incorrect conversion of -=+ symbols to cmmi10 font

[Martin Konôpka]

Binary package hint: inkscape

1.) I type - = + characters (basic mathematical symbols "minus", "equal", "plus") in some font, say Courier 10 Pitch.
2.) I try to convert these characters to Computer Modern cmmi10 fonts.
3.) The converted characters do not represent any of the intended - = + . Instead, I observe quite different forms. See attachment.

(cmmi fonts are those used by default in LaTeX systems to type mathematical content, i.e. in mathematical regime. It is nice when the same fonts for formulas are used also in figures included into LaTeX documents. This is likely the main reason why some people try to use cmmi10 font in Inkscape.)

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: inkscape 0.47.0-2ubuntu2
ProcVersionSignature: Ubuntu 2.6.32-25.44-generic 2.6.32.21+drm33.7
Uname: Linux 2.6.32-25-generic i686
Architecture: i386
Date: Sun Oct 3 18:58:48 2010
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, user)
 LANG=en_GB.utf8
 SHELL=/bin/bash
SourcePackage: inkscape

[Alex Valavanis (valavanisalex)]

Confirmed with inkscape_0.48.0-1ubuntu1 using fonts from ttf-lyx_1.6.7-1

[Alex Valavanis (valavanisalex)]

As with bug #640845, I find that this also occurs in gimp and with OpenOffice.org. It seems like the problem lies within the lyx package... but then, I know very little about font rendering. Can anyone advise?

[Marcel Stimberg (marcelstimberg)]

This isn't a problem of lyx, inkscape etc. but has to do with the way the computer modern fonts are built: LaTeX uses many "hacks" to decide which symbol to use from these fonts, they are not necessarily at the position you'd expect. If you open the Charmap utility and select the cmmi10 font you'll see that at the position where "normal" fonts have +-= you find these "weird shapes" in cmmi10. LaTeX does not use the cmmi10 for these symbols but uses the font cmr10 or cmsys10 instead. So in inkscape etc. you'd have to switch fonts depending whether you are using letters, numbers, symbols, etc. Another possibility would be to use the modern version of the fonts, known as "latin modern" -- these should be more or less standard fonts, I think.

[su_v (suv-lp)]

Marcel Stimberg wrote
> This isn't a problem of lyx, inkscape etc. but has to do
> with the way the computer modern fonts are built: (…)

Thank you for this in-depth information. Closing as 'Invalid' for Inkscape - feel free to reopen if you don't agree and think this needs to be addressed in Inkscape explicitly.

[Alex Valavanis (valavanisalex)]

Closing inkscape (Ubuntu) report as invalid. Please see comment #4 for details

[Jean-Marc Lasgouttes (jmarc)]

This report should be closed as invalid for LyX too, IMO.

[Jean-Marc Lasgouttes (jmarc)]

I only noticed now that I can do it myself