index.rst

otlLib: Routines for working with OpenType Layout

The fontTools.otlLib library provides routines to help you create the subtables and other data structures you need when you are editing a font's GSUB and GPOS tables: substitution and positioning rules, anchors, lookups, coverage tables and so on.

High-level OpenType Layout Lookup Builders

fontTools.otlLib.builder

AlternateSubstBuilder

ChainContextPosBuilder

ChainContextSubstBuilder

LigatureSubstBuilder

MultipleSubstBuilder

CursivePosBuilder

MarkBasePosBuilder

MarkLigPosBuilder

MarkMarkPosBuilder

ReverseChainSingleSubstBuilder

SingleSubstBuilder

ClassPairPosSubtableBuilder

PairPosBuilder

SinglePosBuilder

Common OpenType Layout Data Structures

fontTools.otlLib.builder

buildCoverage

buildLookup

Low-level GSUB Table Lookup Builders

These functions deal with the "simple" lookup types. See above for classes to help build more complex lookups (contextual and chaining lookups).

fontTools.otlLib.builder

buildSingleSubstSubtable

buildMultipleSubstSubtable

buildAlternateSubstSubtable

buildLigatureSubstSubtable

GPOS Shared Table Builders

The functions help build the GPOS shared tables as defined in the OpenType spec: value records, anchors, mark arrays and mark record tables.

fontTools.otlLib.builder

buildValue

buildAnchor

buildMarkArray

buildDevice

buildBaseArray

buildComponentRecord

Low-level GPOS Table Lookup Builders

These functions deal with the "simple" lookup types. See above for classes to help build more complex lookups (contextual and chaining lookups).

fontTools.otlLib.builder

buildCursivePosSubtable

buildLigatureArray

buildMarkBasePos

buildMarkBasePosSubtable

buildMarkLigPos

buildMarkLigPosSubtable

buildPairPosClassesSubtable

buildPairPosGlyphs

buildPairPosGlyphsSubtable

buildSinglePos

buildSinglePosSubtable

GDEF Table Subtable Builders

These functions build subtables for elements of the GDEF table.

fontTools.otlLib.builder

buildAttachList

buildLigCaretList

buildMarkGlyphSetsDef

STAT Table Builder

fontTools.otlLib.builder

buildStatTable