Just a hypothetical question here.
Video memory that you allocate using the memory allocation function from the NV_vertex_array_range extension does not have to be used for a vertex array, right?
So what would happen if you used the glReadPixels and glDrawPixels functions with a pointer to memory allocated this way?
Would it be faster because the image data does not need to cross the bus between the GPU and the CPU?
Or would it do that anyway and be slower?