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33 строки
1.5 KiB
Markdown
33 строки
1.5 KiB
Markdown
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# Graphite engine
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## What is Graphite?
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Graphite is a system that can be used to create “smart fonts” capable of displaying writing systems with various complex behaviors. A smart font contains not only letter shapes but also additional instructions indicating how to combine and position the letters in complex ways.
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Graphite was primarily developed to provide the flexibility needed for minority languages which often need to be written according to slightly different rules than well-known languages that use the same script.
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Examples of complex script behaviors Graphite can handle include:
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* contextual shaping
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* ligatures
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* reordering
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* split glyphs
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* bidirectionality
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* stacking diacritics
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* complex positioning
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* shape aware kerning
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* automatic diacritic collision avoidance
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See [examples of scripts with complex rendering](http://scripts.sil.org/CmplxRndExamples).
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## Graphite system overview
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The Graphite system consists of:
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* A rule-based programming language [Graphite Description Language](http://scripts.sil.org/cms/scripts/page.php?site_id=projects&item_id=graphite_devFont#gdl) (GDL) that can be used to describe the behavior of a writing system
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* A compiler for that language
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* A rendering engine that can serve as the layout component of a text-processing application
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Graphite renders TrueType fonts that have been extended by means of compiling a GDL program.
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Further technical information is available on the [Graphite technical overview](http://scripts.sil.org/cms/scripts/page.php?site_id=projects&item_id=graphite_techAbout) page.
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