/* * Copyright © 2011 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-private.hh" HB_BEGIN_DECLS /* buffer var allocations */ #define indic_category() complex_var_persistent_u8_0() /* indic_category_t */ #define indic_position() complex_var_persistent_u8_1() /* indic_matra_category_t */ #define INDIC_TABLE_ELEMENT_TYPE uint8_t /* Cateories used in the OpenType spec: * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */ /* Note: This enum is duplicated in the -machine.rl source file. * Not sure how to avoid duplication. */ enum indic_category_t { OT_X = 0, OT_C, OT_Ra, /* Not explicitly listed in the OT spec, but used in the grammar. */ OT_V, OT_N, OT_H, OT_ZWNJ, OT_ZWJ, OT_M, OT_SM, OT_VD, OT_A, OT_NBSP }; /* Visual positions in a syllable from left to right. */ enum indic_position_t { POS_PRE, POS_BASE, POS_ABOVE, POS_BELOW, POS_POST, }; /* Categories used in IndicSyllabicCategory.txt from UCD */ /* The assignments are guesswork */ enum indic_syllabic_category_t { INDIC_SYLLABIC_CATEGORY_OTHER = OT_X, INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_X, INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM, INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C, INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C, INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_C, INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C, INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_C, INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_NBSP, INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_C, INDIC_SYLLABIC_CATEGORY_CONSONANT_REPHA = OT_C, INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X, INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N, INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_X, INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X, INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_X, INDIC_SYLLABIC_CATEGORY_VIRAMA = OT_H, INDIC_SYLLABIC_CATEGORY_VISARGA = OT_SM, INDIC_SYLLABIC_CATEGORY_VOWEL = OT_V, INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT = OT_M, INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT = OT_V }; /* Categories used in IndicSMatraCategory.txt from UCD */ enum indic_matra_category_t { INDIC_MATRA_CATEGORY_NOT_APPLICABLE = POS_BASE, INDIC_MATRA_CATEGORY_LEFT = POS_PRE, INDIC_MATRA_CATEGORY_TOP = POS_ABOVE, INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW, INDIC_MATRA_CATEGORY_RIGHT = POS_POST, /* We don't really care much about these since we decompose them * in the generic pre-shaping layer. They will only be used if * the font does not cover the decomposition. In which case, we * define these as aliases to the place we want the split-matra * glyph to show up. Quite arbitrary. */ INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_BOTTOM, INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_LEFT, INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM, INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_BOTTOM, INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_LEFT, INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_LEFT, INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT, INDIC_MATRA_CATEGORY_INVISIBLE = INDIC_MATRA_CATEGORY_NOT_APPLICABLE, INDIC_MATRA_CATEGORY_OVERSTRUCK = INDIC_MATRA_CATEGORY_NOT_APPLICABLE, INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = INDIC_MATRA_CATEGORY_NOT_APPLICABLE }; /* Note: We use ASSERT_STATIC_EXPR_ZERO() instead of ASSERT_STATIC_EXPR() and the comma operation * because gcc fails to optimize the latter and fills the table in at runtime. */ #define INDIC_COMBINE_CATEGORIES(S,M) \ (ASSERT_STATIC_EXPR_ZERO (M == INDIC_MATRA_CATEGORY_NOT_APPLICABLE || (S == INDIC_SYLLABIC_CATEGORY_VIRAMA || S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT)) + \ ASSERT_STATIC_EXPR_ZERO (S < 16 && M < 16) + \ ((M << 4) | S)) #include "hb-ot-shape-complex-indic-table.hh" /* XXX * This is a hack for now. We should: * 1. Move this data into the main Indic table, * and/or * 2. Probe font lookups to determine consonant positions. */ static const struct consonant_position_t { hb_codepoint_t u; indic_position_t