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diff --git a/xorg-server/hw/xfree86/doc/README.fonts b/xorg-server/hw/xfree86/doc/README.fonts deleted file mode 100644 index 0ad2b49d0..000000000 --- a/xorg-server/hw/xfree86/doc/README.fonts +++ /dev/null @@ -1,1158 +0,0 @@ - Fonts in X11R6.9 - - Juliusz Chroboczek, <jch@pps.jussieu.fr> - - 25 March 2004 - -1. Introduction - -This document describes the support for fonts in X11R6.9. Installing fonts -(section 2., page 1) is aimed at the casual user wishing to install fonts in -X11R6.9 the rest of the document describes the font support in more detail. - -We assume some familiarity with digital fonts. If anything is not clear to -you, please consult Appendix: Background (section 5., page 1) at the end of -this document for background information. - -1.1 Two font systems - -X includes two font systems: the original core X11 fonts system, which is -present in all implementations of X11, and the Xft fonts system, which may -not be distributed with implementations of X11 that are not based on X11R6.9 -but will hopefully be included by them in the future - -The core X11 fonts system is directly derived from the fonts system included -with X11R1 in 1987, which could only use monochrome bitmap fonts. Over the -years, it has been more or less happily coerced into dealing with scalable -fonts and rotated glyphs. - -Xft was designed from the start to provide good support for scalable fonts, -and do so efficiently. Unlike the core fonts system, it supports features -such as anti-aliasing and sub-pixel rasterisation. Perhaps more importantly, -it gives applications full control over the way glyphs are rendered, making -fine typesetting and WYSIWIG display possible. Finally, it allows applica- -tions to use fonts that are not installed system-wide for displaying docu- -ments with embedded fonts. - -Xft is not compatible with the core fonts system: usage of Xft requires mak- -ing fairly extensive changes to toolkits (user-interface libraries). While -X.org will continue to maintain the core fonts system, toolkit authors are -encouraged to switch to Xft as soon as possible. - -2. Installing fonts - -This section explains how to configure both Xft and the core fonts system to -access newly-installed fonts. - -2.1 Configuring Xft - -Xft has no configuration mechanism itself, rather it relies upon the fontcon- -fig library to configure and customize fonts. That library is not specific -to X11R6.9 or indeed on any particular font output mechanism. This discus- -sion describes how fontconfig, rather than Xft, works. - -2.1.1 Installing fonts in Xft - -Fontconfig looks for fonts in a set of well-known directories that include -all of X11R6.9's standard font directories (`/usr/X11R6/lib/X11/lib/fonts/*') -by default) as well as a directory called `.fonts/' in the user's home direc- -tory. Installing a font for use by Xft applications is as simple as copying -a font file into one of these directories. - - $ cp lucbr.ttf ~/.fonts/ - -Fontconfig will notice the new font at the next opportunity and rebuild its -list of fonts. If you want to trigger this update from the command line (for -example in order to globally update the system-wide Fontconfig information), -you may run the command `fc-cache'. - - $ fc-cache - -2.1.2 Fine-tuning Xft - -Fontconfig's behaviour is controlled by a set of configuration files: a sys- -tem-wide configuration file, `/etc/fonts/fonts.conf', and a user-specific -file called `.fonts.conf' in the user's home directory (this can be overrid- -den with the `FONTCONFIG_FILE' environment variable). - -Every Fontconfig configuration file must start with the following boiler- -plate: - - <?xml version="1.0"?> - <!DOCTYPE fontconfig SYSTEM "fonts.dtd"> - <fontconfig> - -In addition, every Fontconfig configuration file must end with the following -line: - - </fontconfig> - -The default Fontconfig configuration file includes the directory `~/.fonts/' -in the list of directories searched for font files, and this is where user- -specific font files should be installed. In the unlikely case that a new -font directory needs to be added, this can be done with the following syntax: - - <dir>/usr/local/share/fonts/</dir> - -Another useful option is the ability to disable anti-aliasing (font smooth- -ing) for selected fonts. This can be done with the following syntax: - - <match target="font"> - <test qual="any" name="family"> - <string>Lucida Console</string> - </test> - <edit name="antialias" mode="assign"> - <bool>false</bool> - </edit> - </match> - -Anti-aliasing can be disabled for all fonts by the following incantation: - - <match target="font"> - <edit name="antialias" mode="assign"> - <bool>false</bool> - </edit> - </match> - -Xft supports sub-pixel rasterisation on LCD displays. X11R6.9 should auto- -matically enable this feature on laptops and when using an LCD monitor con- -nected with a DVI cable; you can check whether this was done by typing - - $ xdpyinfo -ext RENDER | grep sub-pixel - -If this doesn't print anything, you will need to configure Render for your -particular LCD hardware manually; this is done with the following syntax: - - <match target="font"> - <edit name="rgba" mode="assign"> - <const>rgb</const> - </edit> - </match> - -The string `rgb' within the `<const>'...