sbw@naucse.UUCP (03/11/87)
I recently posted a query and a summary of responses concerning the Liang-Barsky Polygon clipping algorithm as published in CACM, VOL 26, Nov. 1983. The corrigenda in CACM, VOL 27, April 1984 provided the fix to the original algorithm. It also led me to examine my 'patched' version more closely. I now have a modified version of the algorithm that, while based upon my patch, appears (see below) to produce results identical to the corrected Liang-Barsky algorithm. The modified version is both slightly simpler and slightly faster (it averages about 6% faster over my test data) than the original. Is anyone interested in this modified algorithm (in C)? If so, then I'll post the source to the net (about 150 lines - should it go to net.sources?). I have only done limited testing of the code, using 10 randomly generated polygons (well 7 random and 3 'worst' case) with from 4 to 200 vertices (counting first vertex twice). In all cases the output is exactly the same as the corrected Liang-Barsky algorithm. Anyone who wants to really test it out is welcome to. Please mail me if it has problems.
matt@inuxf.UUCP (03/14/87)
> I recently posted a query and a summary of responses concerning > the Liang-Barsky Polygon clipping algorithm as published in > CACM, VOL 26, Nov. 1983. > ... > > Is anyone interested in this modified algorithm (in C)? If so, > then I'll post the source to the net (about 150 lines - should > it go to net.sources?). > Yes Please post it! And Yes it should go in net.sources (Or whatever the net.police call it these days) with an announcement in this group. Thanks! Matt Verner UUCP: ...ihnp4!inuxc!matt AT&T Graphics Software Labs AT&T: (317) 844-4364 Indianapolis, IN "The whole point of this sentence is to clearly explain the point this sentence is making."