842 lines
35 KiB
C
842 lines
35 KiB
C
/*
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* libtxc_dxtn
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* Version: 1.0
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*
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* Copyright (C) 2004 Roland Scheidegger All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "txc_dxtn.h"
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/* weights used for error function, basically weights (unsquared 2/4/1) according to rgb->luminance conversion
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not sure if this really reflects visual perception */
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#define REDWEIGHT 4
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#define GREENWEIGHT 16
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#define BLUEWEIGHT 1
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#define ALPHACUT 127
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static void fancybasecolorsearch( GLubyte *blkaddr, GLubyte srccolors[4][4][4], GLubyte *bestcolor[2],
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GLint numxpixels, GLint numypixels, GLint type, GLboolean haveAlpha)
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{
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/* use same luminance-weighted distance metric to determine encoding as for finding the base colors */
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/* TODO could also try to find a better encoding for the 3-color-encoding type, this really should be done
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if it's rgba_dxt1 and we have alpha in the block, currently even values which will be mapped to black
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due to their alpha value will influence the result */
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GLint i, j, colors, z;
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GLuint pixerror, pixerrorred, pixerrorgreen, pixerrorblue, pixerrorbest;
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GLint colordist, blockerrlin[2][3];
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GLubyte nrcolor[2];
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GLint pixerrorcolorbest[3];
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GLubyte enc = 0;
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GLubyte cv[4][4];
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GLubyte testcolor[2][3];
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/* fprintf(stderr, "color begin 0 r/g/b %d/%d/%d, 1 r/g/b %d/%d/%d\n",
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bestcolor[0][0], bestcolor[0][1], bestcolor[0][2], bestcolor[1][0], bestcolor[1][1], bestcolor[1][2]);*/
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if (((bestcolor[0][0] & 0xf8) << 8 | (bestcolor[0][1] & 0xfc) << 3 | bestcolor[0][2] >> 3) <
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((bestcolor[1][0] & 0xf8) << 8 | (bestcolor[1][1] & 0xfc) << 3 | bestcolor[1][2] >> 3)) {
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testcolor[0][0] = bestcolor[0][0];
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testcolor[0][1] = bestcolor[0][1];
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testcolor[0][2] = bestcolor[0][2];
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testcolor[1][0] = bestcolor[1][0];
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testcolor[1][1] = bestcolor[1][1];
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testcolor[1][2] = bestcolor[1][2];
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}
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else {
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testcolor[1][0] = bestcolor[0][0];
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testcolor[1][1] = bestcolor[0][1];
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testcolor[1][2] = bestcolor[0][2];
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testcolor[0][0] = bestcolor[1][0];
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testcolor[0][1] = bestcolor[1][1];
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testcolor[0][2] = bestcolor[1][2];
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}
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for (i = 0; i < 3; i ++) {
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cv[0][i] = testcolor[0][i];
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cv[1][i] = testcolor[1][i];
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cv[2][i] = (testcolor[0][i] * 2 + testcolor[1][i]) / 3;
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cv[3][i] = (testcolor[0][i] + testcolor[1][i] * 2) / 3;
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}
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blockerrlin[0][0] = 0;
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blockerrlin[0][1] = 0;
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blockerrlin[0][2] = 0;
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blockerrlin[1][0] = 0;
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blockerrlin[1][1] = 0;
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blockerrlin[1][2] = 0;
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nrcolor[0] = 0;
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nrcolor[1] = 0;
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for (j = 0; j < numypixels; j++) {
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for (i = 0; i < numxpixels; i++) {
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pixerrorbest = 0xffffffff;
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for (colors = 0; colors < 4; colors++) {
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colordist = srccolors[j][i][0] - (cv[colors][0]);
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pixerror = colordist * colordist * REDWEIGHT;
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pixerrorred = colordist;
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colordist = srccolors[j][i][1] - (cv[colors][1]);
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pixerror += colordist * colordist * GREENWEIGHT;
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pixerrorgreen = colordist;
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colordist = srccolors[j][i][2] - (cv[colors][2]);
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pixerror += colordist * colordist * BLUEWEIGHT;
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pixerrorblue = colordist;
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if (pixerror < pixerrorbest) {
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enc = colors;
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pixerrorbest = pixerror;
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pixerrorcolorbest[0] = pixerrorred;
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pixerrorcolorbest[1] = pixerrorgreen;
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pixerrorcolorbest[2] = pixerrorblue;
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}
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}
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if (enc == 0) {
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for (z = 0; z < 3; z++) {
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blockerrlin[0][z] += 3 * pixerrorcolorbest[z];
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}
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nrcolor[0] += 3;
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}
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else if (enc == 2) {
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for (z = 0; z < 3; z++) {
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blockerrlin[0][z] += 2 * pixerrorcolorbest[z];
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}
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nrcolor[0] += 2;
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for (z = 0; z < 3; z++) {
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blockerrlin[1][z] += 1 * pixerrorcolorbest[z];
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}
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nrcolor[1] += 1;
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}
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else if (enc == 3) {
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for (z = 0; z < 3; z++) {
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blockerrlin[0][z] += 1 * pixerrorcolorbest[z];
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}
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nrcolor[0] += 1;
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for (z = 0; z < 3; z++) {
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blockerrlin[1][z] += 2 * pixerrorcolorbest[z];
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}
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nrcolor[1] += 2;
