[HOWTO]New freetype subpixel font rendering for lcd monitors

Message

bi3l · Post by **bi3l** » Sun Aug 24, 2008 8:39 am

I've just updated the tarball with ebuilds for cairo-1.6.4-r1 and libXft-2.1.13.

neuron · Post by **neuron** » Sun Aug 24, 2008 8:51 am

bi3l wrote:I've just updated the tarball with ebuilds for cairo-1.6.4-r1 and libXft-2.1.13.

much appreciated

Mr. Tao · Post by **Mr. Tao** » Sun Aug 24, 2008 8:43 pm

I’m glad I found this topic as I’ve used soor overlay which is not updated for a while. I’m going to test these patches right now. Meanwhile I’ve made repo definition for paludis:

/etc/paludis/lcd-filtering.conf wrote:location = ${ROOT}/usr/portage/local/lcd-filtering
sync = tar+http://ogmrip.sourceforge.net/misc/gent ... ng.tar.bz2
sync_options = "--rsync-option=--exclude=profiles"
master_repository = gentoo
format = ebuild
names_cache = /var/cache/paludis/names
write_cache = /var/cache/paludis/metadata

bi3l · Post by **bi3l** » Sun Aug 24, 2008 9:41 pm

Mr. Tao wrote:I’m glad I found this topic as I’ve used soor overlay which is not updated for a while. I’m going to test these patches right now. Meanwhile I’ve made repo definition for paludis

Very good idea, thanks !!!! And I've just discovered that it's possible to do the same with layman !!!!

Here is the definition:

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<?xml version="1.0" ?>
<layman>
  <overlays>
    <overlay type="tar" src="http://ogmrip.sourceforge.net/misc/gentoo-lcd-filtering.tar.bz2" contact="billl@users.sourceforge.net" name="lcd-filtering">
      <link>http://forums.gentoo.org/viewforum-f-12.html</link>
      <description>LCD filtering</description>
    </overlay>
  </overlays>
</layman>

Put it in /etc/layman/lcd-filtering.xml and add the definition in /etc/layman/layman.cfg:

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overlays  : http://www.gentoo.org/proj/en/overlays/layman-global.txt
            file:///etc/layman/lcd-filtering.xml

Finally, run:

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layman -a lcd-filtering.

yabbadabbadont · Post by **yabbadabbadont** » Sun Aug 24, 2008 10:06 pm

Thanks for the work. It is nice to see someone has stepped up and taken over supporting these patches.

If you are going to the trouble of setting it up for use with layman, you might want to make sure that your ebuilds for packages that are marked stable in portage, are also marked stable instead of keyword masked.

yabbadabbadont · Post by **yabbadabbadont** » Sun Aug 24, 2008 10:32 pm

Hmmm. Just tried it out and it doesn't seem like fontconfig-2.5.0-r1 is actually getting patched properly. The USE flags look correct and it compiled fine, but when portage ran the updates after emerge finished, it complained about "lcddefault" not being a valid fontconfig option... Then the cairo-1.6.4 ebuild failed complaining about LCD_* options not being defined, which leads me back to thinking that fontconfig isn't right.

I want to do some more investigating before I submit a proper error report. (one that actually has exact error messages instead of the crap I just listed.

)

mwhitlock · Post by **mwhitlock** » Sun Aug 24, 2008 10:53 pm

yabbadabbadont wrote:Hmmm. Just tried it out and it doesn't seem like fontconfig-2.5.0-r1 is actually getting patched properly. The USE flags look correct and it compiled fine, but when portage ran the updates after emerge finished, it complained about "lcddefault" not being a valid fontconfig option... Then the cairo-1.6.4 ebuild failed complaining about LCD_* options not being defined, which leads me back to thinking that fontconfig isn't right.

I want to do some more investigating before I submit a proper error report. (one that actually has exact error messages instead of the crap I just listed. )

This might be obvious, but did you emerge fontconfig with the "ubuntu" USE flag enabled? The "newspr" flag only applies to libXft and cairo, while the "ubuntu" flag applies to freetype and fontconfig.

yabbadabbadont · Post by **yabbadabbadont** » Sun Aug 24, 2008 11:03 pm

I already stated that the USE flags looked correct... and if you look at the ebuilds, you will see that the correct ones are on by default.

mwhitlock · Post by **mwhitlock** » Sun Aug 24, 2008 11:07 pm

yabbadabbadont wrote:I already stated that the USE flags looked correct... and if you look at the ebuilds, you will see that the correct ones are on by default.

