Sprite size & performance

[ecv]

Is there a substantial difference in performance using big frame animations vs smaller ones? What about movement?

Thanks.

[mattstyles]

@ivan.popelyshev is pretty hot on all things relating to performance, he might be able to give you a good answer.

As always though, with all things concerning performance get yourself a reproducible measured test case, preferably in-situ (i.e. if this is for a game, try to test it against your game code) and crack through the different options.

[ivan.popelyshev]

@ecv theoretically, only size on screen matters, number of drawn pixels. 

[Fatalist]

Actually I found out that texture size does matter, bigger texture is more expensive to draw, even when drawing the same number of pixels. But you can avoid that performance penalty by using mipmaps.

[ecv]

1 minute ago, Fatalist said:

Actually I found out that texture size does matter, bigger texture is more expensive to draw, even when drawing the same number of pixels. But you can avoid that performance penalty by using mipmaps.

You mean like downscaling a big texture into a little sprite?  

No idea what mipmaps are yet.

 

Will a low-end device handle a non-moving fullscreen sprite animation (24fps), say at VGA or 800x600?

Although I think I'm realizing the pointlessness of this thread, as I've been told, probably profiling is the only valid take on this.

[Fatalist]

19 minutes ago, ecv said:

You mean like downscaling a big texture into a little sprite?

Yes. If you were asking about drawing non-scaled sprites - then bigger is always slower to draw, 2x bigger sprite => ~2x slower to draw.

 

24 minutes ago, ecv said:

Will a low-end device handle a non-moving fullscreen sprite animation (24fps), say at VGA or 800x600?

BTW moving sprites around is almost free.

They can probably handle that, but download size is gonna be pretty large. For fullscreen animations it might be better to use video files.

 

 

[ivan.popelyshev]

If memory is your concern, we can use compressed textures like http://www.celsiusheroes.com/ did. I wrapped their implementation into plugin (v3, ill update to v4 later)  https://github.com/pixijs/pixi-compressed-textures

[Gio]

I am missing some context here, but if you are using WebGL, then you can generate a mip-chain and use mipmaps, and the size of the source image doesn't matter in terms of performance. However:

1. Your source texture must be a power of two
2. A full mip chain uses 33% more memory than just the source texture
3. It takes longer to load that texture to start with
4. If using a spritesheet, you have to be careful, there may be artefacts near the edges of each sprite at lower mip levels

If you use a 2d canvas as opposed to WebGL, the image filtering is way more expensive than the hardware-accelerated filtering that you get with WebGL. As a result it looks much nicer with fewer artefacts, but it's also a lot slower and the source texture size will make a big difference.