public static CMPRBlock optimalCompressDXT1a(ARGBPixel rgba)
{
if (rgba.A < 128)
{
CMPRBlock block = new CMPRBlock();
block._root0._data = 0;
block._root1._data = 0;
block._lookup = 0xFFFFFFFF;
return(block);
}
return(optimalCompressDXT1(rgba));
}
private static CMPRBlock optimalCompressDXT1(ARGBPixel c)
{
CMPRBlock block = new CMPRBlock();
uint indices = 0xAAAAAAAA;
block._root0._data = (ushort)((OMatch5[c.R, 0] << 11) | (OMatch6[c.G, 0] << 5) | OMatch5[c.B, 0]);
block._root1._data = (ushort)((OMatch5[c.R, 1] << 11) | (OMatch6[c.G, 1] << 5) | OMatch5[c.B, 1]);
if (block._root0 < block._root1)
{
VoidPtr.Swap((short *)&block._root0, (short *)&block._root1);
indices ^= 0x55555555;
}
block._lookup = indices;
return(block);
}
private static CMPRBlock compressDXT1(ARGBPixel *pBlock)
{
float * pointData = stackalloc float[48];
Vector3 *points = (Vector3 *)pointData;
extractColorBlockRGB(pBlock, points);
// find min and max colors
Vector3 maxColor, minColor;
findMinMaxColorsBox(points, 16, &maxColor, &minColor);
selectDiagonal(points, 16, &maxColor, &minColor);
insetBBox(&maxColor, &minColor);
ushort color0 = roundAndExpand(&maxColor);
ushort color1 = roundAndExpand(&minColor);
if (color0 < color1)
{
Vector3 t = maxColor;
maxColor = minColor;
minColor = t;
VoidPtr.Swap(&color0, &color1);
}
CMPRBlock block = new CMPRBlock();
block._root0._data = color0;
block._root1._data = color1;
block._lookup = computeIndices4(points, &maxColor, &minColor);
optimizeEndPoints4(points, &block);
return(block);
}
public static CMPRBlock compressDXT1a(ARGBPixel *img, int imgX, int imgY, int imgW, int imgH)
{
uint * pData = stackalloc uint[16];
ARGBPixel *pBlock = (ARGBPixel *)pData;
bool hasAlpha = false;
bool isSingle = true;
ARGBPixel p;
ARGBPixel *sPtr = img + (imgX + imgY * imgW);
int index = 0;
for (int y = 0; y < 4; y++)
{
for (int x = 0; x < 4; x++)
{
p = sPtr[x + y * imgW];
pBlock[index++] = p;
if (p != pBlock[0])
{
isSingle = false;
}
if (p.A < 128)
{
hasAlpha = true;
}
}
}
if (isSingle)
{
return(optimalCompressDXT1a(sPtr[0]));
}
if (!hasAlpha)
{
return(compressDXT1(pBlock));
}
// @@ Handle single RGB, with varying alpha? We need tables for single color compressor in 3 color mode.
//else if (rgba.isSingleColorNoAlpha()) { ... }
float * pointData = stackalloc float[48];
Vector3 *points = (Vector3 *)pointData;
// read block
//Vector3 block[16];
int num = extractColorBlockRGBA(pBlock, points);
// find min and max colors
Vector3 maxColor, minColor;
findMinMaxColorsBox(points, num, &maxColor, &minColor);
selectDiagonal(points, num, &maxColor, &minColor);
insetBBox(&maxColor, &minColor);
ushort color0 = roundAndExpand(&maxColor);
ushort color1 = roundAndExpand(&minColor);
if (color0 < color1)
{
Vector3 t = maxColor;
maxColor = minColor;
minColor = t;
VoidPtr.Swap(&color0, &color1);
}
CMPRBlock block = new CMPRBlock();
block._root0._data = color1;
block._root1._data = color0;
block._lookup = computeIndices3(pBlock, &maxColor, &minColor);
// optimizeEndPoints(block, dxtBlock);
return(block);
}
