rotating bitmaps. In code

Question

Is there a faster way to rotate a large bitmap by 90 or 270 degrees than simply doing a nested loop with inverted coordinates?

The bitmaps are 8bpp and typi

Answer 1

You might be able to improve it by copying in cache-aligned blocks rather than by rows, as at the moment the stride of either src dest will be a miss ( depending whether delphi is row major or column major ).