[Bug 1722508] Re: Font hinting appears broken on 17.10 beta

[gldickens3]

Hello jbicha,

I am not running Kubuntu but I am running KDE Plasma 5 and Qt apps on
several OpenSUSE installations. On my Ubuntu installation I am running
Gnome Shell. As an FYI, I maintain a freetype2 repository with subpixel
rendering enabled for OpenSUSE Leap and Tumbleweed. Like most of the
other Linux desktop OS versions, OpenSUSE does NOT enable subpixel
rendering with the FT_CONFIG_OPTION_SUBPIXEL_RENDERING variable and I
provide that option with my repo. In one of my repos I use the Ubuntu
freetype2 diff file for implementing the subpixel rendering patches.
Several months ago, I noticed that the font rendering changed when I
upgraded my font repositories to freetype-2.7.1 and the difference in
the rendering was caused by the introduction of the
TT_CONFIG_OPTION_SUBPIXEL_HINTING parameter in ftoptions.h. Its not so
much that the font rendering is better or worse but that it is different
than before with freetype-2.6.X. In any event, at that time, I
discovered that the font rendering would be made exactly the same as
before by not defining TT_CONFIG_OPTION_SUBPIXEL_HINTING in freetype2
versions 2.7 and later.

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https://bugs.launchpad.net/bugs/1722508

Title:
  Font hinting appears broken on 17.10 beta

Status in Qt:
  New
Status in freetype package in Ubuntu:
  Confirmed
Status in qtbase-opensource-src package in Ubuntu:
  Confirmed
Status in freetype source package in Artful:
  Confirmed
Status in qtbase-opensource-src source package in Artful:
  Confirmed

Bug description:
  It appears that font hinting in 17.10 (beta) doesn't work as expected.
  The issue is easy to miss if you have antialiasing enabled system-
  wise. However, if you install "gnome-tweak-tool" and disable
  antialiasing there, the problem becomes obvious.

  Here is how it looks on 17.10 beta:
  https://postimg.org/image/3auqsbkqtn/

  And here is how it looks on my 16.04 machine (and this is pretty much how it's supposed to look):
  https://postimg.org/image/85n5ss3l4b/

  * When comparing the pictures make sure you "Open image in new tab"
  and see them without browser zoom, otherwise the problem may no be
  obvious.

  I suspect that this issue is caused by a bug in some base font
  rendering package that Ubuntu uses (edit: the problem is probably
  caused by FreeType 2.8.0, see my comments below). A couple of months
  ago a similar issue was reported (and promptly fixed) in Chromium
  after they had changed something in FreeType rendering
  (https://bugs.chromium.org/p/chromium/issues/detail?id=748997).

  lsb_release -rd
  Description: Ubuntu Artful Aardvark (development branch)
  Release:     17.10

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