position; } consonant_positions[] = { {0x0930, POS_BELOW}, {0x09AC, POS_BELOW}, {0x09AF, POS_POST}, {0x09B0, POS_BELOW}, {0x09F0, POS_BELOW}, {0x0A2F, POS_POST}, {0x0A30, POS_BELOW}, {0x0A35, POS_BELOW}, {0x0A39, POS_BELOW}, {0x0AB0, POS_BELOW}, {0x0B24, POS_BELOW}, {0x0B28, POS_BELOW}, {0x0B2C, POS_BELOW}, {0x0B2D, POS_BELOW}, {0x0B2E, POS_BELOW}, {0x0B2F, POS_POST}, {0x0B30, POS_BELOW}, {0x0B32, POS_BELOW}, {0x0B33, POS_BELOW}, {0x0B5F, POS_POST}, {0x0B71, POS_BELOW}, {0x0C15, POS_BELOW}, {0x0C16, POS_BELOW}, {0x0C17, POS_BELOW}, {0x0C18, POS_BELOW}, {0x0C19, POS_BELOW}, {0x0C1A, POS_BELOW}, {0x0C1B, POS_BELOW}, {0x0C1C, POS_BELOW}, {0x0C1D, POS_BELOW}, {0x0C1E, POS_BELOW}, {0x0C1F, POS_BELOW}, {0x0C20, POS_BELOW}, {0x0C21, POS_BELOW}, {0x0C22, POS_BELOW}, {0x0C23, POS_BELOW}, {0x0C24, POS_BELOW}, {0x0C25, POS_BELOW}, {0x0C26, POS_BELOW}, {0x0C27, POS_BELOW}, {0x0C28, POS_BELOW}, {0x0C2A, POS_BELOW}, {0x0C2B, POS_BELOW}, {0x0C2C, POS_BELOW}, {0x0C2D, POS_BELOW}, {0x0C2E, POS_BELOW}, {0x0C2F, POS_BELOW}, {0x0C30, POS_BELOW}, {0x0C32, POS_BELOW}, {0x0C33, POS_BELOW}, {0x0C35, POS_BELOW}, {0x0C36, POS_BELOW}, {0x0C37, POS_BELOW}, {0x0C38, POS_BELOW}, {0x0C39, POS_BELOW}, {0x0C95, POS_BELOW}, {0x0C96, POS_BELOW}, {0x0C97, POS_BELOW}, {0x0C98, POS_BELOW}, {0x0C99, POS_BELOW}, {0x0C9A, POS_BELOW}, {0x0C9B, POS_BELOW}, {0x0C9C, POS_BELOW}, {0x0C9D, POS_BELOW}, {0x0C9E, POS_BELOW}, {0x0C9F, POS_BELOW}, {0x0CA0, POS_BELOW}, {0x0CA1, POS_BELOW}, {0x0CA2, POS_BELOW}, {0x0CA3, POS_BELOW}, {0x0CA4, POS_BELOW}, {0x0CA5, POS_BELOW}, {0x0CA6, POS_BELOW}, {0x0CA7, POS_BELOW}, {0x0CA8, POS_BELOW}, {0x0CAA, POS_BELOW}, {0x0CAB, POS_BELOW}, {0x0CAC, POS_BELOW}, {0x0CAD, POS_BELOW}, {0x0CAE, POS_BELOW}, {0x0CAF, POS_BELOW}, {0x0CB0, POS_BELOW}, {0x0CB2, POS_BELOW}, {0x0CB3, POS_BELOW}, {0x0CB5, POS_BELOW}, {0x0CB6, POS_BELOW}, {0x0CB7, POS_BELOW}, {0x0CB8, POS_BELOW}, {0x0CB9, POS_BELOW}, {0x0CDE, POS_BELOW}, {0x0D2F, POS_POST}, {0x0D30, POS_POST}, {0x0D32, POS_BELOW}, {0x0D35, POS_POST}, }; /* XXX * This is a hack for now. We should move this data into the main Indic table. */ static const hb_codepoint_t ra_chars[] = { 0x0930, /* Devanagari */ 0x09B0, /* Bengali */ 0x09F0, /* Bengali */ //0x09F1, /* Bengali */ //0x0A30, /* Gurmukhi */ 0x0AB0, /* Gujarati */ 0x0B30, /* Oriya */ //0x0BB0, /* Tamil */ //0x0C30, /* Telugu */ 0x0CB0, /* Kannada */ //0x0D30, /* Malayalam */ }; 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; record = (consonant_position_t *) bsearch (&u, consonant_positions, ARRAY_LENGTH (consonant_positions), sizeof (consonant_positions[0]), compare_codepoint); return record ? record->position : POS_BASE; } static bool is_ra (hb_codepoint_t u) { return !!bsearch (&u, ra_chars, ARRAY_LENGTH (ra_chars), sizeof (ra_chars[0]), compare_codepoint); } static bool is_joiner (const hb_glyph_info_t &info) { return !!(FLAG (info.indic_category()) & (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))); } static bool is_consonant (const hb_glyph_info_t &info) { return !!(FLAG (info.indic_category()) & (FLAG (OT_C) | FLAG (OT_Ra))); } static const struct { hb_tag_t tag; hb_bool_t is_global; } 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'), false}, {HB_TAG('p','r','e','f'), false}, {HB_TAG('b','l','w','f'), false}, {HB_TAG('h','a','l','f'), false}, {HB_TAG('v','a','t','u'), true}, {HB_TAG('p','s','t','f'), false}, {HB_TAG('c','j','c','t'), false}, }; /* Same order as the indic_basic_features array */ enum { _NUKT, AKHN, RPHF, RKRF, PREF, BLWF, HALF, _VATU, PSTF, CJCT, }; static const hb_tag_t indic_other_features[] = { HB_TAG('p','r','e','s'), HB_TAG('a','b','v','s'), HB_TAG('b','l','w','s'), HB_TAG('p','s','t','s'), HB_TAG('h','a','l','n'), HB_TAG('d','i','s','t'), HB_TAG('a','b','v','m'), HB_TAG('b','l','w','m'), }; 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) { 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 (final_reordering, NULL); for (unsigned int i = 0; i < ARRAY_LENGTH (indic_other_features); i++) map->add_bool_feature (indic_other_features[i], true); } bool _hb_ot_shape_complex_prefer_decomposed_indic (void) { /* We want split matras decomposed by the common shaping logic. */ return TRUE; } void _hb_ot_shape_complex_setup_masks_indic (hb_ot_map_t *map, hb_buffer_t *buffer) { 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++) { unsigned int type = get_indic_categories (buffer->info[i].codepoint); buffer->info[i].indic_category() = type & 0x0F; buffer->info[i].indic_position() = type >> 4; if (buffer->info[i].indic_category() == OT_C) { buffer->info[i].indic_position() = consonant_position (buffer->info[i].codepoint); if (is_ra (buffer->info[i].codepoint)) buffer->info[i].indic_category() = OT_Ra; } else if (buffer->info[i].codepoint == 0x200C) buffer->info[i].indic_category() = OT_ZWNJ; else if (buffer->info[i].codepoint == 