unsafe void DecompressBlockDXT5(int x, int y, int width, int height, byte *blockStorage, DDSBitmap image)
{
byte alpha0 = blockStorage[0];
byte alpha1 = blockStorage[1];
ushort alphaCode2 = *((ushort *)(blockStorage + 2));
uint alphaCode1 = *((uint *)(blockStorage + 4));
ushort color0 = *((ushort *)(blockStorage + 8));
ushort color1 = *((ushort *)(blockStorage + 10));
int temp;
temp = (color0 >> 11) * 255 + 16;
byte r0 = (byte)((temp / 32 + temp) / 32);
temp = ((color0 & 0x07E0) >> 5) * 255 + 32;
byte g0 = (byte)((temp / 64 + temp) / 64);
temp = (color0 & 0x001F) * 255 + 16;
byte b0 = (byte)((temp / 32 + temp) / 32);
temp = (color1 >> 11) * 255 + 16;
byte r1 = (byte)((temp / 32 + temp) / 32);
temp = ((color1 & 0x07E0) >> 5) * 255 + 32;
byte g1 = (byte)((temp / 64 + temp) / 64);
temp = (color1 & 0x001F) * 255 + 16;
byte b1 = (byte)((temp / 32 + temp) / 32);
uint code = *((uint *)(blockStorage + 12));
for (int j = 0; j < 4; j++)
{
for (int i = 0; i < 4; i++)
{
int alphaCodeIndex = 3 * (4 * j + i);
int alphaCode;
if (alphaCodeIndex <= 12)
{
alphaCode = (alphaCode2 >> alphaCodeIndex) & 0x07;
}
else if (alphaCodeIndex == 15)
{
alphaCode = (int)((alphaCode2 >> 15) | ((alphaCode1 << 1) & 0x06));
}
else
{
alphaCode = (int)((alphaCode1 >> (alphaCodeIndex - 16)) & 0x07);
}
byte finalAlpha;
if (alphaCode == 0)
{
finalAlpha = alpha0;
}
else if (alphaCode == 1)
{
finalAlpha = alpha1;
}
else
{
if (alpha0 > alpha1)
{
finalAlpha = (byte)(((8 - alphaCode) * alpha0 + (alphaCode - 1) * alpha1) / 7);
}
else
{
if (alphaCode == 6)
{
finalAlpha = 0;
}
else if (alphaCode == 7)
{
finalAlpha = 255;
}
else
{
finalAlpha = (byte)(((6 - alphaCode) * alpha0 + (alphaCode - 1) * alpha1) / 5);
}
}
}
byte colorCode = (byte)((code >> 2 * (4 * j + i)) & 0x03);
int finalColor = 0;
switch (colorCode)
{
case 0:
finalColor = Color.FromArgb(finalAlpha, r0, g0, b0);
break;
case 1:
finalColor = Color.FromArgb(finalAlpha, r1, g1, b1);
break;
case 2:
finalColor = Color.FromArgb(finalAlpha, (byte)((2 * r0 + r1) / 3), (byte)((2 * g0 + g1) / 3), (byte)((2 * b0 + b1) / 3));
break;
case 3:
finalColor = Color.FromArgb(finalAlpha, (byte)((r0 + 2 * r1) / 3), (byte)((g0 + 2 * g1) / 3), (byte)((b0 + 2 * b1) / 3));
break;
}
if (x + i < width && y + j < height)
{
image.SetPixel(x + i, y + j, finalColor);
}
//image[(y + j)*width + (x + i)] = finalColor;
}
}
}
private unsafe void DecompressBlockDXT1(int x, int y, int width, int height, byte *blockStorage, DDSBitmap image)
{
ushort color0 = *((ushort *)(blockStorage));
ushort color1 = *((ushort *)(blockStorage + 2));
int temp;
temp = (color0 >> 11) * 255 + 16;
byte r0 = (byte)((temp / 32 + temp) / 32);
temp = ((color0 & 0x07E0) >> 5) * 255 + 32;
byte g0 = (byte)((temp / 64 + temp) / 64);
temp = (color0 & 0x001F) * 255 + 16;
byte b0 = (byte)((temp / 32 + temp) / 32);
temp = (color1 >> 11) * 255 + 16;
byte r1 = (byte)((temp / 32 + temp) / 32);
temp = ((color1 & 0x07E0) >> 5) * 255 + 32;
byte g1 = (byte)((temp / 64 + temp) / 64);
temp = (color1 & 0x001F) * 255 + 16;
byte b1 = (byte)((temp / 32 + temp) / 32);
uint code = *((uint *)(blockStorage + 4));
for (int j = 0; j < 4; j++)
{
for (int i = 0; i < 4; i++)
{
int finalColor = 0;
byte positionCode = (byte)((code >> 2 * (4 * j + i)) & 0x03);
if (color0 > color1)
{
switch (positionCode)
{
case 0:
finalColor = Color.FromArgb(255, r0, g0, b0);
break;
case 1:
finalColor = Color.FromArgb(255, r1, g1, b1);
break;
case 2:
finalColor = Color.FromArgb(255, (byte)((2 * r0 + r1) / 3), (byte)((2 * g0 + g1) / 3), (byte)((2 * b0 + b1) / 3));
break;
case 3:
finalColor = Color.FromArgb(255, (byte)((r0 + 2 * r1) / 3), (byte)((g0 + 2 * g1) / 3), (byte)((b0 + 2 * b1) / 3));
break;
}
}
else
{
switch (positionCode)
{
case 0:
finalColor = Color.FromArgb(255, r0, g0, b0);
break;
case 1:
finalColor = Color.FromArgb(255, r1, g1, b1);
break;
case 2:
finalColor = Color.FromArgb(255, (byte)((r0 + r1) / 2), (byte)((g0 + g1) / 2), (byte)((b0 + b1) / 2));
break;
case 3:
finalColor = Color.FromArgb(255, 0, 0, 0);
break;
}
}
if (x + i < width && y + j < height)
{
image.SetPixel(x + i, y + j, finalColor);
}
}
}
}