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Diffstat (limited to 'thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh')
| -rw-r--r-- | thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh new file mode 100644 index 0000000000..41bd8bd6cc --- /dev/null +++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh @@ -0,0 +1,436 @@ +/* + * Copyright © 2012 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Behdad Esfahbod + */ + +#ifndef HB_OT_SHAPE_COMPLEX_INDIC_HH +#define HB_OT_SHAPE_COMPLEX_INDIC_HH + +#include "hb.hh" + +#include "hb-ot-shape-complex.hh" + + +/* buffer var allocations */ +#define indic_category() complex_var_u8_0() /* indic_category_t */ +#define indic_position() complex_var_u8_1() /* indic_position_t */ + + +#define INDIC_TABLE_ELEMENT_TYPE uint16_t + +/* Cateories used in the OpenType spec: + * https://docs.microsoft.com/en-us/typography/script-development/devanagari + */ +/* Note: This enum is duplicated in the -machine.rl source file. + * Not sure how to avoid duplication. */ +enum indic_category_t { + OT_X = 0, + OT_C = 1, + OT_V = 2, + OT_N = 3, + OT_H = 4, + OT_ZWNJ = 5, + OT_ZWJ = 6, + OT_M = 7, + OT_SM = 8, + /* OT_VD = 9, UNUSED; we use OT_A instead. */ + OT_A = 10, + OT_PLACEHOLDER = 11, + OT_DOTTEDCIRCLE = 12, + OT_RS = 13, /* Register Shifter, used in Khmer OT spec. */ + OT_Coeng = 14, /* Khmer-style Virama. */ + OT_Repha = 15, /* Atomically-encoded logical or visual repha. */ + OT_Ra = 16, + OT_CM = 17, /* Consonant-Medial. */ + OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */ + OT_CS = 19, + + /* The following are used by Khmer & Myanmar shapers. Defined + * here for them to share. */ + OT_VAbv = 26, + OT_VBlw = 27, + OT_VPre = 28, + OT_VPst = 29, +}; + +#define MEDIAL_FLAGS (FLAG (OT_CM)) + +/* Note: + * + * We treat Vowels and placeholders as if they were consonants. This is safe because Vowels + * cannot happen in a consonant syllable. The plus side however is, we can call the + * consonant syllable logic from the vowel syllable function and get it all right! */ +#define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_CS) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE)) +#define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ)) + + +/* Visual positions in a syllable from left to right. */ +enum indic_position_t { + POS_START = 0, + + POS_RA_TO_BECOME_REPH = 1, + POS_PRE_M = 2, + POS_PRE_C = 3, + + POS_BASE_C = 4, + POS_AFTER_MAIN = 5, + + POS_ABOVE_C = 6, + + POS_BEFORE_SUB = 7, + POS_BELOW_C = 8, + POS_AFTER_SUB = 9, + + POS_BEFORE_POST = 10, + POS_POST_C = 11, + POS_AFTER_POST = 12, + + POS_FINAL_C = 13, + POS_SMVD = 14, + + POS_END = 15 +}; + +/* Categories used in IndicSyllabicCategory.txt from UCD. */ +enum indic_syllabic_category_t { + INDIC_SYLLABIC_CATEGORY_OTHER = OT_X, + + INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_Symbol, + INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM, + INDIC_SYLLABIC_CATEGORY_BRAHMI_JOINING_NUMBER = OT_PLACEHOLDER, /* Don't care. */ + INDIC_SYLLABIC_CATEGORY_CANTILLATION_MARK = OT_A, + INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C, + INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C, + INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_CM, + INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C, + INDIC_SYLLABIC_CATEGORY_CONSONANT_KILLER = OT_M, /* U+17CD only. */ + INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_CM, + INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_PLACEHOLDER, + INDIC_SYLLABIC_CATEGORY_CONSONANT_PRECEDING_REPHA = OT_Repha, + INDIC_SYLLABIC_CATEGORY_CONSONANT_PREFIXED = OT_X, /* Don't care. */ + INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_CM, + INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA = OT_CM, + INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER = OT_CS, + INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK = OT_SM, /* https://github.com/harfbuzz/harfbuzz/issues/552 */ + INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER = OT_Coeng, + INDIC_SYLLABIC_CATEGORY_JOINER = OT_ZWJ, + INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X, + INDIC_SYLLABIC_CATEGORY_NON_JOINER = OT_ZWNJ, + INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N, + INDIC_SYLLABIC_CATEGORY_NUMBER = OT_PLACEHOLDER, + INDIC_SYLLABIC_CATEGORY_NUMBER_JOINER = OT_PLACEHOLDER, /* Don't care. */ + INDIC_SYLLABIC_CATEGORY_PURE_KILLER = OT_M, /* Is like a vowel matra. */ + INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_RS, + INDIC_SYLLABIC_CATEGORY_SYLLABLE_MODIFIER = OT_SM, + INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X, + INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_N, + INDIC_SYLLABIC_CATEGORY_VIRAMA = OT_H, + INDIC_SYLLABIC_CATEGORY_VISARGA = OT_SM, + INDIC_SYLLABIC_CATEGORY_VOWEL = OT_V, + INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT = OT_M, + INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT = OT_V +}; + +/* Categories used in IndicSMatraCategory.txt from UCD */ +enum indic_matra_category_t { + INDIC_MATRA_CATEGORY_NOT_APPLICABLE = POS_END, + + INDIC_MATRA_CATEGORY_LEFT = POS_PRE_C, + INDIC_MATRA_CATEGORY_TOP = POS_ABOVE_C, + INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW_C, + INDIC_MATRA_CATEGORY_RIGHT = POS_POST_C, + + /* These should resolve to the position of the last part of the split sequence. */ + INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT, + INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT, + INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM, + INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_LEFT = INDIC_MATRA_CATEGORY_BOTTOM, + INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT, + INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_TOP, + INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT, + INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT, + + INDIC_MATRA_CATEGORY_OVERSTRUCK = POS_AFTER_MAIN, + INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = POS_PRE_M +}; + +#define INDIC_COMBINE_CATEGORIES(S,M) \ + ( \ + ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \ + ( S | \ + ( \ + ( \ + S == INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL || \ + S == INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK || \ + S == INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER || \ + S == INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA || \ + S == INDIC_SYLLABIC_CATEGORY_VIRAMA || \ + S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT || \ + false \ + ? M : INDIC_MATRA_CATEGORY_NOT_APPLICABLE \ + ) << 8 \ + ) \ + ) \ + ) + +HB_INTERNAL INDIC_TABLE_ELEMENT_TYPE +hb_indic_get_categories (hb_codepoint_t u); + + +static inline bool +is_one_of (const hb_glyph_info_t &info, unsigned int flags) +{ + /* If it ligated, all bets are off. */ + if (_hb_glyph_info_ligated (&info)) return false; + return !!(FLAG_UNSAFE (info.indic_category()) & flags); +} + +static inline bool +is_joiner (const hb_glyph_info_t &info) +{ + return is_one_of (info, JOINER_FLAGS); +} + +static inline bool +is_consonant (const hb_glyph_info_t &info) +{ + return is_one_of (info, CONSONANT_FLAGS); +} + +static inline bool +is_halant (const hb_glyph_info_t &info) +{ + return is_one_of (info, FLAG (OT_H)); +} + +#define IN_HALF_BLOCK(u, Base) (((u) & ~0x7Fu) == (Base)) + +#define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900u)) +#define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980u)) +#define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00u)) +#define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80u)) +#define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00u)) +#define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80u)) +#define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00u)) +#define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80u)) +#define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00u)) +#define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80u)) + + +#define MATRA_POS_LEFT(u) POS_PRE_M +#define MATRA_POS_RIGHT(u) ( \ + IS_DEVA(u) ? POS_AFTER_SUB : \ + IS_BENG(u) ? POS_AFTER_POST : \ + IS_GURU(u) ? POS_AFTER_POST : \ + IS_GUJR(u) ? POS_AFTER_POST : \ + IS_ORYA(u) ? POS_AFTER_POST : \ + IS_TAML(u) ? POS_AFTER_POST : \ + IS_TELU(u) ? (u <= 0x0C42u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \ + IS_KNDA(u) ? (u < 0x0CC3u || u > 0xCD6u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \ + IS_MLYM(u) ? POS_AFTER_POST : \ + IS_SINH(u) ? POS_AFTER_SUB : \ + /*default*/ POS_AFTER_SUB \ + ) +#define MATRA_POS_TOP(u) ( /* BENG and MLYM don't have top matras. */ \ + IS_DEVA(u) ? POS_AFTER_SUB : \ + IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \ + IS_GUJR(u) ? POS_AFTER_SUB : \ + IS_ORYA(u) ? POS_AFTER_MAIN : \ + IS_TAML(u) ? POS_AFTER_SUB : \ + IS_TELU(u) ? POS_BEFORE_SUB : \ + IS_KNDA(u) ? POS_BEFORE_SUB : \ + IS_SINH(u) ? POS_AFTER_SUB : \ + /*default*/ POS_AFTER_SUB \ + ) +#define MATRA_POS_BOTTOM(u) ( \ + IS_DEVA(u) ? POS_AFTER_SUB : \ + IS_BENG(u) ? POS_AFTER_SUB : \ + IS_GURU(u) ? POS_AFTER_POST : \ + IS_GUJR(u) ? POS_AFTER_POST : \ + IS_ORYA(u) ? POS_AFTER_SUB : \ + IS_TAML(u) ? POS_AFTER_POST : \ + IS_TELU(u) ? POS_BEFORE_SUB : \ + IS_KNDA(u) ? POS_BEFORE_SUB : \ + IS_MLYM(u) ? POS_AFTER_POST : \ + IS_SINH(u) ? POS_AFTER_SUB : \ + /*default*/ POS_AFTER_SUB \ + ) + +static inline indic_position_t +matra_position_indic (hb_codepoint_t u, indic_position_t side) +{ + switch ((int) side) + { + case POS_PRE_C: return MATRA_POS_LEFT (u); + case POS_POST_C: return MATRA_POS_RIGHT (u); + case POS_ABOVE_C: return MATRA_POS_TOP (u); + case POS_BELOW_C: return MATRA_POS_BOTTOM (u); + } + return side; +} + +/* XXX + * This is a hack for now. We should move this data into the main Indic table. + * Or completely remove it and just check in the tables. + */ +static const hb_codepoint_t ra_chars[] = { + 0x0930u, /* Devanagari */ + 0x09B0u, /* Bengali */ + 0x09F0u, /* Bengali */ + 0x0A30u, /* Gurmukhi */ /* No Reph */ + 0x0AB0u, /* Gujarati */ + 0x0B30u, /* Oriya */ + 0x0BB0u, /* Tamil */ /* No Reph */ + 0x0C30u, /* Telugu */ /* Reph formed only with ZWJ */ + 0x0CB0u, /* Kannada */ + 0x0D30u, /* Malayalam */ /* No Reph, Logical Repha */ + + 0x0DBBu, /* Sinhala */ /* Reph formed only with ZWJ */ + + 0x179Au, /* Khmer */ +}; + +static inline bool +is_ra (hb_codepoint_t u) +{ + for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++) + if (u == ra_chars[i]) + return true; + return false; +} + +static inline void +set_indic_properties (hb_glyph_info_t &info) +{ + hb_codepoint_t u = info.codepoint; + unsigned int type = hb_indic_get_categories (u); + indic_category_t cat = (indic_category_t) (type & 0x7Fu); + indic_position_t pos = (indic_position_t) (type >> 8); + + + /* + * Re-assign category + */ + + /* The following act more like the Bindus. */ + if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x0953u, 0x0954u))) + cat = OT_SM; + /* The following act like consonants. */ + else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0x0A72u, 0x0A73u, + 0x1CF5u, 0x1CF6u))) + cat = OT_C; + /* TODO: The following should only be allowed after a Visarga. + * For now, just treat them like regular tone marks. */ + else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1CE2u, 0x1CE8u))) + cat = OT_A; + /* TODO: The following should only be allowed after some of + * the nasalization marks, maybe only for U+1CE9..U+1CF1. + * For now, just treat them like tone marks. */ + else if (unlikely (u == 0x1CEDu)) + cat = OT_A; + /* The following take marks in standalone clusters, similar to Avagraha. */ + else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0xA8F2u, 0xA8F7u, + 0x1CE9u, 0x1CECu, + 0x1CEEu, 0x1CF1u))) + { + cat = OT_Symbol; + static_assert (((int) INDIC_SYLLABIC_CATEGORY_AVAGRAHA == OT_Symbol), ""); + } + else if (unlikely (u == 0x0A51u)) + { + /* https://github.com/harfbuzz/harfbuzz/issues/524 */ + cat = OT_M; + pos = POS_BELOW_C; + } + + /* According to ScriptExtensions.txt, these Grantha marks may also be used in Tamil, + * so the Indic shaper needs to know their categories. */ + else if (unlikely (u == 0x11301u || u == 0x11303u)) cat = OT_SM; + else if (unlikely (u == 0x1133Bu || u == 0x1133Cu)) cat = OT_N; + + else if (unlikely (u == 0x0AFBu)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/552 */ + + else if (unlikely (u == 0x0980u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/issues/538 */ + else if (unlikely (u == 0x09FCu)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/1613 */ + else if (unlikely (u == 0x0C80u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/623 */ + else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x2010u, 0x2011u))) + cat = OT_PLACEHOLDER; + else if (unlikely (u == 0x25CCu)) cat = OT_DOTTEDCIRCLE; + + + /* + * Re-assign position. + */ + + if ((FLAG_UNSAFE (cat) & CONSONANT_FLAGS)) + { + pos = POS_BASE_C; + if (is_ra (u)) + cat = OT_Ra; + } + else if (cat == OT_M) + { + pos = matra_position_indic (u, pos); + } + else if ((FLAG_UNSAFE (cat) & (FLAG (OT_SM) /* | FLAG (OT_VD) */ | FLAG (OT_A) | FLAG (OT_Symbol)))) + { + pos = POS_SMVD; + } + + if (unlikely (u == 0x0B01u)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */ + + + + info.indic_category() = cat; + info.indic_position() = pos; +} + +struct hb_indic_would_substitute_feature_t +{ + void init (const hb_ot_map_t *map, hb_tag_t feature_tag, bool zero_context_) + { + zero_context = zero_context_; + map->get_stage_lookups (0/*GSUB*/, + map->get_feature_stage (0/*GSUB*/, feature_tag), + &lookups, &count); + } + + bool would_substitute (const hb_codepoint_t *glyphs, + unsigned int glyphs_count, + hb_face_t *face) const + { + for (unsigned int i = 0; i < count; i++) + if (hb_ot_layout_lookup_would_substitute (face, lookups[i].index, glyphs, glyphs_count, zero_context)) + return true; + return false; + } + + private: + const hb_ot_map_t::lookup_map_t *lookups; + unsigned int count; + bool zero_context; +}; + + +#endif /* HB_OT_SHAPE_COMPLEX_INDIC_HH */ |