nothing

var $;
Array.prototype.remove = function (index) {
    this.splice(index, 1);
};


$(function(){

    function Point(x, y) {
        this.x = x;
        this.y = y;

        return this;
    }

    function Circle(x, y, radius, color) {
        that = new Point(x, y);
        that.max_radius = 48;
        that.radius = radius;
        that.alpha = 1;
        that.color = color;

        that.draw = function (canvas) {

            if (this.alpha <= 0) {
                return;
            }

            canvas.drawEllipse({
                fillStyle: "rgba(" + this.color.join(",") + ", " + this.alpha + ")",
                x: this.x,
                y: this.y,
                width: this.radius,
                height: this.radius,
                fromCenter: true
            });

        }

        that.update = function (game) {

            if (this.radius < this.max_radius) {

                this.radius += 4;

            } else if (this.alpha > 0) {

                this.radius += 4;
                this.alpha -= 0.05;
            }

            console.log(this.alpha);
        }

        return that;
    }

    var game = {
        circles: [],
        init_radius: 8,
        canvas: null,

        init: function () {
            if (game.canvas == null) {
                var w = $(window).width()/2;
                var h = $(window).height()/2;
                game.canvas = $("#game-canvas");
                game.canvas.css({background: "#000"});
                game.canvas[0].width = w;
                game.canvas[0].height = h;

                game.canvas.click(function (e) {

                    var x = e.pageX - this.offsetLeft;
                    var y = e.pageY - this.offsetTop;

                    game.add_circle(x, y);
                });
            }
        },

        add_circle: function (x, y) {

            game.circles.push(new Circle(
                Math.floor(x - game.init_radius / 2),
                Math.floor(y - game.init_radius / 2),
                game.init_radius,
                game.random_color()));
        },

        start: function () {
            setInterval(game.step, 1000 / 30); // 30 fps
            //game.step();
        },

        step: function () {

            var i;
            for(i = 0; i < game.circles.length; i += 1) {

                game.circles[i].update();
            }

            game.draw();


        },

        draw: function () {
            var i;

            game.canvas.clearCanvas();

            for(i = 0; i < game.circles.length; i += 1) {

                game.circles[i].draw(game.canvas);

                if (game.circles[i].alpha <= 0) {
                    game.circles.remove(i);
                }
            }
        },

        random_color: function () {

            var r = Math.floor(127+Math.random()*127);
            var g = Math.floor(127+Math.random()*127);
            var b = Math.floor(127+Math.random()*127);

            return [r, g, b];
        }
    };

    game.init();
    game.start();

});