When setting up the FBO for the g-buffer, we use textures with the internal format GL_RGB32F for the position and normal components. As we are storing geometry information, rather than simply color information, there is a need to use a higher resolution (that is more bits per pixel). The buffer for the diffuse reflectivity just uses GL_RGB8 since we don't need the extra resolution for these values.
The three textures are then attached to the framebuffer at color attachments 0, 1, and 2 using glFramebufferTexture2D. They are then connected to the fragment shader's output variables with the call to glDrawBuffers:
glDrawBuffers(4, drawBuffers);
The array drawBuffers indicates the relationship between the framebuffer's components ...
