unsafe Bitmap Get1bppMask (Bitmap main)
{
Rectangle rect = new Rectangle (0, 0, main.Width, main.Height);
Bitmap result = new Bitmap (main.Width, main.Height, PixelFormat.Format1bppIndexed);
BitmapData dresult = result.LockBits (rect, ImageLockMode.ReadWrite, PixelFormat.Format1bppIndexed);
int w = images [0].Width;
int h = images [0].Height;
byte *scan = (byte *) dresult.Scan0.ToPointer ();
int stride = dresult.Stride;
Bitmap current = null;
for (int idx = 0; idx < images.Length; idx++) {
current = (Bitmap) images [idx];
// Hack for newly added images.
// Probably has to be done somewhere else.
Color c1 = current.GetPixel (0, 0);
if (c1.A != 0 && c1 == back_color)
current.MakeTransparent (back_color);
//
}
int yidx = 0;
int imgidx = 0;
int localy = 0;
int localx = 0;
int factor_y = 0;
int factor_x = 0;
for (int y = 0; y < main.Height; y++) {
if (localy == h) {
localy = 0;
factor_y += 4;
}
factor_x = 0;
localx = 0;
for (int x = 0; x < main.Width; x++) {
if (localx == w) {
localx = 0;
factor_x++;
}
imgidx = factor_y + factor_x;
if (imgidx >= images.Length)
break;
current = (Bitmap) images [imgidx];
Color color = current.GetPixel (localx, localy);
if (color.A == 0) {
int ptridx = yidx + (x >> 3);
scan [ptridx] |= (byte) (0x80 >> (x & 7));
}
localx++;
}
if (imgidx >= images.Length)
break;
yidx += stride;
localy++;
}
result.UnlockBits (dresult);
return result;
}
