There is no way to test via script if a point is inside or outside a poly - 'within' will return if the point is within the rect of the poly, but that's about it. I recently needed such a script, explored many algorithms & then found a very elegant, simple and fast solution developed by Bob Stein in 1997 ( it's described here: http://www.linuxjournal.com/article.php?sid=2029 )
Below is the algorithm converted to work w/ MC/Rev - where p is the point to be tested and pts is the poly's points. A small demo stack ( < 20K) is available - just type the following into your message box: go stack url "http://www.cyburb.com/rev/Pt_In_Poly.rev"; function ptInPoly p, pts put false into inside put item 1 of p into xt put item 2 of p into yt put item 1 of line 1 of pts into xOld put item 2 of line 1 of pts into yOld repeat with i = 2 to the number of lines in pts put item 1 of line i of pts into xNew put item 2 of line i of pts into yNew if (xNew > xOld) then --flip put xOld into x1 put xNew into x2 put yOld into y1 put yNew into y2 else put xNew into x1 put xOld into x2 put yNew into y1 put yOld into y2 end if if (xNew < xt) = (xt <= xOld) and ((yt-y1)*(x2-x1)) < ((y2-y1)*(xt-x1)) then put not inside into inside put xNew into xOld put yNew into yOld end repeat return inside end ptInPoly Eric Holst Thinker Toys, Inc _______________________________________________ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
