/* ----------------------------------------------------------------------------- Copyright (c) 2006 Simon Brown si@sjbrown.co.uk Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. -------------------------------------------------------------------------- */ #include <string.h> #include "squish.h" #include "colourset.h" #include "maths.h" #include "rangefit.h" #include "clusterfit.h" #include "colourblock.h" #include "alpha.h" #include "singlecolourfit.h" namespace squish { static int FixFlags( int flags ) { // grab the flag bits int method = flags & ( kDxt1 | kDxt3 | kDxt5 | kBc4 | kBc5 ); int fit = flags & ( kColourIterativeClusterFit | kColourClusterFit | kColourRangeFit ); int extra = flags & kWeightColourByAlpha; // set defaults if ( method != kDxt3 && method != kDxt5 && method != kBc4 && method != kBc5 ) { method = kDxt1; } if( fit != kColourRangeFit && fit != kColourIterativeClusterFit ) fit = kColourClusterFit; // done return method | fit | extra; } void CompressMasked( u8 const* rgba, int mask, void* block, int flags, float* metric ) { // fix any bad flags flags = FixFlags( flags ); if ( ( flags & ( kBc4 | kBc5 ) ) != 0 ) { u8 alpha[16*4]; for( int i = 0; i < 16; ++i ) { alpha[i*4 + 3] = rgba[i*4 + 0]; // copy R to A } u8* rBlock = reinterpret_cast< u8* >( block ); CompressAlphaDxt5( alpha, mask, rBlock ); if ( ( flags & ( kBc5 ) ) != 0 ) { for( int i = 0; i < 16; ++i ) { alpha[i*4 + 3] = rgba[i*4 + 1]; // copy G to A } u8* gBlock = reinterpret_cast< u8* >( block ) + 8; CompressAlphaDxt5( alpha, mask, gBlock ); } return; } // get the block locations void* colourBlock = block; void* alphaBlock = block; if( ( flags & ( kDxt3 | kDxt5 ) ) != 0 ) colourBlock = reinterpret_cast< u8* >( block ) + 8; // create the minimal point set ColourSet colours( rgba, mask, flags ); // check the compression type and compress colour if( colours.GetCount() == 1 ) { // always do a single colour fit SingleColourFit fit( &colours, flags ); fit.Compress( colourBlock ); } else if( ( flags & kColourRangeFit ) != 0 || colours.GetCount() == 0 ) { // do a range fit RangeFit fit( &colours, flags, metric ); fit.Compress( colourBlock ); } else { // default to a cluster fit (could be iterative or not) ClusterFit fit( &colours, flags, metric ); fit.Compress( colourBlock ); } // compress alpha separately if necessary if( ( flags & kDxt3 ) != 0 ) CompressAlphaDxt3( rgba, mask, alphaBlock ); else if( ( flags & kDxt5 ) != 0 ) CompressAlphaDxt5( rgba, mask, alphaBlock ); } void Decompress( u8* rgba, void const* block, int flags ) { // fix any bad flags flags = FixFlags( flags ); // get the block locations void const* colourBlock = block; void const* alphaBlock = block; if( ( flags & ( kDxt3 | kDxt5 ) ) != 0 ) colourBlock = reinterpret_cast< u8 const* >( block ) + 8; // decompress colour // -- GODOT start -- //DecompressColour( rgba, colourBlock, ( flags & kDxt1 ) != 0 ); if(( flags & ( kBc5 ) ) != 0) DecompressColourBc5( rgba, colourBlock); else DecompressColour( rgba, colourBlock, ( flags & kDxt1 ) != 0 ); // -- GODOT end -- // decompress alpha separately if necessary if( ( flags & kDxt3 ) != 0 ) DecompressAlphaDxt3( rgba, alphaBlock ); else if( ( flags & kDxt5 ) != 0 ) DecompressAlphaDxt5( rgba, alphaBlock ); } int GetStorageRequirements( int width, int height, int flags ) { // fix any bad flags flags = FixFlags( flags ); // compute the storage requirements int blockcount = ( ( width + 3 )/4 ) * ( ( height + 3 )/4 ); int blocksize = ( ( flags & ( kDxt1 | kBc4 ) ) != 0 ) ? 8 : 16; return blockcount*blocksize; } void CopyRGBA( u8 const* source, u8* dest, int flags ) { if (flags & kSourceBGRA) { // convert from bgra to rgba dest[0] = source[2]; dest[1] = source[1]; dest[2] = source[0]; dest[3] = source[3]; } else { for( int i = 0; i < 4; ++i ) *dest++ = *source++; } } void CompressImage( u8 const* rgba, int width, int height, int pitch, void* blocks, int flags, float* metric ) { // fix any bad flags flags = FixFlags( flags ); // loop over blocks #ifdef SQUISH_USE_OPENMP # pragma omp parallel for #endif for( int y = 0; y < height; y += 4 ) { // initialise the block output u8* targetBlock = reinterpret_cast< u8* >( blocks ); int bytesPerBlock = ( ( flags & ( kDxt1 | kBc4 ) ) != 0 ) ? 8 : 16; targetBlock += ( (y / 4) * ( (width + 3) / 4) ) * bytesPerBlock; for( int x = 0; x < width; x += 4 ) { // build the 4x4 block of pixels u8 sourceRgba[16*4]; u8* targetPixel = sourceRgba; int mask = 0; for( int py = 0; py < 4; ++py ) { for( int px = 0; px < 4; ++px ) { // get the source pixel in the image int sx = x + px; int sy = y + py; // enable if we're in the image if( sx < width && sy < height ) { // copy the rgba value u8 const* sourcePixel = rgba + pitch*sy + 4*sx; CopyRGBA(sourcePixel, targetPixel, flags); // enable this pixel mask |= ( 1 << ( 4*py + px ) ); } // advance to the next pixel targetPixel += 4; } } // compress it into the output CompressMasked( sourceRgba, mask, targetBlock, flags, metric ); // advance targetBlock += bytesPerBlock; } } } void CompressImage( u8 const* rgba, int width, int height, void* blocks, int flags, float* metric ) { CompressImage(rgba, width, height, width*4, blocks, flags, metric); } void DecompressImage( u8* rgba, int width, int height, int pitch, void const* blocks, int flags ) { // fix any bad flags flags = FixFlags( flags ); // loop over blocks #ifdef SQUISH_USE_OPENMP # pragma omp parallel for #endif for( int y = 0; y < height; y += 4 ) { // initialise the block input u8 const* sourceBlock = reinterpret_cast< u8 const* >( blocks ); int bytesPerBlock = ( ( flags & ( kDxt1 | kBc4 ) ) != 0 ) ? 