From: Alan Third <alan@idiocy.org>
To: Eli Zaretskii <eliz@gnu.org>
Cc: emacs-devel@gnu.org
Subject: Re: Testing native image scaling
Date: Sun, 20 Jan 2019 20:19:25 +0000 [thread overview]
Message-ID: <20190120201925.GA50268@breton.holly.idiocy.org> (raw)
In-Reply-To: <83y37f9kxd.fsf@gnu.org>
On Sun, Jan 20, 2019 at 09:41:02PM +0200, Eli Zaretskii wrote:
>
> > If we were to add XRender rotation support, I’d be tempted to do both
> > rotation and scaling using affine transformation matrices in both
> > XRender and NS, as they would then both use the same code to calculate
> > the transforms. I believe Windows supports transformation matrices
> > through D2D, but I assume Emacs doesn’t use D2D currently, so it may
> > not be straight forward to add.
>
> Windows can calculate and use transformation matrices without D2D as
> well, it's really quite simple. You calculate the matrix elements,
> and then call a function to install it for the next BitBlt.
Sounds very similar to how XRender works. It might be worth giving
this a go, then.
> > If we were to go that far, it may be worth actually exposing the
> > matrices to lisp and handle the calculations there
>
> What advantages would that give us? Wouldn't it be better to support
> higher-level abstractions for the transformations, like scaling,
> rotation, and shear?
It would simplify the C code, and move those higher level abstractions
into lisp. I’m not sure if that’s a good thing, but hasn’t it been the
stated intention of the Emacs project for a while?
It would make it harder to understand for a human what any given image
spec would be expected to do, but then I don’t know if humans look at
image specs much.
--
Alan Third
next prev parent reply other threads:[~2019-01-20 20:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-19 9:31 Testing native image scaling Eli Zaretskii
2019-01-19 21:45 ` Alan Third
2019-01-20 16:05 ` Eli Zaretskii
2019-01-20 19:26 ` Alan Third
2019-01-20 19:41 ` Eli Zaretskii
2019-01-20 20:19 ` Alan Third [this message]
2019-03-27 2:35 ` YAMAMOTO Mitsuharu
2019-03-27 17:09 ` Eli Zaretskii
2019-03-27 18:35 ` Andy Moreton
2019-03-27 18:42 ` Eli Zaretskii
2019-03-27 19:06 ` Andy Moreton
2019-03-27 19:34 ` Andy Moreton
2019-03-28 2:26 ` YAMAMOTO Mitsuharu
2019-03-28 16:02 ` Eli Zaretskii
2019-03-28 18:06 ` Andy Moreton
2019-03-28 18:19 ` Eli Zaretskii
2019-03-28 19:29 ` Andy Moreton
2019-03-28 20:09 ` Eli Zaretskii
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