| /* |
| * Copyright © 2011,2012 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 |
| */ |
| |
| #include "hb.hh" |
| |
| #ifndef HB_NO_OT_SHAPE |
| |
| #include "hb-ot-shaper-indic.hh" |
| #include "hb-ot-shaper-indic-machine.hh" |
| #include "hb-ot-shaper-vowel-constraints.hh" |
| #include "hb-ot-layout.hh" |
| |
| |
| /* |
| * Indic shaper. |
| */ |
| |
| |
| 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); |
| |
| info.indic_category() = (indic_category_t) (type & 0xFFu); |
| info.indic_position() = (indic_position_t) (type >> 8); |
| } |
| |
| |
| 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); |
| } |
| |
| /* 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! |
| * |
| * Keep in sync with consonant_categories in the generator. */ |
| #define CONSONANT_FLAGS_INDIC (FLAG (I_Cat(C)) | FLAG (I_Cat(CS)) | FLAG (I_Cat(Ra)) | FLAG (I_Cat(CM)) | FLAG (I_Cat(V)) | FLAG (I_Cat(PLACEHOLDER)) | FLAG (I_Cat(DOTTEDCIRCLE))) |
| |
| static inline bool |
| is_consonant (const hb_glyph_info_t &info) |
| { |
| return is_one_of (info, CONSONANT_FLAGS_INDIC); |
| } |
| |
| #define JOINER_FLAGS (FLAG (I_Cat(ZWJ)) | FLAG (I_Cat(ZWNJ))) |
| |
| static inline bool |
| is_joiner (const hb_glyph_info_t &info) |
| { |
| return is_one_of (info, JOINER_FLAGS); |
| } |
| |
| static inline bool |
| is_halant (const hb_glyph_info_t &info) |
| { |
| return is_one_of (info, FLAG (I_Cat(H))); |
| } |
| |
| 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_; |
| lookups = map->get_stage_lookups (0/*GSUB*/, |
| map->get_feature_stage (0/*GSUB*/, feature_tag)); |
| } |
| |
| bool would_substitute (const hb_codepoint_t *glyphs, |
| unsigned int glyphs_count, |
| hb_face_t *face) const |
| { |
| for (const auto &lookup : lookups) |
| if (hb_ot_layout_lookup_would_substitute (face, lookup.index, glyphs, glyphs_count, zero_context)) |
| return true; |
| return false; |
| } |
| |
| private: |
| hb_array_t<const hb_ot_map_t::lookup_map_t> lookups; |
| bool zero_context; |
| }; |
| |
| |
| /* |
| * Indic configurations. Note that we do not want to keep every single script-specific |
| * behavior in these tables necessarily. This should mainly be used for per-script |
| * properties that are cheaper keeping here, than in the code. Ie. if, say, one and |
| * only one script has an exception, that one script can be if'ed directly in the code, |
| * instead of adding a new flag in these structs. |
| */ |
| |
| enum reph_position_t { |
| REPH_POS_AFTER_MAIN = POS_AFTER_MAIN, |
| REPH_POS_BEFORE_SUB = POS_BEFORE_SUB, |
| REPH_POS_AFTER_SUB = POS_AFTER_SUB, |
| REPH_POS_BEFORE_POST = POS_BEFORE_POST, |
| REPH_POS_AFTER_POST = POS_AFTER_POST |
| }; |
| enum reph_mode_t { |
| REPH_MODE_IMPLICIT, /* Reph formed out of initial Ra,H sequence. */ |
| REPH_MODE_EXPLICIT, /* Reph formed out of initial Ra,H,ZWJ sequence. */ |
| REPH_MODE_LOG_REPHA /* Encoded Repha character, needs reordering. */ |
| }; |
| enum blwf_mode_t { |
| BLWF_MODE_PRE_AND_POST, /* Below-forms feature applied to pre-base and post-base. */ |
| BLWF_MODE_POST_ONLY /* Below-forms feature applied to post-base only. */ |
| }; |
| struct indic_config_t |
| { |
| hb_script_t script; |
| bool has_old_spec; |
| hb_codepoint_t virama; |
| reph_position_t reph_pos; |
| reph_mode_t reph_mode; |
| blwf_mode_t blwf_mode; |
| }; |
| |
| static const indic_config_t indic_configs[] = |
| { |
| /* Default. Should be first. */ |
| {HB_SCRIPT_INVALID, false, 0,REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, |
| {HB_SCRIPT_DEVANAGARI,true, 0x094Du,REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, |
| {HB_SCRIPT_BENGALI, true, 0x09CDu,REPH_POS_AFTER_SUB, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, |
| {HB_SCRIPT_GURMUKHI, true, 0x0A4Du,REPH_POS_BEFORE_SUB, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, |
| {HB_SCRIPT_GUJARATI, true, 0x0ACDu,REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, |
| {HB_SCRIPT_ORIYA, true, 0x0B4Du,REPH_POS_AFTER_MAIN, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, |
| {HB_SCRIPT_TAMIL, true, 0x0BCDu,REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, |
| {HB_SCRIPT_TELUGU, true, 0x0C4Du,REPH_POS_AFTER_POST, REPH_MODE_EXPLICIT, BLWF_MODE_POST_ONLY}, |
| {HB_SCRIPT_KANNADA, true, 0x0CCDu,REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT, BLWF_MODE_POST_ONLY}, |
| {HB_SCRIPT_MALAYALAM, true, 0x0D4Du,REPH_POS_AFTER_MAIN, REPH_MODE_LOG_REPHA,BLWF_MODE_PRE_AND_POST}, |
| }; |
| |
| |
| static const hb_ot_map_feature_t |
| indic_features[] = |
| { |
| /* |
| * Basic features. |
| * These features are applied in order, one at a time, after initial_reordering, |
| * constrained to the syllable. |
| */ |
| {HB_TAG('n','u','k','t'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('a','k','h','n'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('r','p','h','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('r','k','r','f'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('p','r','e','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('b','l','w','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('a','b','v','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('h','a','l','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('p','s','t','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('v','a','t','u'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('c','j','c','t'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| /* |
| * Other features. |
| * These features are applied all at once, after final_reordering, constrained |
| * to the syllable. |
| * Default Bengali font in Windows for example has intermixed |
| * lookups for init,pres,abvs,blws features. |
| */ |
| {HB_TAG('i','n','i','t'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('p','r','e','s'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('a','b','v','s'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('b','l','w','s'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('p','s','t','s'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('h','a','l','n'), F_GLOBAL_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| }; |
| |
| /* |
| * Must be in the same order as the indic_features array. |
| */ |
| enum { |
| _INDIC_NUKT, |
| _INDIC_AKHN, |
| INDIC_RPHF, |
| _INDIC_RKRF, |
