RE: [ft-devel] [Patch] Autofit and stem snapping

[Frederic Crozat]

Le mardi 20 septembre 2005 à 15:06 +0200, Frederic Crozat a écrit :
> Le mardi 20 septembre 2005 à 14:55 +0200, Turner, David a écrit :
> > Salut Frédéric,
> > 
> > I've reviewed Owen's patch, which led me to peek inside the
> > sources of libXft and Cairo to understand the difference. I
> > now believe that the problem is in Cairo and that the patch
> > is incorrect.
> 
> Thanks you David, I'll forward this to cairo developers.

Ok, while investigating how to fix this bug in cairo, I found some
problems between rendering of freetype 2.1.9 and 2.1.10 (or HEAD, I
didn't see any big differences between 2.1.10 and CVS HEAD) :

I'm using Xft with gtk (gtk 2.6), which is supposed to "the right thing"
concerning freetype flags.

As you can see on
http://people.mandriva.com/~fcrozat/freetype/subpixel-freetype.png there
is a clear difference (I'd say degradation :) between subpixel for 2.1.9
and 2.1.10.

There is also another rendering difference between 2.1.9 and 2.1.10
(still with Xft) which is triggered by GNOME font propriety dialog,
which allow to dynamically change font properties such as hinting or
aliasing. With 2.1.9, if I start with monochrome (ie no antialiasing)
and switch to grey antialiasing or if I start one application directly
in grey antialiasing, font rendering is always the same. But with 2.1.10
(or CVS HEAD), I don't get the same font rendering. It looks like some
internal state is affecting freetype. Of course, this bug is also
present with using cairo based GTK (2.8) :) See
http://people.mandriva.com/~fcrozat/freetype/change-aa-properties-freetype.png

I hope my report is understandable :)
-- 
Frederic Crozat <address@hidden>
Mandriva