/* * 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-ot-shape-complex-indic-private.hh" #include "hb-ot-shape-private.hh" #define OLD_INDIC_TAG(script) (((hb_tag_t) script) | 0x20000000) #define IS_OLD_INDIC_TAG(tag) ( \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_BENGALI) || \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_DEVANAGARI) || \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_GUJARATI) || \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_GURMUKHI) || \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_KANNADA) || \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_MALAYALAM) || \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_ORIYA) || \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_TAMIL) || \ (tag) == OLD_INDIC_TAG (HB_SCRIPT_TELUGU) \ ) struct indic_options_t { int initialized : 1; int uniscribe_bug_compatible : 1; }; union indic_options_union_t { int i; indic_options_t opts; }; ASSERT_STATIC (sizeof (int) == sizeof (indic_options_union_t)); static indic_options_union_t indic_options_init (void) { indic_options_union_t u; u.i = 0; u.opts.initialized = 1; char *c = getenv ("HB_OT_INDIC_OPTIONS"); u.opts.uniscribe_bug_compatible = c && strstr (c, "uniscribe-bug-compatible"); return u; } inline indic_options_t indic_options (void) { static indic_options_union_t options; if (unlikely (!options.i)) { /* This is idempotent and threadsafe. */ options = indic_options_init (); } return options.opts; } static int compare_codepoint (const void *pa, const void *pb) { hb_codepoint_t a = * (hb_codepoint_t *) pa; hb_codepoint_t b = * (hb_codepoint_t *) pb; return a < b ? -1 : a == b ? 0 : +1; } static indic_position_t consonant_position (hb_codepoint_t u) { consonant_position_t *record; /* Khmer does not have pre-base half forms. */ if (0x1780 <= u && u <= 0x17FF) return POS_BELOW_C; record = (consonant_position_t *) bsearch (&u, consonant_positions, ARRAY_LENGTH (consonant_positions), sizeof (consonant_positions[0]), compare_codepoint); return record ? record->position : POS_BASE_C; } static bool is_ra (hb_codepoint_t u) { return !!bsearch (&u, ra_chars, ARRAY_LENGTH (ra_chars), sizeof (ra_chars[0]), compare_codepoint); } #define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ)) static bool is_joiner (const hb_glyph_info_t &info) { return !!(FLAG (info.indic_category()) & JOINER_FLAGS); } #define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_Ra) | FLAG (OT_V) | FLAG (OT_NBSP) | FLAG (OT_DOTTEDCIRCLE)) static bool is_consonant (const hb_glyph_info_t &info) { /* 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! */ return !!(FLAG (info.indic_category()) & CONSONANT_FLAGS); } #define HALANT_OR_COENG_FLAGS (FLAG (OT_H) | FLAG (OT_Coeng)) static bool is_halant_or_coeng (const hb_glyph_info_t &info) { return !!(FLAG (info.indic_category()) & HALANT_OR_COENG_FLAGS); } static inline void set_indic_properties (hb_glyph_info_t &info) { hb_codepoint_t u = info.codepoint; unsigned int type = get_indic_categories (u); unsigned int cat = type & 0x0F; unsigned int pos = type >> 4; /* The spec says U+0952 is OT_A. However, testing shows that Uniscribe * treats U+0951..U+0952 all as OT_VD. * TESTS: * U+092E,U+0947,U+0952 * U+092E,U+0952,U+0947 * U+092E,U+0947,U+0951 * U+092E,U+0951,U+0947 * */ if (unlikely (hb_in_range (u, 0x0951, 0x0954))) cat = OT_VD; if (cat == OT_X && unlikely (hb_in_range (u, 0x17CB, 0x17D2))) /* Khmer Various signs */ cat = OT_N; /* Khmer Virama is different since it can be used to form a final consonant. */ if (unlikely (u == 0x17D2)) cat = OT_Coeng; if (cat == OT_Repha) { /* There are two kinds of characters marked as Repha: * - The ones that are GenCat=Mn are already positioned visually, ie. after base. (eg. Khmer) * - The ones that are GenCat=Lo is encoded logically, ie. beginning of syllable. (eg. Malayalam) * * We recategorize the first kind to look like a Nukta and attached to the base directly. */ if (_hb_glyph_info_get_general_category (&info) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) cat = OT_N; } /* Assign positions... */ if ((FLAG (cat) & CONSONANT_FLAGS)) { pos = consonant_position (u); if (is_ra (u)) cat = OT_Ra; } else if (cat == OT_SM || cat == OT_VD) { pos = POS_SMVD; } else if (unlikely (u == 0x200C)) cat = OT_ZWNJ; else if (unlikely (u == 0x200D)) cat = OT_ZWJ; else if (unlikely (u == 0x25CC)) cat = OT_DOTTEDCIRCLE; info.indic_category() = cat; info.indic_position() = pos; } struct feature_list_t { hb_tag_t tag; hb_bool_t is_global; }; /* These features are applied one at a time, given the order in this table. */ static const feature_list_t indic_basic_features[] = { {HB_TAG('n','u','k','t'), true}, {HB_TAG('a','k','h','n'), false}, {HB_TAG('r','p','h','f'), false}, {HB_TAG('r','k','r','f'), true}, {HB_TAG('p','r','e','f'), false}, {HB_TAG('b','l','w','f'), false}, {HB_TAG('h','a','l','f'), false}, {HB_TAG('a','b','v','f'), false}, {HB_TAG('p','s','t','f'), false}, {HB_TAG('c','f','a','r'), false}, {HB_TAG('c','j','c','t'), false}, {HB_TAG('v','a','t','u'), true}, }; /* Same order as the indic_basic_features array */ enum { _NUKT, AKHN, RPHF, _RKRF, PREF, BLWF, HALF, ABVF, PSTF, CFAR, CJCT, VATU }; /* These features are applied all at once. */ static const feature_list_t indic_other_features[] = { {HB_TAG('i','n','i','t'), false}, {HB_TAG('p','r','e','s'), true}, {HB_TAG('a','b','v','s'), true}, {HB_TAG('b','l','w','s'), true}, {HB_TAG('p','s','t','s'), true}, {HB_TAG('h','a','l','n'), true}, {HB_TAG('d','i','s','t'), true}, {HB_TAG('a','b','v','m'), true}, {HB_TAG('b','l','w','m'), true}, }; static void initial_reordering (const hb_ot_map_t *map, hb_face_t *face, hb_buffer_t *buffer, void *user_data HB_UNUSED); static void final_reordering (const hb_ot_map_t *map, hb_face_t *face, hb_buffer_t *buffer, void *user_data HB_UNUSED); void _hb_ot_shape_complex_collect_features_indic (hb_ot_map_builder_t *map, const hb_segment_properties_t *props HB_UNUSED) { map->add_bool_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->add_bool_feature (HB_TAG('c','c','m','p')); map->add_gsub_pause (initial_reordering, NULL); for (unsigned int i = 0; i < ARRAY_LENGTH (indic_basic_features); i++) { map->add_bool_feature (indic_basic_features[i].tag, indic_basic_features[i].is_global); map->add_gsub_pause (NULL, NULL); } map->add_gsub_pause (final_reordering, NULL); for (unsigned int i = 0; i < ARRAY_LENGTH (indic_other_features); i++) map->add_bool_feature (indic_other_features[i].tag, indic_other_features[i].is_global); } void _hb_ot_shape_complex_override_features_indic (hb_ot_map_builder_t *map, const hb_segment_properties_t *props HB_UNUSED) { /* Uniscribe does not apply 'kern'. */ if (indic_options ().uniscribe_bug_compatible) map->add_feature (HB_TAG('k','e','r','n'), 0, true); } hb_ot_shape_normalization_mode_t _hb_ot_shape_complex_normalization_preference_indic (void) { /* We want split matras decomposed by the common shaping logic. */ return HB_OT_SHAPE_NORMALIZATION_MODE_DECOMPOSED; } void _hb_ot_shape_complex_setup_masks_indic (hb_ot_map_t *map HB_UNUSED, hb_buffer_t *buffer, hb_font_t *font HB_UNUSED) { HB_BUFFER_ALLOCATE_VAR (buffer, indic_category); HB_BUFFER_ALLOCATE_VAR (buffer, indic_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; for (unsigned int i = 0; i < count; i++) set_indic_properties (buffer->info[i]); } static int compare_indic_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb) { int a = pa->indic_position(); int b = pb->indic_position(); return a < b ? -1 : a == b ? 