RENDERING IN COMPUTER GRAPHICS SYSTEMS

摘要

A graphics system has a rendering space divided into a plurality of rectangular areas, each being sub-divided into a plurality of smaller rectangular areas of a plurality of pixels. Data is received representing a tiled set of polygons to be rendered in a selected one of the rectangular areas. For each polygon, a determination is made whether that polygon is located at least partially inside a selected one of the smaller rectangular areas in the selected rectangular area. If so, which pixels of the plurality of pixels in the selected smaller rectangular area are inside the polygon are identified. Or, if that polygon is not located at least partially inside the selected smaller rectangular area, no further processing of the polygon is performed at one or more of the plurality of pixels in the smaller rectangular area.

主权项

1. A method of rendering in a graphics system having a rendering space divided into a plurality of rectangular areas and having each rectangular area sub-divided into a plurality of smaller rectangular areas each comprising a plurality of pixels, the method comprising:
receiving data representing a tiled set of polygons to be rendered in a selected one of the rectangular areas; for each polygon in the tiled set, determining whether that polygon is located at least partially inside a selected one of the smaller rectangular areas in the selected rectangular area; and if that polygon is located at least partially inside the selected smaller rectangular area, determining which of the plurality of pixels in the selected smaller rectangular area are inside the polygon, or if that polygon is not located at least partially inside the selected smaller rectangular area, performing no further processing of the polygon at one or more of the plurality of pixels in the smaller rectangular area; and wherein the step of determining whether the polygon is located at least partially inside the selected smaller rectangular area comprises: deriving a plurality of edges from the polygon data; and comparing each of the plurality of edges with a sample point associated with the selected smaller rectangular area to determine whether the selected smaller rectangular area is located wholly outside any of the edges; wherein if the selected smaller rectangular area is not located wholly outside any of the edges then the polygon is determined to be located at least partially inside the selected smaller rectangular area.