/* * 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-layout-private.hh" /* * Global Indic shaper options. */ 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; } static 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; } /* * Indic configurations. Note that we do not want to keep every single script-specific * behavior in these tables necessarily. This should mainly be used for per-script * properties that are cheaper keeping here, than in the code. Ie. if, say, one and * only one script has an exception, that one script can be if'ed directly in the code, * instead of adding a new flag in these structs. */ enum base_position_t { BASE_POS_FIRST, BASE_POS_LAST }; enum reph_position_t { REPH_POS_DEFAULT = POS_BEFORE_POST, REPH_POS_AFTER_MAIN = POS_AFTER_MAIN, REPH_POS_BEFORE_SUB = POS_BEFORE_SUB, REPH_POS_AFTER_SUB = POS_AFTER_SUB, REPH_POS_BEFORE_POST = POS_BEFORE_POST, REPH_POS_AFTER_POST = POS_AFTER_POST }; enum reph_mode_t { REPH_MODE_IMPLICIT, /* Reph formed out of initial Ra,H sequence. */ REPH_MODE_EXPLICIT, /* Reph formed out of initial Ra,H,ZWJ sequence. */ REPH_MODE_VIS_REPHA, /* Encoded Repha character, no reordering needed. */ REPH_MODE_LOG_REPHA /* Encoded Repha character, needs reordering. */ }; struct indic_config_t { hb_script_t script; bool has_old_spec; hb_codepoint_t virama; base_position_t base_pos; reph_position_t reph_pos; reph_mode_t reph_mode; }; static const indic_config_t indic_configs[] = { /* Default. Should be first. */ {HB_SCRIPT_INVALID, false, 0,BASE_POS_LAST, REPH_POS_DEFAULT, REPH_MODE_IMPLICIT}, {HB_SCRIPT_DEVANAGARI,true, 0x094D,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT}, {HB_SCRIPT_BENGALI, true, 0x09CD,BASE_POS_LAST, REPH_POS_AFTER_SUB, REPH_MODE_IMPLICIT}, {HB_SCRIPT_GURMUKHI, true, 0x0A4D,BASE_POS_LAST, REPH_POS_BEFORE_SUB, REPH_MODE_IMPLICIT}, {HB_SCRIPT_GUJARATI, true, 0x0ACD,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT}, {HB_SCRIPT_ORIYA, true, 0x0B4D,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_IMPLICIT}, {HB_SCRIPT_TAMIL, true, 0x0BCD,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT}, {HB_SCRIPT_TELUGU, true, 0x0C4D,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_EXPLICIT}, {HB_SCRIPT_KANNADA, true, 0x0CCD,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT}, {HB_SCRIPT_MALAYALAM, true, 0x0D4D,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_LOG_REPHA}, {HB_SCRIPT_SINHALA, false,0x0DCA,BASE_POS_FIRST,REPH_POS_AFTER_MAIN, REPH_MODE_EXPLICIT}, {HB_SCRIPT_KHMER, false,0x17D2,BASE_POS_FIRST,REPH_POS_DEFAULT, REPH_MODE_VIS_REPHA}, }; /* * Indic shaper. */ struct feature_list_t { hb_tag_t tag; hb_bool_t is_global; }; static const feature_list_t indic_features[] = { /* * Basic features. * These features are applied in order, one at a time, after initial_reordering. */ {HB_TAG('n','u','k','t'), true}, {HB_TAG('a','k','h','n'), true}, {HB_TAG('r','p','h','f'), false}, {HB_TAG('r','k','r','f'), true}, {HB_TAG('p','r','e','f'), false}, {HB_TAG('h','a','l','f'), false}, {HB_TAG('b','l','w','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'), true}, {HB_TAG('v','a','t','u'), true}, /* * Other features. * These features are applied all at once, after final_reordering. */ {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}, /* Positioning features, though we don't care about the types. */ {HB_TAG('d','i','s','t'), true}, {HB_TAG('a','b','v','m'), true}, {HB_TAG('b','l','w','m'), true}, }; /* * Must be in the same order as the indic_features array. */ enum { _NUKT, _AKHN, RPHF, _RKRF, PREF, HALF, BLWF, ABVF, PSTF, CFAR, _CJCT, _VATU, INIT, _PRES, _ABVS, _BLWS, _PSTS, _HALN, _DIST, _ABVM, _BLWM, INDIC_NUM_FEATURES, INDIC_BASIC_FEATURES = INIT /* Don't forget to update this! */ }; static void initial_reordering (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer); static void final_reordering (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer); static void collect_features_indic (hb_ot_shape_planner_t *plan) { hb_ot_map_builder_t *map = &plan->map; 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')); unsigned int i = 0; map->add_gsub_pause (initial_reordering); for (; i < INDIC_BASIC_FEATURES; i++) { map->add_bool_feature (indic_features[i].tag, indic_features[i].is_global); map->add_gsub_pause (NULL); } map->add_gsub_pause (final_reordering); for (; i < INDIC_NUM_FEATURES; i++) { map->add_bool_feature (indic_features[i].tag, indic_features[i].is_global); } } static void override_features_indic (hb_ot_shape_planner_t *plan) { /* Uniscribe does not apply 'kern'. */ if (indic_options ().uniscribe_bug_compatible) plan->map.add_feature (HB_TAG('k','e','r','n'), 0, true); } struct would_substitute_feature_t { inline void init (const hb_ot_map_t *map, hb_tag_t feature_tag) { map->get_stage_lookups (0/*GSUB*/, map->get_feature_stage (0/*GSUB*/, feature_tag), &lookups, &count); } inline bool would_substitute (hb_codepoint_t *glyphs, unsigned int glyphs_count, bool zero_context, hb_face_t *face) const { for (unsigned int i = 0; i < count; i++) if (hb_ot_layout_would_substitute_lookup_fast (face, lookups[i].index, glyphs, glyphs_count, zero_context)) return true; return false; } private: const hb_ot_map_t::lookup_map_t *lookups; unsigned int count; }; struct indic_shape_plan_t { ASSERT_POD (); inline bool get_virama_glyph (hb_font_t *font, hb_codepoint_t *pglyph) const { hb_codepoint_t glyph = virama_glyph; if (unlikely (virama_glyph == (hb_codepoint_t) -1)) { if (!config->virama || !font->get_glyph (config->virama, 0, &glyph)) glyph = 0; /* Technically speaking, the spec says we should apply 'locl' to virama too. * Maybe one day... */ /* Our get_glyph() function needs a font, so we can't get the virama glyph * during shape planning... Instead, overwrite it here. It's safe. Don't worry! */ (const_cast (this))->virama_glyph = glyph; } *pglyph = glyph; return glyph != 0; } const indic_config_t *config; bool is_old_spec; hb_codepoint_t virama_glyph; would_substitute_feature_t pref; would_substitute_feature_t blwf; would_substitute_feature_t pstf; hb_mask_t mask_array[INDIC_NUM_FEATURES]; }; static void * data_create_indic (const hb_ot_shape_plan_t *plan) { indic_shape_plan_t *indic_plan = (indic_shape_plan_t *) calloc (1, sizeof (indic_shape_plan_t)); if (unlikely (!indic_plan)) return NULL; indic_plan->config = &indic_configs[0]; for (unsigned int i = 1; i < ARRAY_LENGTH (indic_configs); i++) if (plan->props.script == indic_configs[i].script) { indic_plan->config = &indic_configs[i]; break; } indic_plan->is_old_spec = indic_plan->config->has_old_spec && ((plan->map.get_chosen_script (0) & 0x000000FF) != '2'); indic_plan->virama_glyph = (hb_codepoint_t) -1; indic_plan->pref.init (&plan->map, HB_TAG('p','r','e','f')); indic_plan->blwf.init (&plan->map, HB_TAG('b','l','w','f')); indic_plan->pstf.init (&plan->map, HB_TAG('p','s','t','f')); for (unsigned int i = 0; i < ARRAY_LENGTH (indic_plan->mask_array); i++) indic_plan->mask_array[i] = indic_features[i].is_global ? 0 : plan->map.get_1_mask (indic_features[i].tag); return indic_plan; } static void data_destroy_indic (void *data) { free (data); } static indic_position_t consonant_position_from_face (const indic_shape_plan_t *indic_plan, hb_codepoint_t *glyphs, unsigned int glyphs_len, hb_face_t *face) { bool zero_context = indic_plan->is_old_spec ? false : true; if (indic_plan->pref.would_substitute (glyphs, glyphs_len, zero_context, face)) return POS_BELOW_C; if (indic_plan->blwf.would_substitute (glyphs, glyphs_len, zero_context, face)) return POS_BELOW_C; if (indic_plan->pstf.would_substitute (glyphs, glyphs_len, zero_context, face)) return POS_POST_C; return POS_BASE_C; } static void setup_masks_indic (const hb_ot_shape_plan_t *plan 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; } static void update_consonant_positions (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) { const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data; unsigned int consonant_pos = indic_plan->is_old_spec ? 