ach particle
    for (var particle in particles)
        particles[particle].draw(timeDelta);

    prevTime = currTime;

    if (testRunning)
        requestAnimationFrame(animate);
}

function Particle()
{
    var angle = Math.PI * 2 * PerfTestHelper.random();
    var velocity = minVelocity + ((maxVelocity - minVelocity) * PerfTestHelper.random());
    var x = stageWidth / 2 - particleRadius;
    var y = stageHeight / 2 - particleRadius;
    var dx = Math.cos(angle) * velocity;
    var dy = Math.sin(angle)