private static void Encodedxtcolorblockfaster(GLubyte *blkaddr, GLubyte ***srccolors,
GLint numxpixels, GLint numypixels, GLuint type)
{
GLubyte **bestcolor = stackalloc GLubyte *[2];
GLubyte **basecolors = stackalloc GLubyte *[2];
var bc1 = stackalloc GLubyte[3];
var bc2 = stackalloc GLubyte[3];
basecolors[0] = bc1;
basecolors[1] = bc2;
GLubyte i, j;
GLuint highcv;
var haveAlpha = GlFalse;
var lowcv = highcv = (uint)(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++)
{
if ((type != GlCompressedRgbaS3TcDxt1Ext) || (srccolors[j][i][3] <= Alphacut))
{
var testcv = (uint)(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 = GlTrue;
}
}
}
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];
Fancybasecolorsearch(srccolors, bestcolor, numxpixels, numypixels);
Storedxtencodedblock(blkaddr, srccolors, bestcolor, numxpixels, numypixels, type, haveAlpha);
}
private static void Writedxt5Encodedalphablock(GLubyte *blkaddr, GLubyte alphabase1, GLubyte alphabase2,
GLubyte *alphaenc)
{
*blkaddr++ = alphabase1;
*blkaddr++ = alphabase2;
*blkaddr++ = (byte)(alphaenc[0] | (alphaenc[1] << 3) | ((alphaenc[2] & 3) << 6));
*blkaddr++ =
(byte)((alphaenc[2] >> 2) | (alphaenc[3] << 1) | (alphaenc[4] << 4) | ((alphaenc[5] & 1) << 7));
*blkaddr++ = (byte)((alphaenc[5] >> 1) | (alphaenc[6] << 2) | (alphaenc[7] << 5));
*blkaddr++ = (byte)(alphaenc[8] | (alphaenc[9] << 3) | ((alphaenc[10] & 3) << 6));
*blkaddr++ =
(byte)((alphaenc[10] >> 2) | (alphaenc[11] << 1) | (alphaenc[12] << 4) | ((alphaenc[13] & 1) << 7));
*blkaddr = (byte)((alphaenc[13] >> 1) | (alphaenc[14] << 2) | (alphaenc[15] << 5));
}
// ReSharper disable once FunctionComplexityOverflow
private static void Encodedxt5Alpha(GLubyte *blkaddr, GLubyte ***srccolors,
GLint numxpixels, GLint numypixels)
{
GLubyte *alphabase = stackalloc GLubyte[2];
GLubyte *alphause = stackalloc GLubyte[2];
GLshort *alphatest = stackalloc GLshort[2];
GLubyte *alphaenc1 = stackalloc GLubyte[16];
GLubyte *alphaenc2 = stackalloc GLubyte[16];
GLubyte *alphaenc3 = stackalloc GLubyte[16];
GLubyte *acutValues = stackalloc GLubyte[7];
GLubyte i, j, aindex;
var alphaabsmin = GlFalse;
var alphaabsmax = GlFalse;
GLshort alphadist;
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 = GlTrue;
}
else if (srccolors[j][i][3] == 255)
{
alphaabsmax = GlTrue;
}
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 != 0 && alphaabsmax != 0))
{
*blkaddr++ = srccolors[0][0][3];
blkaddr++;
*blkaddr++ = 0;
*blkaddr++ = 0;
*blkaddr++ = 0;
*blkaddr++ = 0;
*blkaddr++ = 0;
*blkaddr = 0;
return;
}
uint alphablockerror1 = 0x0;
var alphablockerror2 = 0xffffffff;
var alphablockerror3 = 0xffffffff;
if (alphaabsmin != 0)
{
alphause[0] = 0;
}
else
{
alphause[0] = alphabase[0];
}
if (alphaabsmax != 0)
{
alphause[1] = 255;
}
else
{
alphause[1] = alphabase[1];
}
for (aindex = 0; aindex < 7; aindex++)
{
acutValues[aindex] =
(byte)((alphause[0] * (2 * aindex + 1) + alphause[1] * (14 - (2 * aindex + 1))) / 14);