Well the reason I asked is that it "works for me," so something must be different about your setup.

yabbadabbadont · Post by **yabbadabbadont** » Sun Aug 24, 2008 11:15 pm

mwhitlock wrote:
yabbadabbadont wrote:I already stated that the USE flags looked correct... and if you look at the ebuilds, you will see that the correct ones are on by default.
Well the reason I asked is that it "works for me," so something must be different about your setup.

I'm guessing that you added all the packages to your /etc/portage/package.keywords, in which case you are not using the same versions as I listed in my post.

mwhitlock · Post by **mwhitlock** » Sun Aug 24, 2008 11:31 pm

yabbadabbadont wrote:I'm guessing that you added all the packages to your /etc/portage/package.keywords, in which case you are not using the same versions as I listed in my post.

I have ACCEPT_KEYWORDS="~amd64" in my /etc/make.conf because I like running bleeding edge and don't mind reporting problems on bugs.gentoo.org.

But yes, you are correct, I'm not using the version of fontconfig that you listed, so my "works for me" does not apply here.

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[ebuild   R   ] x11-libs/cairo-1.6.4-r1  USE="X glitz newspr opengl svg -debug -directfb -doc -test -xcb" 0 kB [1]
[ebuild   R   ]  x11-libs/libXft-2.1.13  USE="newspr -debug" 0 kB [?=>1]
[ebuild   R   ]   media-libs/fontconfig-2.6.0-r2  USE="ubuntu -doc" 0 kB [?=>1]
[ebuild   R   ]    media-libs/freetype-2.3.7  USE="X ubuntu -bindist -debug -doc -utils" 0 kB [?=>1]

natros · Post by **natros** » Mon Aug 25, 2008 12:03 am

I'm using:

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=media-libs/fontconfig-2.6.0-r2
=media-libs/freetype-2.3.7
=x11-libs/cairo-1.6.4-r1
=x11-libs/libXft-2.1.12

and works pretty well

yabbadabbadont · Post by **yabbadabbadont** » Mon Aug 25, 2008 4:38 am

I just went ahead and keyworded all four of them. Now everything is fine.

Phlogiston · Post by **Phlogiston** » Mon Aug 25, 2008 7:46 am

Mr. Tao wrote:I’m glad I found this topic as I’ve used soor overlay which is not updated for a while. I’m going to test these patches right now. Meanwhile I’ve made repo definition for paludis:
/etc/paludis/lcd-filtering.conf wrote:location = ${ROOT}/usr/portage/local/lcd-filtering
sync = tar+http://ogmrip.sourceforge.net/misc/gent ... ng.tar.bz2
sync_options = "--rsync-option=--exclude=profiles"
master_repository = gentoo
format = ebuild
names_cache = /var/cache/paludis/names
write_cache = /var/cache/paludis/metadata

Oh, thats cool, I did not know that. Is the tarball updated regularly?

bi3l · Post by **bi3l** » Mon Aug 25, 2008 8:09 am

Phlogiston wrote:Oh, thats cool, I did not know that. Is the tarball updated regularly?

Almost as soon as there is a new version of either cairo, libXft, freetype or fontconfig in portage.

Phlogiston · Post by **Phlogiston** » Mon Aug 25, 2008 8:46 am

bi3l wrote:
Phlogiston wrote:Oh, thats cool, I did not know that. Is the tarball updated regularly?
Almost as soon as there is a new version of either cairo, libXft, freetype or fontconfig in portage.

