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Diffstat (limited to 'dxtn/txc_compress_dxtn.c')
| -rw-r--r-- | dxtn/txc_compress_dxtn.c | 840 |
1 files changed, 840 insertions, 0 deletions
diff --git a/dxtn/txc_compress_dxtn.c b/dxtn/txc_compress_dxtn.c new file mode 100644 index 000000000..d279401d7 --- /dev/null +++ b/dxtn/txc_compress_dxtn.c @@ -0,0 +1,840 @@ +/* + * libtxc_dxtn + * Version: 0.1 + * + * Copyright (C) 2004 Roland Scheidegger All Rights Reserved. + * + * 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 + * BRIAN PAUL 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 <stdio.h> +#include <stdlib.h> +#include "txc_dxtn.h" + +#include "GL/gl.h" + +/* weights used for error function, basically weights (unsquared 2/4/1) according to rgb->luminance conversion + not sure if this really reflects visual perception */ +#define REDWEIGHT 4 +#define GREENWEIGHT 16 +#define BLUEWEIGHT 1 + +#define ALPHACUT 127 + +static void fancybasecolorsearch( GLubyte *blkaddr, GLubyte srccolors[4][4][4], GLubyte *bestcolor[2], + GLint numxpixels, GLint numypixels, GLint type, GLboolean haveAlpha) +{ + /* use same luminance-weighted distance metric to determine encoding as for finding the base colors */ + + /* TODO could also try to find a better encoding for the 3-color-encoding type, this really should be done + if it's rgba_dxt1 and we have alpha in the block, currently even values which will be mapped to black + due to their alpha value will influence the result */ + GLint i, j, colors, z; + GLuint pixerror, pixerrorred, pixerrorgreen, pixerrorblue, pixerrorbest; + GLint colordist, blockerrlin[2][3]; + GLubyte nrcolor[2]; + GLint pixerrorcolorbest[3]; + GLubyte enc = 0; + GLubyte cv[4][4]; + GLubyte testcolor[2][3]; + +/* fprintf(stderr, "color begin 0 r/g/b %d/%d/%d, 1 r/g/b %d/%d/%d\n", + bestcolor[0][0], bestcolor[0][1], bestcolor[0][2], bestcolor[1][0], bestcolor[1][1], bestcolor[1][2]);*/ + if (((bestcolor[0][0] & 0xf8) << 8 | (bestcolor[0][1] & 0xfc) << 3 | bestcolor[0][2] >> 3) < + ((bestcolor[1][0] & 0xf8) << 8 | (bestcolor[1][1] & 0xfc) << 3 | bestcolor[1][2] >> 3)) { + testcolor[0][0] = bestcolor[0][0]; + testcolor[0][1] = bestcolor[0][1]; + testcolor[0][2] = bestcolor[0][2]; + testcolor[1][0] = bestcolor[1][0]; + testcolor[1][1] = bestcolor[1][1]; + testcolor[1][2] = bestcolor[1][2]; + } + else { + testcolor[1][0] = bestcolor[0][0]; + testcolor[1][1] = bestcolor[0][1]; + testcolor[1][2] = bestcolor[0][2]; + testcolor[0][0] = bestcolor[1][0]; + testcolor[0][1] = bestcolor[1][1]; + testcolor[0][2] = bestcolor[1][2]; + } + + for (i = 0; i < 3; i ++) { + cv[0][i] = testcolor[0][i]; + cv[1][i] = testcolor[1][i]; + cv[2][i] = (testcolor[0][i] * 2 + testcolor[1][i]) / 3; + cv[3][i] = (testcolor[0][i] + testcolor[1][i] * 2) / 3; + } + + blockerrlin[0][0] = 0; + blockerrlin[0][1] = 0; + blockerrlin[0][2] = 0; + blockerrlin[1][0] = 0; + blockerrlin[1][1] = 0; + blockerrlin[1][2] = 0; + + nrcolor[0] = 0; + nrcolor[1] = 0; + + for (j = 0; j < numypixels; j++) { + for (i = 0; i < numxpixels; i++) { + pixerrorbest = 0xffffffff; + for (colors = 0; colors < 4; colors++) { + colordist = srccolors[j][i][0] - (cv[colors][0]); + pixerror = colordist * colordist * REDWEIGHT; + pixerrorred = colordist; + colordist = srccolors[j][i][1] - (cv[colors][1]); + pixerror += colordist * colordist * GREENWEIGHT; + pixerrorgreen = colordist; + colordist = srccolors[j][i][2] - (cv[colors][2]); + pixerror += colordist * colordist * BLUEWEIGHT; + pixerrorblue = colordist; + if (pixerror < pixerrorbest) { + enc = colors; + pixerrorbest = pixerror; + pixerrorcolorbest[0] = pixerrorred; + pixerrorcolorbest[1] = pixerrorgreen; + pixerrorcolorbest[2] = pixerrorblue; + } + } + if (enc == 0) { + for (z = 0; z < 3; z++) { + blockerrlin[0][z] += 3 * pixerrorcolorbest[z]; + } + nrcolor[0] += 3; + } + else if (enc == 2) { + for (z = 0; z < 3; z++) { + blockerrlin[0][z] += 2 * pixerrorcolorbest[z]; + } + nrcolor[0] += 2; + for (z = 0; z < 3; z++) { + blockerrlin[1][z] += 1 * pixerrorcolorbest[z]; + } + nrcolor[1] += 1; + } + else if (enc == 3) { + for (z = 0; z < 3; z++) { + blockerrlin[0][z] += 1 * pixerrorcolorbest[z]; + } + nrcolor[0] += 1; + for (z = 0; z < 3; z++) { + blockerrlin[1][z] += 2 * pixerrorcolorbest[z]; + } + nrcolor[1] += 2; + } + else if (enc == 1) { + for (z = 0; z < 3; z++) { + blockerrlin[1][z] += 3 * pixerrorcolorbest[z]; + } + nrcolor[1] += 3; + } + } + } + if (nrcolor[0] == 0) nrcolor[0] = 1; + if (nrcolor[1] == 0) nrcolor[1] = 1; + for (j = 0; j < 2; j++) { + for (i = 0; i < 3; i++) { + GLint newvalue = testcolor[j][i] + blockerrlin[j][i] / nrcolor[j]; + if (newvalue <= 0) + testcolor[j][i] = 0; + else if (newvalue >= 255) + testcolor[j][i] = 255; + else testcolor[j][i] = newvalue; + } + } + + if ((abs(testcolor[0][0] - testcolor[1][0]) < 8) && + (abs(testcolor[0][1] - testcolor[1][1]) < 4) && + (abs(testcolor[0][2] - testcolor[1][2]) < 8)) { + /* both colors are so close they might get encoded as the same 16bit values */ + GLubyte coldiffred, coldiffgreen, coldiffblue, coldiffmax, factor, ind0, ind1; + + coldiffred = abs(testcolor[0][0] - testcolor[1][0]); + coldiffgreen = 2 * abs(testcolor[0][1] - testcolor[1][1]); + coldiffblue = abs(testcolor[0][2] - testcolor[1][2]); + coldiffmax = coldiffred; + if (coldiffmax < coldiffgreen) coldiffmax = coldiffgreen; + if (coldiffmax < coldiffblue) coldiffmax = coldiffblue; + if (coldiffmax > 0) { + if (coldiffmax > 4) factor = 2; + else if (coldiffmax > 2) factor = 3; + else factor = 4; + /* Won't do much if the color value is near 255... */ + /* argh so many ifs */ + if (testcolor[1][1] >= testcolor[0][1]) { + ind1 = 1; ind0 = 0; + } + else { + ind1 = 0; ind0 = 1; + } + if ((testcolor[ind1][1] + factor * coldiffgreen) <= 255) + testcolor[ind1][1] += factor * coldiffgreen; + else testcolor[ind1][1] = 255; + if ((testcolor[ind1][0] - testcolor[ind0][1]) > 0) { + if ((testcolor[ind1][0] + factor * coldiffred) <= 255) + testcolor[ind1][0] += factor * coldiffred; + else testcolor[ind1][0] = 255; + } + else { + if ((testcolor[ind0][0] + factor * coldiffred) <= 255) + testcolor[ind0][0] += factor * coldiffred; + else testcolor[ind0][0] = 255; + } + if ((testcolor[ind1][2] - testcolor[ind0][2]) > 0) { + if ((testcolor[ind1][2] + factor * coldiffblue) <= 255) + testcolor[ind1][2] += factor * coldiffblue; + else testcolor[ind1][2] = 255; + } + else { + if ((testcolor[ind0][2] + factor * coldiffblue) <= 255) + testcolor[ind0][2] += factor * coldiffblue; + else testcolor[ind0][2] = 255; + } + } + } + + if (((testcolor[0][0] & 0xf8) << 8 | (testcolor[0][1] & 0xfc) << 3 | testcolor[0][2] >> 3) < + ((testcolor[1][0] & 0xf8) << 8 | (testcolor[1][1] & 0xfc) << 3 | testcolor[1][2]) >> 3) { + for (i = 0; i < 