`</const>' specifies the order of -pixel components on your display, and should be changed to match your hard- -ware; it can be one of `rgb (normal LCD screen), `bgr' (backwards LCD -screen), `vrgb' (LCD screen rotated clockwise) or `vbgr' (LCD screen rotated -counterclockwise). - -2.1.3 Configuring applications - -Because most current applications use the core fonts system by default, it is -necessary to explicitly configure them to use Xft. How this is done depends -on the application. - -XTerm can be set to use Xft by using the `-fa' command line option or by set- -ting the `XTerm*faceName' resource: - - XTerm*faceName: Courier - -or - - $ xterm -fa "Courier" - -For applications based on GTK+ 2.0 (including GNOME 2 applications), the -environment variable `GDK_USE_XFT' should be set to `1': - - $ export GDK_USE_XFT=1 - -GTK+ 2.2 uses Xft by default. - -For KDE applications, you should select ``Anti-alias fonts'' in the ``Fonts'' -panel of KDE's ``Control Center''. Note that this option is misnamed: it -switches KDE to using Xft but doesn't enable anti-aliasing in case it was -disabled by your Xft configuration file. - -(What about Mozilla?) - -2.1.4 Troubleshooting - -If some Xft-based applications don't seem to notice the changes you are mak- -ing to your configuration files, they may be linked against an old version of -Xft. In order to fix the problem, you should relink them against a current -version of Xft; on most systems, it is enough to install the current version -of the Xft and Fontconfig libraries. - -If, for some reason, you cannot upgrade the shared libraries, please check -the Xft(3) manual page included with XFree86 4.2 for the configuration mecha- -nisms of the previous version of Xft. - -2.2 Configuring the core X11 fonts system - -Installing fonts in the core system is a two step process. First, you need -to create a font directory that contains all the relevant font files as well -as some index files. You then need to inform the X server of the existence -of this new directory by including it in the font path. - -2.2.1 Installing bitmap fonts - -The X11R6.9 server can use bitmap fonts in both the cross-platform BDF format -and the somewhat more efficient binary PCF format. (X11R6.9 also supports -the obsolete SNF format.) - -Bitmap fonts are normally distributed in the BDF format. Before installing -such fonts, it is desirable (but not absolutely necessary) to convert the -font files to the PCF format. This is done by using the command `bdftopcf', -e.g. - - $ bdftopcf courier12.bdf - -You will then want to compress the resulting PCF font files: - - $ gzip courier12.pcf - -After the fonts have been converted, you should copy all the font files that -you wish to make available into a arbitrary directory, say -`/usr/local/share/fonts/bitmap/'. You should then create the index file -`fonts.dir' by running the command `mkfontdir' (please see the mkfontdir(1) -manual page for more information): - - $ mkdir /usr/local/share/fonts/bitmap/ - $ cp *.pcf.gz /usr/local/share/fonts/bitmap/ - $ mkfontdir /usr/local/share/fonts/bitmap/ - -All that remains is to tell the X server about the existence of the new font -directory; see Setting the server font path (section 2.2.4, page 1) below. - -2.2.2 Installing scalable fonts - -The X11R6.9 server supports scalable fonts in three formats: Type 1, TrueType -and CIDFont. This section only applies to the first two; for information on -CIDFonts, please see Installing CIDFonts (section 2.2.3, page 1) later in -this document. Previous versions also included support for the Speedo scal- -able font format, but that is disabled in the default builds of X11R6.9 and -not included in X11R7.0 and later releases. - -Installing scalable fonts is very similar to installing bitmap fonts: you -create a directory with the font files, and run `mkfontdir' to create an -index file called `fonts.dir'. - -There is, however, a big difference: `mkfontdir' cannot automatically recog- -nise scalable font files. For that reason, you must first index all the font -files in a file called `fonts.scale'. While this can be done by hand, it is -best done by using the `mkfontscale' utility. - - $ mkfontscale /usr/local/share/fonts/Type1/ - $ mkfontdir /usr/local/share/fonts/Type1/ - -Under some circumstances, it may be necessary to modify the `fonts.scale' -file generated by mkfontscale; for more information, please see the mkfont- -dir(1) and mkfontscale(1) manual pages and Core fonts and internationalisa- -tion (section 4.1, page 1) later in this document. - -2.2.3 Installing CID-keyed fonts - -The CID-keyed font format was designed by Adobe Systems for fonts with large -character sets. A CID-keyed font, or CIDFont for short, contains a collec- -tion of glyphs indexed by character ID (CID). - -In order to map such glyphs to meaningful indices, Adobe provide a set of -CMap files. The PostScript name of a font generated from a CIDFont consists -of the name of the CIDFont and the name of the CMap separated by two dashes. -For example, the font generated from the CIDFont `Munhwa-Regular' using the -CMap `UniKS-UCS2-H' is called - - Munhwa-Regular--UniKS-UCS2-H - -The CIDFont code in X11R6.9 requires a very rigid directory structure. The -main directory must be called `CID' (its location defaults to -`/usr/X11R6/lib/X11/fonts/CID' but it may be located anywhere), and it should -contain a subdirectory for every CID collection. Every subdirectory must -contain subdirectories called CIDFont (containing the actual CIDFont files), -CMap (containing all the needed CMaps), AFM (containing the font metric -files) and CFM (initially empty). For example, in the case of the font -Munhwa-Regular that uses the CID collection Adobe-Korea1-0, the directory -structure should be as follows: - - CID/Adobe-Korea1/CIDFont/Munhwa-Regular - CID/Adobe-Korea1/CMap/UniKS-UCS2-H - CID/Adobe-Korea1/AFM/Munhwa-Regular.afm - CID/Adobe-Korea1/CFM/ - CID/fonts.dir - CID/fonts.scale - -After creating this directory structure and copying the relevant files, you -should create a `fonts.scale' file. This file has the same format as in the -case of (non-CID) scalable fonts, except that its first column contains -PostScript font names with the extension `.cid' appended rather than actual -filenames: - - 1 - Adobe-Korea1/Munhwa-Regular--UniKS-UCS2-H.cid \ - -adobe-munhwa-medium-r-normal--0-0-0-0-p-0-iso10646-1 - -(both names on the same line). Running `mkfontdir' creates the `fonts.dir' -file: - - $ cd /usr/local/share/fonts/CID - $ mkfontdir - -Finally, you should create the font metrics summary files in the directory -`CFM' by running the command `mkcfm': - - $ mkcfm /usr/local/share/fonts/CID - -If no CFM files are available, the server will still be able to use the CID -fonts but querying them will take a long time. You should run `mkcfm' again -whenever a change is made to any of the CID-keyed fonts, or when the CID- -keyed fonts are copied to a machine with a different architecture. - -2.2.4 Setting the server's font path - -The list of directories where the server looks for fonts is known as the font -path. Informing the server of the existence of a new font directory consists -of putting it on the font path. - -The font path is an ordered list; if a client's request matches multiple -fonts, the first one in the font path is the one that gets used. When match- -ing fonts, the server makes two passes over the font path: during the first -pass, it searches for an exact match; during the second, it searches for -fonts suitable for scaling. - -For best results, scalable fonts should appear in the font path before the -bitmap fonts; this way, the server will prefer bitmap fonts to scalable fonts -when an exact match is possible, but will avoid scaling bitmap fonts when a -scalable font can be used. (The `:unscaled' hack, while still supported, -should no longer be necessary in X11R6.9.) - -You may check the font path of the running server by typing the command - - $ xset q - -2.2.4.1 Temporary modification of the font path - -The `xset' utility may be used to modify the font path for the current ses- -sion. The font path is set with the command xset fp; a new element is added -to the front with xset +fp, and added to the end with xset fp+. For example, - - $ xset +fp /usr/local/fonts/Type1 - $ xset fp+ /usr/local/fonts/bitmap - -Conversely, an element may be removed from the front of the font path with -`xset -fp', and removed from the end with `xset fp-'. You may reset the font -path to its default value with `xset fp default'. - -For more information, please consult the xset(1) manual page. - -2.2.4.2 Permanent modification of the font path - -The default font path (the one used just after server startup or after `xset -fp default') is specified in the X server's `xorg.conf' file. It is computed -by appending all the directories mentioned in the `FontPath' entries of the -`Files' section in the order in which they appear. - - FontPath "/usr/local/fonts/Type1" - ... - FontPath "/usr/local/fonts/bitmap" - -For more information, please consult the xorg.conf(5) manual page. - -2.2.5 Troubleshooting - -If you seem to be unable to use some of the fonts you have installed, the -first thing to check is that the `fonts.dir' files are correct and that they -are readable by the server (the X server usually runs as root, beware of NFS- -mounted font directories). If this doesn't help, it is quite possible that -you are trying to use a font in a format that is not supported by your -server. - -X11R6.9 supports the BDF, PCF, SNF, Type 1, TrueType, OpenType and CIDFont -font formats. However, not all X11R6.9 servers come with all the font back- -ends configured in. - -On most platforms, the X11R6.9 servers are modular: the font backends are -included in modules that are loaded at runtime. The modules to be loaded are -specified in the `xorg.conf' file using the `Load' directive: - - Load "type1" - -If you have trouble installing fonts in a specific format, you may want to -check the server's log file in order to see whether the relevant modules are -properly loaded. The list of font modules distributed with X11R6.9 is as -follows: - - o "bitmap": bitmap fonts (`*.bdf', `*.pcf' and `*.snf'); - - o "freetype": TrueType fonts (`*.ttf' and `*.ttc'), OpenType fonts - (`*.otf' and `*.otc') and Type 1 fonts (`*.pfa' and `*.pfb'); - - o "type1": alternate Type 1 backend (`*.pfa' and `*.pfb') and CIDFont - backend; - - o "xtt": alternate TrueType backend (`*.ttf' and `*.ttc'). - -Please note that the argument of the `Load' directive is case-sensitive. - -3. Fonts included with X11R6.9 - -3.1 Standard bitmap fonts - -The Sample Implementation of X11 (SI) comes with a large number of bitmap -fonts, including the `fixed' family, and bitmap versions of Courier, Times, -Helvetica and some members of the Lucida family. In the SI, these fonts are -provided in the ISO 8859-1 encoding (ISO Latin Western-European). - -In X11R6.9, a number of these fonts are provided in Unicode-encoded font -files instead. At build time, these fonts are split into font files encoded -according to legacy encodings, a process which allows us to provide the stan- -dard fonts in a number of regional encodings with no duplication of work. - -For example, the font file - - /usr/X11R6/lib/X11/fonts/misc/6x13.bdf - -with XLFD - - -misc-fixed-medium-r-semicondensed--13-120-75-75-c-60-iso10646-1 - -is a Unicode-encoded version of the standard `fixed' font with added support -for the Latin, Greek, Cyrillic, Georgian, Armenian, IPA and other scripts -plus numerous technical symbols. It contains over 2800 glyphs, covering all -characters of ISO 8859 parts 1-5, 7-10, 13-15, as well as all European IBM -and Microsoft code pages, KOI8, WGL4, and the repertoires of many other char- -acter sets. - -This font is used at build time for generating the font files - - 6x13-ISO8859-1.bdf - 6x13-ISO8859-2.bdf - ... - 6x13-ISO8859-15.bdf - 6x13-KOI8-R.bdf - -with respective XLFDs - - -misc-fixed-medium-r-normal--13-120-75-75-c-60-iso8859-1 - ... - -misc-fixed-medium-r-normal--13-120-75-75-c-60-iso8859-15 - -misc-fixed-medium-r-normal--13-120-75-75-c-60-koi8-r - -The standard short name `fixed' is normally an alias for - - -misc-fixed-medium-r-normal--13-120-75-75-c-60-iso8859-1 - -3.2 The ClearlyU Unicode font family - -The ClearlyU family of fonts provides a set of 12 pt, 100 dpi proportional -fonts with many of the glyphs needed for Unicode text. Together, the fonts -contain approximately 7500 glyphs. - -The main ClearlyU font has the XLFD - - -mutt-clearlyu-medium-r-normal--17-120-100-100-p-101-iso10646-1 - -and resides in the font file - - /usr/X11R6/lib/X11/fonts/misc/cu12.pcf.gz - -Additional ClearlyU fonts include - - -mutt-clearlyu alternate glyphs-medium-r-normal--17-120-100-100-p-91-iso10646-1 - -mutt-clearlyu pua-medium-r-normal--17-120-100-100-p-111-iso10646-1 - -mutt-clearlyu arabic extra-medium-r-normal--17-120-100-100-p-103-fontspecific-0 - -mutt-clearlyu ligature-medium-r-normal--17-120-100-100-p-141-fontspecific-0 - -The Alternate Glyphs font contains additional glyph shapes that are needed -for certain languages. A second alternate glyph font will be provided later -for cases where a character has more than one commonly used alternate shape -(e.g. the Urdu heh). - -The PUA font contains extra glyphs that are useful for certain rendering pur- -poses. - -The Arabic Extra font contains the glyphs necessary for characters that don't -have all of their possible shapes encoded in ISO 10646. The glyphs are -roughly ordered according to the order of the characters in the ISO 10646 -standard. - -The Ligature font contains ligatures for various scripts that may be useful -for improved presentation of text. - -3.3 Standard scalable fonts - -X11R6.9 includes all the scalable fonts distributed with X11R6. - -3.3.1 Standard Type 1 fonts - -The IBM Courier set of fonts cover ISO 8859-1 and ISO 8859-2 as well as Adobe -Standard Encoding. These fonts have XLFD - - -adobe-courier-medium-*-*--0-0-0-0-m-0-*-* - -and reside in the font files - - /usr/X11R6/lib/X11/fonts/Type1/cour*.pfa - -The Adobe Utopia set of fonts only cover ISO 8859-1 as well as Adobe Standard -Encoding. These fonts have XLFD - - -adobe-utopia-*-*-normal--0-0-0-0-p-0-iso8859-1 - -and reside in the font files - - /usr/X11R6/lib/X11/fonts/Type1/UT*.pfa - -Finally, X11R6.9 also comes with Type 1 versions of Bitstream Courier and -Charter. These fonts have XLFD - - -bitstream-courier-*-*-normal--0-0-0-0-m-0-iso8859-1 - -bitstream-charter-*-*-normal--0-0-0-0-p-0-iso8859-1 - -and reside in the font files - - /usr/X11R6/lib/X11/fonts/Type1/c*bt_.pfb - -3.4 The Bigelow & Holmes Luxi family - -X11R6.9 includes the Luxi family of scalable fonts, in both TrueType and -Type 1 format. This family consists of the fonts Luxi Serif, with XLFD - - -b&h-luxi serif-medium-*-normal--*-*-*-*-p-*-*-* - -Luxi Sans, with XLFD - - -b&h-luxi sans-medium-*-normal--*-*-*-*-p-*-*-* - -and Luxi Mono, with XLFD - - -b&h-luxi mono-medium-*-normal--*-*-*-*-m-*-*-* - -Each of these fonts comes Roman, oblique, bold and bold oblique variants The -TrueType version have glyphs covering the basic ASCII Unicode range, the -Latin 1 range, as well as the Extended Latin range and some additional punc- -tuation characters. In particular, these fonts include all the glyphs needed -for ISO 8859 parts 1, 2, 3, 4, 9, 13 and 15, as well as all the glyphs in the -Adobe Standard encoding and the Windows 3.1 character set. - -The glyph coverage of the Type 1 versions is somewhat reduced, and only cov- -ers ISO 8859 parts 1, 2 and 15 as well as the Adobe Standard encoding. - -The Luxi fonts are original designs by Kris Holmes and Charles Bigelow. Luxi -fonts include seriffed, sans serif, and monospaced styles, in roman and -oblique, and normal and bold weights. The fonts share stem weight, x-height, -capital height, ascent and descent, for graphical harmony. - -The character width metrics of Luxi roman and bold fonts match those of core -fonts bundled with popular operating and window systems. - -The license terms for the Luxi fonts are included in the file `COPYRIGHT.BH', -as well as in the License document. - -Charles Bigelow and Kris Holmes from Bigelow and Holmes Inc. developed the -Luxi typeface designs in Ikarus digital format. - -URW++ Design and Development GmbH converted the Ikarus format fonts to True- -Type and Type1 font programs and implemented the grid-fitting "hints" and -kerning tables in the Luxi fonts. - -For more information, please contact <design@bigelowandholmes.com> or -<info@urwpp.de>, or consult the URW++ web site <URL:http://www.urwpp.de>. - -An earlier version of the Luxi fonts was made available under the name -Lucidux. This name should no longer be used due to trademark uncertainties, -and all traces of the Lucidux name have been removed from X11R6.9. - -4. More about core fonts - -This section describes X11R6.9-specific enhancements to the core X11 fonts -system. - -4.1 Core fonts and internationalisation - -The scalable font backends (Type 1 and TrueType) can automatically re-encode -fonts to the encoding specified in the XLFD in `fonts.dir'. For example, a -`fonts.dir' file can contain entries for the Type 1 Courier font such as - - cour.pfa -adobe-courier-medium-r-normal--0-0-0-0-m-0-iso8859-1 - cour.pfa -adobe-courier-medium-r-normal--0-0-0-0-m-0-iso8859-2 - -which will lead to the font being recoded to ISO 8859-1 and ISO 8859-2 -respectively. - -4.1.1 The fontenc layer - -Two of the scalable backends (Type 1 and the FreeType TrueType backend) use a -common fontenc layer for font re-encoding. This allows these backends to -share their encoding data, and allows simple configuration of new locales -independently of font type. - -Please note: the X-TrueType (X-TT) backend is not included in X11R6.9. That -functionality has been merged into the FreeType backend.