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Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-shape-complex-use.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-shape-complex-use.cc | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-shape-complex-use.cc b/gfx/harfbuzz/src/hb-ot-shape-complex-use.cc new file mode 100644 index 000000000..5b19d5d74 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-shape-complex-use.cc @@ -0,0 +1,632 @@ +/* + * Copyright © 2015 Mozilla Foundation. + * Copyright © 2015 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. + * + * Mozilla Author(s): Jonathan Kew + * Google Author(s): Behdad Esfahbod + */ + +#include "hb-ot-shape-complex-use-private.hh" +#include "hb-ot-shape-complex-arabic-private.hh" + +/* buffer var allocations */ +#define use_category() complex_var_u8_0() + + +/* + * Universal Shaping Engine. + * https://www.microsoft.com/typography/OpenTypeDev/USE/intro.htm + */ + +static const hb_tag_t +basic_features[] = +{ + /* + * Basic features. + * These features are applied all at once, before reordering. + */ + HB_TAG('r','k','r','f'), + HB_TAG('a','b','v','f'), + HB_TAG('b','l','w','f'), + HB_TAG('h','a','l','f'), + HB_TAG('p','s','t','f'), + HB_TAG('v','a','t','u'), + HB_TAG('c','j','c','t'), +}; +static const hb_tag_t +arabic_features[] = +{ + HB_TAG('i','s','o','l'), + HB_TAG('i','n','i','t'), + HB_TAG('m','e','d','i'), + HB_TAG('f','i','n','a'), + /* The spec doesn't specify these but we apply anyway, since our Arabic shaper + * does. These are only used in Syriac spec. */ + HB_TAG('m','e','d','2'), + HB_TAG('f','i','n','2'), + HB_TAG('f','i','n','3'), +}; +/* Same order as arabic_features. Don't need Syriac stuff.*/ +enum joining_form_t { + ISOL, + INIT, + MEDI, + FINA, + _NONE +}; +static const hb_tag_t +other_features[] = +{ + /* + * Other features. + * These features are applied all at once, after reordering. + */ + HB_TAG('a','b','v','s'), + HB_TAG('b','l','w','s'), + HB_TAG('h','a','l','n'), + HB_TAG('p','r','e','s'), + HB_TAG('p','s','t','s'), + /* Positioning features, though we don't care about the types. */ + HB_TAG('d','i','s','t'), + 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 +clear_substitution_flags (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer); +static void +record_rphf (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer); +static void +record_pref (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 +collect_features_use (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); + + /* "Default glyph pre-processing group" */ + map->add_global_bool_feature (HB_TAG('l','o','c','l')); + map->add_global_bool_feature (HB_TAG('c','c','m','p')); + map->add_global_bool_feature (HB_TAG('n','u','k','t')); + map->add_global_bool_feature (HB_TAG('a','k','h','n')); + + /* "Reordering group" */ + map->add_gsub_pause (clear_substitution_flags); + map->add_feature (HB_TAG('r','p','h','f'), 1, F_MANUAL_ZWJ); + map->add_gsub_pause (record_rphf); + map->add_gsub_pause (clear_substitution_flags); + map->add_feature (HB_TAG('p','r','e','f'), 1, F_GLOBAL | F_MANUAL_ZWJ); + map->add_gsub_pause (record_pref); + + /* "Orthographic unit shaping group" */ + for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++) + map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ); + + map->add_gsub_pause (reorder); + + /* "Topographical features" */ + for (unsigned int i = 0; i < ARRAY_LENGTH (arabic_features); i++) + map->add_feature (arabic_features[i], 1, F_NONE); + map->add_gsub_pause (NULL); + + /* "Standard typographic