David Saltzman 8f286c86ef Add support for kerning from 'GPOS' tables. ... This commit adds support for kerning from 'GPOS' tables, while maintaining support for basic 'kern' tables. `FT_HAS_KERNING` will be true for a font with either available and `FT_Get_Kerning` will still use the basic 'kern' table data if avilable, otherwise check the GPOS 'kern' feature. This feature is disabled by default; it can be enabled with the `TT_CONFIG_OPTION_GPOS_KERNING` flag. Only basic kerning (pair positioning with just an x advance) is supported from the GPOS layout features; support for that was added to make the existing `FT_Get_Kerning` API more consistently functional. FreeType does not intend to extend itself to further GPOS functionality though; a higher-level library like HarfBuzz can be used instead for that. * include/freetype/config/ftoption.h, include/devel/ftoption.h (TT_CONFIG_OPTION_GPOS_KERNING): New configuration option. * include/freetype/internal/fttrace.h: Add `ttgpos` trace handler. * include/freetype/internal/sfnt.h (SFNT_Interface): Add `load_gpos` and `get_gpos_kerning` fields. (FT_DEFINE_SFNT_INTERFACE): Updated. * include/freetype/internal/tttypes.h: Include `fttypes.h`. (TT_FaceRec) [TT_CONFIG_OPTION_GPOS_KERNING]: Add `gpos_table` and `gpos_kerning_available` fields. * src/sfnt/ttgpos.c, src/sfnt/ttgpos.h: New files. * src/sfnt/sfdriver.c [TT_CONFIG_OPTION_GPOS_KERNING]: Include `ttgpos.h`. (sfnt_interface): Updated. * src/sfnt/sfnt.c: Include `ttgpos.c`. * src/sfnt/sfobjs.c [TT_CONFIG_OPTION_GPOS_KERNING]: Include `ttgpos.h`. (sfnt_load_face) [TT_CONFIG_OPTION_GPOS_KERNING]: Load and free GPOS kerning data; check GPOS kerning availability. * src/truetype/ttdriver.c (tt_get_kerning): Use GPOS kerning if there's no 'kern' table.		2024-01-27 10:55:04 +01:00
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ft2build.h	Update all copyright notices.	2023-01-17 09:18:25 +01:00
ftoption.h	Add support for kerning from 'GPOS' tables.	2024-01-27 10:55:04 +01:00