504 lines
14 KiB
C++
504 lines
14 KiB
C++
/*
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* Copyright © 2015 Mozilla Foundation.
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* Copyright © 2015 Google, Inc.
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*
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* This is part of HarfBuzz, a text shaping library.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*
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* Mozilla Author(s): Jonathan Kew
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* Google Author(s): Behdad Esfahbod
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*/
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#include "hb.hh"
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#ifndef HB_NO_OT_SHAPE
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#include "hb-ot-shape-complex-use-machine.hh"
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#include "hb-ot-shape-complex-use-table.hh"
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#include "hb-ot-shape-complex-arabic.hh"
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#include "hb-ot-shape-complex-arabic-joining-list.hh"
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#include "hb-ot-shape-complex-vowel-constraints.hh"
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/*
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* Universal Shaping Engine.
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* https://docs.microsoft.com/en-us/typography/script-development/use
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*/
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static const hb_tag_t
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use_basic_features[] =
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{
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/*
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* Basic features.
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* These features are applied all at once, before reordering, constrained
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* to the syllable.
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*/
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HB_TAG('r','k','r','f'),
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HB_TAG('a','b','v','f'),
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HB_TAG('b','l','w','f'),
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HB_TAG('h','a','l','f'),
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HB_TAG('p','s','t','f'),
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HB_TAG('v','a','t','u'),
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HB_TAG('c','j','c','t'),
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};
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static const hb_tag_t
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use_topographical_features[] =
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{
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HB_TAG('i','s','o','l'),
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HB_TAG('i','n','i','t'),
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HB_TAG('m','e','d','i'),
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HB_TAG('f','i','n','a'),
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};
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/* Same order as use_topographical_features. */
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enum joining_form_t {
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JOINING_FORM_ISOL,
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JOINING_FORM_INIT,
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JOINING_FORM_MEDI,
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JOINING_FORM_FINA,
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_JOINING_FORM_NONE
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};
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static const hb_tag_t
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use_other_features[] =
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{
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/*
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* Other features.
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* These features are applied all at once, after reordering and
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* clearing syllables.
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*/
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HB_TAG('a','b','v','s'),
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HB_TAG('b','l','w','s'),
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HB_TAG('h','a','l','n'),
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HB_TAG('p','r','e','s'),
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HB_TAG('p','s','t','s'),
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};
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static void
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setup_syllables_use (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer);
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static void
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record_rphf_use (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer);
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static void
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record_pref_use (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer);
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static void
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reorder_use (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer);
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static void
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collect_features_use (hb_ot_shape_planner_t *plan)
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{
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hb_ot_map_builder_t *map = &plan->map;
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/* Do this before any lookups have been applied. */
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map->add_gsub_pause (setup_syllables_use);
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/* "Default glyph pre-processing group" */
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map->enable_feature (HB_TAG('l','o','c','l'));
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map->enable_feature (HB_TAG('c','c','m','p'));
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map->enable_feature (HB_TAG('n','u','k','t'));
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map->enable_feature (HB_TAG('a','k','h','n'), F_MANUAL_ZWJ);
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/* "Reordering group" */
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map->add_gsub_pause (_hb_clear_substitution_flags);
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map->add_feature (HB_TAG('r','p','h','f'), F_MANUAL_ZWJ);
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map->add_gsub_pause (record_rphf_use);
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map->add_gsub_pause (_hb_clear_substitution_flags);
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map->enable_feature (HB_TAG('p','r','e','f'), F_MANUAL_ZWJ);
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map->add_gsub_pause (record_pref_use);
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/* "Orthographic unit shaping group" */
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for (unsigned int i = 0; i < ARRAY_LENGTH (use_basic_features); i++)
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map->enable_feature (use_basic_features[i], F_MANUAL_ZWJ);
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map->add_gsub_pause (reorder_use);
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map->add_gsub_pause (_hb_clear_syllables);
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/* "Topographical features" */
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for (unsigned int i = 0; i < ARRAY_LENGTH (use_topographical_features); i++)
