Issue 15687 - Font substitution incorrectly prefers font name over glyph avalibility
Summary: Font substitution incorrectly prefers font name over glyph avalibility
Alias: None
Product: gsl
Classification: Code
Component: code (show other issues)
Version: OOo 1.1 Beta2
Hardware: PC Linux, all
: P3 Trivial (vote)
Target Milestone: AOO PleaseHelp
Assignee: AOO issues mailing list
QA Contact:
Depends on: 26679
  Show dependency tree
Reported: 2003-06-16 18:25 UTC by sforbes
Modified: 2017-05-20 11:29 UTC (History)
4 users (show)

See Also:
Latest Confirmation in: ---
Developer Difficulty: ---


Note You need to log in before you can comment on or make changes to this issue.
Description sforbes 2003-06-16 18:25:43 UTC
As times new roman, tahoma and arial are default fonts on many microsoft
systems/styles and open office styles, there are widely used.

However, the default linux versions do not contain Hebrew glyphs.

When a Hebrew document created it those fonts is transfered from a system where
those fonts contain Hebrew glyphs, to a system where those fonts are roman only,
OO incorrectly retains the font face, resulting in junk disply.

OO should check to see if the specified font has the avalible glyph, and use it
only if it does- ignoring the font specification if the font on the local system
does not have the correct language glyph
Comment 1 Dieter.Loeschky 2003-08-14 12:55:05 UTC
DL->HDU: Could you please takeover?
Comment 2 Dieter.Loeschky 2003-08-14 13:07:38 UTC
Comment 3 2003-08-14 13:16:22 UTC
Accepted. At least for glyph fallback this should be done. 
Comment 4 2003-08-21 13:49:09 UTC
Selecting the best font for "font fallback" using fixed lists of suitable fallbacks is 
already implemented. The seemingly related problem of selecting the best font for 
"glyph fallback" is much more difficult though. E.g. what is the cultural equivalent of 
a Sans Serif font in Thai? What is the best glyph fallback font when "Comic Sans" 
or "Fangsong Ti" are selected but Hebrew characters are used? The problem is to 
find a font with the same style, that does contain the glyphs that are missing in the 
selected font. 
The current approach is to make the text readable ignoring stylistic mismatches, 
by using a fixed list of glyph fallback fonts. The next step will be to use fixed lists 
for the most important font. This will later be improved by using panose info to 
better match fonts. A problem is that panose matching is mostly designed for Latin 
The best method avoid all this trouble is of course to use 
a) a font suitable to the text 
b) to improve the platform's fonts: a font that says: I'm like X on platform Y it should 
also try to be as compatible as possible to X. 
Comment 5 sforbes 2004-06-21 15:21:15 UTC
adding dina as cc
Comment 6 Martin Hollmichel 2004-08-09 14:09:24 UTC
according to
this issue will be set to OOoLater
Comment 7 alan 2004-08-10 13:47:44 UTC
Hi hdu,

Regarding glyph fallback:
You mentioned that the current approach is to make the text readable ignoring stylistic 
mismatches, by using a fixed list of glyph fallback fonts. Could you tell me where in the code this 
is implemented?

Regarding font fallback:
You mentioned that if a font is not found, a fixed list of suitable fallbacks is used. Is this done 
through VCL.xcu?

Is it possible in the current scheme to make a choice based on which font is missing? That is, if the 
imported document uses "Tahoma" and "Arial", I can fall back to one font for the Tahoma text, and 
a different font for the Arial text? If so, where can I find this implementation in the code?

Comment 8 2004-08-10 14:04:51 UTC
Hi, the font fallback stuff is an area that needs a lot of work invested in it.
The old infrastructure was very inflexible and prevented a lot of improvements.
The new infrastructure is being implemented in the fontlists* child workspaces...

1) search for FALLBACKFONT_NAMELIST in vcl/source/gdi/outdev3.cxx
Yes, I know the algorithm to find good glyph fallback fonts has a lot of
potential for improvement.

2) yes, mostly through VCL.xcu, but if there is no match also using stylistic
info, e.g. font weight from the Font structure in vcl/inc/font.hxx, eventually
also extracting some stylistic info from the font name, e.g. "Serif"

3) yes, just use VCL.xcu to add specific fallback fonts for Tahoma or Arial
the actual code to do this is in vcl/source/gdi/outdev3.cxx in the method

Have fun...
Comment 9 kaplanlior 2008-05-08 20:39:49 UTC
Is this issue still relevant in 2.4.0 ?
Comment 10 Marcus 2017-05-20 11:29:52 UTC
Reset assigne to the default "".