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}
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else if (enc == 1) {
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for (z = 0; z < 3; z++) {
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blockerrlin[1][z] += 3 * pixerrorcolorbest[z];
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}
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nrcolor[1] += 3;
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}
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}
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}
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if (nrcolor[0] == 0) nrcolor[0] = 1;
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if (nrcolor[1] == 0) nrcolor[1] = 1;
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for (j = 0; j < 2; j++) {
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for (i = 0; i < 3; i++) {
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GLint newvalue = testcolor[j][i] + blockerrlin[j][i] / nrcolor[j];
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if (newvalue <= 0)
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testcolor[j][i] = 0;
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else if (newvalue >= 255)
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testcolor[j][i] = 255;
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else testcolor[j][i] = newvalue;
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}
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}
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if ((abs(testcolor[0][0] - testcolor[1][0]) < 8) &&
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(abs(testcolor[0][1] - testcolor[1][1]) < 4) &&
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(abs(testcolor[0][2] - testcolor[1][2]) < 8)) {
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/* both colors are so close they might get encoded as the same 16bit values */
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GLubyte coldiffred, coldiffgreen, coldiffblue, coldiffmax, factor, ind0, ind1;
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coldiffred = abs(testcolor[0][0] - testcolor[1][0]);
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coldiffgreen = 2 * abs(testcolor[0][1] - testcolor[1][1]);
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coldiffblue = abs(testcolor[0][2] - testcolor[1][2]);
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coldiffmax = coldiffred;
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if (coldiffmax < coldiffgreen) coldiffmax = coldiffgreen;
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if (coldiffmax < coldiffblue) coldiffmax = coldiffblue;
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if (coldiffmax > 0) {
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if (coldiffmax > 4) factor = 2;
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else if (coldiffmax > 2) factor = 3;
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else factor = 4;
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/* Won't do much if the color value is near 255... */
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/* argh so many ifs */
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if (testcolor[1][1] >= testcolor[0][1]) {
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ind1 = 1; ind0 = 0;
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}
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else {
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ind1 = 0; ind0 = 1;
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}
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if ((testcolor[ind1][1] + factor * coldiffgreen) <= 255)
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testcolor[ind1][1] += factor * coldiffgreen;
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else testcolor[ind1][1] = 255;
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if ((testcolor[ind1][0] - testcolor[ind0][1]) > 0) {
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if ((testcolor[ind1][0] + factor * coldiffred) <= 255)
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testcolor[ind1][0] += factor * coldiffred;
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else testcolor[ind1][0] = 255;
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}
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else {
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if ((testcolor[ind0][0] + factor * coldiffred) <= 255)
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testcolor[ind0][0] += factor * coldiffred;
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else testcolor[ind0][0] = 255;
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}
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if ((testcolor[ind1][2] - testcolor[ind0][2]) > 0) {
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if ((testcolor[ind1][2] + factor * coldiffblue) <= 255)
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testcolor[ind1][2] += factor * coldiffblue;
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else testcolor[ind1][2] = 255;
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}
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else {
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if ((testcolor[ind0][2] + factor * coldiffblue) <= 255)
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testcolor[ind0][2] += factor * coldiffblue;
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else testcolor[ind0][2] = 255;
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}
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}
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}
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if (((testcolor[0][0] & 0xf8) << 8 | (testcolor[0][1] & 0xfc) << 3 | testcolor[0][2] >> 3) <
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((testcolor[1][0] & 0xf8) << 8 | (testcolor[1][1] & 0xfc) << 3 | testcolor[1][2]) >> 3) {
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for (i = 0; i < 3; i++) {
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bestcolor[0][i] = testcolor[0][i];
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bestcolor[1][i] = testcolor[1][i];
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}
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}
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else {
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for (i = 0; i < 3; i++) {
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bestcolor[0][i] = testcolor[1][i];
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bestcolor[1][i] = testcolor[0][i];
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}
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}
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/* fprintf(stderr, "color end 0 r/g/b %d/%d/%d, 1 r/g/b %d/%d/%d\n",
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bestcolor[0][0], bestcolor[0][1], bestcolor[0][2], bestcolor[1][0], bestcolor[1][1], bestcolor[1][2]);*/
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}
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static void storedxtencodedblock( GLubyte *blkaddr, GLubyte srccolors[4][4][4], GLubyte *bestcolor[2],
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GLint numxpixels, GLint numypixels, GLuint type, GLboolean haveAlpha)
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{
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/* use same luminance-weighted distance metric to determine encoding as for finding the base colors */
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GLint i, j, colors;
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GLuint testerror, testerror2, pixerror, pixerrorbest;
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GLint colordist;
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GLushort color0, color1, tempcolor;
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GLuint bits = 0, bits2 = 0;
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GLubyte *colorptr;
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GLubyte enc = 0;
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GLubyte cv[4][4];
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bestcolor[0][0] = bestcolor[0][0] & 0xf8;
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bestcolor[0][1] = bestcolor[0][1] & 0xfc;
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bestcolor[0][2] = bestcolor[0][2] & 0xf8;
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bestcolor[1][0] = bestcolor[1][0] & 0xf8;
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bestcolor[1][1] = bestcolor[1][1] & 0xfc;
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bestcolor[1][2] = bestcolor[1][2] & 0xf8;
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color0 = bestcolor[0][0] << 8 | bestcolor[0][1] << 3 | bestcolor[0][2] >> 3;
