While it is recommended to use memory barriers when updating a buffer
like we are, since we double buffer it is unlikely we will corrupt a
prior frame, and even if we do since it's just texture data at worst
we might see a tear.
This feture is to allow the use of the key combination <super>+N to
increase the brightness of the screen when using monitors with poor
backlighting. Can help in some games.
N = Night vision
