matrixfurry.com
The open source OpenXR runtime
external: Add bcdec for BC4 decoding
Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2457>
authored by
Beyley Cardellio
and committed by
Marge Bot
a56078e7
83f4422d
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.reuse/dep5
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.reuse/dep5
···
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License: MIT OR Unlicense
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Comment: SPDX-License-Identifier missing.
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Files: src/external/bcdec/bcdec*
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Copyright: 2022, Sergii Kudlai
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License: MIT OR Unlicense
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Comment: SPDX-License-Identifier missing.
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Files: src/external/glad/include/EGL/eglplatform.h
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Copyright: 2007-2020, The Khronos Group Inc.
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License: Apache-2.0
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src/external/CMakeLists.txt
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src/external/CMakeLists.txt
···
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add_library(xrt-external-stb INTERFACE)
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target_include_directories(xrt-external-stb SYSTEM INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/stb)
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# bcdec
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add_library(xrt-external-bcdec INTERFACE)
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target_include_directories(xrt-external-bcdec SYSTEM INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/bcdec)
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# renderdoc
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add_library(xrt-external-renderdoc INTERFACE)
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target_include_directories(
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src/external/bcdec/bcdec.h
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src/external/bcdec/bcdec.h
···
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/* bcdec.h - v0.97
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provides functions to decompress blocks of BC compressed images
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written by Sergii "iOrange" Kudlai in 2022
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This library does not allocate memory and is trying to use as less stack as possible
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The library was never optimized specifically for speed but for the overall size
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it has zero external dependencies and is not using any runtime functions
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Supported BC formats:
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BC1 (also known as DXT1) + it's "binary alpha" variant BC1A (DXT1A)
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BC2 (also known as DXT3)
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BC3 (also known as DXT5)
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BC4 (also known as ATI1N)
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BC5 (also known as ATI2N)
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BC6H (HDR format)
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BC7
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BC1/BC2/BC3/BC7 are expected to decompress into 4*4 RGBA blocks 8bit per component (32bit pixel)
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BC4/BC5 are expected to decompress into 4*4 R/RG blocks 8bit per component (8bit and 16bit pixel)
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BC6H is expected to decompress into 4*4 RGB blocks of either 32bit float or 16bit "half" per
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component (96bit or 48bit pixel)
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For more info, issues and suggestions please visit https://github.com/iOrange/bcdec
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Configuration:
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#define BCDEC_BC4BC5_PRECISE:
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enables more precise but slower BC4/BC5 decoding + signed/unsigned mode
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CREDITS:
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Aras Pranckevicius (@aras-p) - BC1/BC3 decoders optimizations (up to 3x the speed)
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- BC6H/BC7 bits pulling routines optimizations
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- optimized BC6H by moving unquantize out of the loop
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- Split BC6H decompression function into 'half' and
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'float' variants
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Michael Schmidt (@RunDevelopment) - Found better "magic" coefficients for integer interpolation
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of reference colors in BC1 color block, that match with
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the floating point interpolation. This also made it faster
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than integer division by 3!
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bugfixes:
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@linkmauve
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LICENSE: See end of file for license information.
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*/
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#ifndef BCDEC_HEADER_INCLUDED
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#define BCDEC_HEADER_INCLUDED
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#define BCDEC_VERSION_MAJOR 0
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#define BCDEC_VERSION_MINOR 98
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/* if BCDEC_STATIC causes problems, try defining BCDECDEF to 'inline' or 'static inline' */
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#ifndef BCDECDEF
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#ifdef BCDEC_STATIC
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#define BCDECDEF static
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#else
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#ifdef __cplusplus
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#define BCDECDEF extern "C"
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#else
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#define BCDECDEF extern
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#endif
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#endif
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#endif
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/* Used information sources:
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https://docs.microsoft.com/en-us/windows/win32/direct3d10/d3d10-graphics-programming-guide-resources-block-compression
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https://docs.microsoft.com/en-us/windows/win32/direct3d11/bc6h-format
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https://docs.microsoft.com/en-us/windows/win32/direct3d11/bc7-format
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https://docs.microsoft.com/en-us/windows/win32/direct3d11/bc7-format-mode-reference
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! WARNING ! Khronos's BPTC partitions tables contain mistakes, do not use them!
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https://www.khronos.org/registry/DataFormat/specs/1.1/dataformat.1.1.html#BPTC
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! Use tables from here instead !
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https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_texture_compression_bptc.txt
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Leaving it here as it's a nice read
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https://fgiesen.wordpress.com/2021/10/04/gpu-bcn-decoding/
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Fast half to float function from here
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https://gist.github.com/rygorous/2144712
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*/
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#define BCDEC_BC1_BLOCK_SIZE 8
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#define BCDEC_BC2_BLOCK_SIZE 16
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#define BCDEC_BC3_BLOCK_SIZE 16
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#define BCDEC_BC4_BLOCK_SIZE 8
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#define BCDEC_BC5_BLOCK_SIZE 16
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#define BCDEC_BC6H_BLOCK_SIZE 16
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#define BCDEC_BC7_BLOCK_SIZE 16
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#define BCDEC_BC1_COMPRESSED_SIZE(w, h) ((((w)>>2)*((h)>>2))*BCDEC_BC1_BLOCK_SIZE)
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#define BCDEC_BC2_COMPRESSED_SIZE(w, h) ((((w)>>2)*((h)>>2))*BCDEC_BC2_BLOCK_SIZE)
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#define BCDEC_BC3_COMPRESSED_SIZE(w, h) ((((w)>>2)*((h)>>2))*BCDEC_BC3_BLOCK_SIZE)
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#define BCDEC_BC4_COMPRESSED_SIZE(w, h) ((((w)>>2)*((h)>>2))*BCDEC_BC4_BLOCK_SIZE)
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#define BCDEC_BC5_COMPRESSED_SIZE(w, h) ((((w)>>2)*((h)>>2))*BCDEC_BC5_BLOCK_SIZE)
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#define BCDEC_BC6H_COMPRESSED_SIZE(w, h) ((((w)>>2)*((h)>>2))*BCDEC_BC6H_BLOCK_SIZE)
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#define BCDEC_BC7_COMPRESSED_SIZE(w, h) ((((w)>>2)*((h)>>2))*BCDEC_BC7_BLOCK_SIZE)
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BCDECDEF void bcdec_bc1(const void* compressedBlock, void* decompressedBlock, int destinationPitch);
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BCDECDEF void bcdec_bc2(const void* compressedBlock, void* decompressedBlock, int destinationPitch);
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BCDECDEF void bcdec_bc3(const void* compressedBlock, void* decompressedBlock, int destinationPitch);
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#ifndef BCDEC_BC4BC5_PRECISE
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BCDECDEF void bcdec_bc4(const void* compressedBlock, void* decompressedBlock, int destinationPitch);
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BCDECDEF void bcdec_bc5(const void* compressedBlock, void* decompressedBlock, int destinationPitch);
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#else
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BCDECDEF void bcdec_bc4(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned);
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BCDECDEF void bcdec_bc5(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned);
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BCDECDEF void bcdec_bc4_float(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned);
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BCDECDEF void bcdec_bc5_float(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned);
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#endif
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BCDECDEF void bcdec_bc6h_float(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned);
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BCDECDEF void bcdec_bc6h_half(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned);
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BCDECDEF void bcdec_bc7(const void* compressedBlock, void* decompressedBlock, int destinationPitch);
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#endif /* BCDEC_HEADER_INCLUDED */
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#ifdef BCDEC_IMPLEMENTATION
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static void bcdec__color_block(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int onlyOpaqueMode) {
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unsigned short c0, c1;
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unsigned int refColors[4]; /* 0xAABBGGRR */
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unsigned char* dstColors;
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unsigned int colorIndices;
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int i, j, idx;
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unsigned int r0, g0, b0, r1, g1, b1, r, g, b;
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c0 = ((unsigned short*)compressedBlock)[0];
