Tile Based Graphics Rendering

A graphics system for tile by tile converting of vertex data into output images for displaying on a screen the vertex data representing objects by a set of polygons, a polygon being constituted of at least three vertices the system comprising:

• an input for receiving the vertex data, the vertex data at least comprising 3D space coordinates for each vertex in the image,
• a tile processor for
• subdividing the image into a plurality of tiles
• determining polygon strips each polygon strip comprising a sequence of at least one polygon, each succeeding polygon of a polygon strip sharing a side with its preceding polygon, and
• determining sub-strips for each polygon strip each sub-strip comprising those polygons of the polygon strip which at least partly overlap a single one of the tiles and associating that tile with the overlapping sub-strips,
• a polygon-tile database comprising a display list for each tile the display list comprising a respective identification of each one of the sub-strips associated with the tile and
• an output for enabling rendering of the images for display on the screen.