On Fri, 06 Apr 2001 14:55:32 +0200, Ernst Lippe <ernstl@xxxxxxxxx> said: >Other improvements are still possible. I expect that it should be >possible to rewrite the algorithm such that the tile cache contains >only 3 tiles. From what I see the algorithm is the same in the >horizontal and vertical direction. The current implementation uses 3 >extra buffer-rows so when we add 3 extra buffer-columns it should be >possible to rewrite the algorithm so that it processes one tile at a >time instead of a full row. If the algorithm is pixel-by-pixel (each output pixel depends only on exactly one input pixel from each region being iterated over, and those regions are all the same size) there is absolutely no excuse not to use the pixel region iterator, which will automagically minimize tile accesses to the lowest number possible. IIRC, the bumpmap drawable need not be the same size as the input/output drawable, so a pure region iterator cannot be used, but at least using the region iterator for the input & output would limit the use of direct fetches to the bumpmap drawable. Kelly
