canvas.on('click', function(e) {
    var mouse = {
        x: e.pageX - canvasPosition.x,
        y: e.pageY - canvasPosition.y
    }
               
    for (var i=0; i < sortedGameObjectArray.length; i++) {
        var hitTest = sortedGameObjectArray[i].onclick(mouse);
        
        // stop as soon as one hit test succeeds
        if (hitTest) {
            break; // break out of the hit test
        }
    }
});