Ok I'm curios how long it will last

Phlogiston · Post by **Phlogiston** » Mon Aug 25, 2008 4:50 pm

Mr. Tao wrote:I’m glad I found this topic as I’ve used soor overlay which is not updated for a while. I’m going to test these patches right now. Meanwhile I’ve made repo definition for paludis:
/etc/paludis/lcd-filtering.conf wrote:location = ${ROOT}/usr/portage/local/lcd-filtering
sync = tar+http://ogmrip.sourceforge.net/misc/gent ... ng.tar.bz2
sync_options = "--rsync-option=--exclude=profiles"
master_repository = gentoo
format = ebuild
names_cache = /var/cache/paludis/names
write_cache = /var/cache/paludis/metadata

please add profiles/repo_name.

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paludis@1219682970: [QA e.repo_name.unusable] Couldn't open repo_name file in '/usr/local/portage/lcd-filtering/profiles/', falling back to generated name 'x-lcd-filtering' (ignore this message if you have yet to sync this repository).

aronparsons · Post by **aronparsons** » Thu Aug 28, 2008 8:06 pm

http://packages.gentoo.org/package/x11-libs/cairo

http://cairographics.org/news/cairo-1.7.2/

LCD subpixel filtering using FreeType
- -------------------------------------
FreeType 2.3.5 added support for various LCD subpixel filtering, and
fontconfig 2.6.0 added support for configuring LCD filter on a font by font
basis. Cairo now relies on FreeType and fontconfig for subpixel filtering.
This work is based on David Turner's original patch to cairo, maintained
and tested by Sylvain Pasche and others. Thanks all!

mwhitlock · Post by **mwhitlock** » Thu Aug 28, 2008 8:32 pm

aronparsons wrote:Cairo now relies on FreeType and fontconfig for subpixel filtering.

Does this mean we soon won't need cairo in the overlay? Now if only libXft would pick up the slack!

Does anyone know if Qt4 uses Cairo?

natros · Post by **natros** » Thu Aug 28, 2008 9:09 pm

mwhitlock wrote:
aronparsons wrote:Cairo now relies on FreeType and fontconfig for subpixel filtering.
Does this mean we soon won't need cairo in the overlay? Now if only libXft would pick up the slack!

Does anyone know if Qt4 uses Cairo?

Qt does not use Cairo.

aronparsons · Post by **aronparsons** » Thu Aug 28, 2008 9:32 pm

mwhitlock wrote:Does this mean we soon won't need cairo in the overlay? Now if only libXft would pick up the slack!

That's right. libXft is the only package that still needs the LCD filter patches applied upstream. Everything else is in Portage and working great!

kokoko3k · Post by **kokoko3k** » Fri Sep 12, 2008 1:45 pm

What about kde4 and/or qt4?
As far as i know, qt4 doesn't use cairo nor Xft.

Lori · Post by **Lori** » Thu Sep 25, 2008 12:36 pm

One tiny little request... Can you please add EAPI="1" to the freetype and fontconfig ebuilds? I use paludis and I get these nasty warnings: "+/- prefixed IUSE flag names not allowed in this EAPI". I know I could do it manually, but I already configured your tarball as a paludis repository and would be so much nicer if it came with that fix...

mwhitlock · Post by **mwhitlock** » Thu Sep 25, 2008 1:34 pm

kokoko3k wrote:What about kde4 and/or qt4?
As far as i know, qt4 doesn't use cairo nor Xft.

I have the Last.fm player installed, and it uses Qt4, and its fonts look identical to those of the rest of my system, so I would guess that Qt4 refrains from messing with the glyphs it receives from FreeType, which means they remain properly filtered for LCD.

aliquid · Post by **aliquid** » Fri Sep 26, 2008 8:28 am

From cairo 1.8.0 release announcement:

Note also that the code that had been in cairo 1.7.x calling into
freetype's optional lcd_filter function was removed from cairo before
the 1.8.0 release. We do expect this code to come back in some form in
the future.

Sad, but no lcd font rendering for now.

Edit:
Here's a reason:

Remove all lcd_filter code.
We reverted the public API for setting lcd_filter font options back in 1b42bc8033bc , but we had left the implementation which would examine fontconfig and Xft properties for the option, and which would call into freetype for subpixel glyph rasterization. However, I recently realized, (and the test suite had been trying to tell me for a while), that this approach would cause a regression for users who were previously using sub-pixel text, but without sub-pixel rendering built directly into freetype. That's not acceptable, so all the code is coming out for now.