0 : 1; hb_codepoint_t glyphs[2]; if (indic_plan->get_virama_glyph (font, &glyphs[1 - consonant_pos])) { hb_face_t *face = font->face; unsigned int count = buffer->len; for (unsigned int i = 0; i < count; i++) if (buffer->info[i].indic_position() == POS_BASE_C) { glyphs[consonant_pos] = buffer->info[i].codepoint; buffer->info[i].indic_position() = consonant_position_from_face (indic_plan, glyphs, 2, face); } } } /* Rules from: * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */ static void initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan, hb_buffer_t *buffer, unsigned int start, unsigned int end) { const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data; 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 (indic_plan->mask_array[RPHF] && start + 3 <= end && info[start].indic_category() == OT_Ra && info[start + 1].indic_category() == OT_H && (/* TODO Handle other Reph modes. */ (indic_plan->config->reph_mode == REPH_MODE_IMPLICIT && !is_joiner (info[start + 2])) || (indic_plan->config->reph_mode == REPH_MODE_EXPLICIT && info[start + 2].indic_category() == OT_ZWJ) )) { limit += 2; while (limit < end && is_joiner (info[limit])) limit++; base = start; has_reph = true; }; switch (indic_plan->config->base_pos) { case BASE_POS_LAST: { /* -> starting from the end of the syllable, move backwards */ unsigned int i = end; bool seen_below = false; 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 || seen_below)) { base = i; break; } if (info[i].indic_position() == POS_BELOW_C) seen_below = true; /* -> 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 { /* A ZWJ after a Halant stops the base search, and requests an explicit * half form. * A ZWJ before a Halant, requests a subjoined form instead, and hence * search continues. This is particularly important for Bengali * sequence Ra,H,Ya that shouls form Ya-Phalaa by subjoining Ya. */ if (start < i && info[i].indic_category() == OT_ZWJ && info[i - 1].indic_category() == OT_H) break; } } while (i > limit); } break; case BASE_POS_FIRST: { /* In scripts without half forms (eg. Khmer), the first consonant is always the base. */ if (!has_reph) base = limit; /* Find the last base consonant that is not blocked by ZWJ. If there is * a ZWJ right before a base consonant, that would request a subjoined form. */ for (unsigned int i = limit; i < end; i++) if (is_consonant (info[i]) && info[i].indic_position() == POS_BASE_C) { if (limit < i && info[i - 1].indic_category() == OT_ZWJ) break; else base = i; } /* Mark all subsequent consonants as below. */ for (unsigned int i = base + 1; i < end; i++) if (is_consonant (info[i]) && info[i].indic_position() == POS_BASE_C) info[i].indic_position() = POS_BELOW_C; } break; default: abort (); } /* -> 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. * * Only do this for unforced Reph. (ie. not for Ra,H,ZWJ. */ if (has_reph && base == start && start + 2 == limit) { /* Have no other consonant, so Reph is not formed and Ra becomes base. */ has_reph = false; } } if (base < end) info[base].indic_position() = POS_BASE_C; /* 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 (POS_PRE_C, (indic_position_t) 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 (indic_plan->is_old_spec) { 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 misc marks to previous char to move with them. */ { indic_position_t last_pos = POS_START; for (unsigned int i = start; i < end; i++) { if ((FLAG (info[i].indic_category()) & (JOINER_FLAGS | FLAG (OT_N) | FLAG (OT_RS) | HALANT_OR_COENG_FLAGS))) { info[i].indic_position() = last_pos; if (unlikely (indic_options ().uniscribe_bug_compatible && info[i].indic_category() == OT_H && info[i].indic_position() == POS_PRE_M)) { /* * Uniscribe doesn't move the Halant with Left Matra. * TEST: U+092B,U+093F,U+094DE */ 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; } } } else if (info[i].indic_position() != POS_SMVD) { last_pos = (indic_position_t) info[i].indic_position(); } } } /* 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++) if (info[j].indic_position() != POS_SMVD) info[j].indic_position() = info[i].indic_position(); } } { /* Things are out-of-control for post base positions, they may shuffle * around like crazy, so merge clusters. For pre-base stuff, we handle * cluster issues in final reordering. */ buffer->merge_clusters (base, end); /* 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 |= indic_plan->mask_array[RPHF]; /* Pre-base */ mask = indic_plan->mask_array[HALF]; for (unsigned int i = start; i < base; i++) info[i].mask |= mask; /* Base */ mask = 0; if (base < end) info[base].mask |= mask; /* Post-base */ mask = indic_plan->mask_array[BLWF] | indic_plan->mask_array[ABVF] | indic_plan->mask_array[PSTF]; for (unsigned int i = base + 1; i < end; i++) info[i].mask |= mask; } if (indic_plan->mask_array[PREF] && base + 2 < end) { /* Find a Halant,Ra sequence and mark it for pre-base reordering processing. */ for (unsigned int i = base + 1; i + 1 < end; i++) if (is_halant_or_coeng (info[i + (indic_plan->is_old_spec ? 