| /* |
| * Copyright © 2011,2012 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-khmer-machine.hh" |
| #include "hb-ot-shaper-indic.hh" |
| #include "hb-ot-layout.hh" |
| |
| |
| /* |
| * Khmer shaper. |
| */ |
| |
| |
| static const hb_ot_map_feature_t |
| khmer_features[] = |
| { |
| /* |
| * Basic features. |
| * These features are applied all at once, before reordering, constrained |
| * to the syllable. |
| */ |
| {HB_TAG('p','r','e','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('b','l','w','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('a','b','v','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('p','s','t','f'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| {HB_TAG('c','f','a','r'), F_MANUAL_JOINERS | F_PER_SYLLABLE}, |
| /* |
| * Other features. |
| * These features are applied all at once after clearing syllables. |
| */ |
| {HB_TAG('p','r','e','s'), F_GLOBAL_MANUAL_JOINERS}, |
| {HB_TAG('a','b','v','s'), F_GLOBAL_MANUAL_JOINERS}, |
| {HB_TAG('b','l','w','s'), F_GLOBAL_MANUAL_JOINERS}, |
| {HB_TAG('p','s','t','s'), F_GLOBAL_MANUAL_JOINERS}, |
| }; |
| |
| /* |
| * Must be in the same order as the khmer_features array. |
| */ |
| enum { |
| KHMER_PREF, |
| KHMER_BLWF, |
| KHMER_ABVF, |
| KHMER_PSTF, |
| KHMER_CFAR, |
| |
| _KHMER_PRES, |
| _KHMER_ABVS, |
| _KHMER_BLWS, |
| _KHMER_PSTS, |
| |
| KHMER_NUM_FEATURES, |
| KHMER_BASIC_FEATURES = _KHMER_PRES, /* Don't forget to update this! */ |
| }; |
| |
| static inline void |
| set_khmer_properties (hb_glyph_info_t &info) |
| { |
| hb_codepoint_t u = info.codepoint; |
| unsigned int type = hb_indic_get_categories (u); |
| |
| info.khmer_category() = (khmer_category_t) (type & 0xFFu); |
| } |
| |
| static void |
| setup_syllables_khmer (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer); |
| static void |
| reorder_khmer (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer); |
| |
| static void |
| collect_features_khmer (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_khmer); |
| map->add_gsub_pause (reorder_khmer); |
| |
| /* Testing suggests that Uniscribe does NOT pause between basic |
| * features. Test with KhmerUI.ttf and the following three |
| * sequences: |
| * |
| * U+1789,U+17BC |
| * U+1789,U+17D2,U+1789 |
| * U+1789,U+17D2,U+1789,U+17BC |
| * |
| * https://github.com/harfbuzz/harfbuzz/issues/974 |
| */ |
| map->enable_feature (HB_TAG('l','o','c','l'), F_PER_SYLLABLE); |
| map->enable_feature (HB_TAG('c','c','m','p'), F_PER_SYLLABLE); |
| |
| unsigned int i = 0; |
| for (; i < KHMER_BASIC_FEATURES; i++) |
| map->add_feature (khmer_features[i]); |
| |
| /* https://github.com/harfbuzz/harfbuzz/issues/3531 */ |
| map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var |
| |
| for (; i < KHMER_NUM_FEATURES; i++) |
| map->add_feature (khmer_features[i]); |
| } |
| |
| static void |
| override_features_khmer (hb_ot_shape_planner_t *plan) |
| { |
| hb_ot_map_builder_t *map = &plan->map; |
| |
| /* Khmer spec has 'clig' as part of required shaping features: |
| * "Apply feature 'clig' to form ligatures that are desired for |
| * typographical correctness.", hence in overrides... */ |
| map->enable_feature (HB_TAG('c','l','i','g')); |