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c1 = ((unsigned short*)compressedBlock)[1];
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/* Unpack 565 ref colors */
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r0 = (c0 >> 11) & 0x1F;
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g0 = (c0 >> 5) & 0x3F;
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b0 = c0 & 0x1F;
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r1 = (c1 >> 11) & 0x1F;
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g1 = (c1 >> 5) & 0x3F;
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b1 = c1 & 0x1F;
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/* Expand 565 ref colors to 888 */
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r = (r0 * 527 + 23) >> 6;
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g = (g0 * 259 + 33) >> 6;
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b = (b0 * 527 + 23) >> 6;
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refColors[0] = 0xFF000000 | (b << 16) | (g << 8) | r;
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r = (r1 * 527 + 23) >> 6;
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g = (g1 * 259 + 33) >> 6;
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b = (b1 * 527 + 23) >> 6;
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refColors[1] = 0xFF000000 | (b << 16) | (g << 8) | r;
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if (c0 > c1 || onlyOpaqueMode) { /* Standard BC1 mode (also BC3 color block uses ONLY this mode) */
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/* color_2 = 2/3*color_0 + 1/3*color_1
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color_3 = 1/3*color_0 + 2/3*color_1 */
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r = ((2 * r0 + r1) * 351 + 61) >> 7;
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g = ((2 * g0 + g1) * 2763 + 1039) >> 11;
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b = ((2 * b0 + b1) * 351 + 61) >> 7;
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refColors[2] = 0xFF000000 | (b << 16) | (g << 8) | r;
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r = ((r0 + r1 * 2) * 351 + 61) >> 7;
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g = ((g0 + g1 * 2) * 2763 + 1039) >> 11;
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b = ((b0 + b1 * 2) * 351 + 61) >> 7;
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refColors[3] = 0xFF000000 | (b << 16) | (g << 8) | r;
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} else { /* Quite rare BC1A mode */
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/* color_2 = 1/2*color_0 + 1/2*color_1;
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color_3 = 0; */
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r = ((r0 + r1) * 1053 + 125) >> 8;
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g = ((g0 + g1) * 4145 + 1019) >> 11;
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b = ((b0 + b1) * 1053 + 125) >> 8;
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refColors[2] = 0xFF000000 | (b << 16) | (g << 8) | r;
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refColors[3] = 0x00000000;
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}
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colorIndices = ((unsigned int*)compressedBlock)[1];
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/* Fill out the decompressed color block */
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dstColors = (unsigned char*)decompressedBlock;
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for (i = 0; i < 4; ++i) {
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for (j = 0; j < 4; ++j) {
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idx = colorIndices & 0x03;
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((unsigned int*)dstColors)[j] = refColors[idx];
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colorIndices >>= 2;
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}
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dstColors += destinationPitch;
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}
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}
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static void bcdec__sharp_alpha_block(const void* compressedBlock, void* decompressedBlock, int destinationPitch) {
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unsigned short* alpha;
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unsigned char* decompressed;
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int i, j;
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alpha = (unsigned short*)compressedBlock;
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decompressed = (unsigned char*)decompressedBlock;
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for (i = 0; i < 4; ++i) {
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for (j = 0; j < 4; ++j) {
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decompressed[j * 4] = ((alpha[i] >> (4 * j)) & 0x0F) * 17;
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}
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decompressed += destinationPitch;
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}
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}
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static void bcdec__smooth_alpha_block(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int pixelSize) {
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unsigned char* decompressed;
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unsigned char alpha[8];
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int i, j;
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unsigned long long block, indices;
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block = *(unsigned long long*)compressedBlock;
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decompressed = (unsigned char*)decompressedBlock;
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alpha[0] = block & 0xFF;
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alpha[1] = (block >> 8) & 0xFF;
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if (alpha[0] > alpha[1]) {
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/* 6 interpolated alpha values. */
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alpha[2] = (6 * alpha[0] + alpha[1]) / 7; /* 6/7*alpha_0 + 1/7*alpha_1 */
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alpha[3] = (5 * alpha[0] + 2 * alpha[1]) / 7; /* 5/7*alpha_0 + 2/7*alpha_1 */
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alpha[4] = (4 * alpha[0] + 3 * alpha[1]) / 7; /* 4/7*alpha_0 + 3/7*alpha_1 */
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alpha[5] = (3 * alpha[0] + 4 * alpha[1]) / 7; /* 3/7*alpha_0 + 4/7*alpha_1 */
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alpha[6] = (2 * alpha[0] + 5 * alpha[1]) / 7; /* 2/7*alpha_0 + 5/7*alpha_1 */
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alpha[7] = ( alpha[0] + 6 * alpha[1]) / 7; /* 1/7*alpha_0 + 6/7*alpha_1 */
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}
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else {
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/* 4 interpolated alpha values. */
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alpha[2] = (4 * alpha[0] + alpha[1]) / 5; /* 4/5*alpha_0 + 1/5*alpha_1 */
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alpha[3] = (3 * alpha[0] + 2 * alpha[1]) / 5; /* 3/5*alpha_0 + 2/5*alpha_1 */
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alpha[4] = (2 * alpha[0] + 3 * alpha[1]) / 5; /* 2/5*alpha_0 + 3/5*alpha_1 */
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alpha[5] = ( alpha[0] + 4 * alpha[1]) / 5; /* 1/5*alpha_0 + 4/5*alpha_1 */
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alpha[6] = 0x00;
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alpha[7] = 0xFF;
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}
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indices = block >> 16;
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for (i = 0; i < 4; ++i) {
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for (j = 0; j < 4; ++j) {
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decompressed[j * pixelSize] = alpha[indices & 0x07];
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indices >>= 3;
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}
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decompressed += destinationPitch;
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}
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}
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#ifdef BCDEC_BC4BC5_PRECISE
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static void bcdec__bc4_block(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int pixelSize, int isSigned) {
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signed char* sblock;
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unsigned char* ublock;
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int alpha[8];
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int i, j;
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unsigned long long block, indices;
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static int aWeights4[4] = { 13107, 26215, 39321, 52429 };
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static int aWeights6[6] = { 9363, 18724, 28086, 37450, 46812, 56173 };
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block = *(unsigned long long*)compressedBlock;
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if (isSigned) {
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alpha[0] = (char)(block & 0xFF);
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alpha[1] = (char)((block >> 8) & 0xFF);
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if (alpha[0] < -127) alpha[0] = -127; /* -128 clamps to -127 */
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if (alpha[1] < -127) alpha[1] = -127; /* -128 clamps to -127 */
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} else {
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alpha[0] = block & 0xFF;
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alpha[1] = (block >> 8) & 0xFF;
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}
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if (alpha[0] > alpha[1]) {
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/* 6 interpolated alpha values. */
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alpha[2] = (aWeights6[5] * alpha[0] + aWeights6[0] * alpha[1] + 32768) >> 16; /* 6/7*alpha_0 + 1/7*alpha_1 */
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alpha[3] = (aWeights6[4] * alpha[0] + aWeights6[1] * alpha[1] + 32768) >> 16; /* 5/7*alpha_0 + 2/7*alpha_1 */
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alpha[4] = (aWeights6[3] * alpha[0] + aWeights6[2] * alpha[1] + 32768) >> 16; /* 4/7*alpha_0 + 3/7*alpha_1 */
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alpha[5] = (aWeights6[2] * alpha[0] + aWeights6[3] * alpha[1] + 32768) >> 16; /* 3/7*alpha_0 + 4/7*alpha_1 */
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alpha[6] = (aWeights6[1] * alpha[0] + aWeights6[4] * alpha[1] + 32768) >> 16; /* 2/7*alpha_0 + 5/7*alpha_1 */
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alpha[7] = (aWeights6[0] * alpha[0] + aWeights6[5] * alpha[1] + 32768) >> 16; /* 1/7*alpha_0 + 6/7*alpha_1 */
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} else {
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/* 4 interpolated alpha values. */
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alpha[2] = (aWeights4[3] * alpha[0] + aWeights4[0] * alpha[1] + 32768) >> 16; /* 4/5*alpha_0 + 1/5*alpha_1 */
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alpha[3] = (aWeights4[2] * alpha[0] + aWeights4[1] * alpha[1] + 32768) >> 16; /* 3/5*alpha_0 + 2/5*alpha_1 */
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alpha[4] = (aWeights4[1] * alpha[0] + aWeights4[2] * alpha[1] + 32768) >> 16; /* 2/5*alpha_0 + 3/5*alpha_1 */
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alpha[5] = (aWeights4[0] * alpha[0] + aWeights4[3] * alpha[1] + 32768) >> 16; /* 1/5*alpha_0 + 4/5*alpha_1 */
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alpha[6] = isSigned ? -127 : 0;
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alpha[7] = isSigned ? 127 : 255;
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}
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indices = block >> 16;
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if (isSigned) {
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sblock = (char*)decompressedBlock;
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for (i = 0; i < 4; ++i) {
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for (j = 0; j < 4; ++j) {
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sblock[j * pixelSize] = (char)alpha[indices & 0x07];
