Bug 38881 - Add STIX fonts
Summary: Add STIX fonts
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: framework (show other bugs)
Version:
(earliest affected)
unspecified
Hardware: All Windows (All)
: low enhancement
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: Fonts-Bundled
  Show dependency treegraph
 
Reported: 2011-07-01 06:34 UTC by Björn Michaelsen
Modified: 2018-12-18 16:35 UTC (History)
7 users (show)

See Also:
Crash report or crash signature:


Attachments
FontForge screenshots showing STIX-Regular and STIXMath-Regular. (397.66 KB, application/zip)
2013-11-13 01:57 UTC, Owen Genat (retired)
Details

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Description Björn Michaelsen 2011-07-01 06:34:02 UTC
Add STIX fonts

STIX fonts project page

Background: Currently LibO ships the opensymbol fonts, used e.g. for greek and mathematical notation. To quote from the stix page: "The mission of the Scientific and Technical Information Exchange (STIX) font creation project is the preparation of a comprehensive set of fonts that serve the scientific and engineering community in the process from manuscript creation through final publication, both in electronic and print formats." Sounds like a perfect addition to LibO.

Skills: Building

http://www.stixfonts.org/
Comment 1 Björn Michaelsen 2011-10-20 10:43:04 UTC
Not an easyhack, needs license clarification (non-LGPL) and most distros will want to ship this as an external package. Probably only for Windows anyway?
Comment 2 Björn Michaelsen 2011-12-23 12:22:51 UTC Comment hidden (obsolete)
Comment 3 Patrick Welche 2012-02-16 03:57:24 UTC
A highlight of the "SIL Open Font License 1.1" is:

The OFL allows the licensed fonts to be used, studied, modified and
redistributed freely as long as they are not sold by themselves. The
fonts, including any derivative works, can be bundled, embedded, 
redistributed and/or sold with any software provided that any reserved
names are not used by derivative works. The fonts and derivatives,
however, cannot be released under any other type of license. The
requirement for fonts to remain under this license does not apply
to any document created using the fonts or their derivatives.
Comment 4 Florian Reisinger 2012-08-14 13:58:39 UTC Comment hidden (obsolete)
Comment 5 Florian Reisinger 2012-08-14 13:59:54 UTC Comment hidden (obsolete)
Comment 6 Florian Reisinger 2012-08-14 14:04:32 UTC Comment hidden (obsolete)
Comment 7 Florian Reisinger 2012-08-14 14:06:42 UTC Comment hidden (obsolete)
Comment 8 Patrick Welche 2012-08-14 15:09:22 UTC
The NEEDINFO queried the license, and Comment 3 was an attempt to address this.
Comment 9 Michael Meeks 2012-08-15 11:23:12 UTC
Good point :-) the ux-advise guys have been asked to review our default bundled fonts situation, and I guess it'd be good to feed this bug into that process.

Thanks for re-opening !
Comment 10 Patrick Welche 2012-08-15 11:28:34 UTC
Just changed the platform as it isn't really a windows issue...
Comment 11 Florian Reisinger 2012-08-15 17:19:54 UTC
Sorry, overead that - Status set to NEW
Comment 12 Owen Genat (retired) 2013-11-13 01:57:07 UTC
Created attachment 89111 [details]
FontForge screenshots showing STIX-Regular and STIXMath-Regular.

I would be concerned about including the STIX fonts in LO as they contain many invalid uses of code points. Where Unicode does not support a particular character the Private Use Area (U+E000..U+F8FF), Supplemental Private Use Area-A (U+F0000..U+FFFFD), and Supplemental Private Use Area-B (U+100000..U+10FFFD), can be used to encode 6400, 65534, and 65534 characters respectively.

In v1.1.1-Word the STIX fonts include these invalid non-Unicode code points:

- STIX-Bold, 63 glyphs, 0x110000..0x11003c
- STIX-BoldItalic, 2 glyphs, 0x110000..0x110001
- STIX-Italic, 2 glyphs, 0x110000..0x110001
- STIX-Regular, 125 glyphs, 0x110000..0x11007c
- STIXMath-Regular, 926 glyphs, 0x110000..0x11039d

The Bold, BoldItalic, Italic, and Regular fonts all make partial use (~100-350 glyphs) of the Private Use Area, while the Math font does not use this area at all (attached screenshots are indicative). There are also some basic errors reported by FontForge.

While I can appreciate the need for a greater range of math glyphs, pushing non-Unicode fonts of this nature into the LO user-base would seem potentially problematic and at the very least require *extensive* testing i.e., printing, PDF/file-embedding, interop, etc. The current OpenSymbol font by comparison, although less extensive, does not contain any errors or invalid encodings.
Comment 13 Khaled Hosny 2013-11-13 16:12:28 UTC
You will be surprised to know that our own OpenSymbol font uses PUA for characters *already* in Unicode. The STIX Word fonts do not use PUA at all, actually (FontForge is misleading you), those glyphs are not assigned any code points at all and are internal to the fonts.
Comment 14 Khaled Hosny 2013-11-13 16:16:07 UTC
The STIX Regular font seems to use PUA, though. But those are not glyphs that we are interested in, anyway.
Comment 15 Owen Genat (retired) 2013-11-14 03:16:25 UTC
Khaled thanks for your responses. Apologies if my comment / concern was unfounded.

(In reply to comment #13)
> You will be surprised to know that our own OpenSymbol font uses PUA for 
> characters *already* in Unicode.

Well, perhaps disappointed rather than surprised ;) Not ideal, but the PUA is available to include anything so I guess not awful either.

> those glyphs are not assigned any code points at all and are internal to the fonts.

I wasn't as clear as I could have been. I was worried these additional characters at the large hexadecimal offset were the required symbols. I see now they appear to be scaled variants of existing (encoded) glyphs. At least that is what they look like to me. Thanks again and sorry for the noise.
Comment 16 Khaled Hosny 2013-11-14 10:39:28 UTC
(In reply to comment #15)
> > those glyphs are not assigned any code points at all and are internal to the fonts.
> 
> I wasn't as clear as I could have been. I was worried these additional
> characters at the large hexadecimal offset were the required symbols. I see
> now they appear to be scaled variants of existing (encoded) glyphs. At least
> that is what they look like to me. Thanks again and sorry for the noise.

These unencoded glyphs are not accessed directly thus has no separate code points, instead they are used by capable layout applications when e.g. a large glyph is necessary (a display big operator, large parenthesis) etc. instead of linear scaling of the base glyphs (as Math does now, which is aesthetically ugly). It would be a huge improvement to be able to do this in Math, but we are nowhere near this.
Comment 17 Matthew Francis 2014-10-29 13:26:32 UTC
In reply to comment 3: Although it's not ideal in the abstract, a lot of font licenses work this way, and this specific license is both DFSG compatible and FSF approved


In reply to comment 10: Despite appearances, this is a Windows only issue

- OSX bundles the STIX fonts itself since 10.7
- All major Linux distributions provide a package for the STIX fonts, so it would be inappropriate to bundle another copy there

The only real remaining question is whether it would be appropriate for LibreOffice to bundle its own copy on Windows


Platform set -> Windows
Severity set -> enhancement
Comment 18 Volga 2018-12-18 16:35:39 UTC
Liberation font project has a request for adding math fonts.
https://github.com/liberationfonts/liberation-fonts/issues/7
If they are implemented, we can also try to bundle that, and this bug could become invalid.