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color1 = bestcolor[1][0] << 8 | bestcolor[1][1] << 3 | bestcolor[1][2] >> 3;
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if (color0 < color1) {
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tempcolor = color0; color0 = color1; color1 = tempcolor;
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colorptr = bestcolor[0]; bestcolor[0] = bestcolor[1]; bestcolor[1] = colorptr;
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}
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for (i = 0; i < 3; i++) {
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cv[0][i] = bestcolor[0][i];
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cv[1][i] = bestcolor[1][i];
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cv[2][i] = (bestcolor[0][i] * 2 + bestcolor[1][i]) / 3;
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cv[3][i] = (bestcolor[0][i] + bestcolor[1][i] * 2) / 3;
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}
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testerror = 0;
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for (j = 0; j < numypixels; j++) {
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for (i = 0; i < numxpixels; i++) {
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pixerrorbest = 0xffffffff;
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for (colors = 0; colors < 4; colors++) {
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colordist = srccolors[j][i][0] - cv[colors][0];
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pixerror = colordist * colordist * REDWEIGHT;
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colordist = srccolors[j][i][1] - cv[colors][1];
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pixerror += colordist * colordist * GREENWEIGHT;
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colordist = srccolors[j][i][2] - cv[colors][2];
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pixerror += colordist * colordist * BLUEWEIGHT;
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if (pixerror < pixerrorbest) {
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pixerrorbest = pixerror;
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enc = colors;
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}
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}
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testerror += pixerrorbest;
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bits |= enc << (2 * (j * 4 + i));
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}
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}
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/* some hw might disagree but actually decoding should always use 4-color encoding
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for non-dxt1 formats */
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if (type == GL_COMPRESSED_RGB_S3TC_DXT1_EXT || type == GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) {
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for (i = 0; i < 3; i++) {
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cv[2][i] = (bestcolor[0][i] + bestcolor[1][i]) / 2;
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/* this isn't used. Looks like the black color constant can only be used
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with RGB_DXT1 if I read the spec correctly (note though that the radeon gpu disagrees,
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it will decode 3 to black even with DXT3/5), and due to how the color searching works
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it won't get used even then */
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cv[3][i] = 0;
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}
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testerror2 = 0;
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for (j = 0; j < numypixels; j++) {
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for (i = 0; i < numxpixels; i++) {
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pixerrorbest = 0xffffffff;
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if ((type == GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) && (srccolors[j][i][3] <= ALPHACUT)) {
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enc = 3;
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pixerrorbest = 0; /* don't calculate error */
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}
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else {
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/* we're calculating the same what we have done already for colors 0-1 above... */
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for (colors = 0; colors < 3; colors++) {
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colordist = srccolors[j][i][0] - cv[colors][0];
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pixerror = colordist * colordist * REDWEIGHT;
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colordist = srccolors[j][i][1] - cv[colors][1];
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pixerror += colordist * colordist * GREENWEIGHT;
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colordist = srccolors[j][i][2] - cv[colors][2];
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pixerror += colordist * colordist * BLUEWEIGHT;
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if (pixerror < pixerrorbest) {
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pixerrorbest = pixerror;
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/* need to exchange colors later */
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if (colors > 1) enc = colors;
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else enc = colors ^ 1;
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}
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}
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}
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testerror2 += pixerrorbest;
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bits2 |= enc << (2 * (j * 4 + i));
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}
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}
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} else {
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testerror2 = 0xffffffff;
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}
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/* finally we're finished, write back colors and bits */
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if ((testerror > testerror2) || (haveAlpha)) {
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*blkaddr++ = color1 & 0xff;
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*blkaddr++ = color1 >> 8;
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*blkaddr++ = color0 & 0xff;
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*blkaddr++ = color0 >> 8;
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*blkaddr++ = bits2 & 0xff;
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*blkaddr++ = ( bits2 >> 8) & 0xff;
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*blkaddr++ = ( bits2 >> 16) & 0xff;
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*blkaddr = bits2 >> 24;
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}
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else {
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*blkaddr++ = color0 & 0xff;
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*blkaddr++ = color0 >> 8;
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*blkaddr++ = color1 & 0xff;
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*blkaddr++ = color1 >> 8;
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*blkaddr++ = bits & 0xff;
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*blkaddr++ = ( bits >> 8) & 0xff;
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*blkaddr++ = ( bits >> 16) & 0xff;
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*blkaddr = bits >> 24;
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}
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}
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static void encodedxtcolorblockfaster( GLubyte *blkaddr, GLubyte srccolors[4][4][4],
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GLint numxpixels, GLint numypixels, GLuint type )
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{
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/* simplistic approach. We need two base colors, simply use the "highest" and the "lowest" color
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present in the picture as base colors */
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/* define lowest and highest color as shortest and longest vector to 0/0/0, though the
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vectors are weighted similar to their importance in rgb-luminance conversion
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doesn't work too well though...
