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kc3-lang/harfbuzz/src/hb-ot-shape-complex-use.cc

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  • Author : Behdad Esfahbod
    Date : 2021-01-15 19:13:47
    Hash : 0ddade44
    Message : [syllabic] Merge various insert_dotted_circles implementations Fixes https://github.com/harfbuzz/harfbuzz/issues/1810

  • src/hb-ot-shape-complex-use.cc
  • /*
     * Copyright © 2015  Mozilla Foundation.
     * Copyright © 2015  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.
     *
     * Mozilla Author(s): Jonathan Kew
     * Google Author(s): Behdad Esfahbod
     */
    
    #include "hb.hh"
    
    #ifndef HB_NO_OT_SHAPE
    
    #include "hb-ot-shape-complex-use.hh"
    #include "hb-ot-shape-complex-arabic.hh"
    #include "hb-ot-shape-complex-arabic-joining-list.hh"
    #include "hb-ot-shape-complex-vowel-constraints.hh"
    
    /* buffer var allocations */
    #define use_category() complex_var_u8_category()
    
    
    /*
     * Universal Shaping Engine.
     * https://docs.microsoft.com/en-us/typography/script-development/use
     */
    
    static const hb_tag_t
    use_basic_features[] =
    {
      /*
       * Basic features.
       * These features are applied all at once, before reordering.
       */
      HB_TAG('r','k','r','f'),
      HB_TAG('a','b','v','f'),
      HB_TAG('b','l','w','f'),
      HB_TAG('h','a','l','f'),
      HB_TAG('p','s','t','f'),
      HB_TAG('v','a','t','u'),
      HB_TAG('c','j','c','t'),
    };
    static const hb_tag_t
    use_topographical_features[] =
    {
      HB_TAG('i','s','o','l'),
      HB_TAG('i','n','i','t'),
      HB_TAG('m','e','d','i'),
      HB_TAG('f','i','n','a'),
    };
    /* Same order as use_topographical_features. */
    enum joining_form_t {
      USE_ISOL,
      USE_INIT,
      USE_MEDI,
      USE_FINA,
      _USE_NONE
    };
    static const hb_tag_t
    use_other_features[] =
    {
      /*
       * Other features.
       * These features are applied all at once, after reordering and
       * clearing syllables.
       */
      HB_TAG('a','b','v','s'),
      HB_TAG('b','l','w','s'),
      HB_TAG('h','a','l','n'),
      HB_TAG('p','r','e','s'),
      HB_TAG('p','s','t','s'),
    };
    
    static void
    setup_syllables_use (const hb_ot_shape_plan_t *plan,
    		     hb_font_t *font,
    		     hb_buffer_t *buffer);
    static void
    record_rphf_use (const hb_ot_shape_plan_t *plan,
    		 hb_font_t *font,
    		 hb_buffer_t *buffer);
    static void
    record_pref_use (const hb_ot_shape_plan_t *plan,
    		 hb_font_t *font,
    		 hb_buffer_t *buffer);
    static void
    reorder_use (const hb_ot_shape_plan_t *plan,
    	     hb_font_t *font,
    	     hb_buffer_t *buffer);
    
    static void
    collect_features_use (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_use);
    
      /* "Default glyph pre-processing group" */
      map->enable_feature (HB_TAG('l','o','c','l'));
      map->enable_feature (HB_TAG('c','c','m','p'));
      map->enable_feature (HB_TAG('n','u','k','t'));
      map->enable_feature (HB_TAG('a','k','h','n'), F_MANUAL_ZWJ);
    
      /* "Reordering group" */
      map->add_gsub_pause (_hb_clear_substitution_flags);
      map->add_feature (HB_TAG('r','p','h','f'), F_MANUAL_ZWJ);
      map->add_gsub_pause (record_rphf_use);
      map->add_gsub_pause (_hb_clear_substitution_flags);
      map->enable_feature (HB_TAG('p','r','e','f'), F_MANUAL_ZWJ);
      map->add_gsub_pause (record_pref_use);
    
      /* "Orthographic unit shaping group" */
      for (unsigned int i = 0; i < ARRAY_LENGTH (use_basic_features); i++)
        map->enable_feature (use_basic_features[i], F_MANUAL_ZWJ);
    
      map->add_gsub_pause (reorder_use);
      map->add_gsub_pause (_hb_clear_syllables);
    
      /* "Topographical features" */
      for (unsigned int i = 0; i < ARRAY_LENGTH (use_topographical_features); i++)
        map->add_feature (use_topographical_features[i]);
      map->add_gsub_pause (nullptr);
    
