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Diffstat (limited to 'thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc')
| -rw-r--r-- | thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc | 1572 |
1 files changed, 0 insertions, 1572 deletions
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc deleted file mode 100644 index 4a8781c8f8..0000000000 --- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc +++ /dev/null @@ -1,1572 +0,0 @@ -/* - * 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-shape-complex-indic.hh" -#include "hb-ot-shape-complex-indic-machine.hh" -#include "hb-ot-shape-complex-vowel-constraints.hh" -#include "hb-ot-layout.hh" - - -/* - * Indic shaper. - */ - - -/* - * 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 base_position_t { - BASE_POS_LAST_SINHALA, - BASE_POS_LAST -}; -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; - base_position_t base_pos; - 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,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, - {HB_SCRIPT_DEVANAGARI,true, 0x094Du,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, - {HB_SCRIPT_BENGALI, true, 0x09CDu,BASE_POS_LAST, REPH_POS_AFTER_SUB, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, - {HB_SCRIPT_GURMUKHI, true, 0x0A4Du,BASE_POS_LAST, REPH_POS_BEFORE_SUB, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, - {HB_SCRIPT_GUJARATI, true, 0x0ACDu,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, - {HB_SCRIPT_ORIYA, true, 0x0B4Du,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, - {HB_SCRIPT_TAMIL, true, 0x0BCDu,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST}, - {HB_SCRIPT_TELUGU, true, 0x0C4Du,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_EXPLICIT, BLWF_MODE_POST_ONLY}, - {HB_SCRIPT_KANNADA, true, 0x0CCDu,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT, BLWF_MODE_POST_ONLY}, - {HB_SCRIPT_MALAYALAM, true, 0x0D4Du,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_LOG_REPHA,BLWF_MODE_PRE_AND_POST}, - {HB_SCRIPT_SINHALA, false,0x0DCAu,BASE_POS_LAST_SINHALA, - REPH_POS_AFTER_POST, REPH_MODE_EXPLICIT, BLWF_MODE_PRE_AND_POST}, -}; - - - -/* - * Indic shaper. - */ - -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}, - {HB_TAG('a','k','h','n'), F_GLOBAL_MANUAL_JOINERS}, - {HB_TAG('r','p','h','f'), F_MANUAL_JOINERS}, - {HB_TAG('r','k','r','f'), F_GLOBAL_MANUAL_JOINERS}, - {HB_TAG('p','r','e','f'), F_MANUAL_JOINERS}, - {HB_TAG('b','l','w','f'), F_MANUAL_JOINERS}, - {HB_TAG('a','b','v','f'), F_MANUAL_JOINERS}, - {HB_TAG('h','a','l','f'), F_MANUAL_JOINERS}, - {HB_TAG('p','s','t','f'), F_MANUAL_JOINERS}, - {HB_TAG('v','a','t','u'), F_GLOBAL_MANUAL_JOINERS}, - {HB_TAG('c','j','c','t'), F_GLOBAL_MANUAL_JOINERS}, - /* - * 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}, - {HB_TAG('p','r','e','s'), F_GLOBAL_MANUAL_JOINERS}, - {HB_TAG('a','b','v','s'), F_GLOBAL_MANUAL_JOINERS}, - {HB_TAG('b','l','w','s'), F_GLOBAL_MANUAL_JOINERS}, - {HB_TAG('p','s','t','s'), F_GLOBAL_MANUAL_JOINERS}, - {HB_TAG('h','a','l','n'), F_GLOBAL_MANUAL_JOINERS}, -}; - -/* - * 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')); - /* 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')); - - - 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]); - - map->add_gsub_pause (_hb_clear_syllables); -} - -static void -override_features_indic (hb_ot_shape_planner_t *plan) -{ - plan->map.disable_feature (HB_TAG('l','i','g','a')); -} - - -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) -{ - 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 a < b ? -1 : a == b ? 0 : +1; -} - - - -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; - - if (indic_plan->config->base_pos != BASE_POS_LAST) - return; - - 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 (OT_Ra)) && - is_one_of (info[start+1], FLAG (OT_H)) && - is_one_of (info[start+2], FLAG (OT_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() == OT_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() == OT_Repha) - { - limit += 1; - while (limit < end && is_joiner (info[limit])) - limit++; - base = start; - has_reph = true; - } - - switch (indic_plan->config->base_pos) - { - case BASE_POS_LAST: - { - /* -> 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() == OT_ZWJ && - info[i - 1].indic_category() == OT_H) - break; - } - } while (i > limit); - } - break; - - case BASE_POS_LAST_SINHALA: - { - /* Sinhala base positioning is slightly different from main Indic, in that: - * 1. Its ZWJ behavior is different, - * 2. We don't need to look into the font for consonant positions. - */ - - if (!has_reph) - base = limit; - - /* Find the last base consonant that is not blocked by ZWJ. If there is - * a ZWJ right before a base consonant, that would request a subjoined form. */ - for (unsigned int i = limit; i < end; i++) - if (is_consonant (info[i])) - { - if (limit < i && info[i - 1].indic_category() == OT_ZWJ) - break; - else - base = i; - } - - /* Mark all subsequent consonants as below. */ - for (unsigned int i = base + 1; i < end; i++) - if (is_consonant (info[i])) - info[i].indic_position() = POS_BELOW_C; - } - break; - } - - /* -> 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; - - /* Mark final consonants. A final consonant is one appearing after a matra. - * Happens in Sinhala. */ - for (unsigned int i = base + 1; i < end; i++) - if (info[i].indic_category() == OT_M) { - for (unsigned int j = i + 1; j < end; j++) - if (is_consonant (info[j])) { - info[j].indic_position() = POS_FINAL_C; - break; - } - break; - } - - /* 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() == OT_H) - { - unsigned int j; - for (j = end - 1; j > i; j--) - if (is_consonant (info[j]) || - (disallow_double_halants && info[j].indic_category() == OT_H)) - break; - if (info[j].indic_category() != OT_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 (OT_N) | FLAG (OT_RS) | MEDIAL_FLAGS | FLAG (OT_H)))) - { - info[i].indic_position() = last_pos; - if (unlikely (info[i].indic_category() == OT_H && - info[i].indic_position() == POS_PRE_M)) - { - /* - * Uniscribe doesn't move the Halant with Left Matra. - * TEST: U+092B,U+093F,U+094DE - * We follow. This is important for the Sinhala - * U+0DDA split matra since it decomposes to U+0DD9,U+0DCA - * where U+0DD9 is a left matra and U+0DCA is the virama. - * We don't want to move the virama with the left matra. - * TEST: U+0D9A,U+0DDA - */ - 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() == OT_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() == OT_Ra && - info[i+1].indic_category() == OT_H && - (i + 2 == base || - info[i+2].indic_category() != OT_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() == OT_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() == OT_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, - OT_DOTTEDCIRCLE, - OT_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 OT_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() = OT_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 (OT_ZWJ))) - base--; - if (base < end) - while (start < base && - is_one_of (info[base], (FLAG (OT_N) | FLAG (OT_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 (OT_M) | FLAG (OT_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() == OT_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() == OT_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() == OT_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(OT_M) | FLAG (OT_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: - case HB_SCRIPT_SINHALA: - break; - - default: - /* Uniscribe merges the entire syllable into a single cluster... Except for Tamil & Sinhala. - * 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) -{ - _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 - } - - if ((ab == 0x0DDAu || hb_in_range<hb_codepoint_t> (ab, 0x0DDCu, 0x0DDEu))) - { - /* - * Sinhala split matras... Let the fun begin. - * - * These four characters have Unicode decompositions. However, Uniscribe - * decomposes them "Khmer-style", that is, it uses the character itself to - * get the second half. The first half of all four decompositions is always - * U+0DD9. - * - * Now, there are buggy fonts, namely, the widely used lklug.ttf, that are - * broken with Uniscribe. But we need to support them. As such, we only - * do the Uniscribe-style decomposition if the character is transformed into - * its "sec.half" form by the 'pstf' feature. Otherwise, we fall back to - * Unicode decomposition. - * - * Note that we can't unconditionally use Unicode decomposition. That would - * break some other fonts, that are designed to work with Uniscribe, and - * don't have positioning features for the Unicode-style decomposition. - * - * Argh... - * - * The Uniscribe behavior is now documented in the newly published Sinhala - * spec in 2012: - * - * https://docs.microsoft.com/en-us/typography/script-development/sinhala#shaping - */ - - - const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) c->plan->data; - hb_codepoint_t glyph; - if (indic_plan->uniscribe_bug_compatible || - (c->font->get_nominal_glyph (ab, &glyph) && - indic_plan->pstf.would_substitute (&glyph, 1, c->font->face))) - { - /* Ok, safe to use Uniscribe-style decomposition. */ - *a = 0x0DD9u; - *b = ab; - return true; - } - } - - 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_complex_shaper_t _hb_ot_complex_shaper_indic = -{ - collect_features_indic, - override_features_indic, - data_create_indic, - data_destroy_indic, - preprocess_text_indic, - nullptr, /* postprocess_glyphs */ - HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, - decompose_indic, - compose_indic, - setup_masks_indic, - HB_TAG_NONE, /* gpos_tag */ - nullptr, /* reorder_marks */ - HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, - false, /* fallback_position */ -}; - - -#endif |