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This seems to be a rather difficult problem */
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GLubyte *bestcolor[2];
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GLubyte basecolors[2][3];
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GLubyte i, j;
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GLuint lowcv, highcv, testcv;
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GLboolean haveAlpha = GL_FALSE;
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lowcv = highcv = srccolors[0][0][0] * srccolors[0][0][0] * REDWEIGHT +
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srccolors[0][0][1] * srccolors[0][0][1] * GREENWEIGHT +
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srccolors[0][0][2] * srccolors[0][0][2] * BLUEWEIGHT;
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bestcolor[0] = bestcolor[1] = srccolors[0][0];
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for (j = 0; j < numypixels; j++) {
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for (i = 0; i < numxpixels; i++) {
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/* don't use this as a base color if the pixel will get black/transparent anyway */
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if ((type != GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) || (srccolors[j][i][3] > ALPHACUT)) {
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testcv = srccolors[j][i][0] * srccolors[j][i][0] * REDWEIGHT +
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srccolors[j][i][1] * srccolors[j][i][1] * GREENWEIGHT +
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srccolors[j][i][2] * srccolors[j][i][2] * BLUEWEIGHT;
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if (testcv > highcv) {
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highcv = testcv;
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bestcolor[1] = srccolors[j][i];
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}
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else if (testcv < lowcv) {
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lowcv = testcv;
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bestcolor[0] = srccolors[j][i];
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}
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}
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else haveAlpha = GL_TRUE;
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}
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}
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/* make sure the original color values won't get touched... */
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for (j = 0; j < 2; j++) {
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for (i = 0; i < 3; i++) {
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basecolors[j][i] = bestcolor[j][i];
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}
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}
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bestcolor[0] = basecolors[0];
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bestcolor[1] = basecolors[1];
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/* try to find better base colors */
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fancybasecolorsearch(blkaddr, srccolors, bestcolor, numxpixels, numypixels, type, haveAlpha);
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/* find the best encoding for these colors, and store the result */
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storedxtencodedblock(blkaddr, srccolors, bestcolor, numxpixels, numypixels, type, haveAlpha);
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}
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static void writedxt5encodedalphablock( GLubyte *blkaddr, GLubyte alphabase1, GLubyte alphabase2,
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GLubyte alphaenc[16])
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{
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*blkaddr++ = alphabase1;
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*blkaddr++ = alphabase2;
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*blkaddr++ = alphaenc[0] | (alphaenc[1] << 3) | ((alphaenc[2] & 3) << 6);
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*blkaddr++ = (alphaenc[2] >> 2) | (alphaenc[3] << 1) | (alphaenc[4] << 4) | ((alphaenc[5] & 1) << 7);