}
for (j = 0; j < numypixels; j++)
{
for (i = 0; i < numxpixels; i++)
{
if (srccolors[j][i][3] > acutValues[0])
{
alphaenc1[4 * j + i] = 0;
alphadist = (short)(srccolors[j][i][3] - alphause[1]);
}
else if (srccolors[j][i][3] > acutValues[1])
{
alphaenc1[4 * j + i] = 2;
alphadist = (short)(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 = (short)(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 = (short)(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 = (short)(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 = (short)(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 = (short)(srccolors[j][i][3] - (alphause[1] * 1 + alphause[0] * 6) / 7);
}
else
{
alphaenc1[4 * j + i] = 1;
alphadist = (short)(srccolors[j][i][3] - alphause[0]);
}
alphablockerror1 += (uint)(alphadist * alphadist);
}
}
if (alphablockerror1 >= 32)
{
alphablockerror2 = 0;
for (aindex = 0; aindex < 5; aindex++)
{
acutValues[aindex] =
(byte)((alphabase[0] * (10 - (2 * aindex + 1)) + alphabase[1] * (2 * aindex + 1)) / 10);
}
for (j = 0; j < numypixels; j++)
{
for (i = 0; i < numxpixels; i++)
{
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 = (short)(srccolors[j][i][3] - alphabase[0]);
}
else if (srccolors[j][i][3] <= acutValues[1])
{
alphaenc2[4 * j + i] = 2;
alphadist = (short)(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 = (short)(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 = (short)(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 = (short)(srccolors[j][i][3] - (alphabase[0] * 1 + alphabase[1] * 4) / 5);
}
else
{
alphaenc2[4 * j + i] = 1;
alphadist = (short)(srccolors[j][i][3] - alphabase[1]);
}
alphablockerror2 += (uint)(alphadist * alphadist);
}
}
if ((alphablockerror2 > 96) && (alphablockerror1 > 96))
{
GLshort blockerrlin1 = 0;
GLshort blockerrlin2 = 0;
GLubyte nralphainrangelow = 0;
GLubyte nralphainrangehigh = 0;
alphatest[0] = 0xff;
alphatest[1] = 0x0;
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];
}
}
}
if (alphatest[1] <= alphatest[0])
{
alphatest[0] = 1;
alphatest[1] = 254;
}
for (aindex = 0; aindex < 5; aindex++)
{
acutValues[aindex] =
(byte)((alphatest[0] * (10 - (2 * aindex + 1)) + alphatest[1] * (2 * aindex + 1)) / 10);
}
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 += (short)((srccolors[j][i][3] - alphatest[0]));
nralphainrangelow += 1;
}
else if (srccolors[j][i][3] <= acutValues[1])
{
blockerrlin1 +=
(short)((srccolors[j][i][3] - (alphatest[0] * 4 + alphatest[1] * 1) / 5));
blockerrlin2 +=
(short)((srccolors[j][i][3] - (alphatest[0] * 4 + alphatest[1] * 1) / 5));
nralphainrangelow += 1;
nralphainrangehigh += 1;
}
else if (srccolors[j][i][3] <= acutValues[2])
{
blockerrlin1 +=
(short)((srccolors[j][i][3] - (alphatest[0] * 3 + alphatest[1] * 2) / 5));
blockerrlin2 +=
(short)((srccolors[j][i][3] - (alphatest[0] * 3 + alphatest[1] * 2) / 5));
nralphainrangelow += 1;
nralphainrangehigh += 1;
}
else if (srccolors[j][i][3] <= acutValues[3])
