public void Blit(JBitmap target, int srcPx, int srcPy, int srcW, int srcH, int px, int py){
if (target.format != format)
{
throw new Exception("Attempted to blit between bitmaps not of the same format");
}
int bpp = (int)format;
int targetStartX, targetEndX;
int targetStartY, targetEndY;
int copyW, copyH;
targetStartX = Math.Max(px, 0);
targetEndX = Math.Min(px + srcW, target.bitmapData.Width);
targetStartY = Math.Max(py, 0);
targetEndY = Math.Min(py + srcH, target.bitmapData.Height);
copyW = targetEndX - targetStartX;
copyH = targetEndY - targetStartY;
if (copyW < 0)
{
return;
}
if (copyH < 0)
{
return;
}
int sourceStartX = srcPx + targetStartX - px;
int sourceStartY = srcPy + targetStartY - py;
unsafe
{
byte* sourcePtr = (byte*)(bitmapData.Scan0);
byte* targetPtr = (byte*)(target.bitmapData.Scan0);
byte* targetY = targetPtr + targetStartY * target.bitmapData.Stride;
byte* sourceY = sourcePtr + sourceStartY * bitmapData.Stride;
for (int y = 0; y < copyH; y++, targetY += target.bitmapData.Stride, sourceY += bitmapData.Stride)
{
byte* targetOffset = targetY + targetStartX * bpp;
byte* sourceOffset = sourceY + sourceStartX * bpp;
for (int x = 0; x < copyW * bpp; x++, targetOffset++, sourceOffset++)
{
*(targetOffset) = *(sourceOffset);
}
}
}
}