> - -In the fontenc layer, an encoding is defined by a name (such as iso8859-1), -possibly a number of aliases (alternate names), and an ordered collection of -mappings. A mapping defines the way the encoding can be mapped into one of -the target encodings known to fontenc; currently, these consist of Unicode, -Adobe glyph names, and arbitrary TrueType ``cmap''s. - -A number of encodings are hardwired into fontenc, and are therefore always -available; the hardcoded encodings cannot easily be redefined. These -include: - - o iso10646-1: Unicode; - - o iso8859-1: ISO Latin-1 (Western Europe); - - o iso8859-2: ISO Latin-2 (Eastern Europe); - - o iso8859-3: ISO Latin-3 (Southern Europe); - - o iso8859-4: ISO Latin-4 (Northern Europe); - - o iso8859-5: ISO Cyrillic; - - o iso8859-6: ISO Arabic; - - o iso8859-7: ISO Greek; - - o iso8859-8: ISO Hebrew; - - o iso8859-9: ISO Latin-5 (Turkish); - - o iso8859-10: ISO Latin-6 (Nordic); - - o iso8859-15: ISO Latin-9, or Latin-0 (Revised Western-European); - - o koi8-r: KOI8 Russian; - - o koi8-u: KOI8 Ukrainian (see RFC 2319); - - o koi8-ru: KOI8 Russian/Ukrainian; - - o koi8-uni: KOI8 ``Unified'' (Russian, Ukrainian, and Byelorussian); - - o koi8-e: KOI8 ``European,'' ISO-IR-111, or ECMA-Cyrillic; - - o microsoft-symbol and apple-roman: these are only likely to be useful - with TrueType symbol fonts. - -Additional encodings can be added by defining encoding files. When a font -encoding is requested that the fontenc layer doesn't know about, the backend -checks the directory in which the font file resides (not necessarily the -directory with fonts.dir!) for a file named `encodings.dir'. If found, this -file is scanned for the requested encoding, and the relevant encoding defini- -tion file is read in. The `mkfontdir' utility, when invoked with the `-e' -option followed by the name of a directory containing encoding files, can be -used to automatically build `encodings.dir' files. Please see the mkfont- -dir(1) manual page for more details. - -A number of encoding files for common encodings are included with X11R6.9. -Information on writing new encoding files can be found in Format of encodings -directory files (section 4.1.3, page 1) and Format of encoding files (section -4.1.4, page 1) later in this document. - -4.1.2 Backend-specific notes about fontenc - -4.1.2.1 The FreeType backend - -For TrueType and OpenType fonts, the FreeType backend scans the mappings in -order. Mappings with a target of PostScript are ignored; mappings with a -TrueType or Unicode target are checked against all the cmaps in the file. -The first applicable mapping is used. - -For Type 1 fonts, the FreeType backend first searches for a mapping with a -target of PostScript. If one is found, it is used. Otherwise, the backend -searches for a mapping with target Unicode, which is then composed with a -built-in table mapping codes to glyph names. Note that this table only cov- -ers part of the Unicode code points that have been assigned names by Adobe. - -Specifying an encoding value of adobe-fontspecific for a Type 1 font disables -the encoding mechanism. This is useful with symbol and incorrectly encoded -fonts (see Incorrectly encoded fonts (section 4.1.6, page 1) below). - -If a suitable mapping is not found, the FreeType backend defaults to -ISO 8859-1. - -4.1.2.2 Type 1 - -The Type 1 backend behaves similarly to the FreeType backend with Type 1 -fonts, except that it limits all encodings to 8-bit codes. - -4.1.3 Format of encoding directory files - -In order to use a font in an encoding that the font backend does not know -about, you need to have an `encodings.dir' file either in the same directory -as the font file used or in a system-wide location -(`/usr/X11R6/lib/X11/fonts/encodings/' by default). - -The `encodings.dir' file has a similar format to `fonts.dir'. Its first line -specifies the number of encodings, while every successive line has two -columns, the name of the encoding, and the name of the encoding file; this -can be relative to the current directory, or absolute. Every encoding name -should agree with the encoding name defined in the encoding file. For exam- -ple, - - 3 - mulearabic-0 /usr/X11R6/lib/X11/fonts/encodings/mulearabic-0.enc - mulearabic-1 /usr/X11R6/lib/X11/fonts/encodings/mulearabic-1.enc - mulearabic-2 /usr/X11R6/lib/X11/fonts/encodings/mulearabic-2.enc - -The name of an encoding must be specified in the encoding file's `STARTENCOD- -ING' or `ALIAS' line. It is not enough to create an `encodings.dir' entry. - -If your platform supports it (it probably does), encoding files may be com- -pressed or gzipped. - -The `encoding.dir' files are best maintained by the `mkfontdir' utility. -Please see the mkfontdir(1) manual page for more information. - -4.1.4 Format of encoding files - -The encoding files are ``free form,'' i.e. any string of whitespace is equiv- -alent to a single space. Keywords are parsed in a non-case-sensitive manner, -meaning that `size', `SIZE', and `SiZE' all parse as the same keyword; on the -other hand, case is significant in glyph names. - -Numbers can be written in decimal, as in `256', in hexadecimal, as in -`0x100', or in octal, as in `0400'. - -Comments are introduced by a hash sign `#'. A `#' may appear at any point in -a line, and all characters following the `#' are ignored, up to the end of -the line. - -The encoding file starts with the definition of the name of the encoding, and -possibly its alternate names (aliases): - - STARTENCODING mulearabic-0 - ALIAS arabic-0 - -The name of the encoding and its aliases should be suitable for use in an -XLFD font name, and therefore contain exactly one dash `-'. - -The encoding file may then optionally declare the size of the encoding. For -a linear encoding (such as ISO 8859-1), the SIZE line specifies the maximum -code plus one: - - SIZE 0x2B - -For a matrix encoding, it should specify two numbers. The first is the num- -ber of the last row plus one, the other, the highest column number plus one. -In the case of `jisx0208.1990-0' (JIS X 0208(1990), double-byte encoding, -high bit clear), it should be - - SIZE 0x75 0x80 - -In the case of a matrix encoding, a `FIRSTINDEX' line may be included to -specify the minimum glyph index in an encoding. The keyword `FIRSTINDEX' is -followed by two integers, the minimum row number followed by the minimum col- -umn number: - - FIRSTINDEX 0x20 0x20 - -In the case of a linear encoding, a `FIRSTINDEX' line is not very useful. If -for some reason however you chose to include on, it should be followed by a -single integer. - -Note that in most font backends inclusion of a `FIRSTINDEX' line has the side -effect of disabling default glyph generation, and this keyword should there- -fore be avoided