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indices >>= 3;
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}
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sblock += destinationPitch;
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}
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} else {
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ublock = (unsigned char*)decompressedBlock;
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for (i = 0; i < 4; ++i) {
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for (j = 0; j < 4; ++j) {
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ublock[j * pixelSize] = (unsigned char)alpha[indices & 0x07];
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indices >>= 3;
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}
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ublock += destinationPitch;
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}
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}
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}
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static void bcdec__bc4_block_float(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int pixelSize, int isSigned) {
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float* decompressed;
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float alpha[8];
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int i, j;
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unsigned long long block, indices;
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block = *(unsigned long long*)compressedBlock;
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decompressed = (float*)decompressedBlock;
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if (isSigned) {
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alpha[0] = (float)((char)(block & 0xFF)) / 127.0f;
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alpha[1] = (float)((char)((block >> 8) & 0xFF)) / 127.0f;
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if (alpha[0] < -1.0f) alpha[0] = -1.0f; /* -128 clamps to -127 */
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if (alpha[1] < -1.0f) alpha[1] = -1.0f; /* -128 clamps to -127 */
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} else {
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alpha[0] = (float)(block & 0xFF) / 255.0f;
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alpha[1] = (float)((block >> 8) & 0xFF) / 255.0f;
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}
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if (alpha[0] > alpha[1]) {
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/* 6 interpolated alpha values. */
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alpha[2] = (6.0f * alpha[0] + alpha[1]) / 7.0f; /* 6/7*alpha_0 + 1/7*alpha_1 */
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alpha[3] = (5.0f * alpha[0] + 2.0f * alpha[1]) / 7.0f; /* 5/7*alpha_0 + 2/7*alpha_1 */
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alpha[4] = (4.0f * alpha[0] + 3.0f * alpha[1]) / 7.0f; /* 4/7*alpha_0 + 3/7*alpha_1 */
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alpha[5] = (3.0f * alpha[0] + 4.0f * alpha[1]) / 7.0f; /* 3/7*alpha_0 + 4/7*alpha_1 */
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alpha[6] = (2.0f * alpha[0] + 5.0f * alpha[1]) / 7.0f; /* 2/7*alpha_0 + 5/7*alpha_1 */
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alpha[7] = ( alpha[0] + 6.0f * alpha[1]) / 7.0f; /* 1/7*alpha_0 + 6/7*alpha_1 */
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} else {
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/* 4 interpolated alpha values. */
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alpha[2] = (4.0f * alpha[0] + alpha[1]) / 5.0f; /* 4/5*alpha_0 + 1/5*alpha_1 */
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alpha[3] = (3.0f * alpha[0] + 2.0f * alpha[1]) / 5.0f; /* 3/5*alpha_0 + 2/5*alpha_1 */
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alpha[4] = (2.0f * alpha[0] + 3.0f * alpha[1]) / 5.0f; /* 2/5*alpha_0 + 3/5*alpha_1 */
345
+
alpha[5] = ( alpha[0] + 4.0f * alpha[1]) / 5.0f; /* 1/5*alpha_0 + 4/5*alpha_1 */
346
+
alpha[6] = isSigned ? -1.0f : 0.0f;
347
+
alpha[7] = 1.0f;
348
+
}
349
+
350
+
indices = block >> 16;
351
+
for (i = 0; i < 4; ++i) {
352
+
for (j = 0; j < 4; ++j) {
353
+
decompressed[j * pixelSize] = alpha[indices & 0x07];
354
+
indices >>= 3;
355
+
}
356
+
decompressed += destinationPitch;
357
+
}
358
+
}
359
+
#endif /* BCDEC_BC4BC5_PRECISE */
360
+
361
+
typedef struct bcdec__bitstream {
362
+
unsigned long long low;
363
+
unsigned long long high;
364
+
} bcdec__bitstream_t;
365
+
366
+
static int bcdec__bitstream_read_bits(bcdec__bitstream_t* bstream, int numBits) {
367
+
unsigned int mask = (1 << numBits) - 1;
368
+
/* Read the low N bits */
369
+
unsigned int bits = (bstream->low & mask);
370
+
371
+
bstream->low >>= numBits;
372
+
/* Put the low N bits of "high" into the high 64-N bits of "low". */
373
+
bstream->low |= (bstream->high & mask) << (sizeof(bstream->high) * 8 - numBits);
374
+
bstream->high >>= numBits;
375
+
376
+
return bits;
377
+
}
378
+
379
+
static int bcdec__bitstream_read_bit(bcdec__bitstream_t* bstream) {
380
+
return bcdec__bitstream_read_bits(bstream, 1);
381
+
}
382
+
383
+
/* reversed bits pulling, used in BC6H decoding
384
+
why ?? just why ??? */
385
+
static int bcdec__bitstream_read_bits_r(bcdec__bitstream_t* bstream, int numBits) {
386
+
int bits = bcdec__bitstream_read_bits(bstream, numBits);
387
+
/* Reverse the bits. */
388
+
int result = 0;
389
+
while (numBits--) {
390
+
result <<= 1;
391
+
result |= (bits & 1);
392
+
bits >>= 1;
393
+
}
394
+
return result;
395
+
}
396
+
397
+
398
+
399
+
BCDECDEF void bcdec_bc1(const void* compressedBlock, void* decompressedBlock, int destinationPitch) {
400
+
bcdec__color_block(compressedBlock, decompressedBlock, destinationPitch, 0);
401
+
}
402
+
403
+
BCDECDEF void bcdec_bc2(const void* compressedBlock, void* decompressedBlock, int destinationPitch) {
404
+
bcdec__color_block(((char*)compressedBlock) + 8, decompressedBlock, destinationPitch, 1);
405
+
bcdec__sharp_alpha_block(compressedBlock, ((char*)decompressedBlock) + 3, destinationPitch);
406
+
}
407
+
408
+
BCDECDEF void bcdec_bc3(const void* compressedBlock, void* decompressedBlock, int destinationPitch) {
409
+
bcdec__color_block(((char*)compressedBlock) + 8, decompressedBlock, destinationPitch, 1);
410
+
bcdec__smooth_alpha_block(compressedBlock, ((char*)decompressedBlock) + 3, destinationPitch, 4);
411
+
}
412
+
413
+
#ifndef BCDEC_BC4BC5_PRECISE
414
+
BCDECDEF void bcdec_bc4(const void* compressedBlock, void* decompressedBlock, int destinationPitch) {
415
+
bcdec__smooth_alpha_block(compressedBlock, decompressedBlock, destinationPitch, 1);
416
+
#else
417
+
BCDECDEF void bcdec_bc4(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned) {
418
+
bcdec__bc4_block(compressedBlock, decompressedBlock, destinationPitch, 1, isSigned);
419
+
#endif
420
+
}
421
+
422
+
#ifndef BCDEC_BC4BC5_PRECISE
423
+
BCDECDEF void bcdec_bc5(const void* compressedBlock, void* decompressedBlock, int destinationPitch) {
424
+
bcdec__smooth_alpha_block(compressedBlock, decompressedBlock, destinationPitch, 2);
425
+
bcdec__smooth_alpha_block(((char*)compressedBlock) + 8, ((char*)decompressedBlock) + 1, destinationPitch, 2);
426
+
#else
427
+
BCDECDEF void bcdec_bc5(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned) {
428
+
bcdec__bc4_block(compressedBlock, decompressedBlock, destinationPitch, 2, isSigned);
429
+
bcdec__bc4_block(((char*)compressedBlock) + 8, ((char*)decompressedBlock) + 1, destinationPitch, 2, isSigned);
430
+
#endif
431
+
}
432
+
433
+
#ifdef BCDEC_BC4BC5_PRECISE
434
+
BCDECDEF void bcdec_bc4_float(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned) {
435
+
bcdec__bc4_block_float(compressedBlock, decompressedBlock, destinationPitch, 1, isSigned);
436
+
}
437
+
438
+
BCDECDEF void bcdec_bc5_float(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned) {
439
+
bcdec__bc4_block_float(compressedBlock, decompressedBlock, destinationPitch, 2, isSigned);
440
+
bcdec__bc4_block_float(((char*)compressedBlock) + 8, ((float*)decompressedBlock) + 1, destinationPitch, 2, isSigned);
441
+
}
442
+
#endif /* BCDEC_BC4BC5_PRECISE */
443
+
444
+
/* http://graphics.stanford.edu/~seander/bithacks.html#VariableSignExtend */
445
+
static int bcdec__extend_sign(int val, int bits) {
446
+
return (val << (32 - bits)) >> (32 - bits);
447
+
}
448
+
449
+
static int bcdec__transform_inverse(int val, int a0, int bits, int isSigned) {
450
+
/* If the precision of A0 is "p" bits, then the transform algorithm is:
451
+
B0 = (B0 + A0) & ((1 << p) - 1) */
452
+
val = (val + a0) & ((1 << bits) - 1);
453
+
if (isSigned) {
454
+
val = bcdec__extend_sign(val, bits);
455
+
}
456
+
return val;
457
+
}
458
+
459
+
/* pretty much copy-paste from documentation */
460
+
static int bcdec__unquantize(int val, int bits, int isSigned) {
461
+
int unq, s = 0;
462
+
463
+
if (!isSigned) {
464
+
if (bits >= 15) {
465
+
unq = val;
466
+
} else if (!val) {
467
+
unq = 0;
468
+
} else if (val == ((1 << bits) - 1)) {
469
+
unq = 0xFFFF;
470
+
} else {
471
+
unq = ((val << 16) + 0x8000) >> bits;
472
+
}
473
+
} else {
474
+
if (bits >= 16) {
475
+
unq = val;
476
+
} else {
477
+
if (val < 0) {
478
+
s = 1;
479
+
val = -val;
480
+
}
481
+
482
+
if (val == 0) {
483
+
unq = 0;
484
+
} else if (val >= ((1 << (bits - 1)) - 1)) {
485
+
unq = 0x7FFF;
486
+
} else {
487
+
unq = ((val << 15) + 0x4000) >> (bits - 1);
488
+
}
489
+
490
+
if (s) {
491
+
unq = -unq;
492
+
}
493
+
}
494
+
}
495
+
return unq;
496
+
}
497
+
498
+
static int bcdec__interpolate(int a, int b, int* weights, int index) {
499
+
return (a * (64 - weights[index]) + b * weights[index] + 32) >> 6;
500
+
}
501
+
502
+
static unsigned short bcdec__finish_unquantize(int val, int isSigned) {
503
+
int s;
504
+
505
+
if (!isSigned) {
506
+
return (unsigned short)((val * 31) >> 6); /* scale the magnitude by 31 / 64 */
507
+
} else {
508
+
val = (val < 0) ? -(((-val) * 31) >> 5) : (val * 31) >> 5; /* scale the magnitude by 31 / 32 */
509
+
s = 0;
510
+
if (val < 0) {
511
+
s = 0x8000;
512
+
val = -val;
513
+
}
514
+
return (unsigned short)(s | val);
515
+
}
516
+
}
517
+
518
+
/* modified half_to_float_fast4 from https://gist.github.com/rygorous/2144712 */
519
+
static float bcdec__half_to_float_quick(unsigned short half) {
520
+
typedef union {
521
+
unsigned int u;
522
+
float f;
523
+
} FP32;
524
+
525
+
static const FP32 magic = { 113 << 23 };
526
+
static const unsigned int shifted_exp = 0x7c00 << 13; /* exponent mask after shift */
527
+
FP32 o;
528
+
unsigned int exp;
529
+
530
+
o.u = (half & 0x7fff) << 13; /* exponent/mantissa bits */
531
+
exp = shifted_exp & o.u; /* just the exponent */
532
+
o.u += (127 - 15) << 23; /* exponent adjust */
533
+
534
+
/* handle exponent special cases */
535
+
if (exp == shifted_exp) { /* Inf/NaN? */
536
+
o.u += (128 - 16) << 23; /* extra exp adjust */
537
+
} else if (exp == 0) { /* Zero/Denormal? */
538
+
o.u += 1 << 23; /* extra exp adjust */
539
+
o.f -= magic.f; /* renormalize */
540
+
}
541
+
542
+
o.u |= (half & 0x8000) << 16; /* sign bit */
543
+
return o.f;
544
+
}
545
+
546
+
BCDECDEF void bcdec_bc6h_half(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned) {
547
+
static char actual_bits_count[4][14] = {
548
+
{ 10, 7, 11, 11, 11, 9, 8, 8, 8, 6, 10, 11, 12, 16 }, /* W */
549
+
{ 5, 6, 5, 4, 4, 5, 6, 5, 5, 6, 10, 9, 8, 4 }, /* dR */
550
+
{ 5, 6, 4, 5, 4, 5, 5, 6, 5, 6, 10, 9, 8, 4 }, /* dG */
551
+
{ 5, 6, 4, 4, 5, 5, 5, 5, 6, 6, 10, 9, 8, 4 } /* dB */
552
+
};
553
+
554
+
/* There are 32 possible partition sets for a two-region tile.
555
+
Each 4x4 block represents a single shape.
556
+
Here also every fix-up index has MSB bit set. */
557
+
static unsigned char partition_sets[32][4][4] = {
558
+
{ {128, 0, 1, 1}, {0, 0, 1, 1}, { 0, 0, 1, 1}, {0, 0, 1, 129} }, /* 0 */
559
+
{ {128, 0, 0, 1}, {0, 0, 0, 1}, { 0, 0, 0, 1}, {0, 0, 0, 129} }, /* 1 */
560
+
{ {128, 1, 1, 1}, {0, 1, 1, 1}, { 0, 1, 1, 1}, {0, 1, 1, 129} }, /* 2 */
561
+
{ {128, 0, 0, 1}, {0, 0, 1, 1}, { 0, 0, 1, 1}, {0, 1, 1, 129} }, /* 3 */
562
+
{ {128, 0, 0, 0}, {0, 0, 0, 1}, { 0, 0, 0, 1}, {0, 0, 1, 129} }, /* 4 */
563
+
{ {128, 0, 1, 1}, {0, 1, 1, 1}, { 0, 1, 1, 1}, {1, 1, 1, 129} }, /* 5 */
564
+
{ {128, 0, 0, 1}, {0, 0, 1, 1}, { 0, 1, 1, 1}, {1, 1, 1, 129} }, /* 6 */
565
+
{ {128, 0, 0, 0}, {0, 0, 0, 1}, { 0, 0, 1, 1}, {0, 1, 1, 129} }, /* 7 */
566
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 0, 0, 0, 1}, {0, 0, 1, 129} }, /* 8 */
567
+
{ {128, 0, 1, 1}, {0, 1, 1, 1}, { 1, 1, 1, 1}, {1, 1, 1, 129} }, /* 9 */
568
+
{ {128, 0, 0, 0}, {0, 0, 0, 1}, { 0, 1, 1, 1}, {1, 1, 1, 129} }, /* 10 */
569
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 0, 0, 0, 1}, {0, 1, 1, 129} }, /* 11 */
570
+
{ {128, 0, 0, 1}, {0, 1, 1, 1}, { 1, 1, 1, 1}, {1, 1, 1, 129} }, /* 12 */
571
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 1, 1, 1, 1}, {1, 1, 1, 129} }, /* 13 */
