OpenType Layout

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OpenType Layout
Sun Tun Developer Myanmar NLP Research Centre
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OpenType Layout

• What is OpenType
• File Format
• Benefits of OpenType
• Layout Features
• Features for Myanmar Language

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What is OpenType

• Developed jointly by Microsoft and Adobe
• supported by Monotype Imagings compression
  technology
• OpenType provides a series of enhancements to the
  TrueType format
• The most significant of which allows PostScript
  font data to nest inside a TrueType software
  wrapper.

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The main goals of OpenType

• Broader multiplatform support
• To enable fonts to have large character sets.
• Improved Internet and PDF (Portable Document
  Format) publishing
• Better protection for fonts

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OpenType File Format

• sfnt table structure
• Extension of the current TrueType file format
• A single font file may contain
• TrueType outline data
• PostScript (CFF) outline data

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Benefits of OpenType

• Support for large character sets
• Multi-script character sets
• Unicode support
• Glyph alternates supported
• Advanced typography supported
• Better protection of font data
• Font embedding controls

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Layout Features

• Glyph substitution
• Glyph positioning
• Script and Language information

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Glyph Substitution

• Single glyph substitution
• One-to-many substitution
• Multiple glyph substitution
• Aesthetic alternatives
• Contextual glyph substitution

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Glyph Positioning

• Two-dimensional positioning
• Single glyph adjustment
• Adjustment of paired glyphs
• Cursive attachment
• Mark attachment
• Contextual positioning

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Script and Language Information

• Layout features encoded by
• Scripts
• Languages within scripts

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Features for Myanmar Language

• Language Forms
• Conjuncts and Typographical Forms
• Glyph Positioning

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Language Forms

• pre-based ligatures ltprefgt
• above-based ligatures ltabvfgt
• below-based ligatures ltblwfgt
• post-base ligatures ltpstfgt

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Example Below-base form
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Conjuncts and Typographical Forms

• Above-base substitutions ltabvsgt
• Below-base substitutions ltblwsgt
• Post-base substitutions ltpstsgt
• Pre-base substitutions ltpresgt

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Example Pre-base consonant conjunct
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Glyph Positioning

• Below-base marks ltblwmgt
• Above-base marks ltabvmgt

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Registered tags for Myanmar Language Script
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Registered Features
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Common Features
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Font Properties Viewer
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Resources

• OpenType Specification
• http//www.microsoft.com/typography/otspec
• Hidden Link Myanmar
• http//http//www.microsoft.com/typography/
• otfntdev/myanot/default.htm
• Myanmar Encoding Specification
• Site www.mcf.org.mm/unicode
• Contact myanmar-nlp_at_mail4u.com.mm
• MailingList http//groups.google.com/group/myanma
  runicode

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Thank you

• Questions?