;
            y += dy;
        } else {
            y = testY;
        }

        context.fillStyle = color;
        context.beginPath();
        context.arc(x, y, particleRadius, 0, Math.PI * 2);
        context.fill();
    }

    this.draw = draw;
}
</script>
</head>
<canvas></canvas>
</html>
