Hello, I''m trying to copy lines from a 24-bit bitmap into a 32-bit surface. I made the following code to perform the conversion, but it always fails on the memcpy(). Does anyone see what I did wrong? UINT *srcPtr, *destPtr; // Working pointers // The pitch of the destination surface UINT nPitch = ddsd.lPitch >> 2; // Extract bitmap data srcPtr = (UINT *)bitmap->buffer + cx + cy * bitmap->bitmapInfoHeader.biWidth; // Assign a pointer to the memory surface for manipulation destPtr = (UINT *)ddsd.lpSurface; int bytesPerLine = (sprite->width + sprite->widthFill) * 4; // Iterate through each scanline and copy bitmap for (int indexY = 0; indexY < sprite->height; indexY++) { // Copy next line of data to destination memcpy (destPtr, srcPtr, bytesPerLine); // Advance pointers destPtr += nPitch; //(sprite->width + sprite->widthFill); srcPtr += bitmap->bitmapInfoHeader.biWidth; } Thanks a million!

No, actually the surface is the same size as the bitmap. The bitmap is placed on the surface, and the surface is placed on the backbuffer every frame.

They may have the same size in pixels but not in byte. If you have a 24BPP bitmap and a 32BPP surface the latter one needs more bytes to save an image with the same dimensions and the pixels start at different offsets:
24BPP:
Pixel 0, Offset 0; Pixel 1, Offset 3;...
32BPP:
Pixel 0: Offset 0; Pixel 1, Offset 4;...

Do you know know why you have to copy the image pixel by pixel?

I understand that 24-bit has three bytes per pixel and 32-bit has four. But I successfully made a line-by-line copy using similar code to copy a 24-bit bitmap to a 16-bit surface. How come the 16-bit version works but I can''t do the same thing in 32-bit mode? Would I have to switch the parameters the memcpy()?

Thanks...