diff options
Diffstat (limited to 'TextureLoader/src/TextureLoader.cpp')
| -rw-r--r-- | TextureLoader/src/TextureLoader.cpp | 54 |
1 files changed, 42 insertions, 12 deletions
diff --git a/TextureLoader/src/TextureLoader.cpp b/TextureLoader/src/TextureLoader.cpp index 3f5d63d..6b13030 100644 --- a/TextureLoader/src/TextureLoader.cpp +++ b/TextureLoader/src/TextureLoader.cpp @@ -84,27 +84,55 @@ ChannelType SRGBAverage(ChannelType c0, ChannelType c1, ChannelType c2, ChannelT } template <typename ChannelType> -void ComputeCoarseMip(Uint32 NumChannels, bool IsSRGB, const void* pFineMip, Uint32 FineMipStride, void* pCoarseMip, Uint32 CoarseMipStride, Uint32 CoarseMipWidth, Uint32 CoarseMipHeight) +ChannelType LinearAverage(ChannelType c0, ChannelType c1, ChannelType c2, ChannelType c3) { - for (size_t row = 0; row < size_t{CoarseMipHeight}; ++row) - for (size_t col = 0; col < size_t{CoarseMipWidth}; ++col) + static_assert(std::numeric_limits<ChannelType>::is_integer && !std::numeric_limits<ChannelType>::is_signed, "Unsigned integers are expected"); + return static_cast<ChannelType>(static_cast<Uint32>(c0) + static_cast<Uint32>(c1) + static_cast<Uint32>(c2) + static_cast<Uint32>(c3)); +} + +template <typename ChannelType> +void ComputeCoarseMip(Uint32 NumChannels, + bool IsSRGB, + const void* pFineMip, + Uint32 FineMipStride, + Uint32 FineMipWidth, + Uint32 FineMipHeight, + void* pCoarseMip, + Uint32 CoarseMipStride, + Uint32 CoarseMipWidth, + Uint32 CoarseMipHeight) +{ + VERIFY_EXPR(FineMipWidth > 0 && FineMipHeight > 0 && FineMipStride > 0); + VERIFY_EXPR(CoarseMipWidth > 0 && CoarseMipHeight > 0 && CoarseMipStride > 0); + + for (Uint32 row = 0; row < CoarseMipHeight; ++row) + { + auto src_row0 = row * 2; + auto src_row1 = std::min(row * 2 + 1, FineMipHeight - 1); + + auto pSrcRow0 = reinterpret_cast<const ChannelType*>(reinterpret_cast<const Uint8*>(pFineMip) + src_row0 * FineMipStride); + auto pSrcRow1 = reinterpret_cast<const ChannelType*>(reinterpret_cast<const Uint8*>(pFineMip) + src_row1 * FineMipStride); + + for (Uint32 col = 0; col < CoarseMipWidth; ++col) { - auto FineRow0 = reinterpret_cast<const ChannelType*>(reinterpret_cast<const Uint8*>(pFineMip) + row * 2 * size_t{FineMipStride}); - auto FineRow1 = reinterpret_cast<const ChannelType*>(reinterpret_cast<const Uint8*>(pFineMip) + (row * 2 + 1) * size_t{FineMipStride}); + auto src_col0 = col * 2; + auto src_col1 = std::min(col * 2 + 1, FineMipWidth - 1); for (Uint32 c = 0; c < NumChannels; ++c) { - auto Col00 = FineRow0[col * 2 * NumChannels + c]; - auto Col01 = FineRow0[(col * 2 + 1) * NumChannels + c]; - auto Col10 = FineRow1[col * 2 * NumChannels + c]; - auto Col11 = FineRow1[(col * 2 + 1) * NumChannels + c]; - auto& DstCol = reinterpret_cast<ChannelType*>(reinterpret_cast<Uint8*>(pCoarseMip) + row * size_t{CoarseMipStride})[col * NumChannels + c]; + auto Chnl00 = pSrcRow0[src_col0 * NumChannels + c]; + auto Chnl10 = pSrcRow0[src_col1 * NumChannels + c]; + auto Chnl01 = pSrcRow1[src_col0 * NumChannels + c]; + auto Chnl11 = pSrcRow1[src_col1 * NumChannels + c]; + + auto& DstCol = reinterpret_cast<ChannelType*>(reinterpret_cast<Uint8*>(pCoarseMip) + row * CoarseMipStride)[col * NumChannels + c]; if (IsSRGB) - DstCol = SRGBAverage(Col00, Col01, Col10, Col11); + DstCol = SRGBAverage(Chnl00, Chnl01, Chnl10, Chnl11); else - DstCol = (Col00 + Col01 + Col10 + Col11) / 4; + DstCol = LinearAverage(Chnl00, Chnl01, Chnl10, Chnl11); } } + } } template <typename ChannelType> @@ -230,6 +258,7 @@ void CreateTextureFromImage(Image* pSrcImage, { ComputeCoarseMip<Uint8>(NumComponents, IsSRGB, pSubResources[m - 1].pData, pSubResources[m - 1].Stride, + MipWidth, MipHeight, Mips[m].data(), CoarseMipStride, CoarseMipWidth, CoarseMipHeight); } @@ -237,6 +266,7 @@ void CreateTextureFromImage(Image* pSrcImage, { ComputeCoarseMip<Uint16>(NumComponents, IsSRGB, pSubResources[m - 1].pData, pSubResources[m - 1].Stride, + MipWidth, MipHeight, Mips[m].data(), CoarseMipStride, CoarseMipWidth, CoarseMipHeight); } |