I have no experience with opengl. I actually don't want to use it for
rendering purposes. I would like to get histograms of single triangles
in arbitrary positions in an image. I want to try if using openGL
hardware in this way speeds up an image segmentation algorithm.
I know that it is possible to get a histogram of a whole image.
What do i have to do to get a histogram of a triangular patch of a 2D