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 /*

  * Copyright © 2011,2012,2013  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"

 /* buffer var allocations */

 #define sea_category() complex_var_u8_0() /* indic_category_t */

 #define sea_position() complex_var_u8_1() /* indic_position_t */

 /*

  * South-East Asian shaper.

  * Loosely based on the Myanmar spec / shaper.

  * There is no OpenType spec for this.

  */

 static const hb_tag_t

 basic_features[] =

 {

   /*

    * Basic features.

    * These features are applied in order, one at a time, after initial_reordering.

    */

   HB_TAG('p','r','e','f'),

   HB_TAG('a','b','v','f'),

   HB_TAG('b','l','w','f'),

   HB_TAG('p','s','t','f'),

 };

 static const hb_tag_t

 other_features[] =

 {

   /*

    * Other features.

    * These features are applied all at once, after final_reordering.

    */

   HB_TAG('p','r','e','s'),

   HB_TAG('a','b','v','s'),

   HB_TAG('b','l','w','s'),

   HB_TAG('p','s','t','s'),

   /* Positioning features, though we don't care about the types. */

   HB_TAG('d','i','s','t'),

 };

 static void

 setup_syllables (const hb_ot_shape_plan_t *plan,

 		 hb_font_t *font,

 		 hb_buffer_t *buffer);

 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_sea (hb_ot_shape_planner_t *plan)

 {

   hb_ot_map_builder_t *map = &plan->map;

   /* Do this before any lookups have been applied. */

   map->add_gsub_pause (setup_syllables);

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

   map->add_gsub_pause (initial_reordering);

   for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)

   {

     map->add_feature (basic_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);

     map->add_gsub_pause (NULL);

   }

   map->add_gsub_pause (final_reordering);

   for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)

     map->add_feature (other_features[i], 1, F_GLOBAL | F_MANUAL_ZWJ);

 }

 static void

 override_features_sea (hb_ot_shape_planner_t *plan)

 {

   plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);

 }

 enum syllable_type_t {

   consonant_syllable,

   broken_cluster,

   non_sea_cluster,

 };

 #include "hb-ot-shape-complex-sea-machine.hh"

 /* Note: This enum is duplicated in the -machine.rl source file.

  * Not sure how to avoid duplication. */

 enum sea_category_t {

 //  OT_C    = 1,

   OT_GB   = 12, /* Generic Base XXX DOTTED CIRCLE only for now */

 //  OT_H    = 4,  /* Halant */

   OT_IV   = 2,  /* Independent Vowel */

   OT_MR   = 22, /* Medial Ra */

 //  OT_CM   = 17, /* Consonant Medial */

   OT_VAbv = 26,

   OT_VBlw = 27,

   OT_VPre = 28,

   OT_VPst = 29,

   OT_T    = 3,  /* Tone Marks */

 //  OT_A    = 10, /* Anusvara */

 };

 static inline void

 set_sea_properties (hb_glyph_info_t &info)

 {

   hb_codepoint_t u = info.codepoint;

   unsigned int type = hb_indic_get_categories (u);

   indic_category_t cat = (indic_category_t) (type & 0x7F);

   indic_position_t pos = (indic_position_t) (type >> 8);

   /* Medial Ra */

   if (u == 0x1A55 || u == 0xAA34)

     cat = (indic_category_t) OT_MR;

   if (cat == OT_M)

   {

     switch ((int) pos)

     {

       case POS_PRE_C:	cat = (indic_category_t) OT_VPre; break;

       case POS_ABOVE_C:	cat = (indic_category_t) OT_VAbv; break;

       case POS_BELOW_C:	cat = (indic_category_t) OT_VBlw; break;

       case POS_POST_C:	cat = (indic_category_t) OT_VPst; break;

     }

   }

   info.sea_category() = (sea_category_t) cat;

   info.sea_position() = pos;

 }

 static void

 setup_masks_sea (const hb_ot_shape_plan_t *plan HB_UNUSED,

 		 hb_buffer_t              *buffer,

 		 hb_font_t                *font HB_UNUSED)

 {

   HB_BUFFER_ALLOCATE_VAR (buffer, sea_category);