unless absolutely necessary. - -Codes outside the region defined by the `SIZE' and `FIRSTINDEX' lines are -understood to be undefined. Encodings default to linear encoding with a size -of 256 (0x100). This means that you must declare the size of all 16 bit -encodings. - -What follows is one or more mapping sections. A mapping section starts with -a `STARTMAPPING' line stating the target of the mapping. The target may be -one of: - - o Unicode (ISO 10646): - - STARTMAPPING unicode - - o a given TrueType ``cmap'': - - STARTMAPPING cmap 3 1 - - o PostScript glyph names: - - STARTMAPPING postscript - -Every line in a mapping section maps one from the encoding being defined to -the target of the mapping. In mappings with a Unicode or TrueType mapping, -codes are mapped to codes: - - 0x21 0x0660 - 0x22 0x0661 - ... - -As an abbreviation, it is possible to map a contiguous range of codes in a -single line. A line consisting of three integers - - <it/start/ <it/end/ <it/target/ - -is an abbreviation for the range of lines - - start target - - start+1 target+1 - - ... - - end target+end-start - -For example, the line - - 0x2121 0x215F 0x8140 - -is an abbreviation for - - 0x2121 0x8140 - 0x2122 0x8141 - ... - 0x215F 0x817E - -Codes not listed are assumed to map through the identity (i.e. to the same -numerical value). In order to override this default mapping, you may specify -a range of codes to be undefined by using an `UNDEFINE' line: - - UNDEFINE 0x00 0x2A - -or, for a single code, - - UNDEFINE 0x1234 - -PostScript mappings are different. Every line in a PostScript mapping maps a -code to a glyph name - - 0x41 A - 0x42 B - ... - -and codes not explicitly listed are undefined. - -A mapping section ends with an ENDMAPPING line - - ENDMAPPING - -After all the mappings have been defined, the file ends with an ENDENCODING -line - - ENDENCODING - -In order to make future extensions to the format possible, lines starting -with an unknown keyword are silently ignored, as are mapping sections with an -unknown target. - -4.1.5 Using symbol fonts - -Type 1 symbol fonts should be installed using the adobe-fontspecific encod- -ing. - -In an ideal world, all TrueType symbol fonts would be installed using one of -the microsoft-symbol and apple-roman encodings. A number of symbol fonts, -however, are not marked as such; such fonts should be installed using -microsoft-cp1252, or, for older fonts, microsoft-win3.1. - -In order to guarantee consistent results (especially between Type 1 and True- -Type versions of the same font), it is possible to define a special encoding -for a given font. This has already been done for the ZapfDingbats font; see -the file `encodings/adobe-dingbats.enc'. - -4.1.6 Hints about using badly encoded fonts - -A number of text fonts are incorrectly encoded. Incorrect encoding is some- -times done by design, in order to make a font for an exotic script appear -like an ordinary Western text font on systems which are not easily extended -with new locale data. It is often the result of the font designer's laziness -or incompetence; for some reason, most people seem to find it easier to -invent idiosyncratic glyph names rather than follow the Adobe glyph list. - -There are two ways of dealing with such fonts: using them with the encoding -they were designed for, and creating an ad hoc encoding file. - -4.1.6.1 Using fonts with the designer's encoding - -In the case of Type 1 fonts, the font designer can specify a default encod- -ing; this encoding is requested by using the `adobe-fontspecific' encoding in -the XLFD name. Sometimes, the font designer omitted to specify a reasonable -default encoding, in which case you should experiment with `adobe-standard', -`iso8859-1', `microsoft-cp1252', and `microsoft-win3.1'. (The encoding -`microsoft-symbol' doesn't make sense for Type 1 fonts). - -TrueType fonts do not have a default encoding. However, most TrueType fonts -are designed with either Microsoft or Apple platforms in mind, so one of -`microsoft-symbol', `microsoft-cp1252', `microsoft-win3.1', or `apple-roman' -should yield reasonable results. - -4.1.6.2 Specifying an ad hoc encoding file - -It is always possible to define an encoding file to put the glyphs in a font -in any desired order. Again, see the `encodings/adobe-dingbats.enc' file to -see how this is done. - -4.1.6.3 Specifying font aliases - -By following the directions above, you will find yourself with a number of -fonts with unusual names --- with encodings such as `adobe-fontspecific', -`microsoft-win3.1' etc. In order to use these fonts with standard applica- -tions, it may be useful to remap them to their proper names. - -This is done by writing a `fonts.alias' file. The format of this file is very -simple: it consists of a series of lines each mapping an alias name to a font -name. A `fonts.alias' file might look as follows: - - "-ogonki-alamakota-medium-r-normal--0-0-0-0-p-0-iso8859-2" \ - "-ogonki-alamakota-medium-r-normal--0-0-0-0-p-0-adobe-fontspecific" - -(both XLFD names on a single line). The syntax of the `fonts.alias' file is -more precisely described in the mkfontdir(1) manual page. - -4.2 Additional notes about scalable core fonts - -The FreeType (libfreetype-xtt2) backend (module `freetype', formerly known as -xfsft) is able to deal with both TrueType and Type 1 fonts. This puts it in -conflict with the X-TT and Type 1 backends respectively. - -If both the FreeType and the Type 1 backends are loaded, the FreeType backend -will be used for Type 1 fonts. If both the FreeType and X-TT backends are -loaded, X-TT will be used for TrueType fonts. - -4.2.1 About the FreeType backend - -The FreeType (libfreetype-xtt2) backend (formerly xfsft) is a backend based -on version 2 of the FreeType library (see the FreeType web site -<URL:http://www.freetype.org/>) and has the X-TT functionalities for CJKV -support provided by the After X-TT Project (see the After X-TT Project web -site <URL:http://x-tt.sourceforge.jp/>). The FreeType