{
blockerrlin1 +=
(short)((srccolors[j][i][3] - (alphatest[0] * 2 + alphatest[1] * 3) / 5));
blockerrlin2 +=
(short)((srccolors[j][i][3] - (alphatest[0] * 2 + alphatest[1] * 3) / 5));
nralphainrangelow += 1;
nralphainrangehigh += 1;
}
else if (srccolors[j][i][3] <= acutValues[4])
{
blockerrlin1 +=
(short)((srccolors[j][i][3] - (alphatest[0] * 1 + alphatest[1] * 4) / 5));
blockerrlin2 +=
(short)((srccolors[j][i][3] - (alphatest[0] * 1 + alphatest[1] * 4) / 5));
nralphainrangelow += 1;
nralphainrangehigh += 1;
}
else
{
blockerrlin2 += (short)((srccolors[j][i][3] - alphatest[1]));
nralphainrangehigh += 1;
}
}
}
if (nralphainrangelow == 0)
{
nralphainrangelow = 1;
}
if (nralphainrangehigh == 0)
{
nralphainrangehigh = 1;
}
alphatest[0] = (short)(alphatest[0] + (blockerrlin1 / nralphainrangelow));
if (alphatest[0] < 0)
{
alphatest[0] = 0;
}
alphatest[1] = (short)(alphatest[1] + (blockerrlin2 / nralphainrangehigh));
if (alphatest[1] > 255)
{
alphatest[1] = 255;
}
alphablockerror3 = 0;
for (aindex = 0; aindex < 5; aindex++)
{
acutValues[aindex] =
(byte)((alphatest[0] * (10 - (2 * aindex + 1)) + alphatest[1] * (2 * aindex + 1)) / 10);
}
for (j = 0; j < numypixels; j++)
{
for (i = 0; i < numxpixels; i++)
{
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 = (short)(255 - srccolors[j][i][3]);
}
else if (srccolors[j][i][3] <= acutValues[0])
{
alphaenc3[4 * j + i] = 0;
alphadist = (short)(srccolors[j][i][3] - alphatest[0]);
}
else if (srccolors[j][i][3] <= acutValues[1])
{
alphaenc3[4 * j + i] = 2;
alphadist = (short)(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 = (short)(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 = (short)(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 = (short)(srccolors[j][i][3] - (alphatest[0] * 1 + alphatest[1] * 4) / 5);
}
else
{
alphaenc3[4 * j + i] = 1;
alphadist = (short)(srccolors[j][i][3] - alphatest[1]);
}
alphablockerror3 += (uint)(alphadist * alphadist);
}
}
}
}
if ((alphablockerror1 <= alphablockerror2) && (alphablockerror1 <= alphablockerror3))
{
Writedxt5Encodedalphablock(blkaddr, alphause[1], alphause[0], alphaenc1);
}
else if (alphablockerror2 <= alphablockerror3)
{
Writedxt5Encodedalphablock(blkaddr, alphabase[0], alphabase[1], alphaenc2);
}
else
{
Writedxt5Encodedalphablock(blkaddr, (GLubyte)alphatest[0], (GLubyte)alphatest[1], alphaenc3);
}
}
// ReSharper disable once FunctionComplexityOverflow
public static void CompressDxtn(GLint width, GLint height,
GLubyte *srcPixData, GLenum destFormat,
GLubyte *dest, GLint dstRowStride)
{
const int srccomps = 4;
GLubyte * blkaddr = dest;
GLubyte ***srcpixels = stackalloc GLubyte * *[4];
GLubyte ** scpp0 = stackalloc GLubyte *[4];
GLubyte * scp0 = stackalloc GLubyte[4];
GLubyte * scp1 = stackalloc GLubyte[4];
GLubyte * scp2 = stackalloc GLubyte[4];
GLubyte * scp3 = stackalloc GLubyte[4];
scpp0[0] = scp0;
scpp0[1] = scp1;
scpp0[2] = scp2;
scpp0[3] = scp3;
