I am using openGL ES 2.0 and GLSL shader and working on FBO with Renderbuffer, aka offscreen rendering.
It works fine with 30 fps.
But when I use glReadPixels or glcopyteximage2d, it drops to 8 fps.
I did something like:
glBindFramebuffer(GL_FRAMEBUFFER, frameBuf);
//DRAW something
glReadPixels(...); //HERE
glBindFramebuffer(GL_FRAMEBUFFER, 0);
Is there anyway I can improve the speed? I mean when I don't use FBO and use glReadPixels with same parameters, it works 15 fps and I thought using FBO could improve the speed?