572
+
{ {128, 0, 0, 0}, {1, 1, 1, 1}, { 1, 1, 1, 1}, {1, 1, 1, 129} }, /* 14 */
573
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 0, 0, 0, 0}, {1, 1, 1, 129} }, /* 15 */
574
+
{ {128, 0, 0, 0}, {1, 0, 0, 0}, { 1, 1, 1, 0}, {1, 1, 1, 129} }, /* 16 */
575
+
{ {128, 1, 129, 1}, {0, 0, 0, 1}, { 0, 0, 0, 0}, {0, 0, 0, 0} }, /* 17 */
576
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, {129, 0, 0, 0}, {1, 1, 1, 0} }, /* 18 */
577
+
{ {128, 1, 129, 1}, {0, 0, 1, 1}, { 0, 0, 0, 1}, {0, 0, 0, 0} }, /* 19 */
578
+
{ {128, 0, 129, 1}, {0, 0, 0, 1}, { 0, 0, 0, 0}, {0, 0, 0, 0} }, /* 20 */
579
+
{ {128, 0, 0, 0}, {1, 0, 0, 0}, {129, 1, 0, 0}, {1, 1, 1, 0} }, /* 21 */
580
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, {129, 0, 0, 0}, {1, 1, 0, 0} }, /* 22 */
581
+
{ {128, 1, 1, 1}, {0, 0, 1, 1}, { 0, 0, 1, 1}, {0, 0, 0, 129} }, /* 23 */
582
+
{ {128, 0, 129, 1}, {0, 0, 0, 1}, { 0, 0, 0, 1}, {0, 0, 0, 0} }, /* 24 */
583
+
{ {128, 0, 0, 0}, {1, 0, 0, 0}, {129, 0, 0, 0}, {1, 1, 0, 0} }, /* 25 */
584
+
{ {128, 1, 129, 0}, {0, 1, 1, 0}, { 0, 1, 1, 0}, {0, 1, 1, 0} }, /* 26 */
585
+
{ {128, 0, 129, 1}, {0, 1, 1, 0}, { 0, 1, 1, 0}, {1, 1, 0, 0} }, /* 27 */
586
+
{ {128, 0, 0, 1}, {0, 1, 1, 1}, {129, 1, 1, 0}, {1, 0, 0, 0} }, /* 28 */
587
+
{ {128, 0, 0, 0}, {1, 1, 1, 1}, {129, 1, 1, 1}, {0, 0, 0, 0} }, /* 29 */
588
+
{ {128, 1, 129, 1}, {0, 0, 0, 1}, { 1, 0, 0, 0}, {1, 1, 1, 0} }, /* 30 */
589
+
{ {128, 0, 129, 1}, {1, 0, 0, 1}, { 1, 0, 0, 1}, {1, 1, 0, 0} } /* 31 */
590
+
};
591
+
592
+
static int aWeight3[8] = { 0, 9, 18, 27, 37, 46, 55, 64 };
593
+
static int aWeight4[16] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };
594
+
595
+
bcdec__bitstream_t bstream;
596
+
int mode, partition, numPartitions, i, j, partitionSet, indexBits, index, ep_i, actualBits0Mode;
597
+
int r[4], g[4], b[4]; /* wxyz */
598
+
unsigned short* decompressed;
599
+
int* weights;
600
+
601
+
decompressed = (unsigned short*)decompressedBlock;
602
+
603
+
bstream.low = ((unsigned long long*)compressedBlock)[0];
604
+
bstream.high = ((unsigned long long*)compressedBlock)[1];
605
+
606
+
r[0] = r[1] = r[2] = r[3] = 0;
607
+
g[0] = g[1] = g[2] = g[3] = 0;
608
+
b[0] = b[1] = b[2] = b[3] = 0;
609
+
610
+
mode = bcdec__bitstream_read_bits(&bstream, 2);
611
+
if (mode > 1) {
612
+
mode |= (bcdec__bitstream_read_bits(&bstream, 3) << 2);
613
+
}
614
+
615
+
/* modes >= 11 (10 in my code) are using 0 one, others will read it from the bitstream */
616
+
partition = 0;
617
+
618
+
switch (mode) {
619
+
/* mode 1 */
620
+
case 0b00: {
621
+
/* Partitition indices: 46 bits
622
+
Partition: 5 bits
623
+
Color Endpoints: 75 bits (10.555, 10.555, 10.555) */
624
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gy[4] */
625
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* by[4] */
626
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* bz[4] */
627
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* rw[9:0] */
628
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* gw[9:0] */
629
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* bw[9:0] */
630
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* rx[4:0] */
631
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gz[4] */
632
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
633
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* gx[4:0] */
634
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
635
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gz[3:0] */
636
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* bx[4:0] */
637
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
638
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
639
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 5); /* ry[4:0] */
640
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
641
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 5); /* rz[4:0] */
642
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
643
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
644
+
mode = 0;
645
+
} break;
646
+
647
+
/* mode 2 */
648
+
case 0b01: {
649
+
/* Partitition indices: 46 bits
650
+
Partition: 5 bits
651
+
Color Endpoints: 75 bits (7666, 7666, 7666) */
652
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 5; /* gy[5] */
653
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gz[4] */
654
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 5; /* gz[5] */
655
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 7); /* rw[6:0] */
656
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
657
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
658
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* by[4] */
659
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 7); /* gw[6:0] */
660
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 5; /* by[5] */
661
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
662
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gy[4] */
663
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 7); /* bw[6:0] */
664
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
665
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 5; /* bz[5] */
666
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* bz[4] */
667
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* rx[5:0] */
668
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
669
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* gx[5:0] */
670
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gz[3:0] */
671
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* bx[5:0] */
672
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
673
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 6); /* ry[5:0] */
674
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 6); /* rz[5:0] */
675
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
676
+
mode = 1;
677
+
} break;
678
+
679
+
/* mode 3 */
680
+
case 0b00010: {
681
+
/* Partitition indices: 46 bits
682
+
Partition: 5 bits
683
+
Color Endpoints: 72 bits (11.555, 11.444, 11.444) */
684
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* rw[9:0] */
685
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* gw[9:0] */
686
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* bw[9:0] */
687
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* rx[4:0] */
688
+
r[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* rw[10] */
689
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
690
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* gx[3:0] */
691
+
g[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* gw[10] */
692
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
693
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gz[3:0] */
694
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* bx[3:0] */
695
+
b[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* bw[10] */
696
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
697
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
698
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 5); /* ry[4:0] */
699
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
700
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 5); /* rz[4:0] */
701
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
702
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
703
+
mode = 2;
704
+
} break;
705
+
706
+
/* mode 4 */
707
+
case 0b00110: {
708
+
/* Partitition indices: 46 bits
709
+
Partition: 5 bits
710
+
Color Endpoints: 72 bits (11.444, 11.555, 11.444) */
711
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* rw[9:0] */
712
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* gw[9:0] */
713
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* bw[9:0] */
714
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* rx[3:0] */
715
+
r[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* rw[10] */
716
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gz[4] */
717
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
718
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* gx[4:0] */
719
+
g[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* gw[10] */
720
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gz[3:0] */
721
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* bx[3:0] */
722
+
b[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* bw[10] */
723
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
724
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
725
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* ry[3:0] */
726
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
727
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
728
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* rz[3:0] */
729
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gy[4] */
730
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
731
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
732
+
mode = 3;
733
+
} break;
734
+
735
+
/* mode 5 */
736
+
case 0b01010: {
737
+
/* Partitition indices: 46 bits
738
+
Partition: 5 bits
739
+
Color Endpoints: 72 bits (11.444, 11.444, 11.555) */
740
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* rw[9:0] */
741
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* gw[9:0] */
742
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* bw[9:0] */
743
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* rx[3:0] */
744
+
r[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* rw[10] */
745
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* by[4] */
746
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
747
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* gx[3:0] */
748
+
g[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* gw[10] */
749
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
750
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gz[3:0] */
751
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* bx[4:0] */
752
+
b[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* bw[10] */
753
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
754
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* ry[3:0] */
755
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
756
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
757
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* rz[3:0] */
758
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* bz[4] */
759
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
760
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
761
+
mode = 4;
762
+
} break;
763
+
764
+
/* mode 6 */
765
+
case 0b01110: {
766
+
/* Partitition indices: 46 bits
767
+
Partition: 5 bits
768
+
Color Endpoints: 72 bits (9555, 9555, 9555) */
769
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 9); /* rw[8:0] */
770
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* by[4] */
771
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 9); /* gw[8:0] */
772
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gy[4] */
773
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 9); /* bw[8:0] */
774
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* bz[4] */
775
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* rx[4:0] */
776
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gz[4] */
777
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
778
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* gx[4:0] */
779
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
780
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gx[3:0] */
781
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* bx[4:0] */
782
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
783
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
784
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 5); /* ry[4:0] */
785
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
786
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 5); /* rz[4:0] */
787
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
788
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
789
+
mode = 5;
790
+
} break;
791
+
792
+
/* mode 7 */
793
+
case 0b10010: {
794
+
/* Partitition indices: 46 bits
795
+
Partition: 5 bits
796
+
Color Endpoints: 72 bits (8666, 8555, 8555) */
797
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* rw[7:0] */
798
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gz[4] */
799
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* by[4] */
800
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* gw[7:0] */
801
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
802
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gy[4] */
803
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* bw[7:0] */
804
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
805
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* bz[4] */
806
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* rx[5:0] */
807
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
808
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* gx[4:0] */
809
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
810
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gz[3:0] */
811