|
|
*blkaddr++ = (alphaenc[5] >> 1) | (alphaenc[6] << 2) | (alphaenc[7] << 5);
|
|
*blkaddr++ = alphaenc[8] | (alphaenc[9] << 3) | ((alphaenc[10] & 3) << 6);
|
|
*blkaddr++ = (alphaenc[10] >> 2) | (alphaenc[11] << 1) | (alphaenc[12] << 4) | ((alphaenc[13] & 1) << 7);
|
|
*blkaddr++ = (alphaenc[13] >> 1) | (alphaenc[14] << 2) | (alphaenc[15] << 5);
|
|
}
|
|
|
|
static void encodedxt5alpha(GLubyte *blkaddr, GLubyte srccolors[4][4][4],
|
|
GLint numxpixels, GLint numypixels)
|
|
{
|
|
GLubyte alphabase[2], alphause[2];
|
|
GLshort alphatest[2];
|
|
GLuint alphablockerror1, alphablockerror2, alphablockerror3;
|
|
GLubyte i, j, aindex, acutValues[7];
|
|
GLubyte alphaenc1[16], alphaenc2[16], alphaenc3[16];
|
|
GLboolean alphaabsmin = GL_FALSE;
|
|
GLboolean alphaabsmax = GL_FALSE;
|
|
GLshort alphadist;
|
|
|
|
/* find lowest and highest alpha value in block, alphabase[0] lowest, alphabase[1] highest */
|
|
alphabase[0] = 0xff; alphabase[1] = 0x0;
|
|
for (j = 0; j < numypixels; j++) {
|
|
for (i = 0; i < numxpixels; i++) {
|
|
if (srccolors[j][i][3] == 0)
|
|
alphaabsmin = GL_TRUE;
|
|
else if (srccolors[j][i][3] == 255)
|
|
alphaabsmax = GL_TRUE;
|
|
else {
|
|
if (srccolors[j][i][3] > alphabase[1])
|
|
alphabase[1] = srccolors[j][i][3];
|
|
if (srccolors[j][i][3] < alphabase[0])
|
|
alphabase[0] = srccolors[j][i][3];
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
if ((alphabase[0] > alphabase[1]) && !(alphaabsmin && alphaabsmax)) { /* one color, either max or min */
|
|
/* shortcut here since it is a very common case (and also avoids later problems) */
|
|
/* || (alphabase[0] == alphabase[1] && !alphaabsmin && !alphaabsmax) */
|
|
/* could also test for alpha0 == alpha1 (and not min/max), but probably not common, so don't bother */
|
|
|
|
*blkaddr++ = srccolors[0][0][3];
|
|
blkaddr++;
|
|
*blkaddr++ = 0;
|
|
*blkaddr++ = 0;
|
|
*blkaddr++ = 0;
|
|
*blkaddr++ = 0;
|
|
*blkaddr++ = 0;
|
|
*blkaddr++ = 0;
|
|
/* fprintf(stderr, "enc0 used\n");*/
|
|
return;
|
|
}
|
|
|
|
/* find best encoding for alpha0 > alpha1 */
|
|
/* it's possible this encoding is better even if both alphaabsmin and alphaabsmax are true */
|
|
alphablockerror1 = 0x0;
|
|
alphablockerror2 = 0xffffffff;
|
|
alphablockerror3 = 0xffffffff;
|
|
if (alphaabsmin) alphause[0] = 0;
|
|
else alphause[0] = alphabase[0];
|
|
if (alphaabsmax) alphause[1] = 255;
|
|
else alphause[1] = alphabase[1];
|
|
/* calculate the 7 cut values, just the middle between 2 of the computed alpha values */
|
|
for (aindex = 0; aindex < 7; aindex++) {
|
|
/* don't forget here is always rounded down */
|
|
acutValues[aindex] = (alphause[0] * (2*aindex + 1) + alphause[1] * (14 - (2*aindex + 1))) / 14;
|
|
}
|
|
|
|
for (j = 0; j < numypixels; j++) {
|
|
for (i = 0; i < numxpixels; i++) {
|
|
/* maybe it's overkill to have the most complicated calculation just for the error
|
|
calculation which we only need to figure out if encoding1 or encoding2 is better... */
|
|
if (srccolors[j][i][3] > acutValues[0]) {
|
|
alphaenc1[4*j + i] = 0;
|
|
alphadist = srccolors[j][i][3] - alphause[1];
|
|
}
|
|
else if (srccolors[j][i][3] > acutValues[1]) {
|
|
alphaenc1[4*j + i] = 2;
|
|
alphadist = srccolors[j][i][3] - (alphause[1] * 6 + alphause[0] * 1) / 7;
|
|
}
|
|
else if (srccolors[j][i][3] > acutValues[2]) {
|
|
alphaenc1[4*j + i] = 3;
|
|
alphadist = srccolors[j][i][3] - (alphause[1] * 5 + alphause[0] * 2) / 7;
|
|
}
|
|
else if (srccolors[j][i][3] > acutValues[3]) {
|
|
alphaenc1[4*j + i] = 4;
|
|
alphadist = srccolors[j][i][3] - (alphause[1] * 4 + alphause[0] * 3) / 7;
|
|
}
|
|
else if (srccolors[j][i][3] > acutValues[4]) {
|
|
alphaenc1[4*j + i] = 5;
|
|
alphadist = srccolors[j][i][3] - (alphause[1] * 3 + alphause[0] * 4) / 7;
|
|
}
|
|
else if (srccolors[j][i][3] > acutValues[5]) {
|
|
alphaenc1[4*j + i] = 6;
|
|
alphadist = srccolors[j][i][3] - (alphause[1] * 2 + alphause[0] * 5) / 7;
|
|
}
|
|
else if (srccolors[j][i][3] > acutValues[6]) {
|
|
alphaenc1[4*j + i] = 7;
|
|
alphadist = srccolors[j][i][3] - (alphause[1] * 1 + alphause[0] * 6) / 7;
|
|
}
|
|
else {
|
|
alphaenc1[4*j + i] = 1;
|
|
alphadist = srccolors[j][i][3] - alphause[0];
|
|
}
|
|
alphablockerror1 += alphadist * alphadist;
|
|
}
|
|
}
|
|
/* for (i = 0; i < 16; i++) {
|
|
fprintf(stderr, "%d ", alphaenc1[i]);
|
|
}
|
|
fprintf(stderr, "cutVals ");
