Fast Path Finding (part II)

June 18, 2013

Last week we had a first look at a simple path finding algorithm with application to games. This week, let us have a look a the relative performance of the implementations considered: C# with a naïve implementation that scans the whole map multiple times; a C# implementation that uses lists to maintain and visit only the border of the solved region (affording massive speed-ups, one hopes); and C++ versions of these two variants, plus a C++ variant that uses set (as bitmaps) to maintain the border list.


In any quantitative study, the first thing to do is to collect data. The best way is to automate the collection, by, for example, adding a function that puts the player in all legal positions on the map, compute all the shortest paths, and measures how long it takes. One may also consider disabling the on-demand power policy as the CPU may jump (progressively?) in high gear as the data collection progresses, introducing bias.

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