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Re: [whatwg] remove resetClip from the Canvas 2D spec

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 29 Jan 2013 20:23:46 -0800
Message-ID: <CAAWBYDCUM=XXu0_2q1mVS4Vj_6JNBwqxq8wgW5WpXQSWis+hQw@mail.gmail.com>
To: Rik Cabanier <cabanier@gmail.com>
Cc: WHATWG List <whatwg@whatwg.org>, "public-canvas-api@w3.org" <public-canvas-api@w3.org>
On Tue, Jan 29, 2013 at 6:10 PM, Rik Cabanier <cabanier@gmail.com> wrote:
> It restores the graphics state back to the state at 'save' time and this
> includes the clip area.
> 'Clip' is a nested operation so every clip will be the intersection of the
> existing clip area and the new one.
>
> PDF also has no initclip/resetClip and since CG is based on that model,
> maybe they didn't bother to add it.
> I can certainly see its use though (it's used quite often in PostScript)

I find that bizarre, but I've seen weirder APIs, so whatever.

It may still be possible without being too hacky - if the UA manually
rewinds and replays the state stack, only omitting clip() changes, it
would be the same thing.  You'd have to be clever to allow the user to
restore() from that state again, though - maybe by recording the stack
of clip() operations and doing *another* rewind+replay, but this time
with the clip() calls happening again.

My definition of "not too hacky" may be miscalibrated.

~TJ
Received on Wednesday, 30 January 2013 04:24:30 GMT

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