| INDIC_PREF, |
| INDIC_BLWF, |
| INDIC_ABVF, |
| INDIC_HALF, |
| INDIC_PSTF, |
| _INDIC_VATU, |
| _INDIC_CJCT, |
| |
| INDIC_INIT, |
| _INDIC_PRES, |
| _INDIC_ABVS, |
| _INDIC_BLWS, |
| _INDIC_PSTS, |
| _INDIC_HALN, |
| |
| INDIC_NUM_FEATURES, |
| INDIC_BASIC_FEATURES = INDIC_INIT, /* Don't forget to update this! */ |
| }; |
| |
| static void |
| setup_syllables_indic (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer); |
| static void |
| initial_reordering_indic (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer); |
| static void |
| final_reordering_indic (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer); |
| |
| static void |
| collect_features_indic (hb_ot_shape_planner_t *plan) |
| { |
| hb_ot_map_builder_t *map = &plan->map; |
| |
| /* Do this before any lookups have been applied. */ |
| map->add_gsub_pause (setup_syllables_indic); |
| |
| map->enable_feature (HB_TAG('l','o','c','l'), F_PER_SYLLABLE); |
| /* The Indic specs do not require ccmp, but we apply it here since if |
| * there is a use of it, it's typically at the beginning. */ |
| map->enable_feature (HB_TAG('c','c','m','p'), F_PER_SYLLABLE); |
| |
| |
| unsigned int i = 0; |
| map->add_gsub_pause (initial_reordering_indic); |
| |
| for (; i < INDIC_BASIC_FEATURES; i++) { |
| map->add_feature (indic_features[i]); |
| map->add_gsub_pause (nullptr); |
| } |
| |
| map->add_gsub_pause (final_reordering_indic); |
| |
| for (; i < INDIC_NUM_FEATURES; i++) |
| map->add_feature (indic_features[i]); |
| } |
| |
| static void |
| override_features_indic (hb_ot_shape_planner_t *plan) |
| { |
| plan->map.disable_feature (HB_TAG('l','i','g','a')); |
| plan->map.add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var |
| } |
| |
| |
| struct indic_shape_plan_t |
| { |
| bool load_virama_glyph (hb_font_t *font, hb_codepoint_t *pglyph) const |
| { |
| hb_codepoint_t glyph = virama_glyph.get_relaxed (); |
| if (unlikely (glyph == (hb_codepoint_t) -1)) |
| { |
| if (!config->virama || !font->get_nominal_glyph (config->virama, &glyph)) |
| glyph = 0; |
| /* Technically speaking, the spec says we should apply 'locl' to virama too. |
| * Maybe one day... */ |
| |
| /* Our get_nominal_glyph() function needs a font, so we can't get the virama glyph |
| * during shape planning... Instead, overwrite it here. */ |
| virama_glyph.set_relaxed ((int) glyph); |
| } |
| |
| *pglyph = glyph; |
| return glyph != 0; |
| } |
| |
| const indic_config_t *config; |
| |
| bool is_old_spec; |
| #ifndef HB_NO_UNISCRIBE_BUG_COMPATIBLE |
| bool uniscribe_bug_compatible; |
| #else |
| static constexpr bool uniscribe_bug_compatible = false; |
| #endif |
| mutable hb_atomic_int_t virama_glyph; |
| |
| hb_indic_would_substitute_feature_t rphf; |
| hb_indic_would_substitute_feature_t pref; |
| hb_indic_would_substitute_feature_t blwf; |
| hb_indic_would_substitute_feature_t pstf; |
| hb_indic_would_substitute_feature_t vatu; |
| |
| hb_mask_t mask_array[INDIC_NUM_FEATURES]; |
| }; |
| |
| static void * |
| data_create_indic (const hb_ot_shape_plan_t *plan) |
| { |
| indic_shape_plan_t *indic_plan = (indic_shape_plan_t *) hb_calloc (1, sizeof (indic_shape_plan_t)); |
| if (unlikely (!indic_plan)) |
| return nullptr; |
| |
| indic_plan->config = &indic_configs[0]; |
| for (unsigned int i = 1; i < ARRAY_LENGTH (indic_configs); i++) |
| if (plan->props.script == indic_configs[i].script) { |
| indic_plan->config = &indic_configs[i]; |
| break; |
| } |
| |
| indic_plan->is_old_spec = indic_plan->config->has_old_spec && ((plan->map.chosen_script[0] & 0x000000FFu) != '2'); |
| #ifndef HB_NO_UNISCRIBE_BUG_COMPATIBLE |
| indic_plan->uniscribe_bug_compatible = hb_options ().uniscribe_bug_compatible; |
| #endif |
| indic_plan->virama_glyph.set_relaxed (-1); |
| |
| /* Use zero-context would_substitute() matching for new-spec of the main |
| * Indic scripts, and scripts with one spec only, but not for old-specs. |
| * The new-spec for all dual-spec scripts says zero-context matching happens. |
| * |
| * However, testing with Malayalam shows that old and new spec both allow |
| * context. Testing with Bengali new-spec however shows that it doesn't. |
| * So, the heuristic here is the way it is. It should *only* be changed, |
| * as we discover more cases of what Windows does. DON'T TOUCH OTHERWISE. |
| */ |
| bool zero_context = !indic_plan->is_old_spec && plan->props.script != HB_SCRIPT_MALAYALAM; |
| indic_plan->rphf.init (&plan->map, HB_TAG('r','p','h','f'), zero_context); |
| indic_plan->pref.init (&plan->map, HB_TAG('p','r','e','f'), zero_context); |
| indic_plan->blwf.init (&plan->map, HB_TAG('b','l','w','f'), zero_context); |
| indic_plan->pstf.init (&plan->map, HB_TAG('p','s','t','f'), zero_context); |
| indic_plan->vatu.init (&plan->map, HB_TAG('v','a','t','u'), zero_context); |
| |
| for (unsigned int i = 0; i < ARRAY_LENGTH (indic_plan->mask_array); i++) |
| indic_plan->mask_array[i] = (indic_features[i].flags & F_GLOBAL) ? |
| 0 : plan->map.get_1_mask (indic_features[i].tag); |
| |
| return indic_plan; |
| } |
| |
| static void |
| data_destroy_indic (void *data) |
| { |
| hb_free (data); |
| } |
| |
| static indic_position_t |
| consonant_position_from_face (const indic_shape_plan_t *indic_plan, |
| const hb_codepoint_t consonant, |
| const hb_codepoint_t virama, |
| hb_face_t *face) |
| { |
| /* For old-spec, the order of glyphs is Consonant,Virama, |
| * whereas for new-spec, it's Virama,Consonant. However, |
| * some broken fonts (like Free Sans) simply copied lookups |
| * from old-spec to new-spec without modification. |
| * And oddly enough, Uniscribe seems to respect those lookups. |
| * Eg. in the sequence U+0924,U+094D,U+0930, Uniscribe finds |
| * base at 0. The font however, only has lookups matching |
| * 930,94D in 'blwf', not the expected 94D,930 (with new-spec |
| * table). As such, we simply match both sequences. Seems |
| * to work. |
| * |
| * Vatu is done as well, for: |
| * https://github.com/harfbuzz/harfbuzz/issues/1587 |
| */ |
| hb_codepoint_t glyphs[3] = {virama, consonant, virama}; |
| if (indic_plan->blwf.would_substitute (glyphs , 2, face) || |
| indic_plan->blwf.would_substitute (glyphs+1, 2, face) || |
| indic_plan->vatu.would_substitute (glyphs , 2, face) || |
| indic_plan->vatu.would_substitute (glyphs+1, 2, face)) |
