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Re: Image sprites use cases

From: Robert O'Callahan <robert@ocallahan.org>
Date: Fri, 4 Sep 2009 11:00:14 +1200
Message-ID: <11e306600909031600l18bf6357n8bde7671980ef859@mail.gmail.com>
To: Boris Zbarsky <bzbarsky@mit.edu>
Cc: Alex Kaminski <activewidgets@gmail.com>, www-style@w3.org
On Fri, Sep 4, 2009 at 4:26 AM, Boris Zbarsky <bzbarsky@mit.edu> wrote:

> Alex Kaminski wrote:
>
>> So what? Can't you just discard the composite image and release memory
>> after extracting the sprite region?
>>
>
> You're assuming the sprite region gets its own dedicated memory allocation
> separate from the combined image.  That's certainly not the case in Gecko
> right now; sprites are just painted directly out of the big image.  I'm not
> an expert on whether there are good reasons for this.
>

It's simpler, and lower overhead.

In Gecko, sprites don't cause extra memory usage whether you use
background-position or -moz-image-rect. They can be a bit slower than normal
images if you've zoomed the page in or out, because we create temporary
copies to avoid resampling artifacts at the image boundary. But we can even
fix that eventually.

Rob
-- 
"He was pierced for our transgressions, he was crushed for our iniquities;
the punishment that brought us peace was upon him, and by his wounds we are
healed. We all, like sheep, have gone astray, each of us has turned to his
own way; and the LORD has laid on him the iniquity of us all." [Isaiah
53:5-6]
Received on Thursday, 3 September 2009 23:00:51 GMT

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