1 : 0)]) && info[i + (indic_plan->is_old_spec ? 0 : 1)].indic_category() == OT_Ra) { info[i++].mask |= indic_plan->mask_array[PREF]; info[i++].mask |= indic_plan->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 |= indic_plan->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--; /* A ZWJ disables CJCT, however, it's mere presence is enough * to disable ligation. No explicit action needed. */ /* A ZWNJ disables HALF. */ if (non_joiner) info[j].mask &= ~indic_plan->mask_array[HALF]; } while (j > start && !is_consonant (info[j])); } } static void initial_reordering_vowel_syllable (const hb_ot_shape_plan_t *plan, hb_buffer_t *buffer, unsigned int start, unsigned int end) { /* We made the vowels look like consonants. So let's call the consonant logic! */ initial_reordering_consonant_syllable (plan, buffer, start, end); } static void initial_reordering_standalone_cluster (const hb_ot_shape_plan_t *plan, hb_buffer_t *buffer, 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 (plan, buffer, start, end); } static void initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan, hb_buffer_t *buffer, unsigned int start, unsigned int end) { /* We already inserted dotted-circles, so just call the standalone_cluster. */ initial_reordering_standalone_cluster (plan, buffer, start, end); } static void initial_reordering_non_indic_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED, hb_buffer_t *buffer 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. */ } enum syllable_type_t { consonant_syllable, vowel_syllable, standalone_cluster, broken_cluster, non_indic_cluster, }; #include "hb-ot-shape-complex-indic-machine.hh" static void initial_reordering_syllable (const hb_ot_shape_plan_t *plan, 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 consonant_syllable: initial_reordering_consonant_syllable (plan, buffer, start, end); return; case vowel_syllable: initial_reordering_vowel_syllable (plan, buffer, start, end); return; case standalone_cluster: initial_reordering_standalone_cluster (plan, buffer, start, end); return; case broken_cluster: initial_reordering_broken_cluster (plan, buffer, start, end); return; case non_indic_cluster: initial_reordering_non_indic_cluster (plan, buffer, start, end); return; } } static void insert_dotted_circles (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) { hb_codepoint_t dottedcircle_glyph; if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph)) return; hb_glyph_info_t dottedcircle; dottedcircle.codepoint = 0x25CC; set_indic_properties (dottedcircle); dottedcircle.codepoint = dottedcircle_glyph; buffer->clear_output (); buffer->idx = 0; unsigned int last_syllable = 0; while (buffer->idx < buffer->len) { 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)) { hb_glyph_info_t info = dottedcircle; info.cluster = buffer->cur().cluster; info.mask = buffer->cur().mask; info.syllable() = buffer->cur().syllable(); buffer->output_info (info); last_syllable = syllable; } buffer->next_glyph (); } buffer->swap_buffers (); } static void initial_reordering (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) { update_consonant_positions (plan, font, buffer); bool had_broken_clusters = false; find_syllables (plan, buffer, &had_broken_clusters); if (unlikely (had_broken_clusters)) insert_dotted_circles (plan, font, buffer); hb_glyph_info_t *info = buffer->info; unsigned int count = buffer->len; if (unlikely (!count)) return; 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()) { initial_reordering_syllable (plan, buffer, last, i); last = i; last_syllable = info[last].syllable(); } initial_reordering_syllable (plan, buffer, last, count); } static void final_reordering_syllable (const hb_ot_shape_plan_t *plan, hb_buffer_t *buffer, unsigned int start, unsigned int end) { const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data; 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; for (base = start; base < end; base++) if (info[base].indic_position() >= POS_BASE_C) { if (start < base && info[base].indic_position() > POS_BASE_C) base--; break; } /* 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 + 1 < end && start < base) /* Otherwise there can't be any pre-base matra characters. */ { /* If we lost track of base, alas, position before last thingy. */ unsigned int new_pos = base == end ? base - 2 : base - 1; /* Malayalam / Tamil do not have "half" forms or explicit virama forms. * The glyphs formed by 'half' are Chillus or ligated explicit viramas. * We want to position matra after them. */ if (buffer->props.script != HB_SCRIPT_MALAYALAM && buffer->props.script != HB_SCRIPT_TAMIL) { while (new_pos > start && !