| return POS_BELOW_C; |
| if (indic_plan->pstf.would_substitute (glyphs , 2, face) || |
| indic_plan->pstf.would_substitute (glyphs+1, 2, face)) |
| return POS_POST_C; |
| if (indic_plan->pref.would_substitute (glyphs , 2, face) || |
| indic_plan->pref.would_substitute (glyphs+1, 2, face)) |
| return POS_POST_C; |
| return POS_BASE_C; |
| } |
| |
| static void |
| setup_masks_indic (const hb_ot_shape_plan_t *plan HB_UNUSED, |
| hb_buffer_t *buffer, |
| hb_font_t *font HB_UNUSED) |
| { |
| HB_BUFFER_ALLOCATE_VAR (buffer, indic_category); |
| HB_BUFFER_ALLOCATE_VAR (buffer, indic_position); |
| |
| /* We cannot setup masks here. We save information about characters |
| * and setup masks later on in a pause-callback. */ |
| |
| unsigned int count = buffer->len; |
| hb_glyph_info_t *info = buffer->info; |
| for (unsigned int i = 0; i < count; i++) |
| set_indic_properties (info[i]); |
| } |
| |
| static void |
| setup_syllables_indic (const hb_ot_shape_plan_t *plan HB_UNUSED, |
| hb_font_t *font HB_UNUSED, |
| hb_buffer_t *buffer) |
| { |
| HB_BUFFER_ALLOCATE_VAR (buffer, syllable); |
| find_syllables_indic (buffer); |
| foreach_syllable (buffer, start, end) |
| buffer->unsafe_to_break (start, end); |
| } |
| |
| static int |
| compare_indic_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb) |
| { |
| int a = pa->indic_position(); |
| int b = pb->indic_position(); |
| |
| return (int) a - (int) b; |
| } |
| |
| |
| |
| static void |
| update_consonant_positions_indic (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer) |
| { |
| const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data; |
| |
| hb_codepoint_t virama; |
| if (indic_plan->load_virama_glyph (font, &virama)) |
| { |
| hb_face_t *face = font->face; |
| unsigned int count = buffer->len; |
| hb_glyph_info_t *info = buffer->info; |
| for (unsigned int i = 0; i < count; i++) |
| if (info[i].indic_position() == POS_BASE_C) |
| { |
| hb_codepoint_t consonant = info[i].codepoint; |
| info[i].indic_position() = consonant_position_from_face (indic_plan, consonant, virama, face); |
| } |
| } |
| } |
| |
| |
| /* Rules from: |
| * https://docs.microsqoft.com/en-us/typography/script-development/devanagari */ |
| |
| static void |
| initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan, |
| hb_face_t *face, |
| hb_buffer_t *buffer, |
| unsigned int start, unsigned int end) |
| { |
| const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data; |
| hb_glyph_info_t *info = buffer->info; |
| |
| /* https://github.com/harfbuzz/harfbuzz/issues/435#issuecomment-335560167 |
| * // For compatibility with legacy usage in Kannada, |
| * // Ra+h+ZWJ must behave like Ra+ZWJ+h... |
| */ |
| if (buffer->props.script == HB_SCRIPT_KANNADA && |
| start + 3 <= end && |
| is_one_of (info[start ], FLAG (I_Cat(Ra))) && |
| is_one_of (info[start+1], FLAG (I_Cat(H))) && |
| is_one_of (info[start+2], FLAG (I_Cat(ZWJ)))) |
| { |
| buffer->merge_clusters (start+1, start+3); |
| hb_glyph_info_t tmp = info[start+1]; |
| info[start+1] = info[start+2]; |
| info[start+2] = tmp; |
| } |
| |
| /* 1. Find base consonant: |
| * |
| * The shaping engine finds the base consonant of the syllable, using the |
| * following algorithm: starting from the end of the syllable, move backwards |
| * until a consonant is found that does not have a below-base or post-base |
| * form (post-base forms have to follow below-base forms), or that is not a |
| * pre-base-reordering Ra, or arrive at the first consonant. The consonant |
| * stopped at will be the base. |
| * |
| * o If the syllable starts with Ra + Halant (in a script that has Reph) |
| * and has more than one consonant, Ra is excluded from candidates for |
| * base consonants. |
| */ |
| |
| unsigned int base = end; |
| bool has_reph = false; |
| |
| { |
| /* -> If the syllable starts with Ra + Halant (in a script that has Reph) |
| * and has more than one consonant, Ra is excluded from candidates for |
| * base consonants. */ |
| unsigned int limit = start; |
| if (indic_plan->mask_array[INDIC_RPHF] && |
| start + 3 <= end && |
| ( |
| (indic_plan->config->reph_mode == REPH_MODE_IMPLICIT && !is_joiner (info[start + 2])) || |
| (indic_plan->config->reph_mode == REPH_MODE_EXPLICIT && info[start + 2].indic_category() == I_Cat(ZWJ)) |
| )) |
| { |
| /* See if it matches the 'rphf' feature. */ |
| hb_codepoint_t glyphs[3] = {info[start].codepoint, |
| info[start + 1].codepoint, |
| indic_plan->config->reph_mode == REPH_MODE_EXPLICIT ? |
| info[start + 2].codepoint : 0}; |
| if (indic_plan->rphf.would_substitute (glyphs, 2, face) || |
| (indic_plan->config->reph_mode == REPH_MODE_EXPLICIT && |
| indic_plan->rphf.would_substitute (glyphs, 3, face))) |
| { |
| limit += 2; |
| while (limit < end && is_joiner (info[limit])) |
| limit++; |
| base = start; |
| has_reph = true; |
| } |
| } else if (indic_plan->config->reph_mode == REPH_MODE_LOG_REPHA && info[start].indic_category() == I_Cat(Repha)) |
| { |
| limit += 1; |
| while (limit < end && is_joiner (info[limit])) |
| limit++; |
| base = start; |
| has_reph = true; |
| } |
| |
| { |
| /* -> starting from the end of the syllable, move backwards */ |
| unsigned int i = end; |
| bool seen_below = false; |
| do { |
| i--; |
| /* -> until a consonant is found */ |
| if (is_consonant (info[i])) |
| { |
| /* -> that does not have a below-base or post-base form |
| * (post-base forms have to follow below-base forms), */ |
| if (info[i].indic_position() != POS_BELOW_C && |
| (info[i].indic_position() != POS_POST_C || seen_below)) |
| { |
| base = i; |
| break; |
| } |
| if (info[i].indic_position() == POS_BELOW_C) |
| seen_below = true; |
| |
| /* -> or that is not a pre-base-reordering Ra, |
| * |
| * IMPLEMENTATION NOTES: |
| * |
| * Our pre-base-reordering Ra's are marked POS_POST_C, so will be skipped |
| * by the logic above already. |
| */ |
| |
| /* -> or arrive at the first consonant. The consonant stopped at will |
| * be the base. */ |
| base = i; |
| } |
| else |
| { |
| /* A ZWJ after a Halant stops the base search, and requests an explicit |
| * half form. |
| * A ZWJ before a Halant, requests a subjoined form instead, and hence |
| * search continues. This is particularly important for Bengali |
| * sequence Ra,H,Ya that should form Ya-Phalaa by subjoining Ya. */ |
