215759 - Using true type fonts, characters get shaved off at top or bottom

Status: RESOLVED WORKSFORME

(Core Graveyard :: GFX: Gtk, defect)

Description

[Ray Jantz]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624

I have enabled true type fonts using the following lines in my unix.js file:

// TrueType
pref("font.FreeType2.enable", true);
pref("font.freetype2.shared-library", "libfreetype.so.6");
// if libfreetype was built without hinting compiled in
// it is best to leave hinting off
pref("font.FreeType2.autohinted", false);
pref("font.FreeType2.unhinted", false);
// below a certian pixel size anti-aliased fonts produce poor results
pref("font.antialias.min",        10);
pref("font.embedded_bitmaps.max", 1000000);
pref("font.scale.tt_bitmap.dark_text.min", 64);
pref("font.scale.tt_bitmap.dark_text.gain", "0.2");
// sample prefs for TrueType font dirs
pref("font.directory.truetype.1", "/usr/share/fonts/TrueType");
pref("font.directory.truetype.2", "/usr/share/fonts/monotype/TrueType");
pref("font.directory.truetype.3", "/usr/X11R6/lib/X11/fonts/truetype");
pref("font.FreeType2.printing", true);

With the above true type settings, text characters get shaved off at the top or
bottom, to the point where they are sometimes illegible.  When a page is
initially displayed, it looks fine - the problem usually happens when I scroll
up or down the page.

I am running SuSE 8.0.  My video card is Nvidia GeForce 2 MX 400.  I have tried
two monitors - an AquaView 15HP flat-panel monitor and a Smile CA-1414-VS.  This
does not happen in Opera or Konqueror, nor does it happen in an ordinary X-term.



Reproducible: Always

Steps to Reproduce:
1. Set up configuration per "Details" above (SuSE 8.0, Nvidia GeForce 2, etc.)
2. Install Mozilla 1.4
3. Go to a page with lots of text.
4. Scroll up and down a few times

Actual Results:  
Some, but not all characters are shaved off at the top or bottom.

Expected Results:  
The entire character should be displayed with no parts missing or shaved off.

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

->gtk

Comment 2

[Tristan Miller]

I can confirm that this happens with Mozilla/5.0 (X11; U; Linux i686; en-US;
rv:1.7.2) Gecko/20040906 and that it's damned annoying.  Selecting the text with
the mouse or with Ctrl+A redraws the text and fixes it, but as soon as one
scrolls up or down the problem often returns.  If requested, I can provide a
screenshot showing the bug.

Comment 3

[Patrick]

I am seing this too with FireFox 1.0 (Linux/Suse9.1/KDE3.3.1).

In an attempt to put things together, I am listing here bug reports that seem
related to me. Sorry for not doing more analysis (and reading all the comments
of all bugs listed here) or for the bugspam but I really think this linking
might be useful. Please note that this bug is listed too (as I put the same in
different bugs).

bug 172162 Linux
bug 174977 All (was Solaris)
bug 199840 Linux
bug 211704 Linux
bug 215759 Linux
bug 217336 Linux
bug 217825 All (was Linux)
bug 228808 MacOS X
bug 248799 Linux

I built this list by searching for scroll and font in the comments from newest
to oldest going up to the first one of this list (feel free to search further)
and I might have missed some.

I put the OS as it seems there is a link between them: is it due to the usage of
a common deployed library, a bug in an OS' library, ...?

Comment 4

[Gervase Markham [:gerv]]

This is an automated message, with ID "auto-resolve01".

This bug has had no comments for a long time. Statistically, we have found that
bug reports that have not been confirmed by a second user after three months are
highly unlikely to be the source of a fix to the code.

While your input is very important to us, our resources are limited and so we
are asking for your help in focussing our efforts. If you can still reproduce
this problem in the latest version of the product (see below for how to obtain a
copy) or, for feature requests, if it's not present in the latest version and
you still believe we should implement it, please visit the URL of this bug
(given at the top of this mail) and add a comment to that effect, giving more
reproduction information if you have it.

If it is not a problem any longer, you need take no action. If this bug is not
changed in any way in the next two weeks, it will be automatically resolved.
Thank you for your help in this matter.

The latest beta releases can be obtained from:
Firefox:     http://www.mozilla.org/projects/firefox/
Thunderbird: http://www.mozilla.org/products/thunderbird/releases/1.5beta1.html
Seamonkey:   http://www.mozilla.org/projects/seamonkey/

Comment 5

[Tristan Miller]

Bug still occurs with Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12)
Gecko/20050919.

Comment 6

[Mark Stier]

Is that related?

https://stier.is-a-geek.com/~moinmoin/MarksWiki/GentooLinux/ProblemsAndBugs/AntiAliasing

There seems to be a problem with custom dpi settings. Can someone confirm that? Do the same errors occur?

Comment 7

[Mats Palmgren (inactive)]

Please file a new bug if this still occurs in a recent trunk build. Thanks.
http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/

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