3; i++) { + bestcolor[0][i] = testcolor[0][i]; + bestcolor[1][i] = testcolor[1][i]; + } + } + else { + for (i = 0; i < 3; i++) { + bestcolor[0][i] = testcolor[1][i]; + bestcolor[1][i] = testcolor[0][i]; + } + } + +/* fprintf(stderr, "color end 0 r/g/b %d/%d/%d, 1 r/g/b %d/%d/%d\n", + bestcolor[0][0], bestcolor[0][1], bestcolor[0][2], bestcolor[1][0], bestcolor[1][1], bestcolor[1][2]);*/ +} + + + +static void storedxtencodedblock( GLubyte *blkaddr, GLubyte srccolors[4][4][4], GLubyte *bestcolor[2], + GLint numxpixels, GLint numypixels, GLuint type, GLboolean haveAlpha) +{ + /* use same luminance-weighted distance metric to determine encoding as for finding the base colors */ + + GLint i, j, colors; + GLuint testerror, testerror2, pixerror, pixerrorbest; + GLint colordist; + GLushort color0, color1, tempcolor; + GLuint bits = 0, bits2 = 0; + GLubyte *colorptr; + GLubyte enc = 0; + GLubyte cv[4][4]; + + bestcolor[0][0] = bestcolor[0][0] & 0xf8; + bestcolor[0][1] = bestcolor[0][1] & 0xfc; + bestcolor[0][2] = bestcolor[0][2] & 0xf8; + bestcolor[1][0] = bestcolor[1][0] & 0xf8; + bestcolor[1][1] = bestcolor[1][1] & 0xfc; + bestcolor[1][2] = bestcolor[1][2] & 0xf8; + + color0 = bestcolor[0][0] << 8 | bestcolor[0][1] << 3 | bestcolor[0][2] >> 3; + color1 = bestcolor[1][0] << 8 | bestcolor[1][1] << 3 | bestcolor[1][2] >> 3; + if (color0 < color1) { + tempcolor = color0; color0 = color1; color1 = tempcolor; + colorptr = bestcolor[0]; bestcolor[0] = bestcolor[1]; bestcolor[1] = colorptr; + } + + + for (i = 0; i < 3; i ++) { + cv[0][i] = bestcolor[0][i]; + cv[1][i] = bestcolor[1][i]; + cv[2][i] = (bestcolor[0][i] * 2 + bestcolor[1][i]) / 3; + cv[3][i] = (bestcolor[0][i] + bestcolor[1][i] * 2) / 3; + } + + testerror = 0; + for (j = 0; j < numypixels; j++) { + for (i = 0; i < numxpixels; i++) { + pixerrorbest = 0xffffffff; + for (colors = 0; colors < 4; colors++) { + colordist = srccolors[j][i][0] - cv[colors][0]; + pixerror = colordist * colordist * REDWEIGHT; + colordist = srccolors[j][i][1] - cv[colors][1]; + pixerror += colordist * colordist * GREENWEIGHT; + colordist = srccolors[j][i][2] - cv[colors][2]; + pixerror += colordist * colordist * BLUEWEIGHT; + if (pixerror < pixerrorbest) { + pixerrorbest = pixerror; + enc = colors; + } + } + testerror += pixerrorbest; + bits |= enc << (2 * (j * 4 + i)); + } + } + for (i = 0; i < 3; i ++) { + cv[2][i] = (bestcolor[0][i] + bestcolor[1][i]) / 2; + /* this isn't used. Looks like the black color constant can only be used + with RGB_DXT1 if I read the spec correctly (note though that the radeon gpu disagrees, + it will decode 3 to black even with DXT3/5), and due to how the color searching works + it won't get used even then */ + cv[3][i] = 0; + } + testerror2 = 0; + for (j = 0; j < numypixels; j++) { + for (i = 0; i < numxpixels; i++) { + pixerrorbest = 0xffffffff; + if ((type == GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) && (srccolors[j][i][3] <= ALPHACUT)) { + enc = 3; + pixerrorbest = 0; /* don't calculate error */ + } + else { + /* we're calculating the same what we have done already for colors 0-1 above... */ + for (colors = 0; colors < 3; colors++) { + colordist = srccolors[j][i][0] - cv[colors][0]; + pixerror = colordist * colordist * REDWEIGHT; + colordist = srccolors[j][i][1] - cv[colors][1]; + pixerror += colordist * colordist * GREENWEIGHT; + colordist = srccolors[j][i][2] - cv[colors][2]; + pixerror += colordist * colordist * BLUEWEIGHT; + if (pixerror < pixerrorbest) { + pixerrorbest = pixerror; + /* need to exchange colors later */ + if (colors > 1) enc = colors; + else enc = colors ^ 1; + } + } + } + testerror2 += pixerrorbest; + bits2 |= enc << (2 * (j * 4 + i)); + } + } + + + /* finally we're finished, write back colors and bits */ + if ((testerror > testerror2) || (haveAlpha)) { + *blkaddr++ = color1 & 0xff; + *blkaddr++ = color1 >> 8; + *blkaddr++ = color0 & 0xff; + *blkaddr++ = color0 >> 8; + *blkaddr++ = bits2 & 0xff; + *blkaddr++ = ( bits2 >> 8) & 0xff; + *blkaddr++ = ( bits2 >> 16) & 0xff; + *blkaddr = bits2 >> 24; + } + else { + *blkaddr++ = color0 & 0xff; + *blkaddr++ = color0 >> 8; + *blkaddr++ = color1 & 0xff; + *blkaddr++ = color1 >> 8; + *blkaddr++ = bits & 0xff; + *blkaddr++ = ( bits >> 8) & 0xff; + *blkaddr++ = ( bits >> 16) & 0xff; + *blkaddr = bits >> 24; + } +} + +static void encodedxtcolorblockfaster( GLubyte *blkaddr, GLubyte srccolors[4][4][4], + GLint numxpixels, GLint numypixels, GLuint type ) +{ +/* simplistic approach. We need two base colors, simply use the "highest" and the "lowest" color + present in the picture as base colors */ + + /* define lowest and highest color as shortest and longest vector to 0/0/0, though the + vectors are weighted similar to their importance in rgb-luminance conversion + doesn't work too well though... + This seems to be a rather difficult problem */ + + GLubyte *bestcolor[2]; + GLubyte basecolors[2][3]; + GLubyte i, j; + GLuint lowcv, highcv, testcv; + GLboolean haveAlpha = GL_FALSE; + + lowcv = highcv = srccolors[0][0][0] * srccolors[0][0][0] * REDWEIGHT + + srccolors[0][0][1] * srccolors[0][0][1] * GREENWEIGHT + + srccolors[0][0][2] * srccolors[0][0][2] * BLUEWEIGHT; + bestcolor[0] = bestcolor[1] = srccolors[0][0]; + for (j = 0; j < numypixels; j++) { + for (i = 0; i < numxpixels; i++) { + /* don't use this as a base color if the pixel will get black/transparent anyway */ + if ((type != GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) || (srccolors[j][i][3] <= ALPHACUT)) { + testcv = srccolors[j][i][0] * srccolors[j][i][0] * REDWEIGHT + + srccolors[j][i][1] * srccolors[j][i][1] * GREENWEIGHT + + srccolors[j][i][2] * srccolors[j][i][2] * BLUEWEIGHT; + if (testcv > highcv) { + highcv = testcv; + bestcolor[1] = srccolors[j][i]; + } + else if (testcv < lowcv) { + lowcv = testcv; + bestcolor[0] = srccolors[j][i]; + } + } + else haveAlpha = GL_TRUE; + } + } + /* make sure the original color values won't get touched... */ + for (j = 0; j < 2; j++) { + for (i = 0; i < 3; i++) { + basecolors[j][i] = bestcolor[j][i]; + } + } + bestcolor[0] = basecolors[0]; + bestcolor[1] = basecolors[1]; + + /* try to find better base colors */ + fancybasecolorsearch(blkaddr, srccolors, bestcolor, numxpixels, numypixels, type, haveAlpha); + /* find the best encoding for these colors, and store the result */ + storedxtencodedblock(blkaddr, srccolors, bestcolor, numxpixels, numypixels, type, haveAlpha); +} + +static void writedxt5encodedalphablock( GLubyte *blkaddr, GLubyte alphabase1, GLubyte alphabase2, + GLubyte alphaenc[16]) +{ + *blkaddr++ = alphabase1; + *blkaddr++ = alphabase2; + *blkaddr++ = alphaenc[0] | (alphaenc[1] << 3) | ((alphaenc[2] & 3) << 6); + *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 thest 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; + } +} + + |