| if (start < i && |
| info[i].indic_category() == I_Cat(ZWJ) && |
| info[i - 1].indic_category() == I_Cat(H)) |
| break; |
| } |
| } while (i > limit); |
| } |
| |
| /* -> If the syllable starts with Ra + Halant (in a script that has Reph) |
| * and has more than one consonant, Ra is excluded from candidates for |
| * base consonants. |
| * |
| * Only do this for unforced Reph. (ie. not for Ra,H,ZWJ. */ |
| if (has_reph && base == start && limit - base <= 2) { |
| /* Have no other consonant, so Reph is not formed and Ra becomes base. */ |
| has_reph = false; |
| } |
| } |
| |
| |
| /* 2. Decompose and reorder Matras: |
| * |
| * Each matra and any syllable modifier sign in the syllable are moved to the |
| * appropriate position relative to the consonant(s) in the syllable. The |
| * shaping engine decomposes two- or three-part matras into their constituent |
| * parts before any repositioning. Matra characters are classified by which |
| * consonant in a conjunct they have affinity for and are reordered to the |
| * following positions: |
| * |
| * o Before first half form in the syllable |
| * o After subjoined consonants |
| * o After post-form consonant |
| * o After main consonant (for above marks) |
| * |
| * IMPLEMENTATION NOTES: |
| * |
| * The normalize() routine has already decomposed matras for us, so we don't |
| * need to worry about that. |
| */ |
| |
| |
| /* 3. Reorder marks to canonical order: |
| * |
| * Adjacent nukta and halant or nukta and vedic sign are always repositioned |
| * if necessary, so that the nukta is first. |
| * |
| * IMPLEMENTATION NOTES: |
| * |
| * We don't need to do this: the normalize() routine already did this for us. |
| */ |
| |
| |
| /* Reorder characters */ |
| |
| for (unsigned int i = start; i < base; i++) |
| info[i].indic_position() = hb_min (POS_PRE_C, (indic_position_t) info[i].indic_position()); |
| |
| if (base < end) |
| info[base].indic_position() = POS_BASE_C; |
| |
| /* Handle beginning Ra */ |
| if (has_reph) |
| info[start].indic_position() = POS_RA_TO_BECOME_REPH; |
| |
| /* For old-style Indic script tags, move the first post-base Halant after |
| * last consonant. |
| * |
| * Reports suggest that in some scripts Uniscribe does this only if there |
| * is *not* a Halant after last consonant already. We know that is the |
| * case for Kannada, while it reorders unconditionally in other scripts, |
| * eg. Malayalam, Bengali, and Devanagari. We don't currently know about |
| * other scripts, so we block Kannada. |
| * |
| * Kannada test case: |
| * U+0C9A,U+0CCD,U+0C9A,U+0CCD |
| * With some versions of Lohit Kannada. |
| * https://bugs.freedesktop.org/show_bug.cgi?id=59118 |
| * |
| * Malayalam test case: |
| * U+0D38,U+0D4D,U+0D31,U+0D4D,U+0D31,U+0D4D |
| * With lohit-ttf-20121122/Lohit-Malayalam.ttf |
| * |
| * Bengali test case: |
| * U+0998,U+09CD,U+09AF,U+09CD |
| * With Windows XP vrinda.ttf |
| * https://github.com/harfbuzz/harfbuzz/issues/1073 |
| * |
| * Devanagari test case: |
| * U+091F,U+094D,U+0930,U+094D |
| * With chandas.ttf |
| * https://github.com/harfbuzz/harfbuzz/issues/1071 |
| */ |
| if (indic_plan->is_old_spec) |
| { |
| bool disallow_double_halants = buffer->props.script == HB_SCRIPT_KANNADA; |
| for (unsigned int i = base + 1; i < end; i++) |
| if (info[i].indic_category() == I_Cat(H)) |
| { |
| unsigned int j; |
| for (j = end - 1; j > i; j--) |
| if (is_consonant (info[j]) || |
| (disallow_double_halants && info[j].indic_category() == I_Cat(H))) |
| break; |
| if (info[j].indic_category() != I_Cat(H) && j > i) { |
| /* Move Halant to after last consonant. */ |
| hb_glyph_info_t t = info[i]; |
| memmove (&info[i], &info[i + 1], (j - i) * sizeof (info[0])); |
| info[j] = t; |
| } |
| break; |
| } |
| } |
| |
| /* Attach misc marks to previous char to move with them. */ |
| { |
| indic_position_t last_pos = POS_START; |
| for (unsigned int i = start; i < end; i++) |
| { |
| if ((FLAG_UNSAFE (info[i].indic_category()) & (JOINER_FLAGS | FLAG (I_Cat(N)) | FLAG (I_Cat(RS)) | FLAG (I_Cat(CM)) | FLAG (I_Cat(H))))) |
| { |
| info[i].indic_position() = last_pos; |
| if (unlikely (info[i].indic_category() == I_Cat(H) && |
| info[i].indic_position() == POS_PRE_M)) |
| { |
| /* |
| * Uniscribe doesn't move the Halant with Left Matra. |
| * TEST: U+092B,U+093F,U+094D |
| * We follow. |
| */ |
| for (unsigned int j = i; j > start; j--) |
| if (info[j - 1].indic_position() != POS_PRE_M) { |
| info[i].indic_position() = info[j - 1].indic_position(); |
| break; |
| } |
| } |
| } else if (info[i].indic_position() != POS_SMVD) { |
| last_pos = (indic_position_t) info[i].indic_position(); |
| } |
| } |
| } |
| /* For post-base consonants let them own anything before them |
| * since the last consonant or matra. */ |
| { |
| unsigned int last = base; |
| for (unsigned int i = base + 1; i < end; i++) |
| if (is_consonant (info[i])) |
| { |
| for (unsigned int j = last + 1; j < i; j++) |
| if (info[j].indic_position() < POS_SMVD) |
| info[j].indic_position() = info[i].indic_position(); |
| last = i; |
| } else if (info[i].indic_category() == I_Cat(M)) |
| last = i; |
| } |
| |
| |
| { |
| /* Use syllable() for sort accounting temporarily. */ |
| unsigned int syllable = info[start].syllable(); |
| for (unsigned int i = start; i < end; i++) |
| info[i].syllable() = i - start; |
| |
| /* Sit tight, rock 'n roll! */ |
| hb_stable_sort (info + start, end - start, compare_indic_order); |
| /* Find base again */ |
| base = end; |
| for (unsigned int i = start; i < end; i++) |
| if (info[i].indic_position() == POS_BASE_C) |
| { |
| base = i; |
| break; |
| } |
| /* Things are out-of-control for post base positions, they may shuffle |
| * around like crazy. In old-spec mode, we move halants around, so in |
| * that case merge all clusters after base. Otherwise, check the sort |
| * order and merge as needed. |
| * For pre-base stuff, we handle cluster issues in final reordering. |
| * |
| * We could use buffer->sort() for this, if there was no special |
| * reordering of pre-base stuff happening later... |
| * We don't want to merge_clusters all of that, which buffer->sort() |
| * would. Here's a concrete example: |
| * |
| * Assume there's a pre-base consonant and explicit Halant before base, |
