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Diffstat (limited to '')
-rw-r--r-- | gfx/harfbuzz/src/hb-ot-shaper-myanmar.cc | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-shaper-myanmar.cc b/gfx/harfbuzz/src/hb-ot-shaper-myanmar.cc new file mode 100644 index 0000000000..1b2a085a8d --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-shaper-myanmar.cc @@ -0,0 +1,390 @@ +/* + * Copyright © 2011,2012,2013 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Behdad Esfahbod + */ + +#include "hb.hh" + +#ifndef HB_NO_OT_SHAPE + +#include "hb-ot-shaper-myanmar-machine.hh" +#include "hb-ot-shaper-indic.hh" +#include "hb-ot-layout.hh" + + +/* + * Myanmar shaper. + */ + + +static const hb_tag_t +myanmar_basic_features[] = +{ + /* + * Basic features. + * These features are applied in order, one at a time, after reordering, + * constrained to the syllable. + */ + HB_TAG('r','p','h','f'), + HB_TAG('p','r','e','f'), + HB_TAG('b','l','w','f'), + HB_TAG('p','s','t','f'), +}; +static const hb_tag_t +myanmar_other_features[] = +{ + /* + * Other features. + * These features are applied all at once, after clearing syllables. + */ + HB_TAG('p','r','e','s'), + HB_TAG('a','b','v','s'), + HB_TAG('b','l','w','s'), + HB_TAG('p','s','t','s'), +}; + +static inline void +set_myanmar_properties (hb_glyph_info_t &info) +{ + hb_codepoint_t u = info.codepoint; + unsigned int type = hb_indic_get_categories (u); + + info.myanmar_category() = (myanmar_category_t) (type & 0xFFu); +} + + +static inline bool +is_one_of_myanmar (const hb_glyph_info_t &info, unsigned int flags) +{ + /* If it ligated, all bets are off. */ + if (_hb_glyph_info_ligated (&info)) return false; + return !!(FLAG_UNSAFE (info.myanmar_category()) & flags); +} + +/* Note: + * + * We treat Vowels and placeholders as if they were consonants. This is safe because Vowels + * cannot happen in a consonant syllable. The plus side however is, we can call the + * consonant syllable logic from the vowel syllable function and get it all right! + * + * Keep in sync with consonant_categories in the generator. */ +#define CONSONANT_FLAGS_MYANMAR (FLAG (M_Cat(C)) | FLAG (M_Cat(CS)) | FLAG (M_Cat(Ra)) | /* FLAG (M_Cat(CM)) | */ FLAG (M_Cat(IV)) | FLAG (M_Cat(GB)) | FLAG (M_Cat(DOTTEDCIRCLE))) + +static inline bool +is_consonant_myanmar (const hb_glyph_info_t &info) +{ + return is_one_of_myanmar (info, CONSONANT_FLAGS_MYANMAR); +} + + +static bool +setup_syllables_myanmar (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer); +static bool +reorder_myanmar (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer); + +static void +collect_features_myanmar (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_myanmar); + + map->enable_feature (HB_TAG('l','o','c','l'), F_PER_SYLLABLE); + /* The Indic specs do not require ccmp, but we apply it here since if + * there is a use of it, it's typically at the beginning. */ + map->enable_feature (HB_TAG('c','c','m','p'), F_PER_SYLLABLE); + + + map->add_gsub_pause (reorder_myanmar); + + for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_basic_features); i++) + { + map->enable_feature (myanmar_basic_features[i], F_MANUAL_ZWJ | F_PER_SYLLABLE); + map->add_gsub_pause (nullptr); + } + map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var + + for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_other_features); i++) + map->enable_feature (myanmar_other_features[i], F_MANUAL_ZWJ); +} + +static void +setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED, + hb_buffer_t *buffer, + hb_font_t *font HB_UNUSED) +{ + HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_category); + HB_BUFFER_ALLOCATE_VAR (buffer, myanmar_position); + + /* No masks, we just save information about characters. */ + + unsigned int count = buffer->len; + hb_glyph_info_t *info = buffer->info; + for (unsigned int i = 0; i < count; i++) + set_myanmar_properties (info[i]); +} + +static bool +setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED, + hb_font_t *font HB_UNUSED, + hb_buffer_t *buffer) +{ + HB_BUFFER_ALLOCATE_VAR (buffer, syllable); + find_syllables_myanmar (buffer); + foreach_syllable (buffer, start, end) + buffer->unsafe_to_break (start, end); + return false; +} + +static int +compare_myanmar_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb) +{ + int a = pa->myanmar_position(); + int b = pb->myanmar_position(); + + return (int) a - (int) b; +} + + +/* Rules from: + * https://docs.microsoft.com/en-us/typography/script-development/myanmar */ + +static void +initial_reordering_consonant_syllable (hb_buffer_t *buffer, + unsigned int start, unsigned int end) +{ + hb_glyph_info_t *info = buffer->info; + + unsigned int base = end; + bool has_reph = false; + + { + unsigned int limit = start; + if (start + 3 <= end && + info[start ].myanmar_category() == M_Cat(Ra) && + info[start+1].myanmar_category() == M_Cat(As) && + info[start+2].myanmar_category() == M_Cat(H)) + { + limit += 3; + base = start; + has_reph = true; + } + + { + if (!has_reph) + base = limit; + + for (unsigned int i = limit; i < end; i++) + if (is_consonant_myanmar (info[i])) + { + base = i; + break; + } + } + } + + /* Reorder! */ + { + unsigned int i = start; + for (; i < start + (has_reph ? 