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map->add_feature (use_topographical_features[i]);
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map->add_gsub_pause (nullptr);
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/* "Standard typographic presentation" */
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for (unsigned int i = 0; i < ARRAY_LENGTH (use_other_features); i++)
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map->enable_feature (use_other_features[i], F_MANUAL_ZWJ);
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}
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struct use_shape_plan_t
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{
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hb_mask_t rphf_mask;
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arabic_shape_plan_t *arabic_plan;
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};
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static void *
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data_create_use (const hb_ot_shape_plan_t *plan)
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{
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use_shape_plan_t *use_plan = (use_shape_plan_t *) hb_calloc (1, sizeof (use_shape_plan_t));
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if (unlikely (!use_plan))
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return nullptr;
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use_plan->rphf_mask = plan->map.get_1_mask (HB_TAG('r','p','h','f'));
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if (has_arabic_joining (plan->props.script))
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{
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use_plan->arabic_plan = (arabic_shape_plan_t *) data_create_arabic (plan);
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if (unlikely (!use_plan->arabic_plan))
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{
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hb_free (use_plan);
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return nullptr;
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}
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}
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return use_plan;
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}
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static void
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data_destroy_use (void *data)
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{
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use_shape_plan_t *use_plan = (use_shape_plan_t *) data;
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if (use_plan->arabic_plan)
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data_destroy_arabic (use_plan->arabic_plan);
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hb_free (data);
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}
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static void
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setup_masks_use (const hb_ot_shape_plan_t *plan,
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hb_buffer_t *buffer,
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hb_font_t *font HB_UNUSED)
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{
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const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
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/* Do this before allocating use_category(). */
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if (use_plan->arabic_plan)
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{
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setup_masks_arabic_plan (use_plan->arabic_plan, buffer, plan->props.script);
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}
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HB_BUFFER_ALLOCATE_VAR (buffer, use_category);
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/* We cannot setup masks here. We save information about characters
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* and setup masks later on in a pause-callback. */
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unsigned int count = buffer->len;
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hb_glyph_info_t *info = buffer->info;
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for (unsigned int i = 0; i < count; i++)
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info[i].use_category() = hb_use_get_category (info[i].codepoint);
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}
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static void
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setup_rphf_mask (const hb_ot_shape_plan_t *plan,
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hb_buffer_t *buffer)
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{
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const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
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hb_mask_t mask = use_plan->rphf_mask;
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if (!mask) return;
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hb_glyph_info_t *info = buffer->info;
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foreach_syllable (buffer, start, end)
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{
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unsigned int limit = info[start].use_category() == USE(R) ? 1 : hb_min (3u, end - start);
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for (unsigned int i = start; i < start + limit; i++)
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info[i].mask |= mask;
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}
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}
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static void
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setup_topographical_masks (const hb_ot_shape_plan_t *plan,
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hb_buffer_t *buffer)
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{
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const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
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if (use_plan->arabic_plan)
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return;
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static_assert ((JOINING_FORM_INIT < 4 && JOINING_FORM_ISOL < 4 && JOINING_FORM_MEDI < 4 && JOINING_FORM_FINA < 4), "");
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hb_mask_t masks[4], all_masks = 0;
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for (unsigned int i = 0; i < 4; i++)
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{
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masks[i] = plan->map.get_1_mask (use_topographical_features[i]);
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if (masks[i] == plan->map.get_global_mask ())
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masks[i] = 0;
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all_masks |= masks[i];
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}
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if (!all_masks)
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return;
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hb_mask_t other_masks = ~all_masks;
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unsigned int last_start = 0;
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joining_form_t last_form = _JOINING_FORM_NONE;
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hb_glyph_info_t *info = buffer->info;
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foreach_syllable (buffer, start, end)
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{
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use_syllable_type_t syllable_type = (use_syllable_type_t) (info[start].syllable() & 0x0F);
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switch (syllable_type)
