//This sucks.
static public Bitmap generateAlpha(Bitmap source)
{
Bitmap output = new Bitmap(source.Width, source.Height, PixelFormat.Format32bppArgb);
Rectangle r = new Rectangle(0, 0, source.Width, source.Height);
unsafe
{
BitmapData sourceData = source.LockBits(r, ImageLockMode.ReadOnly, source.PixelFormat);
BitmapData outputData = output.LockBits(r, ImageLockMode.WriteOnly, output.PixelFormat);
if (sourceData.PixelFormat == PixelFormat.Format24bppRgb)
{
PixelData24 *sourceBase = (PixelData24 *)sourceData.Scan0;
PixelData32 *outputBase = (PixelData32 *)outputData.Scan0;
int width = source.Width;
int height = source.Height;
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
PixelData24 *pSourcePixel = sourceBase + y * width + x;
PixelData32 *pOututPixel = outputBase + y * width + x;
byte blue = pSourcePixel->blue;
pOututPixel->alpha = (byte)(blue);
pOututPixel->red = (byte)(blue);
pOututPixel->blue = (byte)(blue);
pOututPixel->green = (byte)(blue);
}
}
}
else if (sourceData.PixelFormat == PixelFormat.Format32bppArgb)
{
PixelData32 *sourceBase = (PixelData32 *)sourceData.Scan0;
PixelData32 *outputBase = (PixelData32 *)outputData.Scan0;
int width = source.Width;
int height = source.Height;
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
PixelData32 *pSourcePixel = sourceBase + y * width + x;
PixelData32 *pOututPixel = outputBase + y * width + x;
byte alpha = pSourcePixel->alpha;
pOututPixel->alpha = (byte)(alpha);
pOututPixel->red = (byte)(alpha);
pOututPixel->blue = (byte)(alpha);
pOututPixel->green = (byte)(alpha);
}
}
}
source.UnlockBits(sourceData);
output.UnlockBits(outputData);
}
return(output);
}
public void SetPixel(int x, int y, byte alpha, byte red, byte green, byte blue)
{
switch (bitmap.PixelFormat)
{
case PixelFormat.Format24bppRgb:
PixelData24 *pixel24 = PixelAt24(x, y);
* pixel24 = new PixelData24(red, green, blue);
break;
case PixelFormat.Format32bppArgb:
PixelData32 *pixel32 = PixelAt32(x, y);
* pixel32 = new PixelData32(alpha, red, green, blue);
break;
default:
throw new NotSupportedException();
}
}