8 : 16; sourceBlock += ( (y / 4) * ( (width + 3) / 4) ) * bytesPerBlock; for( int x = 0; x < width; x += 4 ) { // decompress the block u8 targetRgba[4*16]; Decompress( targetRgba, sourceBlock, flags ); // write the decompressed pixels to the correct image locations u8 const* sourcePixel = targetRgba; for( int py = 0; py < 4; ++py ) { for( int px = 0; px < 4; ++px ) { // get the target location int sx = x + px; int sy = y + py; // write if we're in the image if( sx < width && sy < height ) { // copy the rgba value u8* targetPixel = rgba + pitch*sy + 4*sx; CopyRGBA(sourcePixel, targetPixel, flags); } // advance to the next pixel sourcePixel += 4; } } // advance sourceBlock += bytesPerBlock; } } } void DecompressImage( u8* rgba, int width, int height, void const* blocks, int flags ) { DecompressImage( rgba, width, height, width*4, blocks, flags ); } static double ErrorSq(double x, double y) { return (x - y) * (x - y); } static void ComputeBlockWMSE(u8 const *original, u8 const *compressed, unsigned int w, unsigned int h, double &cmse, double &amse) { // Computes the MSE for the block and weights it by the variance of the original block. // If the variance of the original block is less than 4 (i.e. a standard deviation of 1 per channel) // then the block is close to being a single colour. Quantisation errors in single colour blocks // are easier to see than similar errors in blocks that contain more colours, particularly when there // are many such blocks in a large area (eg a blue sky background) as they cause banding. Given that // banding is easier to see than small errors in "complex" blocks, we weight the errors by a factor // of 5. This implies that images with large, single colour areas will have a higher potential WMSE // than images with lots of detail. cmse = amse = 0; unsigned int sum_p[4]; // per channel sum of pixels unsigned int sum_p2[4]; // per channel sum of pixels squared memset(sum_p, 0, sizeof(sum_p)); memset(sum_p2, 0, sizeof(sum_p2)); for( unsigned int py = 0; py < 4; ++py ) { for( unsigned int px = 0; px < 4; ++px ) { if( px < w && py < h ) { double pixelCMSE = 0; for( int i = 0; i < 3; ++i ) { pixelCMSE += ErrorSq(original[i], compressed[i]); sum_p[i] += original[i]; sum_p2[i] += (unsigned int)original[i]*original[i]; } if( original[3] == 0 && compressed[3] == 0 ) pixelCMSE = 0; // transparent in both, so colour is inconsequential amse += ErrorSq(original[3], compressed[3]); cmse += pixelCMSE; sum_p[3] += original[3]; sum_p2[3] += (unsigned int)original[3]*original[3]; } original += 4; compressed += 4; } } unsigned int variance = 0; for( int i = 0; i < 4; ++i ) variance += w*h*sum_p2[i] - sum_p[i]*sum_p[i]; if( variance < 4 * w * w * h * h ) { amse *= 5; cmse *= 5; } } void ComputeMSE( u8 const *rgba, int width, int height, int pitch, u8 const *dxt, int flags, double &colourMSE, double &alphaMSE ) { // fix any bad flags flags = FixFlags( flags ); colourMSE = alphaMSE = 0; // initialise the block input squish::u8 const* sourceBlock = dxt; int bytesPerBlock = ( ( flags & squish::kDxt1 ) != 0 ) ? 8 : 16; // loop over blocks for( int y = 0; y < height; y += 4 ) { for( int x = 0; x < width; x += 4 ) { // decompress the block u8 targetRgba[4*16]; Decompress( targetRgba, sourceBlock, flags ); u8 const* sourcePixel = targetRgba; // copy across to a similar pixel block u8 originalRgba[4*16]; u8* originalPixel = originalRgba; for( int py = 0; py < 4; ++py ) { for( int px = 0; px < 4; ++px ) { int sx = x + px; int sy = y + py; if( sx < width && sy < height ) { u8 const* targetPixel = rgba + pitch*sy + 4*sx; CopyRGBA(targetPixel, originalPixel, flags); } sourcePixel += 4; originalPixel += 4; } } // compute the weighted MSE of the block double blockCMSE, blockAMSE; ComputeBlockWMSE(originalRgba, targetRgba, std::min(4, width - x), std::min(4, height - y), blockCMSE, blockAMSE); colourMSE += blockCMSE; alphaMSE += blockAMSE; // advance sourceBlock += bytesPerBlock; } } colourMSE /= (width * height * 3); alphaMSE /= (width * height); } void ComputeMSE( u8 const *rgba, int width, int height, u8 const *dxt, int flags, double &colourMSE, double &alphaMSE ) { ComputeMSE(rgba, width, height, width*4, dxt, flags, colourMSE, alphaMSE); } } // namespace squish