flappydick/js/util.js

window.reqAnimFrame = window.requestAnimationFrame || (function(fn) {
	return setTimeout(fn, 1000 / 60) });

window.cancelAnimFrame = window.cancelAnimationFrame || window.clearTimeout;

// Random number from min (inclusive) to max (exclusive)
function randInt(min, max) {
	return Math.floor(Math.random() * (max - min)) + min;
}

function makeEventListener(obj) {
	obj.__callbacks = {};
	obj.on = makeEventListener.on;
	obj.off = makeEventListener.off;
	obj.once = makeEventListener.once;
	obj.emit = makeEventListener.emit;
}
makeEventListener.on = function on(name, fn) {
	if (!this.__callbacks[name])
		this.__callbacks[name] = [];

	this.__callbacks[name].push(fn);
}
makeEventListener.once = function once(name, fn) {
	var self = this;

	this.on(name, function f() {
		self.off(name, f);
		fn.apply(arguments);
	});
}
makeEventListener.off = function off(name, fn) {
	if (!this.__callbacks[name])
		return;

	for (var i in this.__callbacks[name]) {
		if (this.__callbacks[name] === fn)
			delete this.__callbacks[name][i];
	}
}
makeEventListener.emit = function emit(name) {
	if (!this.__callbacks[name])
		return;

	var args = [].slice.apply(arguments);
	args.splice(0, 1);

	this.__callbacks[name].forEach(function(f) {
		f.apply(args);
	});
}