378 lines
10 KiB
C++
378 lines
10 KiB
C++
/*
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* Copyright © 2011,2012,2013 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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* Google Author(s): Behdad Esfahbod
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*/
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#include "hb-ot-shape-complex-indic-private.hh"
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/* buffer var allocations */
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#define sea_category() complex_var_u8_0() /* indic_category_t */
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#define sea_position() complex_var_u8_1() /* indic_position_t */
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/*
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* South-East Asian shaper.
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* Loosely based on the Myanmar spec / shaper.
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* There is no OpenType spec for this.
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*/
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static const hb_tag_t
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basic_features[] =
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{
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/*
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* Basic features.
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* These features are applied in order, one at a time, after initial_reordering.
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*/
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HB_TAG('p','r','e','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('p','s','t','f'),
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};
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static const hb_tag_t
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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 final_reordering.
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*/
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HB_TAG('p','r','e','s'),
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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('p','s','t','s'),
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/* Positioning features, though we don't care about the types. */
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HB_TAG('d','i','s','t'),
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};
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static void
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setup_syllables (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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initial_reordering (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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final_reordering (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_sea (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);
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map->add_global_bool_feature (HB_TAG('l','o','c','l'));
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/* The Indic specs do not require ccmp, but we apply it here since if
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* there is a use of it, it's typically at the beginning. */
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map->add_global_bool_feature (HB_TAG('c','c','m','p'));
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map->add_gsub_pause (initial_reordering);
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for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
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{
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map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
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map->add_gsub_pause (NULL);
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}
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map->add_gsub_pause (final_reordering);
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for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
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map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);
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}
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static void
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override_features_sea (hb_ot_shape_planner_t *plan)
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{
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plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);
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}
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enum syllable_type_t {
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consonant_syllable,
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broken_cluster,
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non_sea_cluster,
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};
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#include "hb-ot-shape-complex-sea-machine.hh"
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/* Note: This enum is duplicated in the -machine.rl source file.
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* Not sure how to avoid duplication. */
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enum sea_category_t {
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// OT_C = 1,
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OT_GB = 12, /* Generic Base XXX DOTTED CIRCLE only for now */
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// OT_H = 4, /* Halant */
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OT_IV = 2, /* Independent Vowel */
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OT_MR = 22, /* Medial Ra */
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// OT_CM = 17, /* Consonant Medial */
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OT_VAbv = 26,
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OT_VBlw = 27,
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OT_VPre = 28,
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OT_VPst = 29,
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OT_T = 3, /* Tone Marks */
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// OT_A = 10, /* Anusvara */
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};
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static inline void
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set_sea_properties (hb_glyph_info_t &info)
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{
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hb_codepoint_t u = info.codepoint;
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unsigned int type = hb_indic_get_categories (u);
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indic_category_t cat = (indic_category_t) (type & 0x7F);
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indic_position_t pos = (indic_position_t) (type >> 8);
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/* Medial Ra */
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if (u == 0x1A55 || u == 0xAA34)
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cat = (indic_category_t) OT_MR;
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if (cat == OT_M)
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{
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switch ((int) pos)
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{
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case POS_PRE_C: cat = (indic_category_t) OT_VPre; break;
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case POS_ABOVE_C: cat = (indic_category_t) OT_VAbv; break;
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case POS_BELOW_C: cat = (indic_category_t) OT_VBlw; break;
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case POS_POST_C: cat = (indic_category_t) OT_VPst; break;
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}
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}
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info.sea_category() = (sea_category_t) cat;
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info.sea_position() = pos;
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}
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static void
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setup_masks_sea (const hb_ot_shape_plan_t *plan HB_UNUSED,
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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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HB_BUFFER_ALLOCATE_VAR (buffer, sea_category);
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HB_BUFFER_ALLOCATE_VAR (buffer, sea_position);
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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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for (unsigned int i = 0; i < count; i++)
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set_sea_properties (buffer->info[i]);
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}
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static void
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setup_syllables (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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find_syllables (buffer);
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}
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static int
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compare_sea_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
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{
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int a = pa->sea_position();
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int b = pb->sea_position();
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return a < b ? -1 : a == b ? 0 : +1;
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}
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static void
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initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
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hb_face_t *face,
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hb_buffer_t *buffer,
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unsigned int start, unsigned int end)
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{
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hb_glyph_info_t *info = buffer->info;
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unsigned int base = start;
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/* Reorder! */
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unsigned int i = start;
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for (; i < base; i++)
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info[i].sea_position() = POS_PRE_C;
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if (i < end)
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{
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info[i].sea_position() = POS_BASE_C;
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i++;
