   Point in Polygon (C# Implementation)
  There was a C# source code posted on the MSDN forums about Point in Polygon test:http://social.msdn.microsoft.com/forums/en-US/winforms/thread/95055cdc-60f8-4c22-8270-ab5f9870270a/For some reason, I can't seem to get this to work. I went through the code, and it *makes* sense to me, but I'm not getting the results I'm expecting.This is how I am using the code:Point[] poly = new Point[4];poly[0] = new Point(0, 0);poly[1] = new Point(4, 0);poly[2] = new Point(0, 4);poly[3] = new Point(4, 4);Point p = new Point(1, 1);if (PointInPolygon(p, poly)) { Console.WriteLine("Yes"); }else{ Console.WriteLine("No"); }As you can see above, I passed in an array of points that define a square. Point (1,1) should reside in that square, but the function keeps returning false.Please point out my stupid error. I'm losing too many brain cells right now :(Thank you.   
  That's not a square but an hourglass shaped polygon. Try swapping the order of the points. I haven't checked, but it's also likely that the algorithm expects the polygon's vertices to be defined in either clockwise or counter-clockwise order.   ;  C0D1F1ED, THANK YOU.I knew that it had to be counter-clockwise or clockwise!!! But for some reason, I *thought* what I put down was clockwise... This is what happens when you code for 16 hours straight with no food :(All I had to do was change it to:Point[] poly = new Point[4];poly[0] = new Point(0, 0);poly[1] = new Point(0, 4);poly[2] = new Point(4, 4);poly[3] = new Point(4, 0);