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{
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case use_independent_cluster:
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case use_symbol_cluster:
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case use_hieroglyph_cluster:
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case use_non_cluster:
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/* These don't join. Nothing to do. */
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last_form = _JOINING_FORM_NONE;
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break;
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case use_virama_terminated_cluster:
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case use_sakot_terminated_cluster:
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case use_standard_cluster:
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case use_number_joiner_terminated_cluster:
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case use_numeral_cluster:
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case use_broken_cluster:
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bool join = last_form == JOINING_FORM_FINA || last_form == JOINING_FORM_ISOL;
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if (join)
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{
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/* Fixup previous syllable's form. */
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last_form = last_form == JOINING_FORM_FINA ? JOINING_FORM_MEDI : JOINING_FORM_INIT;
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for (unsigned int i = last_start; i < start; i++)
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info[i].mask = (info[i].mask & other_masks) | masks[last_form];
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}
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/* Form for this syllable. */
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last_form = join ? JOINING_FORM_FINA : JOINING_FORM_ISOL;
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for (unsigned int i = start; i < end; i++)
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info[i].mask = (info[i].mask & other_masks) | masks[last_form];
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break;
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}
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last_start = start;
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}
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}
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static void
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setup_syllables_use (const hb_ot_shape_plan_t *plan,
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hb_font_t *font HB_UNUSED,
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hb_buffer_t *buffer)
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{
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find_syllables_use (buffer);
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foreach_syllable (buffer, start, end)
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buffer->unsafe_to_break (start, end);
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setup_rphf_mask (plan, buffer);
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setup_topographical_masks (plan, buffer);
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}
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static void
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record_rphf_use (const hb_ot_shape_plan_t *plan,
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hb_font_t *font HB_UNUSED,
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hb_buffer_t *buffer)
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{
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const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
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hb_mask_t mask = use_plan->rphf_mask;
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if (!mask) return;
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hb_glyph_info_t *info = buffer->info;
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foreach_syllable (buffer, start, end)
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{
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/* Mark a substituted repha as USE(R). */
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for (unsigned int i = start; i < end && (info[i].mask & mask); i++)
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if (_hb_glyph_info_substituted (&info[i]))
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{
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info[i].use_category() = USE(R);
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break;
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}
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}
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}
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static void
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record_pref_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
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hb_font_t *font HB_UNUSED,
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hb_buffer_t *buffer)
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{
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hb_glyph_info_t *info = buffer->info;
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foreach_syllable (buffer, start, end)
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{
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/* Mark a substituted pref as VPre, as they behave the same way. */
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for (unsigned int i = start; i < end; i++)
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if (_hb_glyph_info_substituted (&info[i]))
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{
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info[i].use_category() = USE(VPre);
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break;
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}
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}
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}
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static inline bool
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is_halant_use (const hb_glyph_info_t &info)
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{
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return (info.use_category() == USE(H) || info.use_category() == USE(HVM)) &&
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!_hb_glyph_info_ligated (&info);
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}
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static void
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reorder_syllable_use (hb_buffer_t *buffer, unsigned int start, unsigned int end)
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{
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use_syllable_type_t syllable_type = (use_syllable_type_t) (buffer->info[start].syllable() & 0x0F);
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/* Only a few syllable types need reordering. */
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if (unlikely (!(FLAG_UNSAFE (syllable_type) &
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(FLAG (use_virama_terminated_cluster) |
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FLAG (use_sakot_terminated_cluster) |
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FLAG (use_standard_cluster) |
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FLAG (use_broken_cluster) |
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0))))
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return;
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hb_glyph_info_t *info = buffer->info;
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#define POST_BASE_FLAGS64 (FLAG64 (USE(FAbv)) | \
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FLAG64 (USE(FBlw)) | \