0 : +1; } /* Rules from: * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */ static void initial_reordering_consonant_syllable (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *basic_mask_array, unsigned int start, unsigned int end) { hb_glyph_info_t *info = buffer->info; /* 1. Find base consonant: * * The shaping engine finds the base consonant of the syllable, using the * following algorithm: starting from the end of the syllable, move backwards * until a consonant is found that does not have a below-base or post-base * form (post-base forms have to follow below-base forms), or that is not a * pre-base reordering Ra, or arrive at the first consonant. The consonant * stopped at will be the base. * * o If the syllable starts with Ra + Halant (in a script that has Reph) * and has more than one consonant, Ra is excluded from candidates for * base consonants. */ unsigned int base = end; bool has_reph = false; { /* -> If the syllable starts with Ra + Halant (in a script that has Reph) * and has more than one consonant, Ra is excluded from candidates for * base consonants. */ unsigned int limit = start; if (basic_mask_array[RPHF] && start + 3 <= end && info[start].indic_category() == OT_Ra && info[start + 1].indic_category() == OT_H && (unlikely (buffer->props.script == HB_SCRIPT_SINHALA) ? info[start + 2].indic_category() == OT_ZWJ /* In Sinhala, form Reph only if ZWJ is present */: !is_joiner (info[start + 2] /* In other scripts, any joiner blocks Reph formation */ ) )) { limit += 2; while (limit < end && is_joiner (info[limit])) limit++; base = start; has_reph = true; }; enum base_position_t { BASE_FIRST, BASE_LAST } base_pos; switch ((hb_tag_t) buffer->props.script) { case HB_SCRIPT_KHMER: base_pos = BASE_FIRST; break; default: base_pos = BASE_LAST; break; } if (base_pos == BASE_LAST) { /* -> starting from the end of the syllable, move backwards */ unsigned int i = end; do { i--; /* -> until a consonant is found */ if (is_consonant (info[i])) { /* -> that does not have a below-base or post-base form * (post-base forms have to follow below-base forms), */ if (info[i].indic_position() != POS_BELOW_C && info[i].indic_position() != POS_POST_C) { base = i; break; } /* -> or that is not a pre-base reordering Ra, * * IMPLEMENTATION NOTES: * * Our pre-base reordering Ra's are marked POS_BELOW, so will be skipped * by the logic above already. */ /* -> or arrive at the first consonant. The consonant stopped at will * be the base. */ base = i; } else if (is_joiner (info[i])) break; } while (i > limit); } else { /* In scripts without half forms (eg. Khmer), the first consonant is always the base. */ if (!has_reph) base = limit; } if (base < start) base = start; /* Just in case... */ /* -> If the syllable starts with Ra + Halant (in a script that has Reph) * and has more than one consonant, Ra is excluded from candidates for * base consonants. */ if (has_reph && base == start) { /* Have no other consonant, so Reph is not formed and Ra becomes base. */ has_reph = false; } } /* 2. Decompose and reorder Matras: * * Each matra and any syllable modifier sign in the cluster are moved to the * appropriate position relative to the consonant(s) in the cluster. The * shaping engine decomposes two- or three-part matras into their constituent * parts before any repositioning. Matra characters are classified by which * consonant in a conjunct they have affinity for and are reordered to the * following positions: * * o Before first half form in the syllable * o After subjoined consonants * o After post-form consonant * o After main consonant (for above marks) * * IMPLEMENTATION NOTES: * * The normalize() routine has already decomposed matras for us, so we don't * need to worry about that. */ /* 3. Reorder marks to canonical order: * * Adjacent nukta and halant or nukta and vedic sign are always repositioned * if necessary, so that the nukta is first. * * IMPLEMENTATION NOTES: * * We don't need to do this: the normalize() routine already did this for us. */ /* Reorder characters */ for (unsigned int i = start; i < base; i++) info[i].indic_position() = MIN ((unsigned int) POS_PRE_C, info[i].indic_position()); if (base < end) info[base].indic_position() = POS_BASE_C; /* Mark final consonants. A final consonant is one appearing after a matra, * like in Khmer. */ for (unsigned int i = base + 1; i < end; i++) if (info[i].indic_category() == OT_M) { for (unsigned int j = i + 1; j < end; j++) if (is_consonant (info[j])) { info[j].indic_position() = POS_FINAL_C; break; } break; } /* Handle beginning Ra */ if (has_reph) info[start].indic_position() = POS_RA_TO_BECOME_REPH; /* For old-style Indic script tags, move the first post-base Halant after * last consonant. */ if (IS_OLD_INDIC_TAG (map->get_chosen_script (0))) { for (unsigned int i = base + 1; i < end; i++) if (info[i].indic_category() == OT_H) { unsigned int j; for (j = end - 1; j > i; j--) if (is_consonant (info[j])) break; if (j > i) { /* Move Halant to after last consonant. */ hb_glyph_info_t t = info[i]; memmove (&info[i], &info[i + 1], (j - i) * sizeof (info[0])); info[j] = t; } break; } } /* Attach ZWJ, ZWNJ, nukta, and halant to previous char to move with them. */ if (!indic_options ().uniscribe_bug_compatible) { /* Please update the Uniscribe branch when touching this! */ for (unsigned int i = start + 1; i < end; i++) if ((FLAG (info[i].indic_category()) & (FLAG (OT_ZWNJ) | FLAG (OT_ZWJ) | FLAG (OT_N) | FLAG (OT_RS) | FLAG (OT_H)))) info[i].indic_position() = info[i - 1].indic_position(); } else { /* * Uniscribe doesn't move the Halant with Left Matra. * TEST: U+092B,U+093F,U+094DE */ /* Please update the non-Uniscribe branch when touching this! */ for (unsigned int i = start + 1; i < end; i++) if ((FLAG (info[i].indic_category()) & (FLAG (OT_ZWNJ) | FLAG (OT_ZWJ) | FLAG (OT_N) | FLAG (OT_RS) | FLAG (OT_H)))) { info[i].indic_position() = info[i - 1].indic_position(); if (info[i].indic_category() == OT_H && info[i].indic_position() == POS_PRE_M) for (unsigned int j = i; j > start; j--) if (info[j - 1].indic_position() != POS_PRE_M) { info[i].indic_position() = info[j - 1].indic_position(); break; } } } /* Re-attach ZWJ, ZWNJ, and halant to next char, for after-base consonants. */ { unsigned int last_halant = end; for (unsigned int i = base + 1; i < end; i++) if (is_halant_or_coeng (info[i])) last_halant = i; else if (is_consonant (info[i])) { for (unsigned int j = last_halant; j < i; j++) info[j].indic_position() = info[i].indic_position(); } } /* We do bubble-sort, skip malicious clusters attempts */ if (end - start < 64) { /* Sit tight, rock 'n roll! */ hb_bubble_sort (info + start, end - start, compare_indic_order); /* Find base again */ base = end; for (unsigned int i = start; i < end; i++) if (info[i].indic_position() == POS_BASE_C) { base = i; break; } } /* Setup masks now */ { hb_mask_t mask; /* Reph */ for (unsigned int i = start; i < end && info[i].indic_position() == POS_RA_TO_BECOME_REPH; i++) info[i].mask |= basic_mask_array[RPHF]; /* Pre-base */ mask = basic_mask_array[HALF] | basic_mask_array[AKHN] | basic_mask_array[CJCT]; for (unsigned int i = start; i < base; i++) info[i].mask |= mask; /* Base */ mask = basic_mask_array[AKHN] | basic_mask_array[CJCT]; if (base < end) info[base].mask |= mask; /* Post-base */ mask = basic_mask_array[BLWF] | basic_mask_array[ABVF] | basic_mask_array[PSTF] | basic_mask_array[CJCT]; for (unsigned int i = base + 1; i < end; i++) info[i].mask |= mask; } /* XXX This will not match for old-Indic spec since the Halant-Ra order is reversed already. */ if (basic_mask_array[PREF] && base + 3 <= end) { /* Find a Halant,Ra sequence and mark it fore pre-base reordering processing. */ for (unsigned int i = base + 1; i + 1 < end; i++) if (is_halant_or_coeng (info[i]) && info[i + 1].indic_category() == OT_Ra) { info[i++].mask |= basic_mask_array[PREF]; info[i++].mask |= basic_mask_array[PREF]; /* 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 */ for (; i < end; i++) info[i].mask |= basic_mask_array[CFAR]; break; } } /* Apply ZWJ/ZWNJ effects */ for (unsigned int i = start + 1; i < end; i++) if (is_joiner (info[i])) { bool non_joiner = info[i].indic_category() == OT_ZWNJ; unsigned int j = i; do { j--; info[j].mask &= ~basic_mask_array[CJCT]; if (non_joiner) info[j].mask &= ~basic_mask_array[HALF]; } while (j > start && !is_consonant (info[j])); } } static void initial_reordering_vowel_syllable (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *basic_mask_array, unsigned