helper.js

var ambianceSound;

 // HELPER FUNCTIONS - not all functions are needed for every game.

/*
 * Toggles mute variable. Called from HTML button.
 */
function toggleMute() {

	if (mute == true) {
		mute = false;
	} else {
		mute = true;

	}

	if (mute == true) {
		stage.addChild(muteButton);
		stage.removeChild(unmuteButton);
		ambianceSound.stop();
	} else {
		stage.addChild(unmuteButton);
		stage.removeChild(muteButton);
		ambianceSound = createjs.Sound.play("song", {loop:-1});
	}
}

/**
 * Shuffles array in place.
 * @param {Array} a items The array containing the items.
 */
function shuffle(a) {
    var j, x, i;
    for (i = a.length; i; i--) {
        j = Math.floor(Math.random() * i);
        x = a[i - 1];
        a[i - 1] = a[j];
        a[j] = x;
    }
}

/*
* Plays a sound if the game is not muted.
*/
function playSound(id) {
	if (mute == false) {
		createjs.Sound.play(id);
	}
}

function sleep(ms) {
	return new Promise(resolve => setTimeout(resolve, ms));
}