3 : 0); i++) + info[i].myanmar_position() = POS_AFTER_MAIN; + for (; i < base; i++) + info[i].myanmar_position() = POS_PRE_C; + if (i < end) + { + info[i].myanmar_position() = POS_BASE_C; + i++; + } + myanmar_position_t pos = POS_AFTER_MAIN; + /* The following loop may be ugly, but it implements all of + * Myanmar reordering! */ + for (; i < end; i++) + { + if (info[i].myanmar_category() == M_Cat(MR)) /* Pre-base reordering */ + { + info[i].myanmar_position() = POS_PRE_C; + continue; + } + if (info[i].myanmar_category() == M_Cat(VPre)) /* Left matra */ + { + info[i].myanmar_position() = POS_PRE_M; + continue; + } + if (info[i].myanmar_category() == M_Cat(VS)) + { + info[i].myanmar_position() = info[i - 1].myanmar_position(); + continue; + } + + if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == M_Cat(VBlw)) + { + pos = POS_BELOW_C; + info[i].myanmar_position() = pos; + continue; + } + + if (pos == POS_BELOW_C && info[i].myanmar_category() == M_Cat(A)) + { + info[i].myanmar_position() = POS_BEFORE_SUB; + continue; + } + if (pos == POS_BELOW_C && info[i].myanmar_category() == M_Cat(VBlw)) + { + info[i].myanmar_position() = pos; + continue; + } + if (pos == POS_BELOW_C && info[i].myanmar_category() != M_Cat(A)) + { + pos = POS_AFTER_SUB; + info[i].myanmar_position() = pos; + continue; + } + info[i].myanmar_position() = pos; + } + } + + /* Sit tight, rock 'n roll! */ + buffer->sort (start, end, compare_myanmar_order); + + /* Flip left-matra sequence. */ + unsigned first_left_matra = end; + unsigned last_left_matra = end; + for (unsigned int i = start; i < end; i++) + { + if (info[i].myanmar_position() == POS_PRE_M) + { + if (first_left_matra == end) + first_left_matra = i; + last_left_matra = i; + } + } + /* https://github.com/harfbuzz/harfbuzz/issues/3863 */ + if (first_left_matra < last_left_matra) + { + /* No need to merge clusters, done already? */ + buffer->reverse_range (first_left_matra, last_left_matra + 1); + /* Reverse back VS, etc. */ + unsigned i = first_left_matra; + for (unsigned j = i; j <= last_left_matra; j++) + if (info[j].myanmar_category() == M_Cat(VPre)) + { + buffer->reverse_range (i, j + 1); + i = j + 1; + } + } +} + +static void +reorder_syllable_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED, + hb_face_t *face HB_UNUSED, + hb_buffer_t *buffer, + unsigned int start, unsigned int end) +{ + myanmar_syllable_type_t syllable_type = (myanmar_syllable_type_t) (buffer->info[start].syllable() & 0x0F); + switch (syllable_type) { + + case myanmar_broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */ + case myanmar_consonant_syllable: + initial_reordering_consonant_syllable (buffer, start, end); + break; + + case myanmar_non_myanmar_cluster: + break; + } +} + +static bool +reorder_myanmar (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer) +{ + bool ret = false; + if (buffer->message (font, "start reordering myanmar")) + { + if (hb_syllabic_insert_dotted_circles (font, buffer, + myanmar_broken_cluster, + M_Cat(DOTTEDCIRCLE))) + ret = true; + + foreach_syllable (buffer, start, end) + reorder_syllable_myanmar (plan, font->face, buffer, start, end); + (void) buffer->message (font, "end reordering myanmar"); + } + + HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category); + HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position); + + return ret; +} + + +const hb_ot_shaper_t _hb_ot_shaper_myanmar = +{ + collect_features_myanmar, + nullptr, /* override_features */ + nullptr, /* data_create */ + nullptr, /* data_destroy */ + nullptr, /* preprocess_text */ + nullptr, /* postprocess_glyphs */ + nullptr, /* decompose */ + nullptr, /* compose */ + setup_masks_myanmar, + nullptr, /* reorder_marks */ + HB_TAG_NONE, /* gpos_tag */ + HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, + HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY, + false, /* fallback_position */ +}; + + +#ifndef HB_NO_OT_SHAPER_MYANMAR_ZAWGYI +/* Ugly Zawgyi encoding. + * Disable all auto processing. + * https://github.com/harfbuzz/harfbuzz/issues/1162 */ +const hb_ot_shaper_t _hb_ot_shaper_myanmar_zawgyi = +{ + nullptr, /* collect_features */ + nullptr, /* override_features */ + nullptr, /* data_create */ + nullptr, /* data_destroy */ + nullptr, /* preprocess_text */ + nullptr, /* postprocess_glyphs */ + nullptr, /* decompose */ + nullptr, /* compose */ + nullptr, /* setup_masks */ + nullptr, /* reorder_marks */ + HB_TAG_NONE, /* gpos_tag */ + HB_OT_SHAPE_NORMALIZATION_MODE_NONE, + HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, + false, /* fallback_position */ +}; +#endif + + +#endif |