module has support for -the ``fontenc'' style of internationalisation (see The fontenc layer (section -4.1.1, page 1)). This backend supports TrueType font files (`*.ttf'), Open- -Type font files (`*.otf'), TrueType Collections (`*.ttc'), OpenType Collec- -tions (`*.otc') and Type 1 font files (`*.pfa' and `*.pfb'). - -In order to access the faces in a TrueType Collection file, the face number -must be specified in the fonts.dir file before the filename, within a pair of -colons, or by setting the 'fn' TTCap option. For example, - - :1:mincho.ttc -misc-pmincho-medium-r-normal--0-0-0-0-p-0-jisx0208.1990-0 - -refers to face 1 in the `mincho.ttc' TrueType Collection file. - -The new FreeType backend supports the extended `fonts.dir' syntax introduced -by X-TrueType with a number of options, collectively known as `TTCap'. A -`TTCap' entry follows the general syntax - - option=value: - -and should be specified before the filename. The new FreeType almost per- -fectly supports TTCap options that are compatible with X-TT 1.4. The Auto- -matic Italic (`ai'), Double Strike (`ds') and Bounding box Width (`bw') -options are indispensable in CJKV. For example, - - mincho.ttc -misc-mincho-medium-r-normal--0-0-0-0-c-0-jisx0208.1990-0 - ds=y:mincho.ttc -misc-mincho-bold-r-normal--0-0-0-0-c-0-jisx0208.1990-0 - ai=0.2:mincho.ttc -misc-mincho-medium-i-normal--0-0-0-0-c-0-jisx0208.1990-0 - ds=y:ai=0.2:mincho.ttc -misc-mincho-bold-i-normal--0-0-0-0-c-0-jisx0208.1990-0 - bw=0.5:mincho.ttc -misc-mincho-medium-r-normal--0-0-0-0-c-0-jisx0201.1976-0 - bw=0.5:ds=y:mincho.ttc -misc-mincho-bold-r-normal--0-0-0-0-c-0-jisx0201.1976-0 - bw=0.5:ai=0.2:mincho.ttc -misc-mincho-medium-i-normal--0-0-0-0-c-0-jisx0201.1976-0 - bw=0.5:ds=y:ai=0.2:mincho.ttc -misc-mincho-bold-i-normal--0-0-0-0-c-0-jisx0201.1976-0 - -setup the complete combination of jisx0208 and jisx0201 using mincho.ttc -only. More information on the TTCap syntax is found on the After X-TT Pro- -ject page <URL:http://x-tt.sourceforge.jp/>. - -The FreeType backend uses the fontenc layer in order to support recoding of -fonts; this was described in The fontenc layer (section 4.1.1, page 1) and -especially FreeType-specific notes about fontenc (section 4.1.2.1, page 1) -earlier in this document. - -4.2.2 About the X-TrueType TrueType backend - -The `X-TrueType' backend is a backend based on version 1 of the FreeType -library. X-TrueType doesn't use the `fontenc' layer for managing font encod- -ings, but instead uses its own database of encodings. - -Since the functionalities for CJKV support introduced by X-TT have been -merged into the new FreeType backend, the X-TT backend will be removed from -X11R6.9's tree near the future. Therefore, the use of FreeType backend is -preferred over the X-TT backend. - -General information on X-TrueType may be found at the After X-TT Project page -<URL:http://x-tt.sourceforge.jp/>. - -4.2.3 Delayed glyph rasterisation - -When loading a proportional fonts which contain a huge number of glyphs, the -old FreeType delayed glyph rasterisation until the time at which the glyph -was first used. The new FreeType (libfreetype-xtt2) has an improved `very -lazy' metric calculation method to speed up the process when loading TrueType -or OpenType fonts. Although the X-TT module also has this method, the -"vl=y" TTCap option must be set if you want to use it. This is the default -method for FreeType when it loads multi-byte fonts. Even if you use a uni- -code font which has tens of thousands of glyphs, this delay will not be wor- -risome as long as you use the new FreeType backend -- its `very lazy' method -is super-fast. - -The maximum error of bitmap position using `very lazy' method is 1 pixel, and -is the same as that of a character-cell spacing. When the X-TT backend is -used with the `vl=y' option, a chipped bitmap is displayed with certain -fonts. However, the new FreeType backend has minimal problem with this, -since it corrects left- and right-side bearings using `italicAngle' in the -TrueType/OpenType post table, and does automatic correction of bitmap posi- -tions when rasterisation so that chipped bitmaps are not displayed. Never- -theless if you don't want to use the `very lazy' method when using multi- -bytes fonts, set `vl=n' in the TTCap option to disable it: - - vl=n:luxirr.ttf -b&h-Luxi Serif-medium-r-normal--0-0-0-0-p-0-iso10646-1 - -Of course, both backends also support an optimisation for character-cell -fonts (fonts with all glyph metrics equal, or terminal fonts). A font with -an XLFD specifying a character-cell spacing `c', as in - - -misc-mincho-medium-r-normal--0-0-0-0-c-0-jisx0208.1990-0 - -or - - fs=c:mincho.ttc -misc-mincho-medium-r-normal--0-0-0-0-p-0-jisx0208.1990-0 - -will not compute the metric for each glyph, but instead trust the font to be -a character-cell font. You are encouraged to make use of this optimisation -when useful, but be warned that not all monospaced fonts are character-cell -fonts. - -5. Appendix: background and terminology - -5.1 Characters and glyphs - -A computer text-processing system inputs keystrokes and outputs glyphs, small -pictures that are assembled on paper or on a computer screen. Keystrokes and -glyphs do not, in general, coincide: for example, if the system does generate -ligatures, then to the sequence of two keystrokes <f><i> will typically cor- -respond a single glyph. Similarly, if the system shapes Arabic glyphs in a -vaguely reasonable manner, then multiple different glyphs may correspond to a -single keystroke. - -The complex transformation rules from keystrokes to glyphs are usually fac- -tored into two simpler transformations, from keystrokes to characters and -from characters to glyphs. You may want to think of characters as the basic -unit of text that is stored e.g. in the buffer of your text editor. While -the definition of a character is intrinsically application-specific, a number -of standardised collections of characters have been defined. - -A coded character set