Function ProcessTexture

Chapter_14/src/Textures.cpp:189–227

* Covert a R8G8B8A8_UNORM texture to BC7 format and generate mips. */

	 * Covert a R8G8B8A8_UNORM texture to BC7 format and generate mips.
	 */
	bool ProcessTexture(Texture& texture, bool generateMips = true, bool quickBC7 = true)
	{
		// Check if there's anything to compress
		if (texture.mips.empty()) return false;

		TextureData* texData = &texture.mips[0];

		// BC7 textures must be aligned to pixel 4x4 blocks. 
		if (texData->width % 4 != 0 || texData->height % 4 != 0) {
			MessageBox(NULL, L"Size of the input texture must be multiple of 4 for compression to work! Make sure to call FormatTexture() before this function to add necessary padding", L"Error", MB_OK);
			return false;
		}

		Image source = {};
		source.width = texData->width;
		source.height = texData->height;
		source.rowPitch = (texData->width * size_t(texData->stride));
		source.slicePitch = (source.rowPitch * source.height);
		source.format = DXGI_FORMAT_R8G8B8A8_UNORM;
		source.pixels = texData->texels;

		TEX_COMPRESS_FLAGS flags = TEX_COMPRESS_DEFAULT;
		if (quickBC7) flags = TEX_COMPRESS_BC7_QUICK;
		ScratchImage scratchBuffer;

		if (generateMips) {
			ScratchImage mips;
			if (FAILED(DirectX::GenerateMipMaps(source, TEX_FILTER_DEFAULT, 0, mips))) return false;
			if (FAILED(Compress(d3d11Device, mips.GetImages(), mips.GetImageCount(), mips.GetMetadata(), DXGI_FORMAT_BC7_UNORM, flags, 1.f, scratchBuffer))) return false;
			mips.Release();
		} else {
			if (FAILED(Compress(d3d11Device, source, DXGI_FORMAT_BC7_UNORM, flags, 1.f, scratchBuffer))) return false;
		}

		// Format the compressed texture into our format, prepping it for use on the GPU
		texture.isBC7Compressed = true;

		return FormatCompressedTexture(scratchBuffer, texture);
	}
#endif

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