int start, unsigned int end) { /* We made the vowels look like consonants. So let's call the consonant logic! */ initial_reordering_consonant_syllable (map, buffer, basic_mask_array, start, end); } static void initial_reordering_standalone_cluster (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *basic_mask_array, unsigned int start, unsigned int end) { /* We treat NBSP/dotted-circle as if they are consonants, so we should just chain. * Only if not in compatibility mode that is... */ if (indic_options ().uniscribe_bug_compatible) { /* For dotted-circle, this is what Uniscribe does: * If dotted-circle is the last glyph, it just does nothing. * Ie. It doesn't form Reph. */ if (buffer->info[end - 1].indic_category() == OT_DOTTEDCIRCLE) return; } initial_reordering_consonant_syllable (map, buffer, basic_mask_array, start, end); } static void initial_reordering_non_indic (const hb_ot_map_t *map HB_UNUSED, hb_buffer_t *buffer HB_UNUSED, hb_mask_t *basic_mask_array HB_UNUSED, unsigned int start HB_UNUSED, unsigned int end HB_UNUSED) { /* Nothing to do right now. If we ever switch to using the output * buffer in the reordering process, we'd need to next_glyph() here. */ } #include "hb-ot-shape-complex-indic-machine.hh" static void initial_reordering (const hb_ot_map_t *map, hb_face_t *face HB_UNUSED, hb_buffer_t *buffer, void *user_data HB_UNUSED) { hb_mask_t basic_mask_array[ARRAY_LENGTH (indic_basic_features)] = {0}; unsigned int num_masks = ARRAY_LENGTH (indic_basic_features); for (unsigned int i = 0; i < num_masks; i++) basic_mask_array[i] = map->get_1_mask (indic_basic_features[i].tag); find_syllables (map, buffer, basic_mask_array); } static void final_reordering_syllable (hb_buffer_t *buffer, hb_mask_t init_mask, hb_mask_t pref_mask, unsigned int start, unsigned int end) { hb_glyph_info_t *info = buffer->info; /* 4. Final reordering: * * After the localized forms and basic shaping forms GSUB features have been * applied (see below), the shaping engine performs some final glyph * reordering before applying all the remaining font features to the entire * cluster. */ /* Find base again */ unsigned int base = end; while (start < base && info[base - 1].indic_position() >= POS_BASE_C) base--; unsigned int start_of_last_cluster = base; /* o Reorder matras: * * If a pre-base matra character had been reordered before applying basic * features, the glyph can be moved closer to the main consonant based on * whether half-forms had been formed. Actual position for the matra is * defined as “after last standalone halant glyph, after initial matra * position and before the main consonant”. If ZWJ or ZWNJ follow this * halant, position is moved after it. */ if (start < base) /* Otherwise there can't be any pre-base matra characters. */ { unsigned int new_pos = base - 1; while (new_pos > start && !(FLAG (info[new_pos].indic_category()) & (FLAG (OT_M) | FLAG (OT_H) | FLAG (OT_Coeng)))) new_pos--; /* If we found no Halant we are done. Otherwise only proceed if the Halant does * not belong to the Matra itself! */ if (is_halant_or_coeng (info[new_pos]) && info[new_pos].indic_position() != POS_PRE_M) { /* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */ if (new_pos + 1 < end && is_joiner (info[new_pos + 1])) new_pos++; /* Now go see if there's actually any matras... */ for (unsigned int i = new_pos; i > start; i--) if (info[i - 1].indic_position () == POS_PRE_M) { unsigned int old_pos = i - 1; hb_glyph_info_t tmp = info[old_pos]; memmove (&info[old_pos], &info[old_pos + 1], (new_pos - old_pos) * sizeof (info[0])); info[new_pos] = tmp; start_of_last_cluster = MIN (new_pos, start_of_last_cluster); new_pos--; } } } /* o Reorder reph: * * Reph’s original position is always at the beginning of the syllable, * (i.e. it is not reordered at the character reordering stage). However, * it will be reordered according to the basic-forms shaping results. * Possible positions for reph, depending on the script, are; after main, * before post-base consonant forms, and