System and method for clipping pixels drawn in one of a plurality of windows in a computer graphics system

摘要

A system and method for performing efficient clipping to visible windows. A window clip buffer is established for each window being written directly to the front frame buffer. The window clip buffer is initialized as having the same dimensions as the window itself and each pixel position is initially set to False (not visible.) The visible regions are determined and the buffer updated to True (visible) for those visible regions. As each pixel is being drawn the window clip buffer is tested. The pixel is drawn to the frame buffer only where the window clip buffer pixel is true (visible.) Changes to window positions on the screen causes the visible regions to be updated.