(is_one_of (info[new_pos], (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++; } else new_pos = start; /* No move. */ } if (start < new_pos && info[new_pos].indic_position () != POS_PRE_M) { /* 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; new_pos--; } buffer->merge_clusters (new_pos, MIN (end, base + 1)); } else { for (unsigned int i = start; i < base; i++) if (info[i].indic_position () == POS_PRE_M) { buffer->merge_clusters (i, MIN (end, base + 1)); break; } } } /* 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; reph_position_t reph_pos = indic_plan->config->reph_pos; /* XXX Figure out old behavior too */ /* 1. If reph should be positioned after post-base consonant forms, * proceed to step 5. */ if (reph_pos == REPH_POS_AFTER_POST) { 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_POS_AFTER_MAIN) { new_reph_pos = base; /* XXX Skip potential pre-base reordering Ra. */ while (new_reph_pos + 1 < end && info[new_reph_pos + 1].indic_position() <= POS_AFTER_MAIN) 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_POS_AFTER_SUB) { 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: { /* Copied from step 2. */ 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; } } /* 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: { /* Yay, one big cluster! Merge before moving. */ buffer->merge_clusters (start, end); /* 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; } } /* o Reorder pre-base reordering consonants: * * If a pre-base reordering consonant is found, reorder it according to * the following rules: */ if (indic_plan->mask_array[PREF] && 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 & indic_plan->mask_array[PREF]) != 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 & indic_plan->mask_array[PREF]) == 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 && !(is_one_of (info[new_pos - 1], FLAG(OT_M) | HALANT_OR_COENG_FLAGS))) new_pos--; /* In Khmer coeng model, a V,Ra can go *after* matras. If it goes after a * split matra, it should be reordered to *before* the left part of such matra. */ if (new_pos > start && info[new_pos - 1].indic_category() == OT_M) { unsigned int old_pos = i; for (unsigned int i = base + 1; i < old_pos; i++) if (info[i].indic_category() == OT_M) { new_pos--; break; } } 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; buffer->merge_clusters (new_pos, old_pos + 1); 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; } } 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_RANGE (HB_UNICODE_GENERAL_CATEGORY_FORMAT, HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))) info[start].mask |= indic_plan->mask_array[INIT]; /* * Finish off the clusters and go home! */ if (indic_options ().uniscribe_bug_compatible) { /* Uniscribe merges the entire cluster. * 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. */ buffer->merge_clusters (start, end); } } static void final_reordering (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) { unsigned int count = buffer->len; if (unlikely (!count)) return; 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 (plan, buffer, last, i); last = i; last_syllable = info[last].syllable(); } final_reordering_syllable (plan, buffer, last, count); /* Zero syllables now... */ for (unsigned int i = 0; i < count; i++) info[i].syllable() = 0; HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category); HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position); } static hb_ot_shape_normalization_mode_t normalization_preference_indic (const hb_ot_shape_plan_t *plan) { return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT; } const hb_ot_complex_shaper_t _hb_ot_complex_shaper_indic = { "indic", collect_features_indic, override_features_indic, data_create_indic, data_destroy_indic, NULL, /* preprocess_text */ normalization_preference_indic, setup_masks_indic, false, /* zero_width_attached_marks */ };