; |
| } |
| } |