Edit
kc3-lang/harfbuzz/src/hb-ot-shape-complex-arabic.cc
Behdad Esfahbod
- src/hb-ot-shape-complex-arabic.cc
-
/* * 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" HB_BEGIN_DECLS /* buffer var allocations */ #define arabic_shaping_action() var2.u32 /* 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) { /* TODO Macroize the magic bit operations */ if (likely (JOINING_TABLE_FIRST <= u && u <= 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 (0x1800 <= u && u <= 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 ((u & ~(0x200C^0x200D)) == 0x200C)) { return u == 0x200C ? JOINING_TYPE_U : JOINING_TYPE_C; } return ((1<<gen_cat) & ((1<<HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)|(1<<HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK)|(1<<HB_UNICODE_GENERAL_CATEGORY_FORMAT))) ? JOINING_TYPE_T : JOINING_TYPE_U; } 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; uint8_t next_state; uint8_t padding; } 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_shape_plan_t *plan, const hb_segment_properties_t *props) { /* ArabicOT spec enables 'cswh' for Arabic where as for basic shaper it's disabled by default. */ plan->map.add_bool_feature (HB_TAG('c','s','w','h')); unsigned int num_features = props->script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES; for (unsigned int i = 0; i < num_features; i++) plan->map.add_bool_feature (arabic_syriac_features[i], false); } void _hb_ot_shape_complex_setup_masks_arabic (hb_ot_shape_context_t *c) { unsigned int count = c->buffer->len; unsigned int prev = 0, state = 0; for (unsigned int i = 0; i < count; i++) { unsigned int this_type = get_joining_type (c->buffer->info[i].codepoint, (hb_unicode_general_category_t) c->buffer->info[i].general_category()); if (unlikely (this_type == JOINING_TYPE_T)) { c->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) c->buffer->info[prev].arabic_shaping_action() = entry->prev_action; c->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}; unsigned int num_masks = c->buffer->props.script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES; for (unsigned int i = 0; i < num_masks; i++) mask_array[i] = c->plan->map.get_1_mask (arabic_syriac_features[i]); for (unsigned int i = 0; i < count; i++) c->buffer->info[i].mask |= mask_array[c->buffer->info[i].arabic_shaping_action()]; } HB_END_DECLS