Edit
kc3-lang/harfbuzz/src/hb-ot-shape-complex-indic.hh
David Corbett
- src/hb-ot-shape-complex-indic.hh
-
/* * 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 */