presentation" and "Positional feature application" */ + for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++) + map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ); +} + +struct use_shape_plan_t +{ + ASSERT_POD (); + + hb_mask_t rphf_mask; + + arabic_shape_plan_t *arabic_plan; +}; + +static bool +has_arabic_joining (hb_script_t script) +{ + /* List of scripts that have data in arabic-table. */ + switch ((int) script) + { + /* Unicode-1.1 additions */ + case HB_SCRIPT_ARABIC: + + /* Unicode-3.0 additions */ + case HB_SCRIPT_MONGOLIAN: + case HB_SCRIPT_SYRIAC: + + /* Unicode-5.0 additions */ + case HB_SCRIPT_NKO: + case HB_SCRIPT_PHAGS_PA: + + /* Unicode-6.0 additions */ + case HB_SCRIPT_MANDAIC: + + /* Unicode-7.0 additions */ + case HB_SCRIPT_MANICHAEAN: + case HB_SCRIPT_PSALTER_PAHLAVI: + + /* Unicode-9.0 additions */ + case HB_SCRIPT_ADLAM: + + return true; + + default: + return false; + } +} + +static void * +data_create_use (const hb_ot_shape_plan_t *plan) +{ + use_shape_plan_t *use_plan = (use_shape_plan_t *) calloc (1, sizeof (use_shape_plan_t)); + if (unlikely (!use_plan)) + return NULL; + + use_plan->rphf_mask = plan->map.get_1_mask (HB_TAG('r','p','h','f')); + + if (has_arabic_joining (plan->props.script)) + { + use_plan->arabic_plan = (arabic_shape_plan_t *) data_create_arabic (plan); + if (unlikely (!use_plan->arabic_plan)) + { + free (use_plan); + return NULL; + } + } + + return use_plan; +} + +static void +data_destroy_use (void *data) +{ + use_shape_plan_t *use_plan = (use_shape_plan_t *) data; + + if (use_plan->arabic_plan) + data_destroy_arabic (use_plan->arabic_plan); + + free (data); +} + +enum syllable_type_t { + independent_cluster, + virama_terminated_cluster, + standard_cluster, + number_joiner_terminated_cluster, + numeral_cluster, + symbol_cluster, + broken_cluster, + non_cluster, +}; + +#include "hb-ot-shape-complex-use-machine.hh" + + +static void +setup_masks_use (const hb_ot_shape_plan_t *plan, + hb_buffer_t *buffer, + hb_font_t *font HB_UNUSED) +{ + const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data; + + /* Do this before allocating use_category(). */ + if (use_plan->arabic_plan) + { + setup_masks_arabic_plan (use_plan->arabic_plan, buffer, plan->props.script); + } + + HB_BUFFER_ALLOCATE_VAR (buffer, use_category); + + /* 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++) + info[i].use_category() = hb_use_get_categories (info[i].codepoint); +} + +static void +setup_rphf_mask (const hb_ot_shape_plan_t *plan, + hb_buffer_t *buffer) +{ + const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data; + + hb_mask_t mask = use_plan->rphf_mask; + if (!mask) return; + + hb_glyph_info_t *info = buffer->info; + + foreach_syllable (buffer, start, end) + { + unsigned int limit = info[start].use_category() == USE_R ? 1 : MIN (3u, end - start); + for (unsigned int i = start; i < start + limit; i++) + info[i].mask |= mask; + } +} + +static void +setup_topographical_masks (const hb_ot_shape_plan_t *plan, + hb_buffer_t *buffer) +{ + const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data; + if (use_plan->arabic_plan) + return; + + ASSERT_STATIC (INIT < 4 && ISOL < 4 && MEDI < 4 && FINA < 4); + hb_mask_t masks[4], all_masks = 0; + for (unsigned int i = 0; i < 4; i++) + { + masks[i] = plan->map.get_1_mask (arabic_features[i]); + if (masks[i] == plan->map.get_global_mask ()) + masks[i] = 0; + all_masks |= masks[i]; + } + if (!all_masks) + return; + hb_mask_t other_masks = ~all_masks; + + unsigned int last_start = 0; + joining_form_t last_form = _NONE; + hb_glyph_info_t *info = buffer->info; + foreach_syllable (buffer, start, end) + { + syllable_type_t syllable_type = (syllable_type_t) (info[start].syllable() & 0x0F); + switch (syllable_type) + { + case independent_cluster: + case symbol_cluster: + case non_cluster: + /* These don't join. Nothing to do. */ + last_form = _NONE; + break; + + case virama_terminated_cluster: + case standard_cluster: + case number_joiner_terminated_cluster: + case numeral_cluster: + case broken_cluster: + + bool join = last_form == FINA || last_form == ISOL; + + if (join) + { + /* Fixup previous syllable's form. */ + last_form = last_form == FINA ? MEDI : INIT; + for (unsigned int i = last_start; i < start; i++) + info[i].mask = (info[i].mask & other_masks) | masks[last_form]; + } + + /* Form for this syllable. */ + last_form = join ? FINA : ISOL; + for (unsigned int i = start; i < end; i++) + info[i].mask = (info[i].mask & other_masks) | masks[last_form]; + + break; + } + + last_start = start; + } +} + +static void +setup_syllables (const hb_ot_shape_plan_t *plan, + hb_font_t *font HB_UNUSED, + hb_buffer_t *buffer) +{ + find_syllables (buffer); + setup_rphf_mask (plan, buffer); + setup_topographical_masks (plan, buffer); +} + +static void +clear_substitution_flags (const hb_ot_shape_plan_t *plan, + 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++) + _hb_glyph_info_clear_substituted (&info[i]); +} + +static void +record_rphf (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer) +{ + const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data; + + hb_mask_t mask = use_plan->rphf_mask; + if (!mask) return; + hb_glyph_info_t *info = buffer->info; + + foreach_syllable (buffer, start, end) + { + /* Mark a substituted repha as USE_R. */ + for (unsigned int i = start; i < end && (info[i].mask & mask); i++) + if (_hb_glyph_info_substituted (&info[i])) + { + info[i].use_category() = USE_R; + break; + } + } +} + +static void +record_pref (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer) +{ + hb_glyph_info_t *info = buffer->info; + + foreach_syllable (buffer, start, end) + { + /* Mark a substituted pref as VPre, as they behave the same way. */ + for (unsigned int i = start; i < end; i++) + if (_hb_glyph_info_substituted (&info[i])) + { + info[i].use_category() = USE_VPre; + break; + } + } +} + +static inline bool +is_halant (const hb_glyph_info_t &info) +{ + return info.use_category() == USE_H && !_hb_glyph_info_ligated (&info); +} + +static void +reorder_syllable (hb_buffer_t *buffer, unsigned int start, unsigned int end) +{ + syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F); + /* Only a few syllable types need reordering. */ + if (unlikely (!(FLAG_SAFE (syllable_type) & + (FLAG (virama_terminated_cluster) | + FLAG (standard_cluster) | + FLAG (broken_cluster) | + 0)))) + return; + + hb_glyph_info_t *info = buffer->info; + +#define BASE_FLAGS (FLAG (USE_B) | FLAG (USE_GB)) + + /* Move things forward. */ + if (info[start].use_category() == USE_R && end - start > 1) + { + /* Got a repha. Reorder it to after first base, before first halant. */ + for (unsigned int i = start + 1; i < end; i++) + if ((FLAG_UNSAFE (info[i].use_category()) & (BASE_FLAGS)) || is_halant (info[i])) + { + /* If we hit a halant, move before it; otherwise it's a base: move to it's + * place, and shift things in between backward. */ + + if (is_halant (info[i])) + i--; + + buffer->merge_clusters (start, i + 1); + hb_glyph_info_t t = info[start]; + memmove (&info[start], &info[start + 1], (i - start) * sizeof (info[0])); + info[i] = t; + + break; + } + } + + /* Move