| * followed by a prebase-reordering (left) Matra: |
| * |
| * C,H,ZWNJ,B,M |
| * |
| * At this point in reordering we would have: |
| * |
| * M,C,H,ZWNJ,B |
| * |
| * whereas in final reordering we will bring the Matra closer to Base: |
| * |
| * C,H,ZWNJ,M,B |
| * |
| * That's why we don't want to merge-clusters anything before the Base |
| * at this point. But if something moved from after Base to before it, |
| * we should merge clusters from base to them. In final-reordering, we |
| * only move things around before base, and merge-clusters up to base. |
| * These two merge-clusters from the two sides of base will interlock |
| * to merge things correctly. See: |
| * https://github.com/harfbuzz/harfbuzz/issues/2272 |
| */ |
| if (indic_plan->is_old_spec || end - start > 127) |
| buffer->merge_clusters (base, end); |
| else |
| { |
| /* Note! syllable() is a one-byte field. */ |
| for (unsigned int i = base; i < end; i++) |
| if (info[i].syllable() != 255) |
| { |
| unsigned int min = i; |
| unsigned int max = i; |
| unsigned int j = start + info[i].syllable(); |
| while (j != i) |
| { |
| min = hb_min (min, j); |
| max = hb_max (max, j); |
| unsigned int next = start + info[j].syllable(); |
| info[j].syllable() = 255; /* So we don't process j later again. */ |
| j = next; |
| } |
| buffer->merge_clusters (hb_max (base, min), max + 1); |
| } |
| } |
| |
| /* Put syllable back in. */ |
| for (unsigned int i = start; i < end; i++) |
| info[i].syllable() = syllable; |
| } |
| |
| /* Setup masks now */ |
| |
| { |
| hb_mask_t mask; |
| |
| /* Reph */ |
| for (unsigned int i = start; i < end && info[i].indic_position() == POS_RA_TO_BECOME_REPH; i++) |
| info[i].mask |= indic_plan->mask_array[INDIC_RPHF]; |
| |
| /* Pre-base */ |
| mask = indic_plan->mask_array[INDIC_HALF]; |
| if (!indic_plan->is_old_spec && |
| indic_plan->config->blwf_mode == BLWF_MODE_PRE_AND_POST) |
| mask |= indic_plan->mask_array[INDIC_BLWF]; |
| for (unsigned int i = start; i < base; i++) |
| info[i].mask |= mask; |
| /* Base */ |
| mask = 0; |
| if (base < end) |
| info[base].mask |= mask; |
| /* Post-base */ |
| mask = indic_plan->mask_array[INDIC_BLWF] | |
| indic_plan->mask_array[INDIC_ABVF] | |
| indic_plan->mask_array[INDIC_PSTF]; |
| for (unsigned int i = base + 1; i < end; i++) |
| info[i].mask |= mask; |
| } |
| |
| if (indic_plan->is_old_spec && |
| buffer->props.script == HB_SCRIPT_DEVANAGARI) |
| { |
| /* Old-spec eye-lash Ra needs special handling. From the |
| * spec: |
| * |
| * "The feature 'below-base form' is applied to consonants |
| * having below-base forms and following the base consonant. |
| * The exception is vattu, which may appear below half forms |
| * as well as below the base glyph. The feature 'below-base |
| * form' will be applied to all such occurrences of Ra as well." |
| * |
| * Test case: U+0924,U+094D,U+0930,U+094d,U+0915 |
| * with Sanskrit 2003 font. |
| * |
| * However, note that Ra,Halant,ZWJ is the correct way to |
| * request eyelash form of Ra, so we wouldbn't inhibit it |
| * in that sequence. |
| * |
| * Test case: U+0924,U+094D,U+0930,U+094d,U+200D,U+0915 |
| */ |
| for (unsigned int i = start; i + 1 < base; i++) |
| if (info[i ].indic_category() == I_Cat(Ra) && |
| info[i+1].indic_category() == I_Cat(H) && |
| (i + 2 == base || |
| info[i+2].indic_category() != I_Cat(ZWJ))) |
| { |
| info[i ].mask |= indic_plan->mask_array[INDIC_BLWF]; |
| info[i+1].mask |= indic_plan->mask_array[INDIC_BLWF]; |
| } |
| } |
| |
| unsigned int pref_len = 2; |
| if (indic_plan->mask_array[INDIC_PREF] && base + pref_len < end) |
| { |
| /* Find a Halant,Ra sequence and mark it for pre-base-reordering processing. */ |
| for (unsigned int i = base + 1; i + pref_len - 1 < end; i++) { |
| hb_codepoint_t glyphs[2]; |
| for (unsigned int j = 0; j < pref_len; j++) |
| glyphs[j] = info[i + j].codepoint; |
| if (indic_plan->pref.would_substitute (glyphs, pref_len, face)) |
| { |
| for (unsigned int j = 0; j < pref_len; j++) |
| info[i++].mask |= indic_plan->mask_array[INDIC_PREF]; |
| break; |
| } |
| } |
| } |
| |
| /* Apply ZWJ/ZWNJ effects */ |
| for (unsigned int i = start + 1; i < end; i++) |
| if (is_joiner (info[i])) { |
| bool non_joiner = info[i].indic_category() == I_Cat(ZWNJ); |
| unsigned int j = i; |
| |
| do { |
| j--; |
| |
| /* ZWJ/ZWNJ should disable CJCT. They do that by simply |
| * being there, since we don't skip them for the CJCT |
| * feature (ie. F_MANUAL_ZWJ) */ |
| |
| /* A ZWNJ disables HALF. */ |
| if (non_joiner) |
| info[j].mask &= ~indic_plan->mask_array[INDIC_HALF]; |
| |
| } while (j > start && !is_consonant (info[j])); |
| } |
| } |
| |
| static void |
| initial_reordering_standalone_cluster (const hb_ot_shape_plan_t *plan, |
| hb_face_t *face, |
| hb_buffer_t *buffer, |
| unsigned int start, unsigned int end) |
| { |
| /* We treat placeholder/dotted-circle as if they are consonants, so we |
| * should just chain. Only if not in compatibility mode that is... */ |
| |
| const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data; |
| if (indic_plan->uniscribe_bug_compatible) |
| { |
| /* For dotted-circle, this is what Uniscribe does: |
| * If dotted-circle is the last glyph, it just does nothing. |
| * Ie. It doesn't form Reph. */ |
| if (buffer->info[end - 1].indic_category() == I_Cat(DOTTEDCIRCLE)) |
| return; |
| } |
| |
| initial_reordering_consonant_syllable (plan, face, buffer, start, end); |
| } |
| |
| static void |
| initial_reordering_syllable_indic (const hb_ot_shape_plan_t *plan, |
| hb_face_t *face, |
| hb_buffer_t *buffer, |
| unsigned int start, unsigned int end) |
| { |
| indic_syllable_type_t syllable_type = (indic_syllable_type_t) (buffer->info[start].syllable() & 0x0F); |
| switch (syllable_type) |
| { |
| case indic_vowel_syllable: /* We made the vowels look like consonants. So let's call the consonant logic! */ |
| case indic_consonant_syllable: |
| initial_reordering_consonant_syllable (plan, face, buffer, start, end); |
| break; |
| |
| case indic_broken_cluster: /* We already inserted dotted-circles, so just call the standalone_cluster. */ |
| case indic_standalone_cluster: |
| initial_reordering_standalone_cluster (plan, face, buffer, start, end); |
| break; |
| |
| case indic_symbol_cluster: |
| case indic_non_indic_cluster: |
| break; |
| } |
| } |
| |