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FLAG64 (USE(FPst)) | \
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FLAG64 (USE(MAbv)) | \
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FLAG64 (USE(MBlw)) | \
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FLAG64 (USE(MPst)) | \
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FLAG64 (USE(MPre)) | \
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FLAG64 (USE(VAbv)) | \
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FLAG64 (USE(VBlw)) | \
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FLAG64 (USE(VPst)) | \
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FLAG64 (USE(VPre)) | \
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FLAG64 (USE(VMAbv)) | \
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FLAG64 (USE(VMBlw)) | \
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FLAG64 (USE(VMPst)) | \
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FLAG64 (USE(VMPre)))
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/* Move things forward. */
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if (info[start].use_category() == USE(R) && end - start > 1)
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{
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/* Got a repha. Reorder it towards the end, but before the first post-base
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* glyph. */
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for (unsigned int i = start + 1; i < end; i++)
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{
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bool is_post_base_glyph = (FLAG64_UNSAFE (info[i].use_category()) & POST_BASE_FLAGS64) ||
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is_halant_use (info[i]);
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if (is_post_base_glyph || i == end - 1)
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{
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/* If we hit a post-base glyph, move before it; otherwise move to the
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* end. Shift things in between backward. */
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if (is_post_base_glyph)
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i--;
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buffer->merge_clusters (start, i + 1);
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hb_glyph_info_t t = info[start];
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memmove (&info[start], &info[start + 1], (i - start) * sizeof (info[0]));
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info[i] = t;
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break;
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}
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}
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}
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/* Move things back. */
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unsigned int j = start;
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for (unsigned int i = start; i < end; i++)
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{
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uint32_t flag = FLAG_UNSAFE (info[i].use_category());
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if (is_halant_use (info[i]))
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{
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/* If we hit a halant, move after it; otherwise move to the beginning, and
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* shift things in between forward. */
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j = i + 1;
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}
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else if (((flag) & (FLAG (USE(VPre)) | FLAG (USE(VMPre)))) &&
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/* Only move the first component of a MultipleSubst. */
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0 == _hb_glyph_info_get_lig_comp (&info[i]) &&
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j < i)
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{
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buffer->merge_clusters (j, i + 1);
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hb_glyph_info_t t = info[i];
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memmove (&info[j + 1], &info[j], (i - j) * sizeof (info[0]));
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info[j] = t;
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}
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}
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}
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static void
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reorder_use (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer)
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{
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if (buffer->message (font, "start reordering USE"))
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{
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hb_syllabic_insert_dotted_circles (font, buffer,
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use_broken_cluster,
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USE(B),
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USE(R));
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foreach_syllable (buffer, start, end)
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reorder_syllable_use (buffer, start, end);
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(void) buffer->message (font, "end reordering USE");
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}
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HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
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}
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static void
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preprocess_text_use (const hb_ot_shape_plan_t *plan,
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hb_buffer_t *buffer,
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hb_font_t *font)
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{
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_hb_preprocess_text_vowel_constraints (plan, buffer, font);
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}
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static bool
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compose_use (const hb_ot_shape_normalize_context_t *c,
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hb_codepoint_t a,
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hb_codepoint_t b,
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hb_codepoint_t *ab)
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{
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/* Avoid recomposing split matras. */
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if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
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return false;
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return (bool)c->unicode->compose (a, b, ab);
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}
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const hb_ot_complex_shaper_t _hb_ot_complex_shaper_use =
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{
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collect_features_use,
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nullptr, /* override_features */
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|
data_create_use,
|
|
data_destroy_use,
|
|
preprocess_text_use,
|
|
nullptr, /* postprocess_glyphs */
|
|
HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
|
|
nullptr, /* decompose */
|
|
compose_use,
|
|
setup_masks_use,
|
|
HB_TAG_NONE, /* gpos_tag */
|
|
nullptr, /* reorder_marks */
|
|
HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
|
|
false, /* fallback_position */
|
|
};
|
|
|
|
|
|
#endif
|