things back. */ + unsigned int j = end; + for (unsigned int i = start; i < end; i++) + { + uint32_t flag = FLAG_UNSAFE (info[i].use_category()); + if ((flag & (BASE_FLAGS)) || is_halant (info[i])) + { + /* If we hit a halant, move after it; otherwise it's a base: move to it's + * place, and shift things in between backward. */ + if (is_halant (info[i])) + j = i + 1; + else + j = i; + } + else if (((flag) & (FLAG (USE_VPre) | FLAG (USE_VMPre))) && + /* Only move the first component of a MultipleSubst. */ + 0 == _hb_glyph_info_get_lig_comp (&info[i]) && + j < i) + { + buffer->merge_clusters (j, i + 1); + hb_glyph_info_t t = info[i]; + memmove (&info[j + 1], &info[j], (i - j) * sizeof (info[0])); + info[j] = t; + } + } +} + +static inline void +insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED, + hb_font_t *font, + hb_buffer_t *buffer) +{ + /* Note: This loop is extra overhead, but should not be measurable. */ + 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_glyph_info_t dottedcircle = {0}; + if (!font->get_nominal_glyph (0x25CCu, &dottedcircle.codepoint)) + return; + dottedcircle.use_category() = hb_use_get_categories (0x25CC); + + buffer->clear_output (); + + buffer->idx = 0; + unsigned int last_syllable = 0; + while (buffer->idx < buffer->len && !buffer->in_error) + { + 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(); + /* TODO Set glyph_props? */ + + /* Insert dottedcircle after possible Repha. */ + while (buffer->idx < buffer->len && !buffer->in_error && + last_syllable == buffer->cur().syllable() && + buffer->cur().use_category() == USE_R) + buffer->next_glyph (); + + 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); + + hb_glyph_info_t *info = buffer->info; + + foreach_syllable (buffer, start, end) + reorder_syllable (buffer, start, end); + + /* Zero syllables now... */ + unsigned int count = buffer->len; + for (unsigned int i = 0; i < count; i++) + info[i].syllable() = 0; + + HB_BUFFER_DEALLOCATE_VAR (buffer, use_category); +} + +static bool +decompose_use (const hb_ot_shape_normalize_context_t *c, + hb_codepoint_t ab, + hb_codepoint_t *a, + hb_codepoint_t *b) +{ + switch (ab) + { + /* Chakma: + * Special case where the Unicode decomp gives matras in the wrong order + * for cluster validation. + */ + case 0x1112Eu : *a = 0x11127u; *b= 0x11131u; return true; + case 0x1112Fu : *a = 0x11127u; *b= 0x11132u; return true; + + /* + * Decompose split matras that don't have Unicode decompositions. + */ + + /* Limbu */ + case 0x1925u : *a = 0x1920u; *b= 0x1923u; return true; + case 0x1926u : *a = 0x1920u; *b= 0x1924u; return true; + + /* Balinese */ + case 0x1B3Cu : *a = 0x1B42u; *b= 0x1B3Cu; return true; + +#if 0 + /* Lepcha */ + case 0x1C29u : *a = no decomp, -> LEFT; return true; + + /* Javanese */ + case 0xA9C0u : *a = no decomp, -> RIGHT; return true; + + /* Sharada */ + case 0x111BFu : *a = no decomp, -> ABOVE; return true; +#endif + } + + return (bool) c->unicode->decompose (ab, a, b); +} + +static bool +compose_use (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; + + return (bool)c->unicode->compose (a, b, ab); +} + + +const hb_ot_complex_shaper_t _hb_ot_complex_shaper_use = +{ + "use", + collect_features_use, + NULL, /* override_features */ + data_create_use, + data_destroy_use, + NULL, /* preprocess_text */ + NULL, /* postprocess_glyphs */ + HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, + decompose_use, + compose_use, + setup_masks_use, + NULL, /* disable_otl */ + HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY, + false, /* fallback_position */ +}; |