ok, so the zoom factor works like on a camera? 2x zoom is 2x height and 2x width?
and the filter or not is like boolean? 0 = off 1 = on?

sorry about all the questions, I am still new to graphics and that (been working in a shell for past 3 years ie. since i started) so all this rotate, opengl and sdl is still quite new to me. and finding working documentation that is up to date for SDL written in pascal is still quite rare apart form what is hosted here on pgd.