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}
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for (; i < end; i++)
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{
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if (info[i].sea_category() == OT_MR) /* Pre-base reordering */
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{
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info[i].sea_position() = POS_PRE_C;
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continue;
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}
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if (info[i].sea_category() == OT_VPre) /* Left matra */
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{
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info[i].sea_position() = POS_PRE_M;
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continue;
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}
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info[i].sea_position() = POS_AFTER_MAIN;
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}
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buffer->merge_clusters (start, end);
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/* Sit tight, rock 'n roll! */
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hb_bubble_sort (info + start, end - start, compare_sea_order);
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}
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static void
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initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan,
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hb_face_t *face,
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hb_buffer_t *buffer,
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unsigned int start, unsigned int end)
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{
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/* We already inserted dotted-circles, so just call the consonant_syllable. */
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initial_reordering_consonant_syllable (plan, face, buffer, start, end);
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}
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static void
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initial_reordering_non_sea_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
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hb_face_t *face HB_UNUSED,
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hb_buffer_t *buffer HB_UNUSED,
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unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
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{
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/* Nothing to do right now. If we ever switch to using the output
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* buffer in the reordering process, we'd need to next_glyph() here. */
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}
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static void
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initial_reordering_syllable (const hb_ot_shape_plan_t *plan,
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hb_face_t *face,
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hb_buffer_t *buffer,
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unsigned int start, unsigned int end)
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{
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syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
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switch (syllable_type) {
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case consonant_syllable: initial_reordering_consonant_syllable (plan, face, buffer, start, end); return;
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case broken_cluster: initial_reordering_broken_cluster (plan, face, buffer, start, end); return;
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case non_sea_cluster: initial_reordering_non_sea_cluster (plan, face, buffer, start, end); return;
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}
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}
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static inline void
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insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
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hb_font_t *font,
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hb_buffer_t *buffer)
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{
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/* Note: This loop is extra overhead, but should not be measurable. */
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bool has_broken_syllables = false;
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unsigned int count = buffer->len;
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for (unsigned int i = 0; i < count; i++)
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if ((buffer->info[i].syllable() & 0x0F) == broken_cluster) {
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has_broken_syllables = true;
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break;
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}
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if (likely (!has_broken_syllables))
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return;
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hb_codepoint_t dottedcircle_glyph;
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if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph))
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return;
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hb_glyph_info_t dottedcircle = {0};
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dottedcircle.codepoint = 0x25CC;
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set_sea_properties (dottedcircle);
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dottedcircle.codepoint = dottedcircle_glyph;
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buffer->clear_output ();
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buffer->idx = 0;
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unsigned int last_syllable = 0;
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while (buffer->idx < buffer->len)
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{
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unsigned int syllable = buffer->cur().syllable();
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syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
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if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
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{
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last_syllable = syllable;
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hb_glyph_info_t info = dottedcircle;
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info.cluster = buffer->cur().cluster;
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info.mask = buffer->cur().mask;
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info.syllable() = buffer->cur().syllable();
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buffer->output_info (info);
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}
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else
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buffer->next_glyph ();
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}
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buffer->swap_buffers ();
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}
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static void
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initial_reordering (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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insert_dotted_circles (plan, font, buffer);
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hb_glyph_info_t *info = buffer->info;
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unsigned int count = buffer->len;
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if (unlikely (!count)) return;
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unsigned int last = 0;
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unsigned int last_syllable = info[0].syllable();
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for (unsigned int i = 1; i < count; i++)
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if (last_syllable != info[i].syllable()) {
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initial_reordering_syllable (plan, font->face, buffer, last, i);
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last = i;
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last_syllable = info[last].syllable();
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}
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initial_reordering_syllable (plan, font->face, buffer, last, count);
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}
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static void
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final_reordering (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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hb_glyph_info_t *info = buffer->info;
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unsigned int count = buffer->len;
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/* Zero syllables now... */
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for (unsigned int i = 0; i < count; i++)
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info[i].syllable() = 0;
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HB_BUFFER_DEALLOCATE_VAR (buffer, sea_category);
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HB_BUFFER_DEALLOCATE_VAR (buffer, sea_position);
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}
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const hb_ot_complex_shaper_t _hb_ot_complex_shaper_sea =
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{
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"sea",
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collect_features_sea,
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override_features_sea,
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NULL, /* data_create */
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NULL, /* data_destroy */
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NULL, /* preprocess_text */
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HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
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NULL, /* decompose */
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NULL, /* compose */
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setup_masks_sea,
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HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
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false, /* fallback_position */
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};
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