1 Troubleshooting GNU FreeFont 2 3So your text looks lousy, although you installed FreeFont and you seem to be 4using it. What do you do? 5 6Before you blame the problem on FreeFont, take the time to double-check that 7the text you are looking at is really rendered with FreeFont. 8 9Be aware that not all Unicode characters are supported by FreeFont, and 10even characters supported by one face, such as Serif, might not be 11supported by other faces such as Sans. 12 13Also, some systems have settings that strongly affect the rendering 14of fonts. It may be worth tweaking these. 15 16glyph substitution 17================== 18 19When given the task of displaying characters in text, modern font rendering 20software usually tries to display *something*, even if the font it is 21*supposed* to be using does not contain glyphs for all the characters in the 22text. The software will snoop through all the fonts on the system to find 23one that has a glyph for the one missing in the desired font. So although 24you have specified FreeSans-bold, you may be looking at a letter from quite 25a different font. 26 27First double-check that the font in question really contains the character 28in question. If you don't have font development software, this can be 29tricky. In the case of FreeFont, you can check if a given character 30range is supported: <http://www.gnu.org/software/freefont/coverage.html> 31 32Next double-check that your application (web browser, text editor, etc) 33has indeed been properly instructed to use the font. 34 35Then double-check that the font is really installed in the system. 36(This depends on the operating system, of course.) 37 38Linux and Unix 39============== 40 41Modern Linux systems use a system called fontconfig, which maintains a font 42cache, for efficiency. 43 44The font cache can really complicate font installation and troubleshooting 45however. It can happen that when a font is newly installed, what is 46displayed is coming out of an old cache entry rather than the new font. 47 48Just what to do depends on how and where the font was installed. 49 50Fonts installed system-wide are usually put in a directory such as 51 /usr/share/fonts/ 52the font cache for these might be in 53 /var/cache/fontconfig/ 54Fonts installed just for one user account will typically be in 55 ~/.fonts/ 56and the cache will be 57 ~/.fontconfig/ 58 59You can clean your local cache merely by emptying the directory 60 ~/.fontconfig/ 61In any case, to clean the cache, you can use the fontconfig command 62 fc-cache -vf 63If run as root, it will clean the system cache, if run as a normal user, 64it cleans only the normal user's cache. 65 66The procedure for local fonts is: 67 1) shut off any program using the fonts in question 68 2) clean the cache 69 3) re-start the program 70The procedure for system-wide fonts is: 71 1) log out of the X Windows session 72 2) in a console, clean the cache 73 3) log in to an X Windows session 74 75LibreOffice / OpenOffice 76======================== 77These products have their own font rendering libraries, which have 78idiosyncratic behavior. 79 80It has recently been reported that as of LibreOffice 3.5.1, font features 81are disabled for OpenType fonts. If you use FreeFont with these products, 82you may want to install the TrueType versions of the fonts. 83 84Windows 85======= 86 87The most common complaint has to do with "blurry text". There are two 88causes. 89 90The first is that ClearType smoothing is turned off. The best way to check 91is to use the native Windows Web browser. Do a search for "ClearType Tuner". 92The Microsoft pages install a tuner for ClearType. A security block notice 93will appear at the top of the window--you have to allow the installation. 94Then check the box "Turn on ClearType". The change happens immediately. 95 96The secont cause is that the FreeFont version with cubic spline outlines is 97installed. As of the 2012 GNU FreeFont release, the TrueType builds have 98quadratic splines, which work best with Windows' rendering software. 99 TTF (TrueType) quadratic splines Windows 7, Vista, Windows XP. 100 OTF (OpenType) cubic splines Linux, Mac 101 102Note also: Firefox has a setting for ClearType: 103 gfx.font_rendering.cleartype_params.rendering_mode 104A value of 2 sets it to old-style GDI rendering, while -1 is the default. 105 106reporting problems 107================== 108 109If you really think you're seeing a bug in FreeFont, or if you have 110a suggestion, consider opening a problem report at 111 https://savannah.gnu.org/bugs/?group=freefont 112It is best that you make a Savannah account and log in with that, so 113you can be e-mailed whenever changes are made to your report. 114 115$Id: troubleshooting.txt,v 1.10 2011-07-16 08:38:06 Stevan_White Exp $ 116