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[whatwg] [canvas] request for {create, get, put}ImageDataHD and ctx.backingStorePixelRatio

From: Darin Fisher <darin@chromium.org>
Date: Mon, 23 Apr 2012 10:33:01 -0700
Message-ID: <CAP0-QptDvzg1GUWG9sWP=U7hFF+fE3GDLXpH0qWkg0MGvf3aow@mail.gmail.com>
On Tue, Apr 17, 2012 at 9:12 PM, Boris Zbarsky <bzbarsky at mit.edu> wrote:

> On 4/17/12 6:32 PM, Darin Fisher wrote:
>> In Chrome at least, getImageData() doesn't actually block to fetch pixels.
>>  The thread is only blocked when the first dereference of the pixel buffer
>> occurs.
> How does that interact with paints that happen after the getImageData
> call?  Or is the point that you send off an async request for a pixel
> snapshot but don't block on it returning until someone tries to reach into
> the pixel buffer?
To answer your second question:  Yes.

I think the implication for the first question is that you would get back a
snapshot of what the pixel data should have been when you called

Received on Monday, 23 April 2012 10:33:01 UTC

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