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* bx[4:0] */
812
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
813
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
814
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 6); /* ry[5:0] */
815
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 6); /* rz[5:0] */
816
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
817
+
mode = 6;
818
+
} break;
819
+
820
+
/* mode 8 */
821
+
case 0b10110: {
822
+
/* Partitition indices: 46 bits
823
+
Partition: 5 bits
824
+
Color Endpoints: 72 bits (8555, 8666, 8555) */
825
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* rw[7:0] */
826
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
827
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* by[4] */
828
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* gw[7:0] */
829
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 5; /* gy[5] */
830
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gy[4] */
831
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* bw[7:0] */
832
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 5; /* gz[5] */
833
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* bz[4] */
834
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* rx[4:0] */
835
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gz[4] */
836
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
837
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* gx[5:0] */
838
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* zx[3:0] */
839
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* bx[4:0] */
840
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
841
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
842
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 5); /* ry[4:0] */
843
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
844
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 5); /* rz[4:0] */
845
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
846
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
847
+
mode = 7;
848
+
} break;
849
+
850
+
/* mode 9 */
851
+
case 0b11010: {
852
+
/* Partitition indices: 46 bits
853
+
Partition: 5 bits
854
+
Color Endpoints: 72 bits (8555, 8555, 8666) */
855
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* rw[7:0] */
856
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
857
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* by[4] */
858
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* gw[7:0] */
859
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 5; /* by[5] */
860
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gy[4] */
861
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 8); /* bw[7:0] */
862
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 5; /* bz[5] */
863
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* bz[4] */
864
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* bw[4:0] */
865
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gz[4] */
866
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
867
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 5); /* gx[4:0] */
868
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
869
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gz[3:0] */
870
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* bx[5:0] */
871
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
872
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 5); /* ry[4:0] */
873
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
874
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 5); /* rz[4:0] */
875
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
876
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
877
+
mode = 8;
878
+
} break;
879
+
880
+
/* mode 10 */
881
+
case 0b11110: {
882
+
/* Partitition indices: 46 bits
883
+
Partition: 5 bits
884
+
Color Endpoints: 72 bits (6666, 6666, 6666) */
885
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 6); /* rw[5:0] */
886
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gz[4] */
887
+
b[3] |= bcdec__bitstream_read_bit(&bstream); /* bz[0] */
888
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 1; /* bz[1] */
889
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* by[4] */
890
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 6); /* gw[5:0] */
891
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 5; /* gy[5] */
892
+
b[2] |= bcdec__bitstream_read_bit(&bstream) << 5; /* by[5] */
893
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 2; /* bz[2] */
894
+
g[2] |= bcdec__bitstream_read_bit(&bstream) << 4; /* gy[4] */
895
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 6); /* bw[5:0] */
896
+
g[3] |= bcdec__bitstream_read_bit(&bstream) << 5; /* gz[5] */
897
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 3; /* bz[3] */
898
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 5; /* bz[5] */
899
+
b[3] |= bcdec__bitstream_read_bit(&bstream) << 4; /* bz[4] */
900
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* rx[5:0] */
901
+
g[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* gy[3:0] */
902
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* gx[5:0] */
903
+
g[3] |= bcdec__bitstream_read_bits(&bstream, 4); /* gz[3:0] */
904
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 6); /* bx[5:0] */
905
+
b[2] |= bcdec__bitstream_read_bits(&bstream, 4); /* by[3:0] */
906
+
r[2] |= bcdec__bitstream_read_bits(&bstream, 6); /* ry[5:0] */
907
+
r[3] |= bcdec__bitstream_read_bits(&bstream, 6); /* rz[5:0] */
908
+
partition = bcdec__bitstream_read_bits(&bstream, 5); /* d[4:0] */
909
+
mode = 9;
910
+
} break;
911
+
912
+
/* mode 11 */
913
+
case 0b00011: {
914
+
/* Partitition indices: 63 bits
915
+
Partition: 0 bits
916
+
Color Endpoints: 60 bits (10.10, 10.10, 10.10) */
917
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* rw[9:0] */
918
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* gw[9:0] */
919
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* bw[9:0] */
920
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 10); /* rx[9:0] */
921
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 10); /* gx[9:0] */
922
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 10); /* bx[9:0] */
923
+
mode = 10;
924
+
} break;
925
+
926
+
/* mode 12 */
927
+
case 0b00111: {
928
+
/* Partitition indices: 63 bits
929
+
Partition: 0 bits
930
+
Color Endpoints: 60 bits (11.9, 11.9, 11.9) */
931
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* rw[9:0] */
932
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* gw[9:0] */
933
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* bw[9:0] */
934
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 9); /* rx[8:0] */
935
+
r[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* rw[10] */
936
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 9); /* gx[8:0] */
937
+
g[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* gw[10] */
938
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 9); /* bx[8:0] */
939
+
b[0] |= bcdec__bitstream_read_bit(&bstream) << 10; /* bw[10] */
940
+
mode = 11;
941
+
} break;
942
+
943
+
/* mode 13 */
944
+
case 0b01011: {
945
+
/* Partitition indices: 63 bits
946
+
Partition: 0 bits
947
+
Color Endpoints: 60 bits (12.8, 12.8, 12.8) */
948
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* rw[9:0] */
949
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* gw[9:0] */
950
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* bw[9:0] */
951
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 8); /* rx[7:0] */
952
+
r[0] |= bcdec__bitstream_read_bits_r(&bstream, 2) << 10;/* rx[10:11] */
953
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 8); /* gx[7:0] */
954
+
g[0] |= bcdec__bitstream_read_bits_r(&bstream, 2) << 10;/* gx[10:11] */
955
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 8); /* bx[7:0] */
956
+
b[0] |= bcdec__bitstream_read_bits_r(&bstream, 2) << 10;/* bx[10:11] */
957
+
mode = 12;
958
+
} break;
959
+
960
+
/* mode 14 */
961
+
case 0b01111: {
962
+
/* Partitition indices: 63 bits
963
+
Partition: 0 bits
964
+
Color Endpoints: 60 bits (16.4, 16.4, 16.4) */
965
+
r[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* rw[9:0] */
966
+
g[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* gw[9:0] */
967
+
b[0] |= bcdec__bitstream_read_bits(&bstream, 10); /* bw[9:0] */
968
+
r[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* rx[3:0] */
969
+
r[0] |= bcdec__bitstream_read_bits_r(&bstream, 6) << 10;/* rw[10:15] */
970
+
g[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* gx[3:0] */
971
+
g[0] |= bcdec__bitstream_read_bits_r(&bstream, 6) << 10;/* gw[10:15] */
972
+
b[1] |= bcdec__bitstream_read_bits(&bstream, 4); /* bx[3:0] */
973
+
b[0] |= bcdec__bitstream_read_bits_r(&bstream, 6) << 10;/* bw[10:15] */
974
+
mode = 13;
975
+
} break;
976
+
977
+
default: {
978
+
/* Modes 10011, 10111, 11011, and 11111 (not shown) are reserved.
979
+
Do not use these in your encoder. If the hardware is passed blocks
980
+
with one of these modes specified, the resulting decompressed block
981
+
must contain all zeroes in all channels except for the alpha channel. */
982
+
for (i = 0; i < 4; ++i) {
983
+
for (j = 0; j < 4; ++j) {
984
+
decompressed[j * 3 + 0] = 0;
985
+
decompressed[j * 3 + 1] = 0;
986
+
decompressed[j * 3 + 2] = 0;
987
+
}
988
+
decompressed += destinationPitch;
989
+
}
990
+
991
+
return;
992
+
}
993
+
}
994
+
995
+
numPartitions = (mode >= 10) ? 0 : 1;
996
+
997
+
actualBits0Mode = actual_bits_count[0][mode];
998
+
if (isSigned) {
999
+
r[0] = bcdec__extend_sign(r[0], actualBits0Mode);
1000
+
g[0] = bcdec__extend_sign(g[0], actualBits0Mode);
1001
+
b[0] = bcdec__extend_sign(b[0], actualBits0Mode);
1002
+
}
1003
+
1004
+
/* Mode 11 (like Mode 10) does not use delta compression,
1005
+
and instead stores both color endpoints explicitly. */
1006
+
if ((mode != 9 && mode != 10) || isSigned) {
1007
+
for (i = 1; i < (numPartitions + 1) * 2; ++i) {
1008
+
r[i] = bcdec__extend_sign(r[i], actual_bits_count[1][mode]);
1009
+
g[i] = bcdec__extend_sign(g[i], actual_bits_count[2][mode]);
1010
+
b[i] = bcdec__extend_sign(b[i], actual_bits_count[3][mode]);
1011
+
}
1012
+
}
1013
+
1014
+
if (mode != 9 && mode != 10) {
1015
+
for (i = 1; i < (numPartitions + 1) * 2; ++i) {
1016
+
r[i] = bcdec__transform_inverse(r[i], r[0], actualBits0Mode, isSigned);
1017
+
g[i] = bcdec__transform_inverse(g[i], g[0], actualBits0Mode, isSigned);
1018
+
b[i] = bcdec__transform_inverse(b[i], b[0], actualBits0Mode, isSigned);
1019
+
}
1020
+
}
1021
+
1022
+
for (i = 0; i < (numPartitions + 1) * 2; ++i) {
1023
+
r[i] = bcdec__unquantize(r[i], actualBits0Mode, isSigned);
1024
+
g[i] = bcdec__unquantize(g[i], actualBits0Mode, isSigned);
1025
+
b[i] = bcdec__unquantize(b[i], actualBits0Mode, isSigned);
1026
+
}
1027
+
1028
+
weights = (mode >= 10) ? aWeight4 : aWeight3;
1029
+
for (i = 0; i < 4; ++i) {
1030
+
for (j = 0; j < 4; ++j) {
1031
+
partitionSet = (mode >= 10) ? ((i|j) ? 0 : 128) : partition_sets[partition][i][j];
1032
+
1033
+
indexBits = (mode >= 10) ? 4 : 3;
1034
+
/* fix-up index is specified with one less bit */
1035
+
/* The fix-up index for subset 0 is always index 0 */
1036
+
if (partitionSet & 0x80) {
1037
+
indexBits--;
1038
+
}
1039
+
partitionSet &= 0x01;
1040
+
1041
+
index = bcdec__bitstream_read_bits(&bstream, indexBits);
1042
+
1043
+
ep_i = partitionSet * 2;
1044
+
decompressed[j * 3 + 0] = bcdec__finish_unquantize(
1045
+
bcdec__interpolate(r[ep_i], r[ep_i+1], weights, index), isSigned);
1046
+
decompressed[j * 3 + 1] = bcdec__finish_unquantize(
1047
+
bcdec__interpolate(g[ep_i], g[ep_i+1], weights, index), isSigned);
1048
+
decompressed[j * 3 + 2] = bcdec__finish_unquantize(
1049
+
bcdec__interpolate(b[ep_i], b[ep_i+1], weights, index), isSigned);
1050
+
}
1051
+
1052
+
decompressed += destinationPitch;
1053
+
}
1054
+
}
1055
+
1056
+
BCDECDEF void bcdec_bc6h_float(const void* compressedBlock, void* decompressedBlock, int destinationPitch, int isSigned) {
1057
+
unsigned short block[16*3];
1058
+
float* decompressed;
1059
+
const unsigned short* b;
1060
+
int i, j;
1061
+
1062
+
bcdec_bc6h_half(compressedBlock, block, 4*3, isSigned);
1063
+
b = block;
1064
+
decompressed = (float*)decompressedBlock;
1065
+
for (i = 0; i < 4; ++i) {
1066
+
for (j = 0; j < 4; ++j) {
1067
+
decompressed[j * 3 + 0] = bcdec__half_to_float_quick(*b++);
1068
+
decompressed[j * 3 + 1] = bcdec__half_to_float_quick(*b++);
1069
+
decompressed[j * 3 + 2] = bcdec__half_to_float_quick(*b++);
1070
+
}
1071
+
decompressed += destinationPitch;
1072
+
}
1073
+
}
1074
+
1075
+
static void bcdec__swap_values(int* a, int* b) {
1076
+
a[0] ^= b[0], b[0] ^= a[0], a[0] ^= b[0];
1077
+
}
1078
+
1079
+
BCDECDEF void bcdec_bc7(const void* compressedBlock, void* decompressedBlock, int destinationPitch) {
1080
+
static char actual_bits_count[2][8] = {
1081
+
{ 4, 6, 5, 7, 5, 7, 7, 5 }, /* RGBA */
1082
+
{ 0, 0, 0, 0, 6, 8, 7, 5 }, /* Alpha */
1083
+
};
1084
+
1085
+
/* There are 64 possible partition sets for a two-region tile.
1086
+
Each 4x4 block represents a single shape.