0x200D) buffer->info[i].indic_category() = OT_ZWJ; } } 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 found_consonant_syllable (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array, unsigned int start, unsigned int end) { unsigned int i; hb_glyph_info_t *info = buffer->info; /* Comments from: * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */ /* 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 = 0; /* -> starting from the end of the syllable, move backwards */ i = end; do { i--; /* -> until a consonant is found */ if (info[i].indic_category() == OT_C) //if ((FLAG (info[i].indic_category()) & (FLAG (OT_C) | FLAG (OT_Ra)))) { /* -> 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 && info[i].indic_position() != POS_POST) { base = i; break; } /* TODO: or that is not a pre-base reordering Ra, */ /* -> or arrive at the first consonant. The consonant stopped at will be the base. */ base = i; } } while (i > start); if (base < start) base = start; /* Just in case... */ /* TODO * 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. */ /* 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 (i = start; i < base; i++) info[i].indic_position() = POS_PRE; info[base].indic_position() = POS_BASE; /* Handle beginning Ra */ if (start + 3 <= end && info[start].indic_category() == OT_Ra && info[start + 1].indic_category() == OT_H && !is_joiner (info[start + 2])) { info[start].indic_position() = POS_POST; info[start].mask = mask_array[RPHF]; } /* For old-style Indic script tags, move the first post-base Halant after * last consonant. */ if ((map->get_chosen_script (0) & 0x000000FF) != '2') { /* We should only do this for Indic scripts which have a version two I guess. */ for (i = base + 1; i < end; i++) if (info[i].indic_category() == OT_H) { unsigned int j; for (j = end - 1; j > i; j--) if ((FLAG (info[j].indic_category()) & (FLAG (OT_C) | FLAG (OT_Ra)))) 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. */ for (i = start + 1; i < end; i++) if ((FLAG (info[i].indic_category()) & (FLAG (OT_ZWNJ) | FLAG (OT_ZWJ) | FLAG (OT_N) | FLAG (OT_H)))) info[i].indic_position() = info[i - 1].indic_position(); /* We do bubble-sort, skip malicious clusters attempts */ if (end - start > 20) return; /* Sit tight, rock 'n roll! */ hb_bubble_sort (info + start, end - start, compare_indic_order); /* Setup masks now */ /* Pre-base */ for (i = start; i < base; i++) info[i].mask |= mask_array[HALF] | mask_array[AKHN] | mask_array[CJCT]; /* Base */ info[base].mask |= mask_array[AKHN] | mask_array[CJCT]; /* Post-base */ for (i = base + 1; i < end; i++) info[i].mask |= mask_array[BLWF] | mask_array[PSTF] | mask_array[CJCT]; /* Apply ZWJ/ZWNJ effects */ for (i = start + 1; i < end; i++) if (is_joiner (info[i])) { bool non_joiner = info[i].indic_category() == OT_ZWNJ; unsigned int j = i - 1; do { info[j].mask &= !mask_array[HALF]; if (non_joiner) info[j].mask &= !mask_array[CJCT]; j--; } while (j > start && !is_consonant (info[j])); } } static void found_vowel_syllable (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array, unsigned int start, unsigned int end) { /* TODO * Not clear to me how this should work. Do the matras move to before the * independent vowel? No idea. */ } static void found_standalone_cluster (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array, unsigned int start, unsigned int end) { /* TODO * Easiest thing to do here is to convert the NBSP to consonant and * call found_consonant_syllable. */ } static void found_non_indic (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array, unsigned int start, unsigned int end) { /* 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 remove_joiners (hb_buffer_t *buffer) { buffer->clear_output (); unsigned int count = buffer->len; for (buffer->idx = 0; buffer->idx < count;) if (unlikely (is_joiner (buffer->info[buffer->idx]))) buffer->skip_glyph (); else buffer->next_glyph (); buffer->swap_buffers (); } static void initial_reordering (const hb_ot_map_t *map, hb_face_t *face, hb_buffer_t *buffer, void *user_data HB_UNUSED) { hb_mask_t 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++) mask_array[i] = map->get_1_mask (indic_basic_features[i].tag); find_syllables (map, buffer, mask_array); remove_joiners (buffer); } static void final_reordering (const hb_ot_map_t *map, hb_face_t *face, hb_buffer_t *buffer, void *user_data HB_UNUSED) { HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category); HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position); } HB_END_DECLS