Edit
kc3-lang/harfbuzz/src/hb-ot-shape-complex-myanmar.cc
Behdad Esfahbod
- src/hb-ot-shape-complex-myanmar.cc
-
/* * 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-ot-shape-complex-myanmar.hh" /* * Myanmar shaper. */ static const hb_tag_t basic_features[] = { /* * Basic features. * These features are applied in order, one at a time, after reordering. */ 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 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 const hb_tag_t positioning_features[] = { /* * Positioning features. * We don't care about the types. */ HB_TAG('d','i','s','t'), /* Pre-release version of Windows 8 Myanmar font had abvm,blwm * features. The released Windows 8 version of the font (as well * as the released spec) used 'mark' instead. The Windows 8 * shaper however didn't apply 'mark' but did apply 'mkmk'. * Perhaps it applied abvm/blwm. This was fixed in a Windows 8 * update, so now it applies mark/mkmk. We are guessing that * it still applies abvm/blwm too. */ HB_TAG('a','b','v','m'), HB_TAG('b','l','w','m'), }; static void setup_syllables (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer); static void reorder (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer); static void clear_syllables (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); 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')); map->add_gsub_pause (reorder); for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++) { map->enable_feature (basic_features[i], F_MANUAL_ZWJ); map->add_gsub_pause (nullptr); } map->add_gsub_pause (clear_syllables); for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++) map->enable_feature (other_features[i], F_MANUAL_ZWJ); for (unsigned int i = 0; i < ARRAY_LENGTH (positioning_features); i++) map->enable_feature (positioning_features[i]); } static void override_features_myanmar (hb_ot_shape_planner_t *plan) { plan->map.disable_feature (HB_TAG('l','i','g','a')); } enum syllable_type_t { consonant_syllable, punctuation_cluster, broken_cluster, non_myanmar_cluster, }; #include "hb-ot-shape-complex-myanmar-machine.hh" 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); /* 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_myanmar_properties (info[i]); } static void setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED, hb_font_t *font HB_UNUSED, hb_buffer_t *buffer) { find_syllables (buffer); foreach_syllable (buffer, start, end) buffer->unsafe_to_break (start, end); } 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 a < b ? -1 : a == b ? 0 : +1; } /* 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() == OT_Ra && info[start+1].myanmar_category() == OT_As && info[start+2].myanmar_category() == OT_H) { limit += 3; base = start; has_reph = true; } { if (!has_reph) base = limit; for (unsigned int i = limit; i < end; i++) if (is_consonant (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++; } indic_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() == OT_MR) /* Pre-base reordering */ { info[i].myanmar_position() = POS_PRE_C; continue; } if (info[i].myanmar_position() < POS_BASE_C) /* Left matra */ { continue; } if (info[i].myanmar_category() == OT_VS) { info[i].myanmar_position() = info[i - 1].myanmar_position(); continue; } if (pos == POS_AFTER_MAIN && info[i].myanmar_category() == OT_VBlw) { pos = POS_BELOW_C; info[i].myanmar_position() = pos; continue; } if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_A) { info[i].myanmar_position() = POS_BEFORE_SUB; continue; } if (pos == POS_BELOW_C && info[i].myanmar_category() == OT_VBlw) { info[i].myanmar_position() = pos; continue; } if (pos == POS_BELOW_C && info[i].myanmar_category() != OT_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); } static void initial_reordering_syllable (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) { syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F); switch (syllable_type) { case broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */ case consonant_syllable: initial_reordering_consonant_syllable (buffer, start, end); break; case punctuation_cluster: case non_myanmar_cluster: break; } } static inline void insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED, hb_font_t *font, hb_buffer_t *buffer) { if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE)) return; /* Note: This loop is extra overhead, but should not be measurable. * TODO Use a buffer scratch flag to remove the loop. */ bool has_broken_syllables = false; unsigned int count = buffer->len; hb_glyph_info_t *info = buffer->info; for (unsigned int i = 0; i < count; i++) if ((info[i].syllable() & 0x0F) == broken_cluster) { has_broken_syllables = true; break; } if (likely (!has_broken_syllables)) return; hb_codepoint_t dottedcircle_glyph; if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph)) return; hb_glyph_info_t dottedcircle = {0}; dottedcircle.codepoint = 0x25CCu; set_myanmar_properties (dottedcircle); dottedcircle.codepoint = dottedcircle_glyph; buffer->clear_output (); buffer->idx = 0; unsigned int last_syllable = 0; while (buffer->idx < buffer->len && buffer->successful) { unsigned int syllable = buffer->cur().syllable(); syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F); if (unlikely (last_syllable != syllable && syllable_type == broken_cluster)) { last_syllable = syllable; hb_glyph_info_t ginfo = dottedcircle; ginfo.cluster = buffer->cur().cluster; ginfo.mask = buffer->cur().mask; ginfo.syllable() = buffer->cur().syllable(); buffer->output_info (ginfo); } else buffer->next_glyph (); } buffer->swap_buffers (); } static void reorder (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) { insert_dotted_circles (plan, font, buffer); foreach_syllable (buffer, start, end) initial_reordering_syllable (plan, font->face, buffer, start, end); HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category); HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position); } static void clear_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED, hb_font_t *font HB_UNUSED, hb_buffer_t *buffer) { hb_glyph_info_t *info = buffer->info; unsigned int count = buffer->len; for (unsigned int i = 0; i < count; i++) info[i].syllable() = 0; } const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar = { collect_features_myanmar, override_features_myanmar, nullptr, /* data_create */ nullptr, /* data_destroy */ nullptr, /* preprocess_text */ nullptr, /* postprocess_glyphs */ HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, nullptr, /* decompose */ nullptr, /* compose */ setup_masks_myanmar, HB_TAG_NONE, /* gpos_tag */ nullptr, /* reorder_marks */ HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY, false, /* fallback_position */ }; /* Ugly Zawgyi encoding. * Disable all auto processing. * https://github.com/harfbuzz/harfbuzz/issues/1162 */ const hb_ot_complex_shaper_t _hb_ot_complex_shaper_myanmar_zawgyi = { nullptr, /* collect_features */ nullptr, /* override_features */ nullptr, /* data_create */ nullptr, /* data_destroy */ nullptr, /* preprocess_text */ nullptr, /* postprocess_glyphs */ HB_OT_SHAPE_NORMALIZATION_MODE_NONE, nullptr, /* decompose */ nullptr, /* compose */ nullptr, /* setup_masks */ HB_TAG_NONE, /* gpos_tag */ nullptr, /* reorder_marks */ HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, false, /* fallback_position */ };