| 摘要 |
A method and apparatus are provided to enable tile based rendering systems to operate with predicated geometry whilst only making a single rasterisation pass. To do this, geometry that is to be predicated is substituted in image data with visibility test objects and associated conditional break points. In rasterisation, when a visibility test object is encountered, a visible pixel count register is updated. On completion of rasterisation of a tile, the associated conditional break points are used to test the visible pixel count register to determine if the predicated geometry should be processed and inserted into tile object lists. If it is, then a tile object list corresponding to the predicated geometry is inserted into the tile object list for the current tile and is rasterised before moving onto the next tile.
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