Mikmacer wrote:
I could switch off this culling and check within GLSL if its the back face or the front face, but I don't want to add a condition at the beginning of each shaders.
A small variation on this is the recommended way to accomplish this, last I checked.
Attach *both* target buffers via MRT, and check the value of gl_FrontFacing to decide which buffer to send this fragment to. Even though it adds a branch to your shader, modern GPUs are much better at branching, and you only use one pass, rather than two.