|
|
for (i = 0; i < 8; i++) {
|
|
fprintf(stderr, "%d ", acutValues[i]);
|
|
}
|
|
fprintf(stderr, "srcVals ");
|
|
for (j = 0; j < numypixels; j++)
|
|
for (i = 0; i < numxpixels; i++) {
|
|
fprintf(stderr, "%d ", srccolors[j][i][3]);
|
|
}
|
|
|
|
fprintf(stderr, "\n");
|
|
}*/
|
|
/* it's not very likely this encoding is better if both alphaabsmin and alphaabsmax
|
|
are false but try it anyway */
|
|
if (alphablockerror1 >= 32) {
|
|
|
|
/* don't bother if encoding is already very good, this condition should also imply
|
|
we have valid alphabase colors which we absolutely need (alphabase[0] <= alphabase[1]) */
|
|
alphablockerror2 = 0;
|
|
for (aindex = 0; aindex < 5; aindex++) {
|
|
/* don't forget here is always rounded down */
|
|
acutValues[aindex] = (alphabase[0] * (10 - (2*aindex + 1)) + alphabase[1] * (2*aindex + 1)) / 10;
|
|
}
|
|
for (j = 0; j < numypixels; j++) {
|
|
for (i = 0; i < numxpixels; i++) {
|
|
/* maybe it's overkill to have the most complicated calculation just for the error
|
|
calculation which we only need to figure out if encoding1 or encoding2 is better... */
|
|
if (srccolors[j][i][3] == 0) {
|
|
alphaenc2[4*j + i] = 6;
|
|
alphadist = 0;
|
|
}
|
|
else if (srccolors[j][i][3] == 255) {
|
|
alphaenc2[4*j + i] = 7;
|
|
alphadist = 0;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[0]) {
|
|
alphaenc2[4*j + i] = 0;
|
|
alphadist = srccolors[j][i][3] - alphabase[0];
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[1]) {
|
|
alphaenc2[4*j + i] = 2;
|
|
alphadist = srccolors[j][i][3] - (alphabase[0] * 4 + alphabase[1] * 1) / 5;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[2]) {
|
|
alphaenc2[4*j + i] = 3;
|
|
alphadist = srccolors[j][i][3] - (alphabase[0] * 3 + alphabase[1] * 2) / 5;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[3]) {
|
|
alphaenc2[4*j + i] = 4;
|
|
alphadist = srccolors[j][i][3] - (alphabase[0] * 2 + alphabase[1] * 3) / 5;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[4]) {
|
|
alphaenc2[4*j + i] = 5;
|
|
alphadist = srccolors[j][i][3] - (alphabase[0] * 1 + alphabase[1] * 4) / 5;
|
|
}
|
|
else {
|
|
alphaenc2[4*j + i] = 1;
|
|
alphadist = srccolors[j][i][3] - alphabase[1];
|
|
}
|
|
alphablockerror2 += alphadist * alphadist;
|
|
}
|
|
}
|
|
|
|
|
|
/* skip this if the error is already very small
|
|
this encoding is MUCH better on average than #2 though, but expensive! */
|
|
if ((alphablockerror2 > 96) && (alphablockerror1 > 96)) {
|
|
GLshort blockerrlin1 = 0;
|
|
GLshort blockerrlin2 = 0;
|
|
GLubyte nralphainrangelow = 0;
|
|
GLubyte nralphainrangehigh = 0;
|
|
alphatest[0] = 0xff;
|
|
alphatest[1] = 0x0;
|
|
/* if we have large range it's likely there are values close to 0/255, try to map them to 0/255 */
|
|
for (j = 0; j < numypixels; j++) {
|
|
for (i = 0; i < numxpixels; i++) {
|
|
if ((srccolors[j][i][3] > alphatest[1]) && (srccolors[j][i][3] < (255 -(alphabase[1] - alphabase[0]) / 28)))
|
|
alphatest[1] = srccolors[j][i][3];
|
|
if ((srccolors[j][i][3] < alphatest[0]) && (srccolors[j][i][3] > (alphabase[1] - alphabase[0]) / 28))
|
|
alphatest[0] = srccolors[j][i][3];
|
|
}
|
|
}
|
|
/* shouldn't happen too often, don't really care about those degenerated cases */
|
|
if (alphatest[1] <= alphatest[0]) {
|
|
alphatest[0] = 1;
|
|
alphatest[1] = 254;
|
|
/* fprintf(stderr, "only 1 or 0 colors for encoding!\n");*/
|
|
}
|
|
for (aindex = 0; aindex < 5; aindex++) {
|
|
/* don't forget here is always rounded down */
|
|
acutValues[aindex] = (alphatest[0] * (10 - (2*aindex + 1)) + alphatest[1] * (2*aindex + 1)) / 10;
|
|
}
|
|
|
|
/* find the "average" difference between the alpha values and the next encoded value.
|
|
This is then used to calculate new base values.
|
|
Should there be some weighting, i.e. those values closer to alphatest[x] have more weight,
|
|
since they will see more improvement, and also because the values in the middle are somewhat
|
|
likely to get no improvement at all (because the base values might move in different directions)?
|
|
OTOH it would mean the values in the middle are even less likely to get an improvement
|
|
*/
|
|
for (j = 0; j < numypixels; j++) {
|
|
for (i = 0; i < numxpixels; i++) {
|
|
if (srccolors[j][i][3] <= alphatest[0] / 2) {
|
|
}
|
|
else if (srccolors[j][i][3] > ((255 + alphatest[1]) / 2)) {
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[0]) {
|
|
