The reset happens during a 'wait state' (aka swap interval, vertical sync command etc) and the frame would be swapped during this very brief window. In the 'olden' days, video was drawn line by line at the upper corner and moving to the lower corner and then there was a delay when the 'cursor' reset to the upper corner. When the drawn one is complete, the contents are passed to the screen for you to see while a new frame is drawn.
While it certainly could be an enforced cap by design (dynamic shadows are 'expensive'), this sounds like it could be vsync as well.īasically (and inaccurately), there is a frame which you see, and a frame which is drawn on.
