here's my problem:

I want to particionate the canvas in 4 virtual quadrants and in every quadrant I want to render the same scene with different colors(with different fragment shaders), to compare some effects in real time. I am not sure how to do that. Should I render the same scene 4 times in 4 different textures and then refill 4 rectangles with those textures? Or should I make another fshader and manually fill all the fragments with those textures? Any posibility to user render buffer objects to increase performance?

Thanks in advance,