blockerrlin1 += (srccolors[j][i][3] - alphatest[0]);
|
|
nralphainrangelow += 1;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[1]) {
|
|
blockerrlin1 += (srccolors[j][i][3] - (alphatest[0] * 4 + alphatest[1] * 1) / 5);
|
|
blockerrlin2 += (srccolors[j][i][3] - (alphatest[0] * 4 + alphatest[1] * 1) / 5);
|
|
nralphainrangelow += 1;
|
|
nralphainrangehigh += 1;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[2]) {
|
|
blockerrlin1 += (srccolors[j][i][3] - (alphatest[0] * 3 + alphatest[1] * 2) / 5);
|
|
blockerrlin2 += (srccolors[j][i][3] - (alphatest[0] * 3 + alphatest[1] * 2) / 5);
|
|
nralphainrangelow += 1;
|
|
nralphainrangehigh += 1;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[3]) {
|
|
blockerrlin1 += (srccolors[j][i][3] - (alphatest[0] * 2 + alphatest[1] * 3) / 5);
|
|
blockerrlin2 += (srccolors[j][i][3] - (alphatest[0] * 2 + alphatest[1] * 3) / 5);
|
|
nralphainrangelow += 1;
|
|
nralphainrangehigh += 1;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[4]) {
|
|
blockerrlin1 += (srccolors[j][i][3] - (alphatest[0] * 1 + alphatest[1] * 4) / 5);
|
|
blockerrlin2 += (srccolors[j][i][3] - (alphatest[0] * 1 + alphatest[1] * 4) / 5);
|
|
nralphainrangelow += 1;
|
|
nralphainrangehigh += 1;
|
|
}
|
|
else {
|
|
blockerrlin2 += (srccolors[j][i][3] - alphatest[1]);
|
|
nralphainrangehigh += 1;
|
|
}
|
|
}
|
|
}
|
|
/* shouldn't happen often, needed to avoid div by zero */
|
|
if (nralphainrangelow == 0) nralphainrangelow = 1;
|
|
if (nralphainrangehigh == 0) nralphainrangehigh = 1;
|
|
alphatest[0] = alphatest[0] + (blockerrlin1 / nralphainrangelow);
|
|
/* fprintf(stderr, "block err lin low %d, nr %d\n", blockerrlin1, nralphainrangelow);
|
|
fprintf(stderr, "block err lin high %d, nr %d\n", blockerrlin2, nralphainrangehigh);*/
|
|
/* again shouldn't really happen often... */
|
|
if (alphatest[0] < 0) {
|
|
alphatest[0] = 0;
|
|
/* fprintf(stderr, "adj alpha base val to 0\n");*/
|
|
}
|
|
alphatest[1] = alphatest[1] + (blockerrlin2 / nralphainrangehigh);
|
|
if (alphatest[1] > 255) {
|
|
alphatest[1] = 255;
|
|
/* fprintf(stderr, "adj alpha base val to 255\n");*/
|
|
}
|
|
|
|
alphablockerror3 = 0;
|
|
for (aindex = 0; aindex < 5; aindex++) {
|
|
/* don't forget here is always rounded down */
|
|
acutValues[aindex] = (alphatest[0] * (10 - (2*aindex + 1)) + alphatest[1] * (2*aindex + 1)) / 10;
|
|
}
|
|
for (j = 0; j < numypixels; j++) {
|
|
for (i = 0; i < numxpixels; i++) {
|
|
/* maybe it's overkill to have the most complicated calculation just for the error
|
|
calculation which we only need to figure out if encoding1 or encoding2 is better... */
|
|
if (srccolors[j][i][3] <= alphatest[0] / 2) {
|
|
alphaenc3[4*j + i] = 6;
|
|
alphadist = srccolors[j][i][3];
|
|
}
|
|
else if (srccolors[j][i][3] > ((255 + alphatest[1]) / 2)) {
|
|
alphaenc3[4*j + i] = 7;
|
|
alphadist = 255 - srccolors[j][i][3];
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[0]) {
|
|
alphaenc3[4*j + i] = 0;
|
|
alphadist = srccolors[j][i][3] - alphatest[0];
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[1]) {
|
|
alphaenc3[4*j + i] = 2;
|
|
alphadist = srccolors[j][i][3] - (alphatest[0] * 4 + alphatest[1] * 1) / 5;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[2]) {
|
|
alphaenc3[4*j + i] = 3;
|
|
alphadist = srccolors[j][i][3] - (alphatest[0] * 3 + alphatest[1] * 2) / 5;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[3]) {
|
|
alphaenc3[4*j + i] = 4;
|
|
alphadist = srccolors[j][i][3] - (alphatest[0] * 2 + alphatest[1] * 3) / 5;
|
|
}
|
|
else if (srccolors[j][i][3] <= acutValues[4]) {
|
|
alphaenc3[4*j + i] = 5;
|
|
alphadist = srccolors[j][i][3] - (alphatest[0] * 1 + alphatest[1] * 4) / 5;
|
|
}
|
|
else {
|
|
alphaenc3[4*j + i] = 1;
|
|
alphadist = srccolors[j][i][3] - alphatest[1];
|
|
}
|
|
alphablockerror3 += alphadist * alphadist;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
/* write the alpha values and encoding back. */
|
|
if ((alphablockerror1 <= alphablockerror2) && (alphablockerror1 <= alphablockerror3)) {
|
|
/* if (alphablockerror1 > 96) fprintf(stderr, "enc1 used, error %d\n", alphablockerror1);*/
|
|
writedxt5encodedalphablock( blkaddr, alphause[1], alphause[0], alphaenc1 );
|
|
}
|
|
else if (alphablockerror2 <= alphablockerror3) {
|
|
/* if (alphablockerror2 > 96) fprintf(stderr, "enc2 used, error %d\n", alphablockerror2);*/
|
|
writedxt5encodedalphablock( blkaddr, alphabase[0], alphabase[1], alphaenc2 );
