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Diffstat (limited to 'plugins/gpu_unai/gpu_inner_quantization.h')
| -rw-r--r-- | plugins/gpu_unai/gpu_inner_quantization.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/plugins/gpu_unai/gpu_inner_quantization.h b/plugins/gpu_unai/gpu_inner_quantization.h new file mode 100644 index 0000000..0e7e3e8 --- /dev/null +++ b/plugins/gpu_unai/gpu_inner_quantization.h @@ -0,0 +1,108 @@ +/*************************************************************************** +* Copyright (C) 2016 PCSX4ALL Team * +* * +* This program is free software; you can redistribute it and/or modify * +* it under the terms of the GNU General Public License as published by * +* the Free Software Foundation; either version 2 of the License, or * +* (at your option) any later version. * +* * +* This program is distributed in the hope that it will be useful, * +* but WITHOUT ANY WARRANTY; without even the implied warranty of * +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * +* GNU General Public License for more details. * +* * +* You should have received a copy of the GNU General Public License * +* along with this program; if not, write to the * +* Free Software Foundation, Inc., * +* 51 Franklin Street, Fifth Floor, Boston, MA 02111-1307 USA. * +***************************************************************************/ + +#ifndef _OP_DITHER_H_ +#define _OP_DITHER_H_ + +static void SetupDitheringConstants() +{ + // Initialize Dithering Constants + // The screen is divided into 8x8 chunks and sub-unitary noise is applied + // using the following matrix. This ensures that data lost in color + // quantization will be added back to the image 'by chance' in predictable + // patterns that are naturally 'smoothed' by your sight when viewed from a + // certain distance. + // + // http://caca.zoy.org/study/index.html + // + // Shading colors are encoded in 4.5, and then are quantitized to 5.0, + // DitherMatrix constants reflect that. + + static const u8 DitherMatrix[] = { + 0, 32, 8, 40, 2, 34, 10, 42, + 48, 16, 56, 24, 50, 18, 58, 26, + 12, 44, 4, 36, 14, 46, 6, 38, + 60, 28, 52, 20, 62, 30, 54, 22, + 3, 35, 11, 43, 1, 33, 9, 41, + 51, 19, 59, 27, 49, 17, 57, 25, + 15, 47, 7, 39, 13, 45, 5, 37, + 63, 31, 55, 23, 61, 29, 53, 21 + }; + + int i, j; + for (i = 0; i < 8; i++) + { + for (j = 0; j < 8; j++) + { + u16 offset = (i << 3) | j; + + u32 component = ((DitherMatrix[offset] + 1) << 4) / 65; //[5.5] -> [5] + + // XXX - senquack - hack Dec 2016 + // Until JohnnyF gets the time to work further on dithering, + // force lower bit of component to 0. This fixes grid pattern + // affecting quality of dithered image, as well as loss of + // detail in dark areas. With lower bit unset like this, existing + // 27-bit accuracy of dithering math is unneeded, could be 24-bit. + // Is 8x8 matrix overkill as a result, can we use 4x4? + component &= ~1; + + gpu_unai.DitherMatrix[offset] = (component) + | (component << 10) + | (component << 20); + } + } +} + +//////////////////////////////////////////////////////////////////////////////// +// Convert padded u32 5.4:5.4:5.4 bgr fixed-pt triplet to final bgr555 color, +// applying dithering if specified by template parameter. +// +// INPUT: +// 'uSrc24' input: 000bbbbbXXXX0gggggXXXX0rrrrrXXXX +// ^ bit 31 +// 'pDst' is a pointer to destination framebuffer pixel, used +// to determine which DitherMatrix[] entry to apply. +// RETURNS: +// u16 output: 0bbbbbgggggrrrrr +// ^ bit 16 +// Where 'X' are fixed-pt bits, '0' is zero-padding, and '-' is don't care +//////////////////////////////////////////////////////////////////////////////// +template <int DITHER> +GPU_INLINE u16 gpuColorQuantization24(u32 uSrc24, const u16 *pDst) +{ + if (DITHER) + { + u16 fbpos = (u32)(pDst - gpu_unai.vram); + u16 offset = ((fbpos & (0x7 << 10)) >> 7) | (fbpos & 0x7); + + //clean overflow flags and add + uSrc24 = (uSrc24 & 0x1FF7FDFF) + gpu_unai.DitherMatrix[offset]; + + if (uSrc24 & (1<< 9)) uSrc24 |= (0x1FF ); + if (uSrc24 & (1<<19)) uSrc24 |= (0x1FF<<10); + if (uSrc24 & (1<<29)) uSrc24 |= (0x1FF<<20); + } + + return ((uSrc24>> 4) & (0x1F )) + | ((uSrc24>> 9) & (0x1F<<5 )) + | ((uSrc24>>14) & (0x1F<<10)); +} + +#endif //_OP_DITHER_H_ |