1087
+
Here also every fix-up index has MSB bit set. */
1088
+
static unsigned char partition_sets[2][64][4][4] = {
1089
+
{ /* Partition table for 2-subset BPTC */
1090
+
{ {128, 0, 1, 1}, {0, 0, 1, 1}, { 0, 0, 1, 1}, {0, 0, 1, 129} }, /* 0 */
1091
+
{ {128, 0, 0, 1}, {0, 0, 0, 1}, { 0, 0, 0, 1}, {0, 0, 0, 129} }, /* 1 */
1092
+
{ {128, 1, 1, 1}, {0, 1, 1, 1}, { 0, 1, 1, 1}, {0, 1, 1, 129} }, /* 2 */
1093
+
{ {128, 0, 0, 1}, {0, 0, 1, 1}, { 0, 0, 1, 1}, {0, 1, 1, 129} }, /* 3 */
1094
+
{ {128, 0, 0, 0}, {0, 0, 0, 1}, { 0, 0, 0, 1}, {0, 0, 1, 129} }, /* 4 */
1095
+
{ {128, 0, 1, 1}, {0, 1, 1, 1}, { 0, 1, 1, 1}, {1, 1, 1, 129} }, /* 5 */
1096
+
{ {128, 0, 0, 1}, {0, 0, 1, 1}, { 0, 1, 1, 1}, {1, 1, 1, 129} }, /* 6 */
1097
+
{ {128, 0, 0, 0}, {0, 0, 0, 1}, { 0, 0, 1, 1}, {0, 1, 1, 129} }, /* 7 */
1098
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 0, 0, 0, 1}, {0, 0, 1, 129} }, /* 8 */
1099
+
{ {128, 0, 1, 1}, {0, 1, 1, 1}, { 1, 1, 1, 1}, {1, 1, 1, 129} }, /* 9 */
1100
+
{ {128, 0, 0, 0}, {0, 0, 0, 1}, { 0, 1, 1, 1}, {1, 1, 1, 129} }, /* 10 */
1101
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 0, 0, 0, 1}, {0, 1, 1, 129} }, /* 11 */
1102
+
{ {128, 0, 0, 1}, {0, 1, 1, 1}, { 1, 1, 1, 1}, {1, 1, 1, 129} }, /* 12 */
1103
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 1, 1, 1, 1}, {1, 1, 1, 129} }, /* 13 */
1104
+
{ {128, 0, 0, 0}, {1, 1, 1, 1}, { 1, 1, 1, 1}, {1, 1, 1, 129} }, /* 14 */
1105
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 0, 0, 0, 0}, {1, 1, 1, 129} }, /* 15 */
1106
+
{ {128, 0, 0, 0}, {1, 0, 0, 0}, { 1, 1, 1, 0}, {1, 1, 1, 129} }, /* 16 */
1107
+
{ {128, 1, 129, 1}, {0, 0, 0, 1}, { 0, 0, 0, 0}, {0, 0, 0, 0} }, /* 17 */
1108
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, {129, 0, 0, 0}, {1, 1, 1, 0} }, /* 18 */
1109
+
{ {128, 1, 129, 1}, {0, 0, 1, 1}, { 0, 0, 0, 1}, {0, 0, 0, 0} }, /* 19 */
1110
+
{ {128, 0, 129, 1}, {0, 0, 0, 1}, { 0, 0, 0, 0}, {0, 0, 0, 0} }, /* 20 */
1111
+
{ {128, 0, 0, 0}, {1, 0, 0, 0}, {129, 1, 0, 0}, {1, 1, 1, 0} }, /* 21 */
1112
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, {129, 0, 0, 0}, {1, 1, 0, 0} }, /* 22 */
1113
+
{ {128, 1, 1, 1}, {0, 0, 1, 1}, { 0, 0, 1, 1}, {0, 0, 0, 129} }, /* 23 */
1114
+
{ {128, 0, 129, 1}, {0, 0, 0, 1}, { 0, 0, 0, 1}, {0, 0, 0, 0} }, /* 24 */
1115
+
{ {128, 0, 0, 0}, {1, 0, 0, 0}, {129, 0, 0, 0}, {1, 1, 0, 0} }, /* 25 */
1116
+
{ {128, 1, 129, 0}, {0, 1, 1, 0}, { 0, 1, 1, 0}, {0, 1, 1, 0} }, /* 26 */
1117
+
{ {128, 0, 129, 1}, {0, 1, 1, 0}, { 0, 1, 1, 0}, {1, 1, 0, 0} }, /* 27 */
1118
+
{ {128, 0, 0, 1}, {0, 1, 1, 1}, {129, 1, 1, 0}, {1, 0, 0, 0} }, /* 28 */
1119
+
{ {128, 0, 0, 0}, {1, 1, 1, 1}, {129, 1, 1, 1}, {0, 0, 0, 0} }, /* 29 */
1120
+
{ {128, 1, 129, 1}, {0, 0, 0, 1}, { 1, 0, 0, 0}, {1, 1, 1, 0} }, /* 30 */
1121
+
{ {128, 0, 129, 1}, {1, 0, 0, 1}, { 1, 0, 0, 1}, {1, 1, 0, 0} }, /* 31 */
1122
+
{ {128, 1, 0, 1}, {0, 1, 0, 1}, { 0, 1, 0, 1}, {0, 1, 0, 129} }, /* 32 */
1123
+
{ {128, 0, 0, 0}, {1, 1, 1, 1}, { 0, 0, 0, 0}, {1, 1, 1, 129} }, /* 33 */
1124
+
{ {128, 1, 0, 1}, {1, 0, 129, 0}, { 0, 1, 0, 1}, {1, 0, 1, 0} }, /* 34 */
1125
+
{ {128, 0, 1, 1}, {0, 0, 1, 1}, {129, 1, 0, 0}, {1, 1, 0, 0} }, /* 35 */
1126
+
{ {128, 0, 129, 1}, {1, 1, 0, 0}, { 0, 0, 1, 1}, {1, 1, 0, 0} }, /* 36 */
1127
+
{ {128, 1, 0, 1}, {0, 1, 0, 1}, {129, 0, 1, 0}, {1, 0, 1, 0} }, /* 37 */
1128
+
{ {128, 1, 1, 0}, {1, 0, 0, 1}, { 0, 1, 1, 0}, {1, 0, 0, 129} }, /* 38 */
1129
+
{ {128, 1, 0, 1}, {1, 0, 1, 0}, { 1, 0, 1, 0}, {0, 1, 0, 129} }, /* 39 */
1130
+
{ {128, 1, 129, 1}, {0, 0, 1, 1}, { 1, 1, 0, 0}, {1, 1, 1, 0} }, /* 40 */
1131
+
{ {128, 0, 0, 1}, {0, 0, 1, 1}, {129, 1, 0, 0}, {1, 0, 0, 0} }, /* 41 */
1132
+
{ {128, 0, 129, 1}, {0, 0, 1, 0}, { 0, 1, 0, 0}, {1, 1, 0, 0} }, /* 42 */
1133
+
{ {128, 0, 129, 1}, {1, 0, 1, 1}, { 1, 1, 0, 1}, {1, 1, 0, 0} }, /* 43 */
1134
+
{ {128, 1, 129, 0}, {1, 0, 0, 1}, { 1, 0, 0, 1}, {0, 1, 1, 0} }, /* 44 */
1135
+
{ {128, 0, 1, 1}, {1, 1, 0, 0}, { 1, 1, 0, 0}, {0, 0, 1, 129} }, /* 45 */
1136
+
{ {128, 1, 1, 0}, {0, 1, 1, 0}, { 1, 0, 0, 1}, {1, 0, 0, 129} }, /* 46 */
1137
+
{ {128, 0, 0, 0}, {0, 1, 129, 0}, { 0, 1, 1, 0}, {0, 0, 0, 0} }, /* 47 */
1138
+
{ {128, 1, 0, 0}, {1, 1, 129, 0}, { 0, 1, 0, 0}, {0, 0, 0, 0} }, /* 48 */
1139
+
{ {128, 0, 129, 0}, {0, 1, 1, 1}, { 0, 0, 1, 0}, {0, 0, 0, 0} }, /* 49 */
1140
+
{ {128, 0, 0, 0}, {0, 0, 129, 0}, { 0, 1, 1, 1}, {0, 0, 1, 0} }, /* 50 */
1141
+
{ {128, 0, 0, 0}, {0, 1, 0, 0}, {129, 1, 1, 0}, {0, 1, 0, 0} }, /* 51 */
1142
+
{ {128, 1, 1, 0}, {1, 1, 0, 0}, { 1, 0, 0, 1}, {0, 0, 1, 129} }, /* 52 */
1143
+
{ {128, 0, 1, 1}, {0, 1, 1, 0}, { 1, 1, 0, 0}, {1, 0, 0, 129} }, /* 53 */
1144
+
{ {128, 1, 129, 0}, {0, 0, 1, 1}, { 1, 0, 0, 1}, {1, 1, 0, 0} }, /* 54 */
1145
+
{ {128, 0, 129, 1}, {1, 0, 0, 1}, { 1, 1, 0, 0}, {0, 1, 1, 0} }, /* 55 */
1146
+
{ {128, 1, 1, 0}, {1, 1, 0, 0}, { 1, 1, 0, 0}, {1, 0, 0, 129} }, /* 56 */
1147
+
{ {128, 1, 1, 0}, {0, 0, 1, 1}, { 0, 0, 1, 1}, {1, 0, 0, 129} }, /* 57 */
1148
+
{ {128, 1, 1, 1}, {1, 1, 1, 0}, { 1, 0, 0, 0}, {0, 0, 0, 129} }, /* 58 */
1149
+
{ {128, 0, 0, 1}, {1, 0, 0, 0}, { 1, 1, 1, 0}, {0, 1, 1, 129} }, /* 59 */
1150
+
{ {128, 0, 0, 0}, {1, 1, 1, 1}, { 0, 0, 1, 1}, {0, 0, 1, 129} }, /* 60 */
1151
+
{ {128, 0, 129, 1}, {0, 0, 1, 1}, { 1, 1, 1, 1}, {0, 0, 0, 0} }, /* 61 */
1152
+
{ {128, 0, 129, 0}, {0, 0, 1, 0}, { 1, 1, 1, 0}, {1, 1, 1, 0} }, /* 62 */
1153
+
{ {128, 1, 0, 0}, {0, 1, 0, 0}, { 0, 1, 1, 1}, {0, 1, 1, 129} } /* 63 */
1154
+
},
1155
+
{ /* Partition table for 3-subset BPTC */
1156
+
{ {128, 0, 1, 129}, {0, 0, 1, 1}, { 0, 2, 2, 1}, { 2, 2, 2, 130} }, /* 0 */
1157
+
{ {128, 0, 0, 129}, {0, 0, 1, 1}, {130, 2, 1, 1}, { 2, 2, 2, 1} }, /* 1 */
1158
+
{ {128, 0, 0, 0}, {2, 0, 0, 1}, {130, 2, 1, 1}, { 2, 2, 1, 129} }, /* 2 */
1159
+
{ {128, 2, 2, 130}, {0, 0, 2, 2}, { 0, 0, 1, 1}, { 0, 1, 1, 129} }, /* 3 */
1160
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, {129, 1, 2, 2}, { 1, 1, 2, 130} }, /* 4 */
1161
+
{ {128, 0, 1, 129}, {0, 0, 1, 1}, { 0, 0, 2, 2}, { 0, 0, 2, 130} }, /* 5 */
1162
+
{ {128, 0, 2, 130}, {0, 0, 2, 2}, { 1, 1, 1, 1}, { 1, 1, 1, 129} }, /* 6 */
1163
+
{ {128, 0, 1, 1}, {0, 0, 1, 1}, {130, 2, 1, 1}, { 2, 2, 1, 129} }, /* 7 */
1164
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, {129, 1, 1, 1}, { 2, 2, 2, 130} }, /* 8 */
1165
+
{ {128, 0, 0, 0}, {1, 1, 1, 1}, {129, 1, 1, 1}, { 2, 2, 2, 130} }, /* 9 */
1166
+
{ {128, 0, 0, 0}, {1, 1, 129, 1}, { 2, 2, 2, 2}, { 2, 2, 2, 130} }, /* 10 */
1167
+
{ {128, 0, 1, 2}, {0, 0, 129, 2}, { 0, 0, 1, 2}, { 0, 0, 1, 130} }, /* 11 */
1168
+
{ {128, 1, 1, 2}, {0, 1, 129, 2}, { 0, 1, 1, 2}, { 0, 1, 1, 130} }, /* 12 */
1169
+
{ {128, 1, 2, 2}, {0, 129, 2, 2}, { 0, 1, 2, 2}, { 0, 1, 2, 130} }, /* 13 */
1170
+
{ {128, 0, 1, 129}, {0, 1, 1, 2}, { 1, 1, 2, 2}, { 1, 2, 2, 130} }, /* 14 */
1171
+
{ {128, 0, 1, 129}, {2, 0, 0, 1}, {130, 2, 0, 0}, { 2, 2, 2, 0} }, /* 15 */
1172
+
{ {128, 0, 0, 129}, {0, 0, 1, 1}, { 0, 1, 1, 2}, { 1, 1, 2, 130} }, /* 16 */
1173
+
{ {128, 1, 1, 129}, {0, 0, 1, 1}, {130, 0, 0, 1}, { 2, 2, 0, 0} }, /* 17 */
1174
+
{ {128, 0, 0, 0}, {1, 1, 2, 2}, {129, 1, 2, 2}, { 1, 1, 2, 130} }, /* 18 */
1175
+
{ {128, 0, 2, 130}, {0, 0, 2, 2}, { 0, 0, 2, 2}, { 1, 1, 1, 129} }, /* 19 */
1176
+
{ {128, 1, 1, 129}, {0, 1, 1, 1}, { 0, 2, 2, 2}, { 0, 2, 2, 130} }, /* 20 */
1177
+
{ {128, 0, 0, 129}, {0, 0, 0, 1}, {130, 2, 2, 1}, { 2, 2, 2, 1} }, /* 21 */
1178
+
{ {128, 0, 0, 0}, {0, 0, 129, 1}, { 0, 1, 2, 2}, { 0, 1, 2, 130} }, /* 22 */
