# Combine framebuffer-textures to default framebuffer

I know frame-buffers are not textures themselves, but they do contain a texture, given they are set up correctly, which I believe mine are, as:

(status == GL_FRAMEBUFFER_COMPLETE)


returns true.

The reason I am using multiple frame-buffers is so that I can perform some post-processing on individual objects/layers - is this even a best-practice approach?. So I render to a bunch of textures, and to not end up with a black screen, due to never rendering to the default frame-buffer, I need to somehow combine the frame-buffers/textures into the default frame-buffer.

My naive approach would be to bind the default frame-buffer and then just make a simple shader-program that would write each texture back to the screen.

This seems like a task that could be optimized through some built-in function specially for this as it must be a standard thing now'a'days, so what is the correct way to combine a bunch of frame-buffers/textures into one (the default frame-buffer)?