完善shapeCollision 支持多边形

source/src/Math/MathHelper.ts

@@ -1,4 +1,8 @@
 class MathHelper {
+    public static readonly Epsilon: number = 0.00001;
+    public static readonly Rad2Deg = 57.29578;
+    public static readonly Deg2Rad = 0.0174532924;
+
     /**
      * 将弧度转换成角度。
      * @param radians 用弧度表示的角
@@ -48,4 +52,9 @@ class MathHelper {
     public static maxOf(a: number, b: number, c: number, d: number){
         return Math.max(a, Math.max(b, Math.max(c, d)));
     }
+
+    public static pointOnCirlce(circleCenter: Vector2, radius: number, angleInDegrees: number){
+        let radians = MathHelper.toRadians(angleInDegrees);
+        return new Vector2(Math.cos(radians) * radians + circleCenter.x, Math.sin(radians) * radians + circleCenter.y);
+    }
 }

source/src/Math/Vector2.ts

@@ -3,6 +3,26 @@ class Vector2 {
     public x: number = 0;
     public y: number = 0;
 
+    private static readonly unitYVector = new Vector2(0, 1);
+    private static readonly unitXVector = new Vector2(1, 0);
+    private static readonly unitVector2 = new Vector2(1, 1);
+    private static readonly zeroVector2 = new Vector2(0, 0);
+    public static get zero(){
+        return Vector2.zeroVector2;
+    }
+
+    public static get one(){
+        return Vector2.unitVector2;
+    }
+
+    public static get unitX(){
+        return Vector2.unitXVector;
+    }
+
+    public static get unitY(){
+        return Vector2.unitYVector;
+    }
+
     /**
      * 从两个值构造一个带有X和Y的二维向量。
      * @param x 二维空间中的x坐标
@@ -90,4 +110,12 @@ class Vector2 {
         let v1 = value1.x - value2.x, v2 = value1.y - value2.y;
         return Math.sqrt((v1 * v1) + (v2 * v2));
     }
+
+    public static negate(value: Vector2){
+        let result: Vector2 = new Vector2();
+        result.x = -value.x;
+        result.y = -value.y;
+
+        return result;
+    }
 }