Create a hole in a polygon

Summary

This article explains how to create a donut-hole style polygon.

Procedure

1. Set one part to specify the outer boundary of the polygon.
2. Set another part to determine the boundary of the hole. The hole's boundary points must be ordered in the opposite direction from the polygon's points (in other words, counter-clockwise vs. clockwise).
   
   Example:
   

   Code:
   point1.x = -117
   point1.y = 34
   
   point2.x = -120
   point2.y = 34
   
   point3.x = -120
   point3.y = 37
   
   point4.x = -117
   point4.y = 37
   
   geometry1.points = {point1, point2, point3, point4}
   
   point5.x = -118
   point5.y = 35
   
   point6.x = -118
   point6.y = 36
   
   point7.x = -119
   point7.y = 36
   
   point8.x = -119
   point8.y = 35
   
   geometry2.points = {point5, point6, point7, point8}

   
   Geometry2 now has a hole within geometry 1.