private static unsafe void _sRGBColor(
void *src, int srcWidth, int srcHeight, int srcStrideBytes, void *dest, int destWidth, int destHeight, int destStrideBytes
)
{
if ((destWidth < srcWidth / 2) || (destHeight < srcHeight / 2))
{
throw new ArgumentOutOfRangeException();
}
byte *pSrc = (byte *)src, pDest = (byte *)dest;
unchecked {
for (var y = 0; y < destHeight; y++)
{
byte *srcRow = pSrc + ((y * 2) * srcStrideBytes);
byte *destRow = pDest + (y * destStrideBytes);
for (var x = 0; x < destWidth; x++)
{
var a = srcRow + ((x * 2) * 4);
var b = a + 4;
var c = a + srcStrideBytes;
var d = b + srcStrideBytes;
var result = destRow + (x * 4);
result[0] = ColorSpace.AveragesRGB(a[0], b[0], c[0], d[0]);
result[1] = ColorSpace.AveragesRGB(a[1], b[1], c[1], d[1]);
result[2] = ColorSpace.AveragesRGB(a[2], b[2], c[2], d[2]);
// The alpha channel is always linear
result[3] = Average(a[3], b[3], c[3], d[3]);
}
}
}
}