| |
| /* Uniscribe does not apply 'kern' in Khmer. */ |
| if (hb_options ().uniscribe_bug_compatible) |
| { |
| map->disable_feature (HB_TAG('k','e','r','n')); |
| } |
| |
| map->disable_feature (HB_TAG('l','i','g','a')); |
| } |
| |
| |
| struct khmer_shape_plan_t |
| { |
| hb_mask_t mask_array[KHMER_NUM_FEATURES]; |
| }; |
| |
| static void * |
| data_create_khmer (const hb_ot_shape_plan_t *plan) |
| { |
| khmer_shape_plan_t *khmer_plan = (khmer_shape_plan_t *) hb_calloc (1, sizeof (khmer_shape_plan_t)); |
| if (unlikely (!khmer_plan)) |
| return nullptr; |
| |
| for (unsigned int i = 0; i < ARRAY_LENGTH (khmer_plan->mask_array); i++) |
| khmer_plan->mask_array[i] = (khmer_features[i].flags & F_GLOBAL) ? |
| 0 : plan->map.get_1_mask (khmer_features[i].tag); |
| |
| return khmer_plan; |
| } |
| |
| static void |
| data_destroy_khmer (void *data) |
| { |
| hb_free (data); |
| } |
| |
| static void |
| setup_masks_khmer (const hb_ot_shape_plan_t *plan HB_UNUSED, |
| hb_buffer_t *buffer, |
| hb_font_t *font HB_UNUSED) |
| { |
| HB_BUFFER_ALLOCATE_VAR (buffer, khmer_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++) |
| set_khmer_properties (info[i]); |
| } |
| |
| static void |
| setup_syllables_khmer (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_khmer (buffer); |
| foreach_syllable (buffer, start, end) |
| buffer->unsafe_to_break (start, end); |
| } |
| |
| |
| /* Rules from: |
| * https://docs.microsoft.com/en-us/typography/script-development/devanagari */ |
| |
| static void |
| reorder_consonant_syllable (const hb_ot_shape_plan_t *plan, |
| hb_face_t *face HB_UNUSED, |
| hb_buffer_t *buffer, |
| unsigned int start, unsigned int end) |
| { |
| const khmer_shape_plan_t *khmer_plan = (const khmer_shape_plan_t *) plan->data; |
| hb_glyph_info_t *info = buffer->info; |
| |
| /* Setup masks. */ |
| { |
| /* Post-base */ |
| hb_mask_t mask = khmer_plan->mask_array[KHMER_BLWF] | |
| khmer_plan->mask_array[KHMER_ABVF] | |
| khmer_plan->mask_array[KHMER_PSTF]; |
| for (unsigned int i = start + 1; i < end; i++) |
| info[i].mask |= mask; |
| } |
| |
| unsigned int num_coengs = 0; |
| for (unsigned int i = start + 1; i < end; i++) |
| { |
| /* """ |
| * When a COENG + (Cons | IndV) combination are found (and subscript count |
| * is less than two) the character combination is handled according to the |
| * subscript type of the character following the COENG. |
| * |
| * ... |
| * |
| * Subscript Type 2 - The COENG + RO characters are reordered to immediately |
| * before the base glyph. Then the COENG + RO characters are assigned to have |
| * the 'pref' OpenType feature applied to them. |
| * """ |
| */ |
| if (info[i].khmer_category() == K_Cat(H) && num_coengs <= 2 && i + 1 < end) |
| { |
| num_coengs++; |
| |
| if (info[i + 1].khmer_category() == K_Cat(Ra)) |
| { |
| for (unsigned int j = 0; j < 2; j++) |
| info[i + j].mask |= khmer_plan->mask_array[KHMER_PREF]; |
| |
| /* Move the Coeng,Ro sequence to the start. */ |
| buffer->merge_clusters (start, i + 2); |
| hb_glyph_info_t t0 = info[i]; |
| hb_glyph_info_t t1 = info[i + 1]; |
| memmove (&info[start + 2], &info[start], (i - start) * sizeof (info[0])); |
| info[start] = t0; |
