Iterating edges of a polygon

-=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- (c) WidthPadding Industries 1987 0\|610\|0 -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=-
SoCoder -> Snippet Home -> Misc

Phoenix	Created : 25 February 2010 Edited : 25 February 2010 Iterating edges of a polygon
This is neat and trivial trick I found the other day which is useful when you want to iterate through consecutive pairs of vertices (edges) of a polygon. `i` is the index of the first vertex, and `j` is the index of the following vertex. for(int i = vertices.size()-1, j = 0; j < vertices.size(); i = j, ++j) { // Do something with the edge here } --v This connects the last and the first vertex without you having to add a special case after the loop. Amazing, isn't?

Comments