1179
+
{ {128, 0, 0, 0}, {1, 1, 0, 0}, {130, 2, 129, 0}, { 2, 2, 1, 0} }, /* 23 */
1180
+
{ {128, 1, 2, 130}, {0, 129, 2, 2}, { 0, 0, 1, 1}, { 0, 0, 0, 0} }, /* 24 */
1181
+
{ {128, 0, 1, 2}, {0, 0, 1, 2}, {129, 1, 2, 2}, { 2, 2, 2, 130} }, /* 25 */
1182
+
{ {128, 1, 1, 0}, {1, 2, 130, 1}, {129, 2, 2, 1}, { 0, 1, 1, 0} }, /* 26 */
1183
+
{ {128, 0, 0, 0}, {0, 1, 129, 0}, { 1, 2, 130, 1}, { 1, 2, 2, 1} }, /* 27 */
1184
+
{ {128, 0, 2, 2}, {1, 1, 0, 2}, {129, 1, 0, 2}, { 0, 0, 2, 130} }, /* 28 */
1185
+
{ {128, 1, 1, 0}, {0, 129, 1, 0}, { 2, 0, 0, 2}, { 2, 2, 2, 130} }, /* 29 */
1186
+
{ {128, 0, 1, 1}, {0, 1, 2, 2}, { 0, 1, 130, 2}, { 0, 0, 1, 129} }, /* 30 */
1187
+
{ {128, 0, 0, 0}, {2, 0, 0, 0}, {130, 2, 1, 1}, { 2, 2, 2, 129} }, /* 31 */
1188
+
{ {128, 0, 0, 0}, {0, 0, 0, 2}, {129, 1, 2, 2}, { 1, 2, 2, 130} }, /* 32 */
1189
+
{ {128, 2, 2, 130}, {0, 0, 2, 2}, { 0, 0, 1, 2}, { 0, 0, 1, 129} }, /* 33 */
1190
+
{ {128, 0, 1, 129}, {0, 0, 1, 2}, { 0, 0, 2, 2}, { 0, 2, 2, 130} }, /* 34 */
1191
+
{ {128, 1, 2, 0}, {0, 129, 2, 0}, { 0, 1, 130, 0}, { 0, 1, 2, 0} }, /* 35 */
1192
+
{ {128, 0, 0, 0}, {1, 1, 129, 1}, { 2, 2, 130, 2}, { 0, 0, 0, 0} }, /* 36 */
1193
+
{ {128, 1, 2, 0}, {1, 2, 0, 1}, {130, 0, 129, 2}, { 0, 1, 2, 0} }, /* 37 */
1194
+
{ {128, 1, 2, 0}, {2, 0, 1, 2}, {129, 130, 0, 1}, { 0, 1, 2, 0} }, /* 38 */
1195
+
{ {128, 0, 1, 1}, {2, 2, 0, 0}, { 1, 1, 130, 2}, { 0, 0, 1, 129} }, /* 39 */
1196
+
{ {128, 0, 1, 1}, {1, 1, 130, 2}, { 2, 2, 0, 0}, { 0, 0, 1, 129} }, /* 40 */
1197
+
{ {128, 1, 0, 129}, {0, 1, 0, 1}, { 2, 2, 2, 2}, { 2, 2, 2, 130} }, /* 41 */
1198
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, {130, 1, 2, 1}, { 2, 1, 2, 129} }, /* 42 */
1199
+
{ {128, 0, 2, 2}, {1, 129, 2, 2}, { 0, 0, 2, 2}, { 1, 1, 2, 130} }, /* 43 */
1200
+
{ {128, 0, 2, 130}, {0, 0, 1, 1}, { 0, 0, 2, 2}, { 0, 0, 1, 129} }, /* 44 */
1201
+
{ {128, 2, 2, 0}, {1, 2, 130, 1}, { 0, 2, 2, 0}, { 1, 2, 2, 129} }, /* 45 */
1202
+
{ {128, 1, 0, 1}, {2, 2, 130, 2}, { 2, 2, 2, 2}, { 0, 1, 0, 129} }, /* 46 */
1203
+
{ {128, 0, 0, 0}, {2, 1, 2, 1}, {130, 1, 2, 1}, { 2, 1, 2, 129} }, /* 47 */
1204
+
{ {128, 1, 0, 129}, {0, 1, 0, 1}, { 0, 1, 0, 1}, { 2, 2, 2, 130} }, /* 48 */
1205
+
{ {128, 2, 2, 130}, {0, 1, 1, 1}, { 0, 2, 2, 2}, { 0, 1, 1, 129} }, /* 49 */
1206
+
{ {128, 0, 0, 2}, {1, 129, 1, 2}, { 0, 0, 0, 2}, { 1, 1, 1, 130} }, /* 50 */
1207
+
{ {128, 0, 0, 0}, {2, 129, 1, 2}, { 2, 1, 1, 2}, { 2, 1, 1, 130} }, /* 51 */
1208
+
{ {128, 2, 2, 2}, {0, 129, 1, 1}, { 0, 1, 1, 1}, { 0, 2, 2, 130} }, /* 52 */
1209
+
{ {128, 0, 0, 2}, {1, 1, 1, 2}, {129, 1, 1, 2}, { 0, 0, 0, 130} }, /* 53 */
1210
+
{ {128, 1, 1, 0}, {0, 129, 1, 0}, { 0, 1, 1, 0}, { 2, 2, 2, 130} }, /* 54 */
1211
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 2, 1, 129, 2}, { 2, 1, 1, 130} }, /* 55 */
1212
+
{ {128, 1, 1, 0}, {0, 129, 1, 0}, { 2, 2, 2, 2}, { 2, 2, 2, 130} }, /* 56 */
1213
+
{ {128, 0, 2, 2}, {0, 0, 1, 1}, { 0, 0, 129, 1}, { 0, 0, 2, 130} }, /* 57 */
1214
+
{ {128, 0, 2, 2}, {1, 1, 2, 2}, {129, 1, 2, 2}, { 0, 0, 2, 130} }, /* 58 */
1215
+
{ {128, 0, 0, 0}, {0, 0, 0, 0}, { 0, 0, 0, 0}, { 2, 129, 1, 130} }, /* 59 */
1216
+
{ {128, 0, 0, 130}, {0, 0, 0, 1}, { 0, 0, 0, 2}, { 0, 0, 0, 129} }, /* 60 */
1217
+
{ {128, 2, 2, 2}, {1, 2, 2, 2}, { 0, 2, 2, 2}, {129, 2, 2, 130} }, /* 61 */
1218
+
{ {128, 1, 0, 129}, {2, 2, 2, 2}, { 2, 2, 2, 2}, { 2, 2, 2, 130} }, /* 62 */
1219
+
{ {128, 1, 1, 129}, {2, 0, 1, 1}, {130, 2, 0, 1}, { 2, 2, 2, 0} } /* 63 */
1220
+
}
1221
+
};
1222
+
1223
+
static int aWeight2[] = { 0, 21, 43, 64 };
1224
+
static int aWeight3[] = { 0, 9, 18, 27, 37, 46, 55, 64 };
1225
+
static int aWeight4[] = { 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };
1226
+
1227
+
static unsigned char sModeHasPBits = 0b11001011;
1228
+
1229
+
bcdec__bitstream_t bstream;
1230
+
int mode, partition, numPartitions, numEndpoints, i, j, k, rotation, partitionSet;
1231
+
int indexSelectionBit, indexBits, indexBits2, index, index2;
1232
+
int endpoints[6][4];
1233
+
char indices[4][4];
1234
+
int r, g, b, a;
1235
+
int* weights, * weights2;
1236
+
unsigned char* decompressed;
1237
+
1238
+
decompressed = (unsigned char*)decompressedBlock;
1239
+
1240
+
bstream.low = ((unsigned long long*)compressedBlock)[0];
1241
+
bstream.high = ((unsigned long long*)compressedBlock)[1];
1242
+
1243
+
for (mode = 0; mode < 8 && (0 == bcdec__bitstream_read_bit(&bstream)); ++mode);
1244
+
1245
+
/* unexpected mode, clear the block (transparent black) */
1246
+
if (mode >= 8) {
1247
+
for (i = 0; i < 4; ++i) {
1248
+
for (j = 0; j < 4; ++j) {
1249
+
decompressed[j * 4 + 0] = 0;
1250
+
decompressed[j * 4 + 1] = 0;
1251
+
decompressed[j * 4 + 2] = 0;
1252
+
decompressed[j * 4 + 3] = 0;
1253
+
}
1254
+
decompressed += destinationPitch;
1255
+
}
1256
+
1257
+
return;
1258
+
}
1259
+
1260
+
partition = 0;
1261
+
numPartitions = 1;
1262
+
rotation = 0;
1263
+
indexSelectionBit = 0;
1264
+
1265
+
if (mode == 0 || mode == 1 || mode == 2 || mode == 3 || mode == 7) {
1266
+
numPartitions = (mode == 0 || mode == 2) ? 3 : 2;
1267
+
partition = bcdec__bitstream_read_bits(&bstream, (mode == 0) ? 4 : 6);
1268
+
}
1269
+
1270
+
numEndpoints = numPartitions * 2;
1271
+
1272
+
if (mode == 4 || mode == 5) {
1273
+
rotation = bcdec__bitstream_read_bits(&bstream, 2);
1274
+
1275
+
if (mode == 4) {
1276
+
indexSelectionBit = bcdec__bitstream_read_bit(&bstream);
1277
+
}
1278
+
}
1279
+
1280
+
/* Extract endpoints */
1281
+
/* RGB */
1282
+
for (i = 0; i < 3; ++i) {
1283
+
for (j = 0; j < numEndpoints; ++j) {
1284
+
endpoints[j][i] = bcdec__bitstream_read_bits(&bstream, actual_bits_count[0][mode]);
1285
+
}
1286
+
}
1287
+
/* Alpha (if any) */
1288
+
if (actual_bits_count[1][mode] > 0) {
1289
+
for (j = 0; j < numEndpoints; ++j) {
1290
+
endpoints[j][3] = bcdec__bitstream_read_bits(&bstream, actual_bits_count[1][mode]);
1291
+
}
1292
+
}
1293
+
1294
+
/* Fully decode endpoints */
1295
+
/* First handle modes that have P-bits */
1296
+
if (mode == 0 || mode == 1 || mode == 3 || mode == 6 || mode == 7) {
1297
+
for (i = 0; i < numEndpoints; ++i) {
1298
+
/* component-wise left-shift */
1299
+
for (j = 0; j < 4; ++j) {
1300
+
endpoints[i][j] <<= 1;
1301
+
}
1302
+
}
1303
+
1304
+
/* if P-bit is shared */
1305
+
if (mode == 1) {
1306
+
i = bcdec__bitstream_read_bit(&bstream);
1307
+
j = bcdec__bitstream_read_bit(&bstream);
1308
+
1309
+
/* rgb component-wise insert pbits */
1310
+
for (k = 0; k < 3; ++k) {
1311
+
endpoints[0][k] |= i;
1312
+
endpoints[1][k] |= i;
1313
+
endpoints[2][k] |= j;
1314
+
endpoints[3][k] |= j;
1315
+
}
1316
+
} else if (sModeHasPBits & (1 << mode)) {
1317
+
/* unique P-bit per endpoint */
1318
+
for (i = 0; i < numEndpoints; ++i) {
1319
+
j = bcdec__bitstream_read_bit(&bstream);
1320
+
for (k = 0; k < 4; ++k) {
1321
+
endpoints[i][k] |= j;
1322
+
}
1323
+
}
1324
+
}
1325
+
}
1326
+
1327
+
for (i = 0; i < numEndpoints; ++i) {
1328
+
/* get color components precision including pbit */
1329
+
j = actual_bits_count[0][mode] + ((sModeHasPBits >> mode) & 1);
1330
+
1331
+
for (k = 0; k < 3; ++k) {
1332
+
/* left shift endpoint components so that their MSB lies in bit 7 */
1333
+
endpoints[i][k] = endpoints[i][k] << (8 - j);
1334
+
/* Replicate each component's MSB into the LSBs revealed by the left-shift operation above */
1335
+
endpoints[i][k] = endpoints[i][k] | (endpoints[i][k] >> j);
1336
+
}
1337
+
1338
+
/* get alpha component precision including pbit */
1339
+
