/* * Copyright © 2010 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" #include "hb-ot-shape-private.hh" /* buffer var allocations */ #define arabic_shaping_action() complex_var_temporary_u16() /* arabic shaping action */ /* * Bits used in the joining tables */ enum { JOINING_TYPE_U = 0, JOINING_TYPE_R = 1, JOINING_TYPE_D = 2, JOINING_TYPE_C = JOINING_TYPE_D, JOINING_GROUP_ALAPH = 3, JOINING_GROUP_DALATH_RISH = 4, NUM_STATE_MACHINE_COLS = 5, /* We deliberately don't have a JOINING_TYPE_L since that's unused in Unicode. */ JOINING_TYPE_T = 6, JOINING_TYPE_X = 7 /* means: use general-category to choose between U or T. */ }; /* * Joining types: */ #include "hb-ot-shape-complex-arabic-table.hh" static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_category_t gen_cat) { if (likely (hb_in_range (u, JOINING_TABLE_FIRST, JOINING_TABLE_LAST))) { unsigned int j_type = joining_table[u - JOINING_TABLE_FIRST]; if (likely (j_type != JOINING_TYPE_X)) return j_type; } /* Mongolian joining data is not in ArabicJoining.txt yet */ if (unlikely (hb_in_range (u, 0x1800, 0x18AF))) { /* All letters, SIBE SYLLABLE BOUNDARY MARKER, and NIRUGU are D */ if (gen_cat == HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER || u == 0x1807 || u == 0x180A) return JOINING_TYPE_D; } if (unlikely (hb_in_range (u, 0x200C, 0x200D))) { return u == 0x200C ? JOINING_TYPE_U : JOINING_TYPE_C; } return (FLAG(gen_cat) & (FLAG(HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | FLAG(HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | FLAG(HB_UNICODE_GENERAL_CATEGORY_FORMAT))) ? JOINING_TYPE_T : JOINING_TYPE_U; } static hb_codepoint_t get_arabic_shape (hb_codepoint_t u, unsigned int shape) { if (likely (hb_in_range (u, SHAPING_TABLE_FIRST, SHAPING_TABLE_LAST)) && shape < 4) return shaping_table[u - SHAPING_TABLE_FIRST][shape]; return u; } static uint16_t get_ligature (hb_codepoint_t first, hb_codepoint_t second) { if (unlikely (!second)) return 0; for (unsigned i = 0; i < ARRAY_LENGTH (ligature_table); i++) if (ligature_table[i].first == first) for (unsigned j = 0; j < ARRAY_LENGTH (ligature_table[i].ligatures); j++) if (ligature_table[i].ligatures[j].second == second) return ligature_table[i].ligatures[j].ligature; return 0; } static const hb_tag_t arabic_syriac_features[] = { HB_TAG('i','n','i','t'), HB_TAG('m','e','d','i'), HB_TAG('f','i','n','a'), HB_TAG('i','s','o','l'), /* Syriac */ HB_TAG('m','e','d','2'), HB_TAG('f','i','n','2'), HB_TAG('f','i','n','3'), HB_TAG_NONE }; /* Same order as the feature array */ enum { INIT, MEDI, FINA, ISOL, /* Syriac */ MED2, FIN2, FIN3, NONE, COMMON_NUM_FEATURES = 4, SYRIAC_NUM_FEATURES = 7, TOTAL_NUM_FEATURES = NONE }; static const struct arabic_state_table_entry { uint8_t prev_action; uint8_t curr_action; uint16_t next_state; } arabic_state_table[][NUM_STATE_MACHINE_COLS] = { /* jt_U, jt_R, jt_D, jg_ALAPH, jg_DALATH_RISH */ /* State 0: prev was U, not willing to join. */ { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,6}, }, /* State 1: prev was R or ISOL/ALAPH, not willing to join. */ { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, }, /* State 2: prev was D/ISOL, willing to join. */ { {NONE,NONE,0}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, }, /* State 3: prev was D/FINA, willing to join. */ { {NONE,NONE,0}, {MEDI,FINA,1}, {MEDI,FINA,3}, {MEDI,FINA,4}, {MEDI,FINA,6}, }, /* State 4: prev was FINA ALAPH, not willing to join. */ { {NONE,NONE,0}, {MED2,ISOL,1}, {MED2,ISOL,2}, {MED2,FIN2,5}, {MED2,ISOL,6}, }, /* State 5: prev was FIN2/FIN3 ALAPH, not willing to join. */ { {NONE,NONE,0}, {ISOL,ISOL,1}, {ISOL,ISOL,2}, {ISOL,FIN2,5}, {ISOL,ISOL,6}, }, /* State 6: prev was DALATH/RISH, not willing to join. */ { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, } }; void _hb_ot_shape_complex_collect_features_arabic (hb_ot_map_builder_t *map, const hb_segment_properties_t *props) { /* For Language forms (in