GLubyte **scpp1 = stackalloc GLubyte *[4];
GLubyte * scp10 = stackalloc GLubyte[4];
GLubyte * scp11 = stackalloc GLubyte[4];
GLubyte * scp12 = stackalloc GLubyte[4];
GLubyte * scp13 = stackalloc GLubyte[4];
scpp1[0] = scp10;
scpp1[1] = scp11;
scpp1[2] = scp12;
scpp1[3] = scp13;
GLubyte **scpp2 = stackalloc GLubyte *[4];
GLubyte * scp20 = stackalloc GLubyte[4];
GLubyte * scp21 = stackalloc GLubyte[4];
GLubyte * scp22 = stackalloc GLubyte[4];
GLubyte * scp23 = stackalloc GLubyte[4];
scpp2[0] = scp20;
scpp2[1] = scp21;
scpp2[2] = scp22;
scpp2[3] = scp23;
GLubyte **scpp3 = stackalloc GLubyte *[4];
GLubyte * scp30 = stackalloc GLubyte[4];
GLubyte * scp31 = stackalloc GLubyte[4];
GLubyte * scp32 = stackalloc GLubyte[4];
GLubyte * scp33 = stackalloc GLubyte[4];
scpp3[0] = scp30;
scpp3[1] = scp31;
scpp3[2] = scp32;
scpp3[3] = scp33;
srcpixels[0] = scpp0;
srcpixels[1] = scpp1;
srcpixels[2] = scpp2;
srcpixels[3] = scpp3;
GLchan *srcaddr;
GLint numxpixels, numypixels;
GLint i, j;
GLint dstRowDiff;
switch (destFormat)
{
case GlCompressedRgbS3TcDxt1Ext:
case GlCompressedRgbaS3TcDxt1Ext:
dstRowDiff = dstRowStride >= (width * 2) ? dstRowStride - (((width + 3) & ~3) * 2) : 0;
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 GlCompressedRgbaS3TcDxt3Ext:
dstRowDiff = dstRowStride >= (width * 4) ? dstRowStride - (((width + 3) & ~3) * 4) : 0;
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++ = (byte)((srcpixels[0][0][3] >> 4) | (srcpixels[0][1][3] & 0xf0));
*blkaddr++ = (byte)((srcpixels[0][2][3] >> 4) | (srcpixels[0][3][3] & 0xf0));
*blkaddr++ = (byte)((srcpixels[1][0][3] >> 4) | (srcpixels[1][1][3] & 0xf0));
*blkaddr++ = (byte)((srcpixels[1][2][3] >> 4) | (srcpixels[1][3][3] & 0xf0));
*blkaddr++ = (byte)((srcpixels[2][0][3] >> 4) | (srcpixels[2][1][3] & 0xf0));
*blkaddr++ = (byte)((srcpixels[2][2][3] >> 4) | (srcpixels[2][3][3] & 0xf0));
*blkaddr++ = (byte)((srcpixels[3][0][3] >> 4) | (srcpixels[3][1][3] & 0xf0));
*blkaddr++ = (byte)((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 GlCompressedRgbaS3TcDxt5Ext:
dstRowDiff = dstRowStride >= (width * 4) ? dstRowStride - (((width + 3) & ~3) * 4) : 0;
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:
throw new ArgumentException(string.Format("libdxtn: Bad dstFormat {0} in tx_compress_dxtn\n",
destFormat));
}
}
// ReSharper disable once FunctionComplexityOverflow
private static void Fancybasecolorsearch(GLubyte ***srccolors, GLubyte **bestcolor,
GLint numxpixels, GLint numypixels)
{
GLint i, j;
GLint * blockerrlin0 = stackalloc GLint[3];
GLint * blockerrlin1 = stackalloc GLint[3];
GLint **blockerrlin = stackalloc GLint *[2];
blockerrlin[0] = blockerrlin0;
blockerrlin[1] = blockerrlin1;
GLubyte * nrcolor = stackalloc GLubyte[2];
GLint * pixerrorcolorbest = stackalloc GLint[3];
GLubyte enc = 0;
GLubyte **cv = stackalloc GLubyte *[4];
GLubyte * cv0 = stackalloc GLubyte[4];
GLubyte * cv1 = stackalloc GLubyte[4];
GLubyte * cv2 = stackalloc GLubyte[4];