j = actual_bits_count[1][mode] + ((sModeHasPBits >> mode) & 1);
1340
+
1341
+
/* left shift endpoint components so that their MSB lies in bit 7 */
1342
+
endpoints[i][3] = endpoints[i][3] << (8 - j);
1343
+
/* Replicate each component's MSB into the LSBs revealed by the left-shift operation above */
1344
+
endpoints[i][3] = endpoints[i][3] | (endpoints[i][3] >> j);
1345
+
}
1346
+
1347
+
/* If this mode does not explicitly define the alpha component */
1348
+
/* set alpha equal to 1.0 */
1349
+
if (!actual_bits_count[1][mode]) {
1350
+
for (j = 0; j < numEndpoints; ++j) {
1351
+
endpoints[j][3] = 0xFF;
1352
+
}
1353
+
}
1354
+
1355
+
/* Determine weights tables */
1356
+
indexBits = (mode == 0 || mode == 1) ? 3 : ((mode == 6) ? 4 : 2);
1357
+
indexBits2 = (mode == 4) ? 3 : ((mode == 5) ? 2 : 0);
1358
+
weights = (indexBits == 2) ? aWeight2 : ((indexBits == 3) ? aWeight3 : aWeight4);
1359
+
weights2 = (indexBits2 == 2) ? aWeight2 : aWeight3;
1360
+
1361
+
/* Quite inconvenient that indices aren't interleaved so we have to make 2 passes here */
1362
+
/* Pass #1: collecting color indices */
1363
+
for (i = 0; i < 4; ++i) {
1364
+
for (j = 0; j < 4; ++j) {
1365
+
partitionSet = (numPartitions == 1) ? ((i | j) ? 0 : 128) : partition_sets[numPartitions - 2][partition][i][j];
1366
+
1367
+
indexBits = (mode == 0 || mode == 1) ? 3 : ((mode == 6) ? 4 : 2);
1368
+
/* fix-up index is specified with one less bit */
1369
+
/* The fix-up index for subset 0 is always index 0 */
1370
+
if (partitionSet & 0x80) {
1371
+
indexBits--;
1372
+
}
1373
+
1374
+
indices[i][j] = bcdec__bitstream_read_bits(&bstream, indexBits);
1375
+
}
1376
+
}
1377
+
1378
+
/* Pass #2: reading alpha indices (if any) and interpolating & rotating */
1379
+
for (i = 0; i < 4; ++i) {
1380
+
for (j = 0; j < 4; ++j) {
1381
+
partitionSet = (numPartitions == 1) ? ((i|j) ? 0 : 128) : partition_sets[numPartitions - 2][partition][i][j];
1382
+
partitionSet &= 0x03;
1383
+
1384
+
index = indices[i][j];
1385
+
1386
+
if (!indexBits2) {
1387
+
r = bcdec__interpolate(endpoints[partitionSet * 2][0], endpoints[partitionSet * 2 + 1][0], weights, index);
1388
+
g = bcdec__interpolate(endpoints[partitionSet * 2][1], endpoints[partitionSet * 2 + 1][1], weights, index);
1389
+
b = bcdec__interpolate(endpoints[partitionSet * 2][2], endpoints[partitionSet * 2 + 1][2], weights, index);
1390
+
a = bcdec__interpolate(endpoints[partitionSet * 2][3], endpoints[partitionSet * 2 + 1][3], weights, index);
1391
+
} else {
1392
+
index2 = bcdec__bitstream_read_bits(&bstream, (i|j) ? indexBits2 : (indexBits2 - 1));
1393
+
/* The index value for interpolating color comes from the secondary index bits for the texel
1394
+
if the mode has an index selection bit and its value is one, and from the primary index bits otherwise.
1395
+
The alpha index comes from the secondary index bits if the block has a secondary index and
1396
+
the block either doesn’t have an index selection bit or that bit is zero, and from the primary index bits otherwise. */
1397
+
if (!indexSelectionBit) {
1398
+
r = bcdec__interpolate(endpoints[partitionSet * 2][0], endpoints[partitionSet * 2 + 1][0], weights, index);
1399
+
g = bcdec__interpolate(endpoints[partitionSet * 2][1], endpoints[partitionSet * 2 + 1][1], weights, index);
1400
+
b = bcdec__interpolate(endpoints[partitionSet * 2][2], endpoints[partitionSet * 2 + 1][2], weights, index);
1401
+
a = bcdec__interpolate(endpoints[partitionSet * 2][3], endpoints[partitionSet * 2 + 1][3], weights2, index2);
1402
+
} else {
1403
+
r = bcdec__interpolate(endpoints[partitionSet * 2][0], endpoints[partitionSet * 2 + 1][0], weights2, index2);
1404
+
g = bcdec__interpolate(endpoints[partitionSet * 2][1], endpoints[partitionSet * 2 + 1][1], weights2, index2);
1405
+
b = bcdec__interpolate(endpoints[partitionSet * 2][2], endpoints[partitionSet * 2 + 1][2], weights2, index2);
1406
+
a = bcdec__interpolate(endpoints[partitionSet * 2][3], endpoints[partitionSet * 2 + 1][3], weights, index);
1407
+
}
1408
+
}
1409
+
1410
+
switch (rotation) {
1411
+
case 1: { /* 01 – Block format is Scalar(R) Vector(AGB) - swap A and R */
1412
+
bcdec__swap_values(&a, &r);
1413
+
} break;
1414
+
case 2: { /* 10 – Block format is Scalar(G) Vector(RAB) - swap A and G */
1415
+
bcdec__swap_values(&a, &g);
1416
+
} break;
1417
+
case 3: { /* 11 - Block format is Scalar(B) Vector(RGA) - swap A and B */
1418
+
bcdec__swap_values(&a, &b);
1419
+
} break;
1420
+
}
1421
+
1422
+
decompressed[j * 4 + 0] = r;
1423
+
decompressed[j * 4 + 1] = g;
1424
+
decompressed[j * 4 + 2] = b;
1425
+
decompressed[j * 4 + 3] = a;
1426
+
}
1427
+
1428
+
decompressed += destinationPitch;
1429
+
}
1430
+
}
1431
+
1432
+
#endif /* BCDEC_IMPLEMENTATION */
1433
+
1434
+
/* LICENSE:
1435
+
1436
+
This software is available under 2 licenses -- choose whichever you prefer.
1437
+
1438
+
------------------------------------------------------------------------------
1439
+
ALTERNATIVE A - MIT License
1440
+
1441
+
Copyright (c) 2022 Sergii Kudlai
1442
+
1443
+
Permission is hereby granted, free of charge, to any person obtaining a copy of
1444
+
this software and associated documentation files (the "Software"), to deal in
1445
+
the Software without restriction, including without limitation the rights to
1446
+
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
1447
+
of the Software, and to permit persons to whom the Software is furnished to do
1448
+
so, subject to the following conditions:
1449
+
1450
+
The above copyright notice and this permission notice shall be included in all
1451
+
copies or substantial portions of the Software.
1452
+
1453
+
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
1454
+
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1455
+
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
1456
+
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
1457
+
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
1458
+
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
1459
+
SOFTWARE.
1460
+
1461
+
------------------------------------------------------------------------------
1462
+
ALTERNATIVE B - The Unlicense
1463
+
1464
+
This is free and unencumbered software released into the public domain.
1465
+
1466
+
Anyone is free to copy, modify, publish, use, compile, sell, or
1467
+
distribute this software, either in source code form or as a compiled
1468
+
binary, for any purpose, commercial or non-commercial, and by any
1469
+
means.
1470
+
1471
+
In jurisdictions that recognize copyright laws, the author or authors
1472
+
of this software dedicate any and all copyright interest in the
1473
+
software to the public domain. We make this dedication for the benefit
1474
+
of the public at large and to the detriment of our heirs and
1475
+
successors. We intend this dedication to be an overt act of
1476
+
relinquishment in perpetuity of all present and future rights to this
1477
+
software under copyright law.
1478
+
1479
+
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
1480
+
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
1481
+
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
1482
+
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
1483
+
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
1484
+
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
1485
+
OTHER DEALINGS IN THE SOFTWARE.
1486
+
1487
+
For more information, please refer to <https://unlicense.org>
1488
+
1489
+
*/