2009/12/6 Timothée Lecomte <email@example.com>
I precisely need it to run as fast as the refresh rate, and it already is running fast enough, either with opengl or with pure 2D. However, it burns too much CPU to my taste, since the drawing part takes more time than the processing part, although the latter is quite heavy (FFT...), so I think there is room for large improvements.
As you rightly say, I am drawing the texture off by one. As far as alternatives to pure glTexSubImage2D, I have considered and tried to use PBO, but it does not decrease the time needed by the two glTexSubImage2D calls. I don't really see how I could use glCopyTexSubImage2D instead of glTexSubImage2D.