One rasterization approach to spatial predicate

How to provide cost effective, high performance spatial relation/spatial predicate implementation is one important issue for Internet map server design. To avoid the disadvantages of computational geometry algorithm approach, it proposes one improved method, combined with the rendering engine, which can enhance the filter accuracy. This proposal can record coverage area of border grid cells accurately based on subpixel accuracy, so it can determine spatial relation through judging coverage area of the corresponding grid cells. As side effects, the rendering engine can preserve feature attribute information (polygon IDs etc.) in the cell structure which offers more useful hints for spatial relation judgment. The prototype adopting the above methods is presented and the related benchmark result details reveal the effectiveness and efficiency of the proposal.