4. Fonts and Internationalisation

Details about the font support in this version of XFree86 can be found in the README.fonts document.

4.1. TrueType support

This version of XFree86 comes with two TrueType backends, known as `xfsft' (the "freetype" module) and `X-TrueType' (the "xtt" module). Both of these backends are based on the FreeType library.

4.2. CID font support

Support for CID-keyed fonts is included in this version of XFree86. The CID-keyed font format was designed by Adobe Systems for fonts with large character sets. The CID-keyed font support in XFree86 was donated by SGI. See the LICENSE document for a copy of the CID Font Code Public License.

4.3. Internationalisation of the scalable font backends

A new ``fontenc'' layer has been added to allow the scalable font backends to use a common method of font re-encoding. This re-encoding makes it possible to uses fonts in encodings other than their their native encoding. This layer is used by the Type1 and Speedo backends and the `xfsft' version of the TrueType backend. The `X-TrueType' version of the TrueType backend uses a different re-encoding method based on loadable encoding modules.

4.4. Large font optimisation

The glyph metrics array, which all the X clients using a particular font have access to, is now placed in shared memory, so as to reduce redundant memory consumption. For non-local clients, the glyph metrics array is transmitted in a compressed format.

4.5. Unicode/ISO 10646 support

What is included:

• All ``-misc-fixed-*'' BDF fonts are now available in the ISO10646-1 encoding and cover at least the 614 characters found in ISO 8859-{1-5,7-10,14,15}, CP1252, and MES-1. The non-bold fonts also cover all Windows Glyph List 4 (WGL4) characters, including those found in all 8-bit MS-DOS/Windows code pages. The 8-bit variants of the ``-misc-fixed-*'' BDF fonts (ISO8859-1, ISO8859-2, KOI8-R, etc.) have all been automatically generated from the new ISO10646-1 master fonts.
• Some ``-misc-fixed-*'' BDF ISO10646-1 fonts now cover a comprehensive Unicode repertoire of over 3000 characters including all Latin, Greek, Cyrillic, Armenian, Gregorian, Hebrew, IPA, and APL characters, plus numerous scientific, typographic, technical, and backwards-compatibility symbols. Some of these fonts also cover Arabic, Ethiopian, Thai, Han/Kanji, Hangul, full ISO 8859, and more. For the 6x13 font there is now a 12x13ja Kanji extension and for the 9x18 font there is a 18x18ja Kanji/Han/Hangul extension, which covers all ISO-2022-JP-2 (RFC 1554) characters. The 9x18 font can also be used to implement simple combining characters by accent overstriking. For more information, read Markus Kuhn's UTF-8 and Unicode FAQ.
• Mark Leisher's ClearlyU proportional font (similar to Computer Modern).
• ISO 10646/Unicode UTF-8 Level 1 support added to xterm (enabled with the -u8 option).
• Both the xfsft (the "freetype" module) and the X-TrueType (the "xtt" module) TrueType font backends support Unicode-encoded fonts.

Known problems:

• Xlib does not yet fully support UTF-8 as a locale, which means that xterm UTF-8 keyboard support is at the moment a temporary hack.
• Most ISO10646-1 fonts encode no characters above U+31FF. This avoids the inefficient allocation and transmission of a >700 kB large XFontStruct structure, which would happen if the (not very important) ligatures and symbols above U+f000 were present.
• ISO 10646 Level 2 combining characters are not yet supported by xterm (will be needed for instance for Thai and IPA).
• Switching between a half-width and full-width font pair (such as 9x18 and 18x18ja) is not yet supported by xterm (will be needed for CJK scripts).

4.6. Lucidux fonts from Bigelow and Holmes

XFree86 now includes the ``Lucidux'' family of professionally hinted Type 1 fonts. This family consists of the fonts ``Lucidux Serif'', ``Lucidux Sans'' and ``Lucidux Mono'' in Roman and oblique variants, and includes over 370 glyphs in each font covering among others the glyphs needed for ISO 8859-1, 2, 3, 4, 9 and 15. Bold variants will be included in a future release. The design and font outlines were donated by Charles Bigelow and Kris Holmes from Bigelow and Holmes Inc., and the hinting was donated by Berthold Horn and Blenda Horn from Y&Y, Inc. For more information, please contact [email protected] or [email protected] , or consult Y&Y's web site.