public static int FindMatch(this ColorPalette pal, ARGBPixel pixel)
{
int bestDist = Int32.MaxValue, bestIndex = 0;
for (int i = 0, c = pal.Entries.Length; i < c; i++)
{
int dist = pixel.DistanceTo(pal.Entries[i]);
if (dist < bestDist)
{
bestIndex = i;
if (dist == 0)
{
break;
}
bestDist = dist;
}
}
return(bestIndex);
}
public static unsafe Bitmap IndexColors(this Bitmap src, ColorPalette palette, PixelFormat format)
{
int w = src.Width, h = src.Height;
int entries = palette.Entries.Length;
switch (format)
{
case PixelFormat.Format4bppIndexed: { entries = Math.Min(entries, 16); break; }
case PixelFormat.Format8bppIndexed: { entries = Math.Min(entries, 256); break; }
default: { throw new ArgumentException("Pixel format is not an indexed format."); }
}
Bitmap dst = new Bitmap(w, h, format);
dst.Palette = palette;
BitmapData sData = src.LockBits(new Rectangle(0, 0, w, h), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
BitmapData dData = dst.LockBits(new Rectangle(0, 0, w, h), ImageLockMode.ReadWrite, format);
ARGBPixel *sPtr = (ARGBPixel *)sData.Scan0;
for (int y = 0; y < h; y++)
{
byte *dPtr = (byte *)dData.Scan0 + (y * dData.Stride);
for (int x = 0; x < w; x++)
{
ARGBPixel p = *sPtr++;
int bestDist = Int32.MaxValue, bestIndex = 0;
for (int z = 0; z < entries; z++)
{
int dist = p.DistanceTo(palette.Entries[z]);
if (dist < bestDist)
{
bestDist = dist;
bestIndex = z;
}
}
if (format == PixelFormat.Format4bppIndexed)
{
byte val = *dPtr;
if ((x % 2) == 0)
{
*dPtr = (byte)((bestIndex << 4) | (val & 0x0F));
}
else
{
*dPtr++ = (byte)((val & 0xF0) | (bestIndex & 0x0F));
}
}
else
{
*dPtr++ = (byte)bestIndex;
}
}
}
dst.UnlockBits(dData);
src.UnlockBits(sData);
return(dst);
}
public static CMPRBlock Encode(ARGBPixel *block, int width, bool fast)
{
CMPRBlock p = new CMPRBlock();
uint * pData = stackalloc uint[16];
ARGBPixel *pColor = (ARGBPixel *)pData;
bool isSingle = true, hasAlpha = false, allAlpha = true;
for (int y = 0, i = 0; y < 4; y++, block += width)
{
for (int x = 0; x < 4; i++)
{
pColor[i] = block[x++];
if (pData[i] != pData[0])
{
isSingle = false;
}
if (pColor[i].A < 0x80)
{
hasAlpha = true;
}
else
{
allAlpha = false;
}
}
}
/*
* Foreach block:
* copy block to buffer
* mirror remaning colors?
*
* If block is single color:
* run optiml compress?
* else
* Initialize color set
* Compress block using color set
*
*
*/
//BlockDecoder decoder = new BlockDecoder(width, 4, 4, 4);
//bool isSingle = true, hasAlpha = false, allAlpha = true;
//for (int i = 0; i < 16; i++)
//{
// int index = decoder[i];
// pColor[i] = block[index];
// if (pData[i] != pData[0]) isSingle = false;
// if (pColor[i].A < 0x80) hasAlpha = true;
// else allAlpha = false;
//}
//bool isSingle = true, hasAlpha = false, allAlpha = true;
//ARGBPixel* ptr = block;
//int index = 0;
//for (int y = 0; y < 4; y++, ptr += width - 4)
//{
// for (int x = 0; x < 4; x++, ptr++, index++)
// {
// pColor[index] = block[(y * width) + x];
// if (pData[0] != pData[index]) isSingle = false;
// if (pColor[index].A < 0x80) hasAlpha = true;
// else allAlpha = false;
// }
//}
//if (allAlpha)
//{
// p._root0._data = 0;
// p._root1._data = 0xFFFF;
// p._lookup = 0xFFFFFFFF;
//}
//else if (isSingle)
//{
// p._root0 = (RGB565Pixel)(*block);
// p._root1._data = 0;
// p._lookup = 0x00000000;
//}
//else
//{
uint * palData = stackalloc uint[4];
ARGBPixel *palCol = (ARGBPixel *)palData;
int bestDist = -1;
for (int i = 0; i < 16; i++)
{
ARGBPixel p1 = pColor[i];
for (int x = i + 1; x < 16; x++)
{
ARGBPixel p2 = pColor[x];
int d = p1.DistanceTo(p2);
if (d > bestDist)
{
bestDist = d;
palCol[2] = p1;
palCol[3] = p2;
}
}
}
wRGB565Pixel smax = (wRGB565Pixel)palCol[2];
wRGB565Pixel smin = (wRGB565Pixel)palCol[3];
if (smax < smin)
{
smax = (wRGB565Pixel)palCol[3]; smin = (wRGB565Pixel)palCol[2];
}
if (hasAlpha)
{
p._root0 = smin;
p._root1 = smax;
palCol[0] = (ARGBPixel)smin;
palCol[1] = (ARGBPixel)smax;
palCol[2] = new ARGBPixel(255, (byte)((palCol[0].R + palCol[1].R) >> 1), (byte)((palCol[0].G + palCol[1].G) >> 1), (byte)((palCol[0].B + palCol[1].B) >> 1));
palCol[3] = new ARGBPixel();
}
else
{
p._root0 = smax;
p._root1 = smin;
palCol[0] = (ARGBPixel)smax;
palCol[1] = (ARGBPixel)smin;
palCol[2] = new ARGBPixel(255, (byte)(((palCol[0].R << 1) + palCol[1].R) / 3), (byte)(((palCol[0].G << 1) + palCol[1].G) / 3), (byte)(((palCol[0].B << 1) + palCol[1].B) / 3));
palCol[3] = new ARGBPixel(255, (byte)(((palCol[1].R << 1) + palCol[0].R) / 3), (byte)(((palCol[1].G << 1) + palCol[0].G) / 3), (byte)(((palCol[1].B << 1) + palCol[0].B) / 3));
}
uint indicies = 0;
for (int i = 0, shift = 30; i < 16; i++, shift -= 2)
{
uint index = 3;
if (pColor[i].A >= 0x80)
{
int bd = int.MaxValue;
for (int x = 0; x < ((hasAlpha) ? 4 : 3); x++)
{
int dist = palCol[x].DistanceTo(pColor[i]);
if (dist < bd)
{
bd = dist; index = (uint)x;
}
}
}
indicies |= index << shift;
}
p._lookup = indicies;
//p = DXT1Fast.Compress(pColor);
//}
return(p);
}
