ActionScript 3 QuickTip #4: Dynamic Frame Rates

This is a *very* cool new feature in ActionScript 3. We now have the ability to dynamically change the SWF frame rate at runtime using ActionScript. In the example below I have a somewhat creepy clown who is animating from side-to-side on the screen. You can use the slider to change the frame rate from 0 to 800 and something. There are a lot of applications for this such as lowering the frame rate for slower machines dynamically. The AS 3 code from the example is posted below:

1. this.stage.frameRate = 0;
2. rate.text = “0 fps”;
3.  
4. thumb.addEventListener(MouseEvent.MOUSE_DOWN, starter);
5. thumb.addEventListener(MouseEvent.MOUSE_UP, stopper);
6. thumb.addEventListener(MouseEvent.MOUSE_OUT, stopper);
7. thumb.addEventListener(MouseEvent.MOUSE_MOVE, mover);
8. function starter(args:Event)
9. {
10.         thumb.startDrag(false, new Rectangle(track.x, thumb.y, track.width, 0));
11. }
12. function stopper(args:Event)
13. {
14.         thumb.stopDrag();
15. }
16. function mover(args:Event)
17. {
18.         var dist:Number = (thumb.x – track.x) / (track.width + track.x);
19.         this.stage.frameRate = Math.round(dist*1000);
20.         rate.text = Math.round(dist*1000).toString() + ” fps”;
21. }