R drawBuffer

Usage
The setting of r_drawBuffer controls into which buffer the renderer draws the world. The renderer has two buffers, the "front" buffer is the buffer that is shown on the display while the "back" buffer is not visible. Rendering to the front buffer makes the intermediate steps of the rendering process visible, which results in a lot of flickering.

To avoid this the renderer usually draws to the "back" buffer and when it finished, it flips the front and back buffer, so that the change from one frame to the next is instant.