var bmp, stage = new Stage("#ourCanvas");
bmp = new Bitmap("img/atLogo.png");
//（0.5,0.5）==〉The center is the point of rotation
bmp.originX = 0.5;
bmp.originY = 0.5;
//bind click event, the event monitor can be accurate to pixel
bmp.onClick(function () {
    //apply a random filter to the bmp
    bmp.setFilter(Math.random(), Math.random(), Math.random(), 1);
});
//add object to stage
stage.add(bmp);

var step = 0.01;
//loop
stage.onTick(function () {
    bmp.rotation += 0.5;
    if (bmp.scaleX > 1.5 || bmp.scaleX < 0.5) {
        step *= -1;
    }
    bmp.scaleX += step;
    bmp.scaleY += step;
});