| static void |
| initial_reordering_indic (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer) |
| { |
| if (!buffer->message (font, "start reordering indic initial")) |
| return; |
| |
| update_consonant_positions_indic (plan, font, buffer); |
| hb_syllabic_insert_dotted_circles (font, buffer, |
| indic_broken_cluster, |
| I_Cat(DOTTEDCIRCLE), |
| I_Cat(Repha), |
| POS_END); |
| |
| foreach_syllable (buffer, start, end) |
| initial_reordering_syllable_indic (plan, font->face, buffer, start, end); |
| |
| (void) buffer->message (font, "end reordering indic initial"); |
| } |
| |
| static void |
| final_reordering_syllable_indic (const hb_ot_shape_plan_t *plan, |
| hb_buffer_t *buffer, |
| unsigned int start, unsigned int end) |
| { |
| const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data; |
| hb_glyph_info_t *info = buffer->info; |
| |
| |
| /* This function relies heavily on halant glyphs. Lots of ligation |
| * and possibly multiple substitutions happened prior to this |
| * phase, and that might have messed up our properties. Recover |
| * from a particular case of that where we're fairly sure that a |
| * class of I_Cat(H) is desired but has been lost. */ |
| /* We don't call load_virama_glyph(), since we know it's already |
| * loaded. */ |
| hb_codepoint_t virama_glyph = indic_plan->virama_glyph.get_relaxed (); |
| if (virama_glyph) |
| { |
| for (unsigned int i = start; i < end; i++) |
| if (info[i].codepoint == virama_glyph && |
| _hb_glyph_info_ligated (&info[i]) && |
| _hb_glyph_info_multiplied (&info[i])) |
| { |
| /* This will make sure that this glyph passes is_halant() test. */ |
| info[i].indic_category() = I_Cat(H); |
| _hb_glyph_info_clear_ligated_and_multiplied (&info[i]); |
| } |
| } |
| |
| |
| /* 4. Final reordering: |
| * |
| * After the localized forms and basic shaping forms GSUB features have been |
| * applied (see below), the shaping engine performs some final glyph |
| * reordering before applying all the remaining font features to the entire |
| * syllable. |
| */ |
| |
| bool try_pref = !!indic_plan->mask_array[INDIC_PREF]; |
| |
| /* Find base again */ |
| unsigned int base; |
| for (base = start; base < end; base++) |
| if (info[base].indic_position() >= POS_BASE_C) |
| { |
| if (try_pref && base + 1 < end) |
| { |
| for (unsigned int i = base + 1; i < end; i++) |
| if ((info[i].mask & indic_plan->mask_array[INDIC_PREF]) != 0) |
| { |
| if (!(_hb_glyph_info_substituted (&info[i]) && |
| _hb_glyph_info_ligated_and_didnt_multiply (&info[i]))) |
| { |
| /* Ok, this was a 'pref' candidate but didn't form any. |
| * Base is around here... */ |
| base = i; |
| while (base < end && is_halant (info[base])) |
| base++; |
| info[base].indic_position() = POS_BASE_C; |
| |
| try_pref = false; |
| } |
| break; |
| } |
| } |
| /* For Malayalam, skip over unformed below- (but NOT post-) forms. */ |
| if (buffer->props.script == HB_SCRIPT_MALAYALAM) |
| { |
| for (unsigned int i = base + 1; i < end; i++) |
| { |
| while (i < end && is_joiner (info[i])) |
| i++; |
| if (i == end || !is_halant (info[i])) |
| break; |
| i++; /* Skip halant. */ |
| while (i < end && is_joiner (info[i])) |
| i++; |
| if (i < end && is_consonant (info[i]) && info[i].indic_position() == POS_BELOW_C) |
| { |
| base = i; |
| info[base].indic_position() = POS_BASE_C; |
| } |
| } |
| } |
| |
| if (start < base && info[base].indic_position() > POS_BASE_C) |
| base--; |
| break; |
| } |
| if (base == end && start < base && |
| is_one_of (info[base - 1], FLAG (I_Cat(ZWJ)))) |
| base--; |
| if (base < end) |
| while (start < base && |
| is_one_of (info[base], (FLAG (I_Cat(N)) | FLAG (I_Cat(H))))) |
| base--; |
| |
| |
| /* o Reorder matras: |
| * |
| * If a pre-base matra character had been reordered before applying basic |
| * features, the glyph can be moved closer to the main consonant based on |
| * whether half-forms had been formed. Actual position for the matra is |
| * defined as “after last standalone halant glyph, after initial matra |
| * position and before the main consonant”. If ZWJ or ZWNJ follow this |
| * halant, position is moved after it. |
| * |
| * IMPLEMENTATION NOTES: |
| * |
| * It looks like the last sentence is wrong. Testing, with Windows 7 Uniscribe |
| * and Devanagari shows that the behavior is best described as: |
| * |
| * "If ZWJ follows this halant, matra is NOT repositioned after this halant. |
| * If ZWNJ follows this halant, position is moved after it." |
| * |
| * Test case, with Adobe Devanagari or Nirmala UI: |
| * |
| * U+091F,U+094D,U+200C,U+092F,U+093F |
| * (Matra moves to the middle, after ZWNJ.) |
| * |
| * U+091F,U+094D,U+200D,U+092F,U+093F |
| * (Matra does NOT move, stays to the left.) |
| * |
| * https://github.com/harfbuzz/harfbuzz/issues/1070 |
| */ |
| |
| if (start + 1 < end && start < base) /* Otherwise there can't be any pre-base matra characters. */ |
| { |
| /* If we lost track of base, alas, position before last thingy. */ |
| unsigned int new_pos = base == end ? base - 2 : base - 1; |
| |
| /* Malayalam / Tamil do not have "half" forms or explicit virama forms. |
| * The glyphs formed by 'half' are Chillus or ligated explicit viramas. |
| * We want to position matra after them. |
| */ |
| if (buffer->props.script != HB_SCRIPT_MALAYALAM && buffer->props.script != HB_SCRIPT_TAMIL) |
| { |
| search: |
| while (new_pos > start && |
| !(is_one_of (info[new_pos], (FLAG (I_Cat(M)) | FLAG (I_Cat(H)))))) |
| new_pos--; |
| |
| /* If we found no Halant we are done. |
| * Otherwise only proceed if the Halant does |
| * not belong to the Matra itself! */ |
| if (is_halant (info[new_pos]) && |
| info[new_pos].indic_position() != POS_PRE_M) |
| { |
| #if 0 // See comment above |
| /* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */ |
| if (new_pos + 1 < end && is_joiner (info[new_pos + 1])) |
| new_pos++; |
| #endif |
| if (new_pos + 1 < end) |
| { |
| /* -> If ZWJ follows this halant, matra is NOT repositioned after this halant. */ |
| if (info[new_pos + 1].indic_category() == I_Cat(ZWJ)) |
| { |
| /* Keep searching. */ |
| if (new_pos > start) |
| { |
| new_pos--; |
| goto search; |
| } |
| } |
| /* -> If ZWNJ follows this halant, position is moved after it. |
| * |
| * IMPLEMENTATION NOTES: |
| * |
