Graphite

from Wikipedia, the free encyclopedia

Graphite (also SILGraphite , formerly OpenGraphite ) is a project to create a Unicode- compatible so-called Smartfont format with the associated software system for processing, which is being developed by SIL International under the direction of Sharon Correll with the support of UNESCO .

The format is openly documented and its implementation is freely available as free software under the terms of the GNU Lesser General Public License (LGPL) and the Common Public License (CPL).

Graphite was developed for the representation of characters from minority languages ​​(→ flexibility or “smart” ness). Like AAT , unlike OpenType, characters that are not yet standardized in Unicode can be encoded temporarily via the so-called Private Use Area (U + E000 to U + F8FF) instead of as defined as letters (Lo = Letter, other) for example, treat them as diacritics .

technology

It is based on the TrueType format, which has been extended by three new tables with rules in the Graphite Description Language (GDL). In addition to the GDL, Graphite consists of a compiler for the GDL, which adds the additional rules to the TrueType files. There is also a rasterization engine for such Graphite fonts with a corresponding GDL interpreter. The engine can also be used in real-time applications and thus, for example, display editable text in a program window and react directly to replacement, insertion, removal or marking of text parts and update the display accordingly. In addition to the character strings to be displayed, it receives e.g. B. also the cursor position and provides not only the relative positioning of the characters to each other, but also the flow of text and line breaks. It can thus be used as a backend for word processing applications and has already been built into experimental versions of a Mozilla browser (SILA) and OpenOffice.org in this function . It supports bidirectional text (e.g. Arabic script), context-dependent shaping for characters and the generation of diacritical marks and ligatures from specified characters as components.

use

There is a simple text editor called Worldpad with support for Graphite. Frank Tang, the former head of internationalization at Netscape , is working on a graphite-enhanced Mozilla browser called SILA, of which trial versions are available. From version 3.2, OpenOffice also offers Graphite support. Before that, OpenOffice had supported around 110 languages. With the Graphite Engine, users can use the software for hundreds of other languages, which is particularly interesting for minority languages ​​that otherwise hardly receive any attention. The OpenOffice offshoot LibreOffice has contained the Graphite Engine since its first version (3.3) and from version 3.4 onwards it offers a completely rewritten Graphite Engine that is supposed to offer significant speed improvements and increased stability.

Charis SIL and Doulos SIL are implemented in this format along with a number of other character sets.

history

The project started in the mid-1990s. In 1998, the (Windows) software began to be written behind closed doors, which initially ran under the name WinRend , which was changed to its current name in 2000. The software system (as the initial name suggests) was originally written for Windows . After the first free publication (version 0.8), contact was made with the free software community via various mailing lists , and platform independence was sought for the program library. Work on SILA began and the results were published for the first time on October 11, 2002. Graphite development was moved to SourceForge , where version 0.9 was released on November 15, 2002. Under the direction of Daniel Glassey, who was primarily responsible for GNU / Linux support, Graphite was ported to Linux and made compatible with Pango font screening software . In the meantime it has also been ported to macOS .

The current version of the Graphite2 engine is 1.3.1 and that of the compiler is 5.0.2.

See also

  • XeTeX , a variant of the typesetting program TeX , with the developer of which we work and which supports the Graphite format.

Apple's Apple Type Services for Unicode Imaging ( ATSUI ) and Microsoft's Uniscribe are alternatives to Graphite's rendering engine for rendering smart fonts from the respective smart font systems of these companies (AAT and OpenType) and were implemented in their operating systems (Mac OS and Windows from Windows) 2000).

Web links

Individual evidence

  1. ↑ sil.org/sil/news/2003/unesco.htm ( Memento of the original from November 29, 2009 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / sil.org
  2. ↑ http://www.openoffice.org/dev_docs/features/3.2/rc1.html accessed on December 21, 2009
  3. ↑ OpenOffice now with Graphite software from SIL , accessed March 16, 2010.
  4. ↑ scripts.sil.org/cms/scripts/page.php?site_id=nrsi&item_id=GraphiteFonts
  5. ↑ www.techknowlogia.org/TKL_active_pages2/CurrentArticles/main.asp?ArticleID=349 ( Memento of the original from January 25, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.techknowlogia.org
  6. ↑ www.mozdev.org/projects/overview/sila/ ( Memento of the original from June 29, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.mozdev.org
  7. ↑ sf.net/project/shownotes.php?release_id=122337 ( Memento of the original from September 14, 2005 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / sourceforge.net
  8. ↑ www.linux.com/archive/feature/52884
  9. ↑ News