drawing shapes on a canvas when the user clicks

src/utils.js

@@ -0,0 +1,48 @@
+
+export function throttleEvent(type, name, obj) {
+	obj = obj || window;
+	let running = false;
+
+	let throttle = () => {
+		if (!running) {
+			running = true;
+
+			requestAnimationFrame(() => {
+				obj.dispatchEvent(new CustomEvent(name));
+				running = false;
+			});
+		}
+	}
+
+	obj.addEventListener(type, throttle);
+}
+
+throttleEvent('resize', 'optimizedResize');
+
+export function clone(obj) {
+	return JSON.parse(JSON.stringify(obj));
+}
+
+export function extend(obj, src) {
+	for (let key in src) {
+		if (src.hasOwnProperty(key)) obj[key] = src[key];
+	}
+
+	return obj;
+}
+
+export function hypotenuse(a, b) {
+	if (b == null) b = a;
+
+	return Math.sqrt(a*a + b*b);
+}
+
+export function random(min, max) {
+	if (max == null) {
+		max = min;
+		min = 0;
+	}
+
+	return min + Math.floor(Math.random() * (max - min + 1));
+}
+