It seems there is a limitation in glDrawPixels in that scan lines must be on a 32bit boundary. Two questions does 32bit boundary mean the scan line has to be a multiple of 4 (eg 4, 8, 16 … 4 x N)? Is this limitation specific to the windows implementation of OpenGL? Are there plans to change this in the future?

Thanks in Advance

Look at the functions glPixelStore for further details on packing and aligning of pixel data and check the related functions glPixelTransfer, glPixelMap, and glPixelZoom, too.