GLubyte * cv3 = stackalloc GLubyte[4];
cv[0] = cv0;
cv[1] = cv1;
cv[2] = cv2;
cv[3] = cv3;
GLubyte **testcolor = stackalloc GLubyte *[2];
GLubyte * tc0 = stackalloc GLubyte[3];
GLubyte * tc1 = stackalloc GLubyte[3];
testcolor[0] = tc0;
testcolor[1] = tc1;
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] = (byte)((testcolor[0][i] * 2 + testcolor[1][i]) / 3);
cv[3][i] = (byte)((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++)
{
var pixerrorbest = 0xffffffff;
GLint colors;
for (colors = 0; colors < 4; colors++)
{
var colordist = srccolors[j][i][0] - (cv[colors][0]);
var pixerror = (uint)(colordist * colordist * Redweight);
var pixerrorred = (uint)colordist;
colordist = srccolors[j][i][1] - (cv[colors][1]);
pixerror += (uint)(colordist * colordist * Greenweight);
var pixerrorgreen = (uint)colordist;
colordist = srccolors[j][i][2] - (cv[colors][2]);
pixerror += (uint)(colordist * colordist * Blueweight);
var pixerrorblue = (uint)colordist;
if (pixerror < pixerrorbest)
{
enc = (byte)colors;
pixerrorbest = pixerror;
pixerrorcolorbest[0] = (int)pixerrorred;
pixerrorcolorbest[1] = (int)pixerrorgreen;
pixerrorcolorbest[2] = (int)pixerrorblue;
}
}
GLint z;
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++)
{
var 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] = (byte)newvalue;
}
}
}
if ((Math.Abs(testcolor[0][0] - testcolor[1][0]) < 8) &&
(Math.Abs(testcolor[0][1] - testcolor[1][1]) < 4) &&
(Math.Abs(testcolor[0][2] - testcolor[1][2]) < 8))
{
var coldiffred = (byte)Math.Abs(testcolor[0][0] - testcolor[1][0]);
var coldiffgreen = (byte)(2 * Math.Abs(testcolor[0][1] - testcolor[1][1]));
var coldiffblue = (byte)Math.Abs(testcolor[0][2] - testcolor[1][2]);
var coldiffmax = coldiffred;
if (coldiffmax < coldiffgreen)
{
coldiffmax = coldiffgreen;
}
if (coldiffmax < coldiffblue)
{
coldiffmax = coldiffblue;
}
if (coldiffmax > 0)
{
GLubyte factor;
if (coldiffmax > 4)
{
factor = 2;
}
else if (coldiffmax > 2)
{
factor = 3;
}
else
{
factor = 4;
}
GLubyte ind0;
GLubyte ind1;
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] += (byte)(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] += (byte)(factor * coldiffred);
}
else
{
testcolor[ind1][0] = 255;
}
}
else
{
if ((testcolor[ind0][0] + factor * coldiffred) <= 255)
{
testcolor[ind0][0] += (byte)(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] += (byte)(factor * coldiffblue);
}
else
{
testcolor[ind1][2] = 255;
}
}
else
{
if ((testcolor[ind0][2] + factor * coldiffblue) <= 255)
{
testcolor[ind0][2] += (byte)(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];
}
}
}
private static void Storedxtencodedblock(GLubyte *blkaddr, GLubyte ***srccolors, GLubyte **bestcolor,
GLint numxpixels, GLint numypixels, GLuint type, GLboolean haveAlpha)
{
GLint i, j, colors;
GLuint pixerror, pixerrorbest;
GLint colordist;
GLuint bits = 0, bits2 = 0;
GLubyte enc = 0;
GLubyte **cv = stackalloc GLubyte *[4];
