新增shape形状

source/src/Physics/Shapes/Polygon.ts

@@ -0,0 +1,40 @@
+///<reference path="./Shape.ts" />
+class Polygon extends Shape {
+    public points: Vector2[];
+
+    constructor(vertCount: number, radius: number){
+        super();
+        this.setPoints(Polygon.buildSymmertricalPolygon(vertCount, radius));
+    }
+
+    public setPoints(points: Vector2[]){
+        this.points = points;
+        this.recalculateCenterAndEdgeNormals();
+    }
+
+    public recalculateCenterAndEdgeNormals(){
+
+    }
+
+    public static findPolygonCenter(points: Vector2[]){
+        let x = 0, y = 0;
+
+        for (let i = 0; i < points.length; i++){
+            x += points[i].x;
+            y += points[i].y;
+        }
+
+        return new Vector2(x / points.length, y / points.length);
+    }
+
+    public static buildSymmertricalPolygon(vertCount: number, radius: number){
+        let verts = new Vector2[vertCount];
+
+        for (let i = 0; i < vertCount; i ++){
+            let a = 2 * Math.PI * (i / vertCount);
+            verts[i] = new Vector2(Math.cos(a), Math.sign(a) * radius);
+        }
+
+        return verts;
+    }
+}