|
|
}
|
|
else {
|
|
/* fprintf(stderr, "enc3 used, error %d\n", alphablockerror3);*/
|
|
writedxt5encodedalphablock( blkaddr, (GLubyte)alphatest[0], (GLubyte)alphatest[1], alphaenc3 );
|
|
}
|
|
}
|
|
|
|
static void extractsrccolors( GLubyte srcpixels[4][4][4], const GLchan *srcaddr,
|
|
GLint srcRowStride, GLint numxpixels, GLint numypixels, GLint comps)
|
|
{
|
|
GLubyte i, j, c;
|
|
const GLchan *curaddr;
|
|
for (j = 0; j < numypixels; j++) {
|
|
curaddr = srcaddr + j * srcRowStride * comps;
|
|
for (i = 0; i < numxpixels; i++) {
|
|
for (c = 0; c < comps; c++) {
|
|
srcpixels[j][i][c] = *curaddr++ / (CHAN_MAX / 255);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
void tx_compress_dxtn(GLint srccomps, GLint width, GLint height, const GLubyte *srcPixData,
|
|
GLenum destFormat, GLubyte *dest, GLint dstRowStride)
|
|
{
|
|
GLubyte *blkaddr = dest;
|
|
GLubyte srcpixels[4][4][4];
|
|
const GLchan *srcaddr = srcPixData;
|
|
GLint numxpixels, numypixels;
|
|
GLint i, j;
|
|
GLint dstRowDiff;
|
|
|
|
switch (destFormat) {
|
|
case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
|
|
case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
|
|
/* hmm we used to get called without dstRowStride... */
|
|
dstRowDiff = dstRowStride >= (width * 2) ? dstRowStride - (((width + 3) & ~3) * 2) : 0;
|
|
/* fprintf(stderr, "dxt1 tex width %d tex height %d dstRowStride %d\n",
|
|
width, height, dstRowStride); */
|
|
for (j = 0; j < height; j += 4) {
|
|
if (height > j + 3) numypixels = 4;
|
|
else numypixels = height - j;
|
|
srcaddr = srcPixData + j * width * srccomps;
|
|
for (i = 0; i < width; i += 4) {
|
|
if (width > i + 3) numxpixels = 4;
|
|
else numxpixels = width - i;
|
|
extractsrccolors(srcpixels, srcaddr, width, numxpixels, numypixels, srccomps);
|
|
encodedxtcolorblockfaster(blkaddr, srcpixels, numxpixels, numypixels, destFormat);
|
|
srcaddr += srccomps * numxpixels;
|
|
blkaddr += 8;
|
|
}
|
|
blkaddr += dstRowDiff;
|
|
}
|
|
break;
|
|
case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
|
|
dstRowDiff = dstRowStride >= (width * 4) ? dstRowStride - (((width + 3) & ~3) * 4) : 0;
|
|
/* fprintf(stderr, "dxt3 tex width %d tex height %d dstRowStride %d\n",
|
|
width, height, dstRowStride); */
|
|
for (j = 0; j < height; j += 4) {
|
|
if (height > j + 3) numypixels = 4;
|
|
else numypixels = height - j;
|
|
srcaddr = srcPixData + j * width * srccomps;
|
|
for (i = 0; i < width; i += 4) {
|
|
if (width > i + 3) numxpixels = 4;
|
|
else numxpixels = width - i;
|
|
extractsrccolors(srcpixels, srcaddr, width, numxpixels, numypixels, srccomps);
|
|
*blkaddr++ = (srcpixels[0][0][3] >> 4) | (srcpixels[0][1][3] & 0xf0);
|
|
*blkaddr++ = (srcpixels[0][2][3] >> 4) | (srcpixels[0][3][3] & 0xf0);
|
|
*blkaddr++ = (srcpixels[1][0][3] >> 4) | (srcpixels[1][1][3] & 0xf0);
|
|
*blkaddr++ = (srcpixels[1][2][3] >> 4) | (srcpixels[1][3][3] & 0xf0);
|
|
*blkaddr++ = (srcpixels[2][0][3] >> 4) | (srcpixels[2][1][3] & 0xf0);
|
|
*blkaddr++ = (srcpixels[2][2][3] >> 4) | (srcpixels[2][3][3] & 0xf0);
|
|
*blkaddr++ = (srcpixels[3][0][3] >> 4) | (srcpixels[3][1][3] & 0xf0);
|
|
*blkaddr++ = (srcpixels[3][2][3] >> 4) | (srcpixels[3][3][3] & 0xf0);
|
|
encodedxtcolorblockfaster(blkaddr, srcpixels, numxpixels, numypixels, destFormat);
|
|
srcaddr += srccomps * numxpixels;
|
|
blkaddr += 8;
|
|
}
|
|
blkaddr += dstRowDiff;
|
|
}
|
|
break;
|
|
case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
|
|
dstRowDiff = dstRowStride >= (width * 4) ? dstRowStride - (((width + 3) & ~3) * 4) : 0;
|
|
/* fprintf(stderr, "dxt5 tex width %d tex height %d dstRowStride %d\n",
|
|
width, height, dstRowStride); */
|
|
for (j = 0; j < height; j += 4) {
|
|
if (height > j + 3) numypixels = 4;
|
|
else numypixels = height - j;
|
|
srcaddr = srcPixData + j * width * srccomps;
|
|
for (i = 0; i < width; i += 4) {
|
|
if (width > i + 3) numxpixels = 4;
|
|
else numxpixels = width - i;
|
|
extractsrccolors(srcpixels, srcaddr, width, numxpixels, numypixels, srccomps);
|
|
encodedxt5alpha(blkaddr, srcpixels, numxpixels, numypixels);
|
|
encodedxtcolorblockfaster(blkaddr + 8, srcpixels, numxpixels, numypixels, destFormat);
|
|
srcaddr += srccomps * numxpixels;
|
|
blkaddr += 16;
|
|
}
|
|
blkaddr += dstRowDiff;
|
|
}
|
|
break;
|
|
default:
|
|
/* fprintf(stderr, "libdxtn: Bad dstFormat %d in tx_compress_dxtn\n", destFormat); */
|
|
return;
|
|
}
|
|
}
|