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 /*

  * Copyright © 2010,2012  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-private.hh"

 #include "hb-ot-shape-private.hh"

 /* buffer var allocations */

 #define arabic_shaping_action() complex_var_u8_0() /* arabic shaping action */

 /*

  * Bits used in the joining tables

  */

 enum {

   JOINING_TYPE_U		= 0,

   JOINING_TYPE_L		= 1,

   JOINING_TYPE_R		= 2,

   JOINING_TYPE_D		= 3,

   JOINING_TYPE_C		= JOINING_TYPE_D,

   JOINING_GROUP_ALAPH		= 4,

   JOINING_GROUP_DALATH_RISH	= 5,

   NUM_STATE_MACHINE_COLS	= 6,

   JOINING_TYPE_T = 7,

   JOINING_TYPE_X = 8  /* 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<hb_codepoint_t> (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<hb_codepoint_t> (u, 0x1800, 0x18AF)))

   {

     if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1880, 0x1886)))

       return JOINING_TYPE_U;

     /* All letters, SIBE SYLLABLE BOUNDARY MARKER, and NIRUGU are D */

     if ((FLAG(gen_cat) & (FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) |

 			  FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER)))

 	|| u == 0x1807 || u == 0x180A)

       return JOINING_TYPE_D;

   }

   /* 'Phags-pa joining data is not in ArabicJoining.txt yet. */

   if (unlikely (hb_in_range<hb_codepoint_t> (u, 0xA840, 0xA872)))

   {

       if (unlikely (u == 0xA872))

 	return JOINING_TYPE_L;

       return JOINING_TYPE_D;

   }

   if (unlikely (hb_in_range<hb_codepoint_t> (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 const hb_tag_t arabic_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,

   ARABIC_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_L,          jt_R,          jt_D,          jg_ALAPH,      jg_DALATH_RISH */

   /* State 0: prev was U, not willing to join. */

   { {NONE,NONE,0}, {NONE,ISOL,2}, {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,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, },

   /* State 2: prev was D/L in ISOL form, willing to join. */

   { {NONE,NONE,0}, {NONE,ISOL,2}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, },

   /* State 3: prev was D in FINA form, willing to join. */

   { {NONE,NONE,0}, {NONE,ISOL,2}, {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}, {NONE,ISOL,2}, {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}, {NONE,ISOL,2}, {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,2}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, }

 };

 static void

 nuke_joiners (const hb_ot_shape_plan_t *plan,

 	      hb_font_t *font,

 	      hb_buffer_t *buffer);

 static void

 arabic_fallback_shape (const hb_ot_shape_plan_t *plan,

 		       hb_font_t *font,

 		       hb_buffer_t *buffer);

 static void

 collect_features_arabic (hb_ot_shape_planner_t *plan)

 {

   hb_ot_map_builder_t *map = &plan->map;

   /* 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_gsub_pause (nuke_joiners);

   map->add_global_bool_feature (HB_TAG('c','c','m','p'));

   map->add_global_bool_feature (HB_TAG('l','o','c','l'));

   map->add_gsub_pause (NULL);

   for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++)

     map->add_feature (arabic_features[i], 1, i < 4 ? F_HAS_FALLBACK : F_NONE); /* The first four features have fallback. */

   map->add_gsub_pause (NULL);

   map->add_feature (HB_TAG('r','l','i','g'), 1, F_GLOBAL|F_HAS_FALLBACK);

   map->add_gsub_pause (arabic_fallback_shape);

   map->add_global_bool_feature (HB_TAG('c','a','l','t'));

   map->add_gsub_pause (NULL);

   map->add_global_bool_feature (HB_TAG('m','s','e','t'));

 }

 #include "hb-ot-shape-complex-arabic-fallback.hh"

 struct arabic_shape_plan_t

 {

   ASSERT_POD ();

   /* The "+ 1" in the next array is to accommodate for the "NONE" command,

    * which is not an OpenType feature, but this simplifies the code by not

    * having to do a "if (... < NONE) ..." and just rely on the fact that

    * mask_array[NONE] == 0. */

   hb_mask_t mask_array[ARABIC_NUM_FEATURES + 1];

   bool do_fallback;

   arabic_fallback_plan_t *fallback_plan;

 };

 static void *

 data_create_arabic (const hb_ot_shape_plan_t *plan)

