This project is designed to be a super class or workshop of another project that needs the user to choose a closed polygon.

There are three different types of polygon deformation implemented:

	Global: Click and drag a vertex to define it's new location. All other vertices are moved following a discrete tractrix.
	Local: Click and drag a vertex to define it's new location. Just the two adjacent vertices are effected by this deformation but the possible vertex positions are limited.
	Mirror: Click on the vertex that shall be mirrored. The new vertex position is on the other side of the connecting line of the adjacent vertices.