/// <summary>Copies an <see cref="ArgbColor"/> into another, with forced opaque alpha.</summary>
/// <param name="destination">The destination color.</param>
/// <param name="source">The source color.</param>
internal static unsafe void CopyWithAlpha(ArgbColor *destination, ArgbColor *source, byte alpha)
{
destination->B = source->B;
destination->G = source->G;
destination->R = source->R;
destination->A = alpha;
}
private unsafe void CopyToArgbAlpha1(SurfaceData surfaceData)
{
fixed(byte *dataPointer = data)
fixed(ArgbColor * palettePointer = palette)
{
byte *destinationRowPointer = (byte *)surfaceData.DataPointer;
byte *sourceColorPointer = dataPointer;
byte *sourceAlphaPointer = dataPointer + Width * Height;
byte alphaData = 0;
byte alphaState = 0;
for (int i = Height; i-- != 0; destinationRowPointer += surfaceData.Stride)
{
ArgbColor *destinationPointer = (ArgbColor *)destinationRowPointer;
for (int j = Width; j-- != 0; alphaState--, alphaData >>= 1)
{
if (alphaState == 0)
{
alphaState = 8;
alphaData = *sourceAlphaPointer++;
}
ArgbColor.CopyWithAlpha(destinationPointer++, palettePointer + *sourceColorPointer++, (alphaData & 1) != 0 ? (byte)255 : (byte)0);
}
}
}
}
/// <summary>Copies an <see cref="ArgbColor"/> into another, with forced opaque alpha.</summary>
/// <param name="destination">The destination color.</param>
/// <param name="source">The source color.</param>
internal static unsafe void CopyOpaque(ArgbColor *destination, ArgbColor *source)
{
destination->B = source->B;
destination->G = source->G;
destination->R = source->R;
destination->A = 255;
}
public ArgbSurface(SurfaceData surfaceData, bool alphaPremultiplied = false)
: base(surfaceData.Width, surfaceData.Height, 8, alphaPremultiplied)
{
int rowLength = sizeof(uint) * Width;
int dataLength = rowLength * Height;
if (surfaceData.Stride < rowLength)
{
throw new ArgumentException();
}
data = new byte[dataLength];
unsafe
{
fixed(byte *dataPointer = data)
{
byte *destinationRowPointer = dataPointer;
byte *sourceRowPointer = (byte *)surfaceData.DataPointer;
for (int i = Height; i-- != 0; destinationRowPointer += rowLength, sourceRowPointer += surfaceData.Stride)
{
ArgbColor *destinationPointer = (ArgbColor *)destinationRowPointer;
ArgbColor *sourcePointer = (ArgbColor *)sourceRowPointer;
for (int j = Width; j-- != 0;)
{
*destinationPointer++ = *sourcePointer++;
}
}
}
}
}
private unsafe void CopyToArgbAlpha4(SurfaceData surfaceData)
{
// Use a precalculated alpha table for very fast conversions.
var alphaTable = stackalloc byte[16];
for (int i = 0; i < 16; i++)
alphaTable[i] = (byte)(i * (255 * 2185) >> 15); // x / 15 = x * 2185 >> 15 (for 0 ≤ x ≤ 15 * 255)
fixed(byte *dataPointer = data)
fixed(ArgbColor * palettePointer = palette)
{
byte *destinationRowPointer = (byte *)surfaceData.DataPointer;
byte *sourceColorPointer = dataPointer;
byte *sourceAlphaPointer = dataPointer + Width * Height;
byte alphaData = 0;
bool alphaState = false;
for (int i = Height; i-- != 0; destinationRowPointer += surfaceData.Stride)
{
ArgbColor *destinationPointer = (ArgbColor *)destinationRowPointer;
for (int j = Width; j-- != 0;)
{
ArgbColor.CopyWithAlpha(destinationPointer++, palettePointer + *sourceColorPointer++, alphaTable[(alphaState = !alphaState) ? (alphaData = *sourceAlphaPointer++) & 0xF : alphaData >> 4]);
}
}
}
}
/// <summary>Merges two colors for DXT decompression.</summary>
/// <param name="result">The storage to be used for the result.</param>
/// <param name="color1">A color.</param>
/// <param name="color2">A color.</param>
internal static unsafe void DxtMergeHalves(ArgbColor *result, ArgbColor *color1, ArgbColor *color2)
{
result->B = (byte)((color1->B + color2->B) >> 1);
result->G = (byte)((color1->G + color2->G) >> 1);
result->R = (byte)((color1->R + color2->R) >> 1);
result->A = 255;
}
/// <summary>Merges two colors for DXT decompression.</summary>
/// <param name="result">The storage to be used for the result.</param>
/// <param name="minColor">The color whose weight will be 1/3.</param>
/// <param name="maxColor">The color whose weight will be 2/3.</param>
internal static unsafe void DxtMergeThirds(ArgbColor *result, ArgbColor *minColor, ArgbColor *maxColor)
{
// Formula used here:
// x / 3 = x * 683 >> 11 (for 0 ≤ x ≤ 3 * 255)
// Need to verify that this is indeed faster, but it'll do the work for now.
result->B = (byte)((minColor->B + maxColor->B + maxColor->B) * 683 >> 11);
result->G = (byte)((minColor->G + maxColor->G + maxColor->G) * 683 >> 11);
result->R = (byte)((minColor->R + maxColor->R + maxColor->R) * 683 >> 11);
result->A = 255;
}
private unsafe void CopyToArgbAlpha8(SurfaceData surfaceData)
{
fixed(byte *dataPointer = data)
fixed(ArgbColor * palettePointer = palette)
{
byte *destinationRowPointer = (byte *)surfaceData.DataPointer;
byte *sourceColorPointer = dataPointer;
byte *sourceAlphaPointer = dataPointer + Width * Height;
for (int i = Height; i-- != 0; destinationRowPointer += surfaceData.Stride)
{
ArgbColor *destinationPointer = (ArgbColor *)destinationRowPointer;
for (int j = Width; j-- != 0;)
{
ArgbColor.CopyWithAlpha(destinationPointer++, palettePointer + *sourceColorPointer++, *sourceAlphaPointer++);
}
}
}
}
private unsafe void CopyToArgbTransparent(SurfaceData surfaceData)
{
int rowLength = Width;
fixed(byte *dataPointer = data)
fixed(ArgbColor * palettePointer = palette)
{
byte *destinationRowPointer = (byte *)surfaceData.DataPointer;
byte *sourcePointer = dataPointer;
for (int i = Height; i-- != 0; destinationRowPointer += surfaceData.Stride)
{
ArgbColor *destinationPointer = (ArgbColor *)destinationRowPointer;
for (int j = Width; j-- != 0;)
{
*destinationPointer++ = palettePointer[*sourcePointer++];
}
}
}
}
protected unsafe override void CopyToArgbInternal(SurfaceData surfaceData)
{
int rowLength = sizeof(uint) * Width;
fixed(byte *dataPointer = data)
{
byte *destinationRowPointer = (byte *)surfaceData.DataPointer;
byte *sourceRowPointer = dataPointer;
for (int i = Height; i-- != 0; destinationRowPointer += surfaceData.Stride, sourceRowPointer += rowLength)
{
ArgbColor *destinationPointer = (ArgbColor *)destinationRowPointer;
ArgbColor *sourcePointer = (ArgbColor *)sourceRowPointer;
for (int j = Width; j-- != 0;)
{
*destinationPointer++ = *sourcePointer++;
}
}
}
}