   HB_BUFFER_ALLOCATE_VAR (buffer, sea_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_sea_properties (buffer->info[i]);

 }

 static void

 setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,

 		 hb_font_t *font HB_UNUSED,

 		 hb_buffer_t *buffer)

 {

   find_syllables (buffer);

 }

 static int

 compare_sea_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)

 {

   int a = pa->sea_position();

   int b = pb->sea_position();

   return a < b ? -1 : a == b ? 0 : +1;

 }

 static void

 initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,

 				       hb_face_t *face,

 				       hb_buffer_t *buffer,

 				       unsigned int start, unsigned int end)

 {

   hb_glyph_info_t *info = buffer->info;

   unsigned int base = start;

   /* Reorder! */

   unsigned int i = start;

   for (; i < base; i++)

     info[i].sea_position() = POS_PRE_C;

   if (i < end)

   {

     info[i].sea_position() = POS_BASE_C;

     i++;

   }

   for (; i < end; i++)

   {

     if (info[i].sea_category() == OT_MR) /* Pre-base reordering */

     {

       info[i].sea_position() = POS_PRE_C;

       continue;

     }

     if (info[i].sea_category() == OT_VPre) /* Left matra */

     {

       info[i].sea_position() = POS_PRE_M;

       continue;

     }

     info[i].sea_position() = POS_AFTER_MAIN;

   }

   buffer->merge_clusters (start, end);

   /* Sit tight, rock 'n roll! */

   hb_bubble_sort (info + start, end - start, compare_sea_order);

 }

 static void

 initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan,

 				   hb_face_t *face,

 				   hb_buffer_t *buffer,

 				   unsigned int start, unsigned int end)

 {

   /* We already inserted dotted-circles, so just call the consonant_syllable. */

   initial_reordering_consonant_syllable (plan, face, buffer, start, end);

 }

 static void

 initial_reordering_non_sea_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,

 				    hb_face_t *face 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. */

 }

 static void

 initial_reordering_syllable (const hb_ot_shape_plan_t *plan,

 			     hb_face_t *face,

 			     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, face, buffer, start, end); return;

   case broken_cluster:		initial_reordering_broken_cluster      (plan, face, buffer, start, end); return;

   case non_sea_cluster:		initial_reordering_non_sea_cluster     (plan, face, buffer, start, end); return;

   }

 }

 static inline void

 insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,

 		       hb_font_t *font,

 		       hb_buffer_t *buffer)

 {

   /* Note: This loop is extra overhead, but should not be measurable. */

   bool has_broken_syllables = false;

   unsigned int count = buffer->len;

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

     if ((buffer->info[i].syllable() & 0x0F) == broken_cluster) {

       has_broken_syllables = true;

       break;

     }

   if (likely (!has_broken_syllables))

     return;

   hb_codepoint_t dottedcircle_glyph;

   if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph))

     return;

   hb_glyph_info_t dottedcircle = {0};

   dottedcircle.codepoint = 0x25CC;

   set_sea_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))

     {

       last_syllable = syllable;

       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);

     }

     else

       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)

 {

   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, font->face, buffer, last, i);

       last = i;

       last_syllable = info[last].syllable();

     }

   initial_reordering_syllable (plan, font->face, buffer, last, count);

 }

 static void

 final_reordering (const hb_ot_shape_plan_t *plan,

 		  hb_font_t *font HB_UNUSED,

 		  hb_buffer_t *buffer)

 {

   hb_glyph_info_t *info = buffer->info;

   unsigned int count = buffer->len;

   /* Zero syllables now... */

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

     info[i].syllable() = 0;

   HB_BUFFER_DEALLOCATE_VAR (buffer, sea_category);

   HB_BUFFER_DEALLOCATE_VAR (buffer, sea_position);

 }

 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_sea =

 {

   "sea",

   collect_features_sea,

   override_features_sea,

   NULL, /* data_create */

   NULL, /* data_destroy */

   NULL, /* preprocess_text */

   HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,

   NULL, /* decompose */

   NULL, /* compose */

   setup_masks_sea,

   HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,

   false, /* fallback_position */

 };