This replace `GPU_clear()` by `GPU_clear_color()` and `GPU_clear_depth()`. Since we always set the clear value before clearing, it is unecessary to track the clear color state. Moreover, it makes it clearer what we clear the framebuffer to.
This replace `GPU_clear()` by `GPU_clear_color()` and `GPU_clear_depth()`. Since we always set the clear value before clearing, it is unecessary to track the clear color state. Moreover, it makes it clearer what we clear the framebuffer to.