| * This is taken care of by the state-machine. A Halant,ZWNJ is a terminating |
| * sequence for a consonant syllable; any pre-base matras occurring after it |
| * will belong to the subsequent syllable. |
| */ |
| } |
| } |
| else |
| new_pos = start; /* No move. */ |
| } |
| |
| if (start < new_pos && info[new_pos].indic_position () != POS_PRE_M) |
| { |
| /* Now go see if there's actually any matras... */ |
| for (unsigned int i = new_pos; i > start; i--) |
| if (info[i - 1].indic_position () == POS_PRE_M) |
| { |
| unsigned int old_pos = i - 1; |
| if (old_pos < base && base <= new_pos) /* Shouldn't actually happen. */ |
| base--; |
| |
| hb_glyph_info_t tmp = info[old_pos]; |
| memmove (&info[old_pos], &info[old_pos + 1], (new_pos - old_pos) * sizeof (info[0])); |
| info[new_pos] = tmp; |
| |
| /* Note: this merge_clusters() is intentionally *after* the reordering. |
| * Indic matra reordering is special and tricky... */ |
| buffer->merge_clusters (new_pos, hb_min (end, base + 1)); |
| |
| new_pos--; |
| } |
| } else { |
| for (unsigned int i = start; i < base; i++) |
| if (info[i].indic_position () == POS_PRE_M) { |
| buffer->merge_clusters (i, hb_min (end, base + 1)); |
| break; |
| } |
| } |
| } |
| |
| |
| /* o Reorder reph: |
| * |
| * Reph’s original position is always at the beginning of the syllable, |
| * (i.e. it is not reordered at the character reordering stage). However, |
| * it will be reordered according to the basic-forms shaping results. |
| * Possible positions for reph, depending on the script, are; after main, |
| * before post-base consonant forms, and after post-base consonant forms. |
| */ |
| |
| /* Two cases: |
| * |
| * - If repha is encoded as a sequence of characters (Ra,H or Ra,H,ZWJ), then |
| * we should only move it if the sequence ligated to the repha form. |
| * |
| * - If repha is encoded separately and in the logical position, we should only |
| * move it if it did NOT ligate. If it ligated, it's probably the font trying |
| * to make it work without the reordering. |
| */ |
| if (start + 1 < end && |
| info[start].indic_position() == POS_RA_TO_BECOME_REPH && |
| ((info[start].indic_category() == I_Cat(Repha)) ^ |
| _hb_glyph_info_ligated_and_didnt_multiply (&info[start]))) |
| { |
| unsigned int new_reph_pos; |
| reph_position_t reph_pos = indic_plan->config->reph_pos; |
| |
| /* 1. If reph should be positioned after post-base consonant forms, |
| * proceed to step 5. |
| */ |
| if (reph_pos == REPH_POS_AFTER_POST) |
| { |
| goto reph_step_5; |
| } |
| |
| /* 2. If the reph repositioning class is not after post-base: target |
| * position is after the first explicit halant glyph between the |
| * first post-reph consonant and last main consonant. If ZWJ or ZWNJ |
| * are following this halant, position is moved after it. If such |
| * position is found, this is the target position. Otherwise, |
| * proceed to the next step. |
| * |
| * Note: in old-implementation fonts, where classifications were |
| * fixed in shaping engine, there was no case where reph position |
| * will be found on this step. |
| */ |
| { |
| new_reph_pos = start + 1; |
| while (new_reph_pos < base && !is_halant (info[new_reph_pos])) |
| new_reph_pos++; |
| |
| if (new_reph_pos < base && is_halant (info[new_reph_pos])) |
| { |
| /* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */ |
| if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1])) |
| new_reph_pos++; |
| goto reph_move; |
| } |
| } |
| |
| /* 3. If reph should be repositioned after the main consonant: find the |
| * first consonant not ligated with main, or find the first |
| * consonant that is not a potential pre-base-reordering Ra. |
| */ |
| if (reph_pos == REPH_POS_AFTER_MAIN) |
| { |
| new_reph_pos = base; |
| while (new_reph_pos + 1 < end && info[new_reph_pos + 1].indic_position() <= POS_AFTER_MAIN) |
| new_reph_pos++; |
| if (new_reph_pos < end) |
| goto reph_move; |
| } |
| |
| /* 4. If reph should be positioned before post-base consonant, find |
| * first post-base classified consonant not ligated with main. If no |
| * consonant is found, the target position should be before the |
| * first matra, syllable modifier sign or vedic sign. |
| */ |
| /* This is our take on what step 4 is trying to say (and failing, BADLY). */ |
| if (reph_pos == REPH_POS_AFTER_SUB) |
| { |
| new_reph_pos = base; |
| while (new_reph_pos + 1 < end && |
| !( FLAG_UNSAFE (info[new_reph_pos + 1].indic_position()) & (FLAG (POS_POST_C) | FLAG (POS_AFTER_POST) | FLAG (POS_SMVD)))) |
| new_reph_pos++; |
| if (new_reph_pos < end) |
| goto reph_move; |
| } |
| |
| /* 5. If no consonant is found in steps 3 or 4, move reph to a position |
| * immediately before the first post-base matra, syllable modifier |
| * sign or vedic sign that has a reordering class after the intended |
| * reph position. For example, if the reordering position for reph |
| * is post-main, it will skip above-base matras that also have a |
| * post-main position. |
| */ |
| reph_step_5: |
| { |
| /* Copied from step 2. */ |
| new_reph_pos = start + 1; |
| while (new_reph_pos < base && !is_halant (info[new_reph_pos])) |
| new_reph_pos++; |
| |
| if (new_reph_pos < base && is_halant (info[new_reph_pos])) |
| { |
| /* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */ |
| if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1])) |
| new_reph_pos++; |
| goto reph_move; |
| } |
| } |
| /* See https://github.com/harfbuzz/harfbuzz/issues/2298#issuecomment-615318654 */ |
| |
| /* 6. Otherwise, reorder reph to the end of the syllable. |
| */ |
| { |
| new_reph_pos = end - 1; |
| while (new_reph_pos > start && info[new_reph_pos].indic_position() == POS_SMVD) |
| new_reph_pos--; |
| |
| /* |
| * If the Reph is to be ending up after a Matra,Halant sequence, |
| * position it before that Halant so it can interact with the Matra. |
| * However, if it's a plain Consonant,Halant we shouldn't do that. |
| * Uniscribe doesn't do this. |
| * TEST: U+0930,U+094D,U+0915,U+094B,U+094D |
| */ |
| if (!indic_plan->uniscribe_bug_compatible && |
| unlikely (is_halant (info[new_reph_pos]))) |
| { |
| for (unsigned int i = base + 1; i < new_reph_pos; i++) |
| if (info[i].indic_category() == I_Cat(M)) { |
| /* Ok, got it. */ |
| new_reph_pos--; |
| } |
| } |
| |
| goto reph_move; |
| } |
| |
| reph_move: |
| { |
