Polygon -- An SVG polygon

Description

An SVG polygon. The coordinates must form a list called PointList. (the difference with Polyline is that the last coordinate is reconnected to the first)

i1 : Polygon{PointList=>{[0,10],[100,10],[90,90],[0,80]},"stroke"=>"red","fill"=>"white"}

o1 = Polygon{cache => CacheTable{}                         }
             PointList => {|  0 |, | 100 |, | 90 |, |  0 |}
                           | 10 |  |  10 |  | 90 |  | 80 |
                           |  0 |  |  0  |  |  0 |  |  0 |
                           |  1 |  |  1  |  |  1 |  |  1 |
             style => MutableHashTable{...2...}

o1 : Polygon

For the programmer

The object Polygon is an instance of the type GraphicsType, with ancestor classes GraphicsPoly < GraphicsObject < GraphicsAncestor < HashTable < Thing.