I know a bit of SDL and also OpenGL, but how the GUI mechanisms in U++ are working is much more difficult for me to embrace.
Well, right now I am trying to solve OpenGL puzzle... I have implemented two rendering paths, "fixed" (as in GL 1.0) and GLES 2.0 compatible (hopefully) code using shaders. Strange thing is that in "fixed" mode, rendering colored rectangles is order of magnitude faster than with shader, no matter what I am trying to do...