| /* Move */ |
| buffer->merge_clusters (start, new_reph_pos + 1); |
| hb_glyph_info_t reph = info[start]; |
| memmove (&info[start], &info[start + 1], (new_reph_pos - start) * sizeof (info[0])); |
| info[new_reph_pos] = reph; |
| |
| if (start < base && base <= new_reph_pos) |
| base--; |
| } |
| } |
| |
| |
| /* o Reorder pre-base-reordering consonants: |
| * |
| * If a pre-base-reordering consonant is found, reorder it according to |
| * the following rules: |
| */ |
| |
| if (try_pref && base + 1 < end) /* Otherwise there can't be any pre-base-reordering Ra. */ |
| { |
| for (unsigned int i = base + 1; i < end; i++) |
| if ((info[i].mask & indic_plan->mask_array[INDIC_PREF]) != 0) |
| { |
| /* 1. Only reorder a glyph produced by substitution during application |
| * of the <pref> feature. (Note that a font may shape a Ra consonant with |
| * the feature generally but block it in certain contexts.) |
| */ |
| /* Note: We just check that something got substituted. We don't check that |
| * the <pref> feature actually did it... |
| * |
| * Reorder pref only if it ligated. */ |
| if (_hb_glyph_info_ligated_and_didnt_multiply (&info[i])) |
| { |
| /* |
| * 2. Try to find a target position the same way as for pre-base matra. |
| * If it is found, reorder pre-base consonant glyph. |
| * |
| * 3. If position is not found, reorder immediately before main |
| * consonant. |
| */ |
| |
| unsigned int new_pos = base; |
| /* Malayalam / Tamil do not have "half" forms or explicit virama forms. |
| * The glyphs formed by 'half' are Chillus or ligated explicit viramas. |
| * We want to position matra after them. |
| */ |
| if (buffer->props.script != HB_SCRIPT_MALAYALAM && buffer->props.script != HB_SCRIPT_TAMIL) |
| { |
| while (new_pos > start && |
| !(is_one_of (info[new_pos - 1], FLAG(I_Cat(M)) | FLAG (I_Cat(H))))) |
| new_pos--; |
| } |
| |
| if (new_pos > start && is_halant (info[new_pos - 1])) |
| { |
| /* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */ |
| if (new_pos < end && is_joiner (info[new_pos])) |
| new_pos++; |
| } |
| |
| { |
| unsigned int old_pos = i; |
| |
| buffer->merge_clusters (new_pos, old_pos + 1); |
| hb_glyph_info_t tmp = info[old_pos]; |
| memmove (&info[new_pos + 1], &info[new_pos], (old_pos - new_pos) * sizeof (info[0])); |
| info[new_pos] = tmp; |
| |
| if (new_pos <= base && base < old_pos) |
| base++; |
| } |
| } |
| |
| break; |
| } |
| } |
| |
| |
| /* Apply 'init' to the Left Matra if it's a word start. */ |
| if (info[start].indic_position () == POS_PRE_M) |
| { |
| if (!start || |
| !(FLAG_UNSAFE (_hb_glyph_info_get_general_category (&info[start - 1])) & |
| FLAG_RANGE (HB_UNICODE_GENERAL_CATEGORY_FORMAT, HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK))) |
| info[start].mask |= indic_plan->mask_array[INDIC_INIT]; |
| else |
| buffer->unsafe_to_break (start - 1, start + 1); |
| } |
| |
| |
| /* |
| * Finish off the clusters and go home! |
| */ |
| if (indic_plan->uniscribe_bug_compatible) |
| { |
| switch ((hb_tag_t) plan->props.script) |
| { |
| case HB_SCRIPT_TAMIL: |
| break; |
| |
| default: |
| /* Uniscribe merges the entire syllable into a single cluster... Except for Tamil. |
| * This means, half forms are submerged into the main consonant's cluster. |
| * This is unnecessary, and makes cursor positioning harder, but that's what |
| * Uniscribe does. */ |
| buffer->merge_clusters (start, end); |
| break; |
| } |
| } |
| } |
| |
| |
| static void |
| final_reordering_indic (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font HB_UNUSED, |
| hb_buffer_t *buffer) |
| { |
| unsigned int count = buffer->len; |
| if (unlikely (!count)) return; |
| |
| if (buffer->message (font, "start reordering indic final")) { |
| foreach_syllable (buffer, start, end) |
| final_reordering_syllable_indic (plan, buffer, start, end); |
| (void) buffer->message (font, "end reordering indic final"); |
| } |
| |
| HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category); |
| HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position); |
| } |
| |
| |
| static void |
| preprocess_text_indic (const hb_ot_shape_plan_t *plan, |
| hb_buffer_t *buffer, |
| hb_font_t *font) |
| { |
| const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data; |
| if (!indic_plan->uniscribe_bug_compatible) |
| _hb_preprocess_text_vowel_constraints (plan, buffer, font); |
| } |
| |
| static bool |
| decompose_indic (const hb_ot_shape_normalize_context_t *c, |
| hb_codepoint_t ab, |
| hb_codepoint_t *a, |
| hb_codepoint_t *b) |
| { |
| switch (ab) |
| { |
| /* Don't decompose these. */ |
| case 0x0931u : return false; /* DEVANAGARI LETTER RRA */ |
| // https://github.com/harfbuzz/harfbuzz/issues/779 |
| case 0x09DCu : return false; /* BENGALI LETTER RRA */ |
| case 0x09DDu : return false; /* BENGALI LETTER RHA */ |
| case 0x0B94u : return false; /* TAMIL LETTER AU */ |
| |
| |
| /* |
| * Decompose split matras that don't have Unicode decompositions. |
| */ |
| |
| #if 0 |
| /* Gujarati */ |
| /* This one has no decomposition in Unicode, but needs no decomposition either. */ |
| /* case 0x0AC9u : return false; */ |
| |
| /* Oriya */ |
| case 0x0B57u : *a = no decomp, -> RIGHT; return true; |
| #endif |
| } |
| |
| return (bool) c->unicode->decompose (ab, a, b); |
| } |
| |
| static bool |
| compose_indic (const hb_ot_shape_normalize_context_t *c, |
| hb_codepoint_t a, |
| hb_codepoint_t b, |
| hb_codepoint_t *ab) |
| { |
| /* Avoid recomposing split matras. */ |
| if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a))) |
| return false; |
| |
| /* Composition-exclusion exceptions that we want to recompose. */ |
| if (a == 0x09AFu && b == 0x09BCu) { *ab = 0x09DFu; return true; } |
| |
| return (bool) c->unicode->compose (a, b, ab); |
| } |
| |
| |
| const hb_ot_shaper_t _hb_ot_shaper_indic = |
| { |
| collect_features_indic, |
| override_features_indic, |
| data_create_indic, |
| data_destroy_indic, |
| preprocess_text_indic, |
| nullptr, /* postprocess_glyphs */ |
| decompose_indic, |
| compose_indic, |
| setup_masks_indic, |
| nullptr, /* reorder_marks */ |
| HB_TAG_NONE, /* gpos_tag */ |
| HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, |
| HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, |
| false, /* fallback_position */ |
| }; |
| |
| |
| #endif |