diff options
Diffstat (limited to 'text/shape.h')
| -rw-r--r-- | text/shape.h | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/text/shape.h b/text/shape.h index 6e56819..9381754 100644 --- a/text/shape.h +++ b/text/shape.h @@ -31,7 +31,12 @@ * y_bearing, width, height; 0 when * no plan positions marks without * GPOS; x_bearing INT16_MIN: none), - * u32 0 + * u32 fallback_offset (Arabic fallback shaping, 0 when no + * plan falls back: u8 lookups, u8 + * feature[7] each is for (init, + * medi, fina, isol, rlig x3), u32 + * size, then a GSUB table of just + * those lookups) * Offsets are from the section's start. A plan (VEGA_PLAN_BYTES): * u32 script (ISO 15924 as a tag: 'Latn'), u8 direction, u8 native * direction (of its script; 0 when it has none), u8 shaper, u8 flags, @@ -67,18 +72,22 @@ enum { VEGA_MASK_RPHF = VEGA_MASK_SHAPER, VEGA_MASK_PREF, VEGA_MASK_BLWF, VEGA_M enum { VEGA_MASK_KHMER_PREF = VEGA_MASK_SHAPER, VEGA_MASK_KHMER_BLWF, VEGA_MASK_KHMER_ABVF, VEGA_MASK_KHMER_PSTF, VEGA_MASK_KHMER_CFAR }; /* Khmer */ enum { VEGA_MASK_USE_RPHF = VEGA_MASK_INIT + 1 }; /* USE: that, and Arabic's for its joining forms */ +enum { VEGA_MASK_ARABIC_RLIG = VEGA_MASK_INIT + 1 }; /* Arabic, for fallback shaping */ /* The stages a plan names: Indic's, whose features decide a consonant's * position by whether they would substitute it. */ enum { VEGA_STAGE_RPHF, VEGA_STAGE_PREF, VEGA_STAGE_BLWF, VEGA_STAGE_PSTF, VEGA_STAGE_VATU }; /* Shaper flags: Indic's font follows the old specification (deva, not * dev2); Thai's font has no Thai script of its own, so its marks take the - * font's private-use glyphs where it has them. */ -enum { VEGA_INDIC_OLD_SPEC = 1, VEGA_THAI_PUA = 2 }; + * font's private-use glyphs where it has them; Arabic's font lacks Arabic's + * forms, so lookups made from its presentation forms stand in; Arabic's + * font stretches (stch) what the stretching feature multiplied. */ +enum { VEGA_INDIC_OLD_SPEC = 1, VEGA_THAI_PUA = 2, VEGA_ARABIC_FALLBACK = 4, VEGA_ARABIC_STCH = 8 }; /* Step flags; pauses, which the shaper tells apart. */ enum { VEGA_STEP_AUTO_ZWNJ = 1, VEGA_STEP_AUTO_ZWJ = 2, VEGA_STEP_RANDOM = 4, VEGA_STEP_PER_SYLLABLE = 8 }; enum { VEGA_STEP_PAUSE = 0xFFFF }; enum { VEGA_PAUSE_SYLLABLES = 1, VEGA_PAUSE_INITIAL_REORDERING, VEGA_PAUSE_FINAL_REORDERING, VEGA_PAUSE_CLEAR_SYLLABLES, - VEGA_PAUSE_CLEAR_SUBSTITUTED, VEGA_PAUSE_RECORD_RPHF, VEGA_PAUSE_RECORD_PREF }; + VEGA_PAUSE_CLEAR_SUBSTITUTED, VEGA_PAUSE_RECORD_RPHF, VEGA_PAUSE_RECORD_PREF, VEGA_PAUSE_ARABIC_FALLBACK, + VEGA_PAUSE_RECORD_STCH }; typedef struct { const unsigned char *p; uint32_t size; } VegaTable; /* Which glyphs may be in a set, as three 64-bit patterns of glyph bits @@ -103,6 +112,10 @@ typedef struct { uint32_t cmap_count, plan_count; const unsigned char *cmap, *advances, *plans, *steps, *extents; VegaTable gdef, gsub, gpos, kern; + VegaTable fallback; /* Arabic fallback shaping's lookups, a GSUB table */ + uint32_t fallback_count; + uint8_t fallback_features[7]; /* what each is for: init, medi, fina, isol, rlig x3 (0..6) */ + VegaLookup *fallback_lookups; uint32_t glyph_classes, attach_classes, mark_sets; /* in GDEF; 0 when absent */ VegaLookup *lookups[2]; /* GSUB, GPOS */ uint32_t lookup_count[2]; |