GLubyte * cv0 = stackalloc GLubyte[4];
GLubyte * cv1 = stackalloc GLubyte[4];
GLubyte * cv2 = stackalloc GLubyte[4];
GLubyte * cv3 = stackalloc GLubyte[4];
cv[0] = cv0;
cv[1] = cv1;
cv[2] = cv2;
cv[3] = cv3;
bestcolor[0][0] = (byte)(bestcolor[0][0] & 0xf8);
bestcolor[0][1] = (byte)(bestcolor[0][1] & 0xfc);
bestcolor[0][2] = (byte)(bestcolor[0][2] & 0xf8);
bestcolor[1][0] = (byte)(bestcolor[1][0] & 0xf8);
bestcolor[1][1] = (byte)(bestcolor[1][1] & 0xfc);
bestcolor[1][2] = (byte)(bestcolor[1][2] & 0xf8);
var color0 = (ushort)(bestcolor[0][0] << 8 | bestcolor[0][1] << 3 | bestcolor[0][2] >> 3);
var color1 = (ushort)(bestcolor[1][0] << 8 | bestcolor[1][1] << 3 | bestcolor[1][2] >> 3);
if (color0 < color1)
{
var tempcolor = color0;
color0 = color1;
color1 = tempcolor;
var 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] = (byte)((bestcolor[0][i] * 2 + bestcolor[1][i]) / 3);
cv[3][i] = (byte)((bestcolor[0][i] + bestcolor[1][i] * 2) / 3);
}
uint 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 = (uint)(colordist * colordist * Redweight);
colordist = (srccolors[j][i][1] - cv[colors][1]);
pixerror += (uint)(colordist * colordist * Greenweight);
colordist = srccolors[j][i][2] - cv[colors][2];
pixerror += (uint)(colordist * colordist * Blueweight);
if (pixerror < pixerrorbest)
{
pixerrorbest = pixerror;
enc = (byte)colors;
}
}
testerror += pixerrorbest;
bits |= (uint)(enc << (2 * (j * 4 + i)));
}
}
for (i = 0; i < 3; i++)
{
cv[2][i] = (byte)((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;
}
uint testerror2 = 0;
for (j = 0; j < numypixels; j++)
{
for (i = 0; i < numxpixels; i++)
{
pixerrorbest = 0xffffffff;
if ((type == GlCompressedRgbaS3TcDxt1Ext) && (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 = (uint)(colordist * colordist * Redweight);
colordist = srccolors[j][i][1] - cv[colors][1];
pixerror += (uint)(colordist * colordist * Greenweight);
colordist = srccolors[j][i][2] - cv[colors][2];
pixerror += (uint)(colordist * colordist * Blueweight);
if (pixerror < pixerrorbest)
{
pixerrorbest = pixerror;
/* need to exchange colors later */
if (colors > 1)
{
enc = (byte)colors;
}
else
{
enc = (byte)(colors ^ 1);
}
}
}
}
testerror2 += pixerrorbest;
bits2 |= (uint)(enc << (2 * (j * 4 + i)));
}
}
/* finally we're finished, write back colors and bits */
if ((testerror > testerror2) || (haveAlpha != GlFalse))
{
*blkaddr++ = (byte)(color1 & 0xff);
*blkaddr++ = (byte)(color1 >> 8);
*blkaddr++ = (byte)(color0 & 0xff);
*blkaddr++ = (byte)(color0 >> 8);
*blkaddr++ = (byte)(bits2 & 0xff);
*blkaddr++ = (byte)((bits2 >> 8) & 0xff);
*blkaddr++ = (byte)((bits2 >> 16) & 0xff);
*blkaddr = (byte)(bits2 >> 24);
}
else
{
*blkaddr++ = (byte)(color0 & 0xff);
*blkaddr++ = (byte)(color0 >> 8);
*blkaddr++ = (byte)(color1 & 0xff);
*blkaddr++ = (byte)(color1 >> 8);
*blkaddr++ = (byte)(bits & 0xff);
*blkaddr++ = (byte)((bits >> 8) & 0xff);
*blkaddr++ = (byte)((bits >> 16) & 0xff);
*blkaddr = (byte)(bits >> 24);
}
}