is a set of characters together with a mapping from -integer codes --- known as codepoints --- to characters. Examples of coded -character sets include US-ASCII, ISO 8859-1, KOI8-R, and JIS X 0208(1990). - -A coded character set need not use 8 bit integers to index characters. Many -early systems used 6 bit character sets, while 16 bit (or more) character -sets are necessary for ideographic writing systems. - -5.2 Font files, fonts, and XLFD - -Traditionally, typographers speak about typefaces and founts. A typeface is -a particular style or design, such as Times Italic, while a fount is a -molten-lead incarnation of a given typeface at a given size. - -Digital fonts come in font files. A font file contains the information nec- -essary for generating glyphs of a given typeface, and applications using font -files may access glyph information in an arbitrary order. - -Digital fonts may consist of bitmap data, in which case they are said to be -bitmap fonts. They may also consist of a mathematical description of glyph -shapes, in which case they are said to be scalable fonts. Common formats for -scalable font files are Type 1 (sometimes incorrectly called ATM fonts or -PostScript fonts), TrueType and OpenType. - -The glyph data in a digital font needs to be indexed somehow. How this is -done depends on the font file format. In the case of Type 1 fonts, glyphs -are identified by glyph names. In the case of TrueType fonts, glyphs are -indexed by integers corresponding to one of a number of indexing schemes -(usually Unicode --- see below). - -The X11 core fonts system uses the data in a font file to generate font -instances, which are collections of glyphs at a given size indexed according -to a given encoding. - -X11 core font instances are usually specified using a notation known as the X -Logical Font Description (XLFD). An XLFD starts with a dash `-', and con- -sists of fourteen fields separated by dashes, for example: - - -adobe-courier-medium-r-normal--12-120-75-75-m-70-iso8859-1 - -Or particular interest are the last two fields `iso8859-1', which specify the -font instance's encoding. - -A scalable font is specified by an XLFD which contains zeroes instead of some -fields: - - -adobe-courier-medium-r-normal--0-0-0-0-m-0-iso8859-1 - -X11 font instances may also be specified by short name. Unlike an XLFD, a -short name has no structure and is simply a conventional name for a font -instance. Two short names are of particular interest, as the server will not -start if font instances with these names cannot be opened. These are -`fixed', which specifies the fallback font to use when the requested font -cannot be opened, and `cursor', which specifies the set of glyphs to be used -by the mouse pointer. - -Short names are usually implemented as aliases to XLFDs; the standard `fixed' -and `cursor' aliases are defined in - - /usr/X11R6/lib/X11/font/misc/fonts.alias - -5.3 Unicode - -Unicode (urlnam <URL:http://www.unicode.org>) is a coded character set with -the goal of uniquely identifying all characters for all scripts, current and -historical. While Unicode was explicitly not designed as a glyph encoding -scheme, it is often possible to use it as such. - -Unicode is an open character set, meaning that codepoint assignments may be -added to Unicode at any time (once specified, though, an assignment can never -be changed). For this reason, a Unicode font will be sparse, meaning that it -only defines glyphs for a subset of the character registry of Unicode. - -The Unicode standard is defined in parallel with the international standard -ISO 10646. Assignments in the two standards are always equivalent, and we -often use the terms Unicode and ISO 10646 interchangeably. - -When used in the X11 core fonts system, Unicode-encoded fonts should have the -last two fields of their XLFD set to `iso10646-1'. - -6. References - -X11R6.9 comes with extensive documentation in the form of manual pages and -typeset documents. Before installing fonts, you really should read the font- -config(3) and mkfontdir(1) manual pages; other manual pages of interest -include X(7), Xserver(1), xset(1), Xft(3), xlsfonts(1) and showfont(1). In -addition, you may want to read the X Logical Font Description document, by -Jim Flowers, which is provided in the file `xc/doc/xlfd.PS.Z'. - -The latest released version of the X11R6.9 documentation (including this doc- -ument and all manual pages) can be found from current X11R6.9 documentation -<URL:http://wiki.x.org/>. - -The comp.fonts FAQ <URL:http://www.netmeg.net/faq/computers/fonts/>, which is -unfortunately no longer being maintained, contains a wealth of information -about digital fonts. - -Xft and Fontconfig are described on Keith Packard's Fontconfig site -<URL:http://www.fontconfig.org>. - -The xfsft home page <URL:http://www.dcs.ed.ac.uk/home/jec/programs/xfsft/> -has been superseded by this document, and is now obsolete; you may however -still find some of the information that it contains useful. Joerg Pommnitz' -xfsft page <URL:http://www.joerg-pommnitz.de/TrueType/xfsft.html> is the -canonical source for the `ttmkfdir' utility, which is the ancestor of -mkfontscale. - -The author's software pages <URL:http://www.pps.jussieu.fr/~jch/software/> -might or might not contain related scribbles and development versions of -software. - -The documentation of X-TrueType is available from the After X-TT Project page -<URL:http://x-tt.sourceforge.jp/>. - -A number of East-Asian CIDFonts are available from O'Reilly's FTP site -<URL:ftp://ftp.oreilly.com/pub/examples/nutshell/cjkv/adobe/>. - -While the Unicode consortium site <URL:http://www.unicode.org> may be of -interest, you are more likely to find what you need in Markus Kuhn's UTF-8 -and Unicode FAQ <URL:http://www.cl.cam.ac.uk/~mgk25/unicode.html>. - -The IANA RFC documents, available from a number of sites throughout the -world, often provide interesting information about character set issues; see -for example RFC 373. - - -$XdotOrg$ |