Normalize function

src/geo/vertex.ts

@@ -1,32 +1,55 @@
 class Vertex {
     public x : number;
     public y : number;
+
     public constructor (x:number, y:number) {
         this.x = x;
         this.y = y;
     }
+
     public equals(point:Vertex):boolean {
         return this.x == point.x && this.y == point.y;
     }
+
     public clone():Vertex {
         return new Vertex(this.x, this.y);
     }
+
     public static Add(a:Vertex, b:Vertex) {
         return new Vertex(a.x + b.x, a.y + b.y);
     }
+
     public static Subtract(a:Vertex, b:Vertex) {
         return new Vertex(a.x - b.x, a.y - b.y);
     }
+
     public setCoords(x:number, y:number):void {
         this.x = x;
         this.y = y;
     }
+
     public setTo(v:Vertex):void {
         this.x = v.x;
         this.y = v.y;
     }
-    public translate(offset:Vertex) {
+
+    public translate(offset:Vertex):void {
         this.x += offset.x;
         this.y += offset.y;
     }
+
+    public normalise():void {
+        let mod = 1.0 / Util.distance(Vertex.Zero, this);
+        this.x *= mod;
+        this.y *= mod;
+    }
+
+    public normalised():Vertex {
+        let output:Vertex = this.clone();
+        output.normalise();
+        return output;
+    }
+
+
+    public static Zero:Vertex = new Vertex(0, 0);
 }