| info[start + 1] = t1; |
| |
| /* Mark the subsequent stuff with 'cfar'. Used in Khmer. |
| * Read the feature spec. |
| * This allows distinguishing the following cases with MS Khmer fonts: |
| * U+1784,U+17D2,U+179A,U+17D2,U+1782 |
| * U+1784,U+17D2,U+1782,U+17D2,U+179A |
| */ |
| if (khmer_plan->mask_array[KHMER_CFAR]) |
| for (unsigned int j = i + 2; j < end; j++) |
| info[j].mask |= khmer_plan->mask_array[KHMER_CFAR]; |
| |
| num_coengs = 2; /* Done. */ |
| } |
| } |
| |
| /* Reorder left matra piece. */ |
| else if (info[i].khmer_category() == K_Cat(VPre)) |
| { |
| /* Move to the start. */ |
| buffer->merge_clusters (start, i + 1); |
| hb_glyph_info_t t = info[i]; |
| memmove (&info[start + 1], &info[start], (i - start) * sizeof (info[0])); |
| info[start] = t; |
| } |
| } |
| } |
| |
| static void |
| reorder_syllable_khmer (const hb_ot_shape_plan_t *plan, |
| hb_face_t *face, |
| hb_buffer_t *buffer, |
| unsigned int start, unsigned int end) |
| { |
| khmer_syllable_type_t syllable_type = (khmer_syllable_type_t) (buffer->info[start].syllable() & 0x0F); |
| switch (syllable_type) |
| { |
| case khmer_broken_cluster: /* We already inserted dotted-circles, so just call the consonant_syllable. */ |
| case khmer_consonant_syllable: |
| reorder_consonant_syllable (plan, face, buffer, start, end); |
| break; |
| |
| case khmer_non_khmer_cluster: |
| break; |
| } |
| } |
| |
| static void |
| reorder_khmer (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer) |
| { |
| if (buffer->message (font, "start reordering khmer")) |
| { |
| hb_syllabic_insert_dotted_circles (font, buffer, |
| khmer_broken_cluster, |
| K_Cat(DOTTEDCIRCLE), |
| (unsigned) -1); |
| |
| foreach_syllable (buffer, start, end) |
| reorder_syllable_khmer (plan, font->face, buffer, start, end); |
| (void) buffer->message (font, "end reordering khmer"); |
| } |
| HB_BUFFER_DEALLOCATE_VAR (buffer, khmer_category); |
| } |
| |
| |
| static bool |
| decompose_khmer (const hb_ot_shape_normalize_context_t *c, |
| hb_codepoint_t ab, |
| hb_codepoint_t *a, |
| hb_codepoint_t *b) |
| { |
| switch (ab) |
| { |
| /* |
| * Decompose split matras that don't have Unicode decompositions. |
| */ |
| |
| /* Khmer */ |
| case 0x17BEu : *a = 0x17C1u; *b= 0x17BEu; return true; |
| case 0x17BFu : *a = 0x17C1u; *b= 0x17BFu; return true; |
| case 0x17C0u : *a = 0x17C1u; *b= 0x17C0u; return true; |
| case 0x17C4u : *a = 0x17C1u; *b= 0x17C4u; return true; |
| case 0x17C5u : *a = 0x17C1u; *b= 0x17C5u; return true; |
| } |
| |
| return (bool) c->unicode->decompose (ab, a, b); |
| } |
| |
| static bool |
| compose_khmer (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_shaper_t _hb_ot_shaper_khmer = |
| { |
| collect_features_khmer, |
| override_features_khmer, |
| data_create_khmer, |
| data_destroy_khmer, |
| nullptr, /* preprocess_text */ |
| nullptr, /* postprocess_glyphs */ |
| decompose_khmer, |
| compose_khmer, |
| setup_masks_khmer, |
| nullptr, /* reorder_marks */ |
| HB_TAG_NONE, /* gpos_tag */ |
| HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT, |
| HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE, |
| false, /* fallback_position */ |
| }; |
| |
| |
| #endif |