[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kde-devel
Subject:    Re: plans for a free, OpenGL-based equivalent to Direct2D ?
From:       Benoit Jacob <jacob.benoit.1 () gmail ! com>
Date:       2010-12-14 22:57:02
Message-ID: AANLkTi=JXGM67ks4wo2ggBwVKHmFGSSw_BDgTiSzqRGy () mail ! gmail ! com
[Download RAW message or body]

2010/12/14 Aaron J. Seigo <aseigo@kde.org>:
> On Tuesday, December 14, 2010, Benoit Jacob wrote:
>> Different users have different priorities. For example, Gecko wants
>> pixel-exact rendering
>
> risking being "pedantic" ... this isn't actually true. it's true most of the
> time, but some of the time pixel perfect is irrelevant. "*gasp*, what?"
>
> case in point: bluring.
>
> when a blur is applied, it's not important to ensure "pixel perfection" for
> what is being blurred.

Sure, I never said that everything needed to be pixel-exact.

And many things only need to be half-pixel-exact, i.e. we have unit
tests with a certain tolerance.

Benoit

> this is one kind of trick that driver writers rely on
> to optimize such cases, but they can only do so by recognizing the
> state+shader fingerprint of that, which is typically application specific. as
> a result of these identifiable fingerprints, they can avoid overhead in some
> blurs which remove "must be pixel-perfect here" as a requirement.
>
> this the kind of thing (to over-generalize/-simplify) they do to make blurred
> areas in various games and the blur in windows 7 so performant. (i'm told that
> win7 uses a rather sub-optimal blur algo, actually, but that because it can be
> "fingerprinted" by the driver, windows drivers are highly optimized for it and
> so it's very fast in spite of the implementation.)
>
> the moral here is that it's probably best to present as uniform an appearance
> as we can to the drivers (which is a combination of state+shader, not an API)
> and let the graphics gurus show us what we actually need ;)
>
> --
> Aaron J. Seigo
> humru othro a kohnu se
> GPG Fingerprint: 8B8B 2209 0C6F 7C47 B1EA  EE75 D6B7 2EB1 A7F1 DB43
>
> KDE core developer sponsored by Qt Development Frameworks
>
>
>>> Visit http://mail.kde.org/mailman/listinfo/kde-devel#unsub to unsubscribe <<
>
>
 
>> Visit http://mail.kde.org/mailman/listinfo/kde-devel#unsub to unsubscribe <<

[prev in list] [next in list] [prev in thread] [next in thread]