Aren’t BMP’s a joy to work with? Not only are the rows bottom-up but the color sequence is BGR instead of the usual RGB. Obviously, to fix that you have to swap the red and blue channels for each pixel in the image.
Aspect ratio distortion (i.e. stretching) could be caused by not setting the X and Y resolutions to the same value. Most DS’s do not support independent X and Y resolutions so another possibility is that you found a bug.
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