ArabicOT speak), we do the iso/fina/medi/init together, * then rlig and calt each in their own stage. This makes IranNastaliq's ALLAH * ligature work correctly. It's unfortunate though... * * This also makes Arial Bold in Windows7 work. See: * https://bugzilla.mozilla.org/show_bug.cgi?id=644184 * * TODO: Add test cases for these two. */ map->add_bool_feature (HB_TAG('c','c','m','p')); map->add_bool_feature (HB_TAG('l','o','c','l')); map->add_gsub_pause (NULL, NULL); unsigned int num_features = props->script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES; for (unsigned int i = 0; i < num_features; i++) map->add_bool_feature (arabic_syriac_features[i], false); map->add_gsub_pause (NULL, NULL); map->add_bool_feature (HB_TAG('r','l','i','g')); map->add_gsub_pause (NULL, NULL); map->add_bool_feature (HB_TAG('c','a','l','t')); map->add_gsub_pause (NULL, NULL); /* ArabicOT spec enables 'cswh' for Arabic where as for basic shaper it's disabled by default. */ map->add_bool_feature (HB_TAG('c','s','w','h')); } hb_ot_shape_normalization_mode_t _hb_ot_shape_complex_normalization_preference_arabic (void) { return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS; } static void arabic_fallback_shape (hb_font_t *font, hb_buffer_t *buffer) { unsigned int count = buffer->len; hb_codepoint_t glyph; /* Shape to presentation forms */ for (unsigned int i = 0; i < count; i++) { hb_codepoint_t u = buffer->info[i].codepoint; hb_codepoint_t shaped = get_arabic_shape (u, buffer->info[i].arabic_shaping_action()); if (shaped != u && hb_font_get_glyph (font, shaped, 0, &glyph)) buffer->info[i].codepoint = shaped; } /* Mandatory ligatures */ buffer->clear_output (); for (buffer->idx = 0; buffer->idx + 1 < count;) { hb_codepoint_t ligature = get_ligature (buffer->info[buffer->idx].codepoint, buffer->info[buffer->idx + 1].codepoint); if (likely (!ligature) || !(hb_font_get_glyph (font, ligature, 0, &glyph))) { buffer->next_glyph (); continue; } buffer->replace_glyphs (2, 1, &ligature); /* Technically speaking we can skip marks and stuff, like the GSUB path does. * But who cares, we're in fallback! */ } for (; buffer->idx < count;) buffer->next_glyph (); buffer->swap_buffers (); } void _hb_ot_shape_complex_setup_masks_arabic (hb_ot_map_t *map, hb_buffer_t *buffer, hb_font_t *font) { unsigned int count = buffer->len; unsigned int prev = 0, state = 0; HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action); for (unsigned int i = 0; i < count; i++) { unsigned int this_type = get_joining_type (buffer->info[i].codepoint, _hb_glyph_info_get_general_category (&buffer->info[i])); if (unlikely (this_type == JOINING_TYPE_T)) { buffer->info[i].arabic_shaping_action() = NONE; continue; } const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; if (entry->prev_action != NONE) buffer->info[prev].arabic_shaping_action() = entry->prev_action; buffer->info[i].arabic_shaping_action() = entry->curr_action; prev = i; state = entry->next_state; } hb_mask_t mask_array[TOTAL_NUM_FEATURES + 1] = {0}; hb_mask_t total_masks = 0; unsigned int num_masks = buffer->props.script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES; for (unsigned int i = 0; i < num_masks; i++) { mask_array[i] = map->get_1_mask (arabic_syriac_features[i]); total_masks |= mask_array[i]; } if (total_masks) { /* Has OpenType tables */ for (unsigned int i = 0; i < count; i++) buffer->info[i].mask |= mask_array[buffer->info[i].arabic_shaping_action()]; } else if (buffer->props.script == HB_SCRIPT_ARABIC) { /* Fallback Arabic shaping to Presentation Forms */ /* Pitfalls: * - This path fires if user force-set init/medi/fina/isol off, * - If font does not declare script 'arab', well, what to do? * Most probably it's safe to assume that init/medi/fina/isol * still mean Arabic shaping, although they do not have to. */ arabic_fallback_shape (font, buffer); } HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action); }