A rotozoomer in RRPGE, using the Graphics Accelerator, for specification 00.008.000 (in July, 2014). Just an example program, experimenting with how the hardware may be utilized for common tasks.
Trigonometry sucks. It took ridiculous amounts of time until I got the maths right for this simple stuff (it is simple, but once starting coding, you will mix up signs, add the wrong numbers, mix up X and Y, and all at once, aargh). At least the same principles should apply for any further tasks needing rotation.