MetaPong: A JavaScript Animation Library | Hacker News Reader

MetaPong: A JavaScript Animation Library

metapong.com

32 pointsstevethyc16 comments

A default image for the demo would be useful. Like using your own logo: http://metapong.com/img/metapong-logo-565.png

Done.

The stutter is very jarring, you really should use requestAnimationFrame instead of setTimeout.

And maybe also put the container height into a variable when the window gets resized, instead of grabbing it from the DOM all the time (not sure if that will make a meaningful difference, but I'd try it).

I'll look into requestAnimationFrame. I will a/b test the window size var, but I suspect it won't make a difference. But I'll try it.

Ok, switched to requestAnimationFrame. Removed the param on the variable system cycle clock speed--not necessary. The right way is to just use requestAnimationFrame.

The animation quality is really bad i.e. jerky. The best advice for smooth animation is to leave DOM alone as much as you can.

1) cache all that you can in variables (i.e. not only cache DOM access but group/batch it). 2) implement requestAnimationFrame. but most of all 3) don't animate top/left properties - instead work with GPU-accelerated ones like transform (not only will they perform faster as no reflows/pains are needed - but the movement will also be sub-pixel i.e. smoother)

Reload and try it now. I'm using a better system clock now and its way faster.

I haven't tried using the transform functions for all movement (just rotation), but I'll do that next.

Also, note the "PongIt" link that appears after you start a new animation. Cute feature to make a quick animation based on some images. Check out a timely example that only took me a few minutes to create:

http://metapong.com/pongit.html?bg=000000&params={%22image_u...

Nice little script you got there!

But I don't think you should call it an "Animation Library". An animation library is much more to me.

For comparison, TweenJS is a animation library.

I struggled with the name, and I agree that doesn't quite capture what it does and what it's for. Any suggestions for a better short description?

1) A demo that doesn't work when clicking the start button :`-( The developer was too lazy to put in a default image...

2) When using the logo of the page as url and typing a count of 999, the animation is very jerky. Animations with GSAP I saw where much smoother.

Yeah, 999 is a lot of sprites to move around. Point well taken about the example image though. The text in the help actually works. I'll get the insta-start example working.

This library is definitely not meant to complete with something like GSAP. It's a subset of functionality to allow a quick and fun animations and it just uses CSS to animate so it's not for hard-core games and so forth.

Ok, I've added the three included example images in there as the default. Again thanks for the feedback!

Thanks to EVERYBODY for all of the quick feedback! Keep it coming!

I found two problems with the demo:

1) When speed is reduced and bouncing image was touching lower edge, the slider would appear and glitch the logic. This is on Firefox.

3) After zoom-in, objects off-screen would freeze, unable to cope with their situation.

Still very jerky for me - I am using Firefox under Windows 7

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