 {

   arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) calloc (1, sizeof (arabic_shape_plan_t));

   if (unlikely (!arabic_plan))

     return NULL;

   arabic_plan->do_fallback = plan->props.script == HB_SCRIPT_ARABIC;

   for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) {

     arabic_plan->mask_array[i] = plan->map.get_1_mask (arabic_features[i]);

     if (i < 4)

       arabic_plan->do_fallback = arabic_plan->do_fallback && plan->map.needs_fallback (arabic_features[i]);

   }

   return arabic_plan;

 }

 static void

 data_destroy_arabic (void *data)

 {

   arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) data;

   arabic_fallback_plan_destroy (arabic_plan->fallback_plan);

   free (data);

 }

 static void

 arabic_joining (hb_buffer_t *buffer)

 {

   unsigned int count = buffer->len;

   unsigned int prev = (unsigned int) -1, state = 0;

   HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action);

   /* Check pre-context */

   if (!(buffer->flags & HB_BUFFER_FLAG_BOT))

     for (unsigned int i = 0; i < buffer->context_len[0]; i++)

     {

       unsigned int this_type = get_joining_type (buffer->context[0][i], buffer->unicode->general_category (buffer->context[0][i]));

       if (unlikely (this_type == JOINING_TYPE_T))

 	continue;

       const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];

       state = entry->next_state;

       break;

     }

   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 && prev != (unsigned int) -1)

       for (; prev < i; prev++)

 	buffer->info[prev].arabic_shaping_action() = entry->prev_action;

     buffer->info[i].arabic_shaping_action() = entry->curr_action;

     prev = i;

     state = entry->next_state;

   }

   if (!(buffer->flags & HB_BUFFER_FLAG_EOT))

     for (unsigned int i = 0; i < buffer->context_len[1]; i++)

     {

       unsigned int this_type = get_joining_type (buffer->context[1][i], buffer->unicode->general_category (buffer->context[1][i]));

       if (unlikely (this_type == JOINING_TYPE_T))

 	continue;

       const arabic_state_table_entry *entry = &arabic_state_table[state][this_type];

       if (entry->prev_action != NONE && prev != (unsigned int) -1)

 	buffer->info[prev].arabic_shaping_action() = entry->prev_action;

       break;

     }

   HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);

 }

 static void

 setup_masks_arabic (const hb_ot_shape_plan_t *plan,

 		    hb_buffer_t              *buffer,

 		    hb_font_t                *font HB_UNUSED)

 {

   const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;

   arabic_joining (buffer);

   unsigned int count = buffer->len;

   for (unsigned int i = 0; i < count; i++)

     buffer->info[i].mask |= arabic_plan->mask_array[buffer->info[i].arabic_shaping_action()];

 }

 static void

 nuke_joiners (const hb_ot_shape_plan_t *plan HB_UNUSED,

 	      hb_font_t *font HB_UNUSED,

 	      hb_buffer_t *buffer)

 {

   unsigned int count = buffer->len;

   for (unsigned int i = 0; i < count; i++)

     if (_hb_glyph_info_is_zwj (&buffer->info[i]))

       _hb_glyph_info_flip_joiners (&buffer->info[i]);

 }

 static void

 arabic_fallback_shape (const hb_ot_shape_plan_t *plan,

 		       hb_font_t *font,

 		       hb_buffer_t *buffer)

 {

   const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;

   if (!arabic_plan->do_fallback)

     return;

 retry:

   arabic_fallback_plan_t *fallback_plan = (arabic_fallback_plan_t *) hb_atomic_ptr_get (&arabic_plan->fallback_plan);

   if (unlikely (!fallback_plan))

   {

     /* This sucks.  We need a font to build the fallback plan... */

     fallback_plan = arabic_fallback_plan_create (plan, font);

     if (unlikely (!hb_atomic_ptr_cmpexch (&(const_cast<arabic_shape_plan_t *> (arabic_plan))->fallback_plan, NULL, fallback_plan))) {

       arabic_fallback_plan_destroy (fallback_plan);

       goto retry;

     }

   }

   arabic_fallback_plan_shape (fallback_plan, font, buffer);

 }

 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =

 {

   "arabic",

   collect_features_arabic,

   NULL, /* override_features */

   data_create_arabic,

   data_destroy_arabic,

   NULL, /* preprocess_text_arabic */

   HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT,

   NULL, /* decompose */

   NULL, /* compose */

   setup_masks_arabic,

   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,

   true, /* fallback_position */

 };