after post-base consonant forms. */ /* If there's anything after the Ra that has the REPH pos, it ought to be halant. * Which means that the font has failed to ligate the Reph. In which case, we * shouldn't move. */ if (start + 1 < end && info[start].indic_position() == POS_RA_TO_BECOME_REPH && info[start + 1].indic_position() != POS_RA_TO_BECOME_REPH) { unsigned int new_reph_pos; enum reph_position_t { REPH_AFTER_MAIN, REPH_BEFORE_SUBSCRIPT, REPH_AFTER_SUBSCRIPT, REPH_BEFORE_POSTSCRIPT, REPH_AFTER_POSTSCRIPT } reph_pos; /* XXX Figure out old behavior too */ switch ((hb_tag_t) buffer->props.script) { case HB_SCRIPT_MALAYALAM: case HB_SCRIPT_ORIYA: reph_pos = REPH_AFTER_MAIN; break; case HB_SCRIPT_GURMUKHI: reph_pos = REPH_BEFORE_SUBSCRIPT; break; case HB_SCRIPT_BENGALI: reph_pos = REPH_AFTER_SUBSCRIPT; break; default: case HB_SCRIPT_DEVANAGARI: case HB_SCRIPT_GUJARATI: case HB_SCRIPT_SINHALA: reph_pos = REPH_BEFORE_POSTSCRIPT; break; case HB_SCRIPT_KANNADA: case HB_SCRIPT_TAMIL: case HB_SCRIPT_TELUGU: reph_pos = REPH_AFTER_POSTSCRIPT; break; } /* 1. If reph should be positioned after post-base consonant forms, * proceed to step 5. */ if (reph_pos == REPH_AFTER_POSTSCRIPT) { goto reph_step_5; } /* 2. If the reph repositioning class is not after post-base: target * position is after the first explicit halant glyph between the * first post-reph consonant and last main consonant. If ZWJ or ZWNJ * are following this halant, position is moved after it. If such * position is found, this is the target position. Otherwise, * proceed to the next step. * * Note: in old-implementation fonts, where classifications were * fixed in shaping engine, there was no case where reph position * will be found on this step. */ { new_reph_pos = start + 1; while (new_reph_pos < base && !is_halant_or_coeng (info[new_reph_pos])) new_reph_pos++; if (new_reph_pos < base && is_halant_or_coeng (info[new_reph_pos])) { /* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */ if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1])) new_reph_pos++; goto reph_move; } } /* 3. If reph should be repositioned after the main consonant: find the * first consonant not ligated with main, or find the first * consonant that is not a potential pre-base reordering Ra. */ if (reph_pos == REPH_AFTER_MAIN) { new_reph_pos = base; /* XXX Skip potential pre-base reordering Ra. */ while (new_reph_pos < end && !( FLAG (info[new_reph_pos + 1].indic_position()) & (FLAG (POS_BELOW_C) | FLAG (POS_POST_C) | FLAG (POS_AFTER_POST) | FLAG (POS_SMVD)))) new_reph_pos++; if (new_reph_pos < end) goto reph_move; } /* 4. If reph should be positioned before post-base consonant, find * first post-base classified consonant not ligated with main. If no * consonant is found, the target position should be before the * first matra, syllable modifier sign or vedic sign. */ /* This is our take on what step 4 is trying to say (and failing, BADLY). */ if (reph_pos == REPH_AFTER_SUBSCRIPT) { new_reph_pos = base; while (new_reph_pos < end && !( FLAG (info[new_reph_pos + 1].indic_position()) & (FLAG (POS_POST_C) | FLAG (POS_AFTER_POST) | FLAG (POS_SMVD)))) new_reph_pos++; if (new_reph_pos < end) goto reph_move; } /* 5. If no consonant is found in steps 3 or 4, move reph to a position * immediately before the first post-base matra, syllable modifier * sign or vedic sign that has a reordering class after the intended * reph position. For example, if the reordering position for reph * is post-main, it will skip above-base matras that also have a * post-main position. */ reph_step_5: { /* XXX */ } /* 6. Otherwise, reorder reph to the end of the syllable. */ { new_reph_pos = end - 1; while (new_reph_pos > start && info[new_reph_pos].indic_position() == POS_SMVD) new_reph_pos--; /* * If the Reph is to be ending up after a Matra,Halant sequence, * position it before that Halant so it can interact with the Matra. * However, if it's a plain Consonant,Halant we shouldn't do that. * Uniscribe doesn't do this. * TEST: U+0930,U+094D,U+0915,U+094B,U+094D */ if (!indic_options ().uniscribe_bug_compatible && unlikely (is_halant_or_coeng (info[new_reph_pos]))) { for (unsigned int i = base + 1; i < new_reph_pos; i++) if (info[i].indic_category() == OT_M) { /* Ok, got it. */ new_reph_pos--; } } goto reph_move; } reph_move: { /* Move */ hb_glyph_info_t reph = info[start]; memmove (&info[start], &info[start + 1], (new_reph_pos - start) * sizeof (info[0])); info[new_reph_pos] = reph; start_of_last_cluster = start; /* Yay, one big cluster! */ } } /* o Reorder pre-base reordering consonants: * * If a pre-base reordering consonant is found, reorder it according to * the following rules: */ if (pref_mask && base + 1 < end) /* Otherwise there can't be any pre-base reordering Ra. */ { for (unsigned int i = base + 1; i < end; i++) if ((info[i].mask & pref_mask) != 0) { /* 1. Only reorder a glyph produced by substitution during application * of the feature. (Note that a font may shape a Ra consonant with * the feature generally but block it in certain contexts.) */ if (i + 1 == end || (info[i + 1].mask & pref_mask) == 0) { /* * 2. Try to find a target position the same way as for pre-base matra. * If it is found, reorder pre-base consonant glyph. * * 3. If position is not found, reorder immediately before main * consonant. */ unsigned int new_pos = base; while (new_pos > start + 1 && !(FLAG (info[new_pos - 1].indic_category()) & (FLAG (OT_M) | FLAG (OT_H) | FLAG (OT_Coeng)))) new_pos--; if (new_pos > start && is_halant_or_coeng (info[new_pos - 1])) /* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */ if (new_pos < end && is_joiner (info[new_pos])) new_pos++; { unsigned int old_pos = i; hb_glyph_info_t tmp = info[old_pos]; memmove (&info[new_pos + 1], &info[new_pos], (old_pos - new_pos) * sizeof (info[0])); info[new_pos] = tmp; start_of_last_cluster = MIN (new_pos, start_of_last_cluster); } } break; } } /* Apply 'init' to the Left Matra if it's a word start. */ if (info[start].indic_position () == POS_PRE_M && (!start || !(FLAG (_hb_glyph_info_get_general_category (&info[start - 1])) & (FLAG (HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER) | FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER) | FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) | FLAG (HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER) | FLAG (HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER) | FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK))))) info[start].mask |= init_mask; /* Finish off the clusters and go home! */ if (!indic_options ().uniscribe_bug_compatible) { /* This is what Uniscribe does. Ie. add cluster boundaries after Halant,ZWNJ. * This means, half forms are submerged into the main consonants cluster. * This is unnecessary, and makes cursor positioning harder, but that's what * Uniscribe does. */ unsigned int cluster_start = start; for (unsigned int i = start + 1; i < start_of_last_cluster; i++) if (is_halant_or_coeng (info[i - 1]) && info[i].indic_category() == OT_ZWNJ) { i++; buffer->merge_clusters (cluster_start, i); cluster_start = i; } start_of_last_cluster = cluster_start; } buffer->merge_clusters (start_of_last_cluster, end); } static void final_reordering (const hb_ot_map_t *map, hb_face_t *face HB_UNUSED, hb_buffer_t *buffer, void *user_data HB_UNUSED) { unsigned int count = buffer->len; if (!count) return; hb_mask_t init_mask = map->get_1_mask (HB_TAG('i','n','i','t')); hb_mask_t pref_mask = map->get_1_mask (HB_TAG('p','r','e','f')); hb_glyph_info_t *info = buffer->info; unsigned int last = 0; unsigned int last_syllable = info[0].syllable(); for (unsigned int i = 1; i < count; i++) if (last_syllable != info[i].syllable()) { final_reordering_syllable (buffer, init_mask, pref_mask, last, i); last = i; last_syllable = info[last].syllable(); } final_reordering_syllable (buffer, init_mask, pref_mask, last, count); HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category); HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position); }