Feature: adding wave 3 and 4 + new moves : half_part_rotation & rotation

js/tools.js

@@ -22,3 +22,48 @@ function heriter(destination, source) {
         } 
     } 
 }
+
+function distance(point1, point2) {
+	return Math.sqrt(Math.pow(point2.x - point1.x, 2) + Math.pow(point2.y - point1.y, 2));
+}
+
+function normalize(vector) {
+	var norm = Math.sqrt(vector.x * vector.x + vector.y * vector.y);
+	if (norm == 0)
+		return {
+			x : 0,
+			y : 0
+		};
+
+	var x = vector.x / norm;
+	var y = vector.y / norm;
+	return {
+		x : x,
+		y : y
+	}
+}
+
+function angle(vector1, vector2) {
+	if ((vector1.x == 0 && vector1.y == 0)
+			&& (vector1.x == 0 && vector1.y == 0)) {
+		return 0;
+	}
+
+	if (vector1.x == 0 && vector1.y == 0) {
+		return Math.acos(vector2.x
+				/ Math.sqrt(vector2.x * vector2.x + vector2.y * vector2.y));
+	}
+	
+	if (vector2.x == 0 && vector2.y == 0) {
+		return Math.acos(vector1.x
+				/ Math.sqrt(vector1.x * vector1.x + vector1.y * vector1.y));
+	}
+	
+	var 	product = vector1.x * vector2.x + vector1.y * vector2.y,
+		alpha = Math.acos(product
+			/ (Math.sqrt(vector1.x * vector1.x + vector1.y * vector1.y) * Math
+					.sqrt(vector2.x * vector2.x + vector2.y * vector2.y))),
+		sign = normalize(vector1).y > normalize(vector2).y ? -1 : 1;
+		
+	return sign * alpha;
+}