      /* "Standard typographic presentation" */
      for (unsigned int i = 0; i < ARRAY_LENGTH (use_other_features); i++)
        map->enable_feature (use_other_features[i], F_MANUAL_ZWJ);
    }
    
    struct use_shape_plan_t
    {
      hb_mask_t rphf_mask;
    
      arabic_shape_plan_t *arabic_plan;
    };
    
    static void *
    data_create_use (const hb_ot_shape_plan_t *plan)
    {
      use_shape_plan_t *use_plan = (use_shape_plan_t *) calloc (1, sizeof (use_shape_plan_t));
      if (unlikely (!use_plan))
        return nullptr;
    
      use_plan->rphf_mask = plan->map.get_1_mask (HB_TAG('r','p','h','f'));
    
      if (has_arabic_joining (plan->props.script))
      {
        use_plan->arabic_plan = (arabic_shape_plan_t *) data_create_arabic (plan);
        if (unlikely (!use_plan->arabic_plan))
        {
          free (use_plan);
          return nullptr;
        }
      }
    
      return use_plan;
    }
    
    static void
    data_destroy_use (void *data)
    {
      use_shape_plan_t *use_plan = (use_shape_plan_t *) data;
    
      if (use_plan->arabic_plan)
        data_destroy_arabic (use_plan->arabic_plan);
    
      free (data);
    }
    
    enum use_syllable_type_t {
      use_independent_cluster,
      use_virama_terminated_cluster,
      use_sakot_terminated_cluster,
      use_standard_cluster,
      use_number_joiner_terminated_cluster,
      use_numeral_cluster,
      use_symbol_cluster,
      use_hieroglyph_cluster,
      use_broken_cluster,
      use_non_cluster,
    };
    
    #include "hb-ot-shape-complex-use-machine.hh"
    
    
    static void
    setup_masks_use (const hb_ot_shape_plan_t *plan,
    		 hb_buffer_t              *buffer,
    		 hb_font_t                *font HB_UNUSED)
    {
      const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
    
      /* Do this before allocating use_category(). */
      if (use_plan->arabic_plan)
      {
        setup_masks_arabic_plan (use_plan->arabic_plan, buffer, plan->props.script);
      }
    
      HB_BUFFER_ALLOCATE_VAR (buffer, use_category);
    
      /* We cannot setup masks here.  We save information about characters
       * and setup masks later on in a pause-callback. */
    
      unsigned int count = buffer->len;
      hb_glyph_info_t *info = buffer->info;
      for (unsigned int i = 0; i < count; i++)
        info[i].use_category() = hb_use_get_category (info[i].codepoint);
    }
    
    static void
    setup_rphf_mask (const hb_ot_shape_plan_t *plan,
    		 hb_buffer_t *buffer)
    {
      const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
    
      hb_mask_t mask = use_plan->rphf_mask;
      if (!mask) return;
    
      hb_glyph_info_t *info = buffer->info;
    
      foreach_syllable (buffer, start, end)
      {
        unsigned int limit = info[start].use_category() == USE_R ? 1 : hb_min (3u, end - start);
        for (unsigned int i = start; i < start + limit; i++)
          info[i].mask |= mask;
      }
    }
    
    static void
    setup_topographical_masks (const hb_ot_shape_plan_t *plan,
    			   hb_buffer_t *buffer)
    {
      const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
      if (use_plan->arabic_plan)
        return;
    
      static_assert ((USE_INIT < 4 && USE_ISOL < 4 && USE_MEDI < 4 && USE_FINA < 4), "");
      hb_mask_t masks[4], all_masks = 0;
      for (unsigned int i = 0; i < 4; i++)
      {
        masks[i] = plan->map.get_1_mask (use_topographical_features[i]);
        if (masks[i] == plan->map.get_global_mask ())
          masks[i] = 0;
        all_masks |= masks[i];
      }
      if (!all_masks)
        return;
      hb_mask_t other_masks = ~all_masks;
    
      unsigned int last_start = 0;
      joining_form_t last_form = _USE_NONE;
      hb_glyph_info_t *info = buffer->info;
      foreach_syllable (buffer, start, end)
      {
        use_syllable_type_t syllable_type = (use_syllable_type_t) (info[start].syllable() & 0x0F);
        switch (syllable_type)
        {
          case use_independent_cluster:
          case use_symbol_cluster:
          case use_hieroglyph_cluster:
          case use_non_cluster:
    	/* These don't join.  Nothing to do. */
    	last_form = _USE_NONE;
    	break;
    
          case use_virama_terminated_cluster:
          case use_sakot_terminated_cluster:
          case use_standard_cluster:
          case use_number_joiner_terminated_cluster:
          case use_numeral_cluster:
          case use_broken_cluster:
    
    	bool join = last_form == USE_FINA || last_form == USE_ISOL;
    
    	if (join)
    	{
    	  /* Fixup previous syllable's form. */
    	  last_form = last_form == USE_FINA ? USE_MEDI : USE_INIT;
    	  for (unsigned int i = last_start; i < start; i++)
    	    info[i].mask = (info[i].mask & other_masks) | masks[last_form];
    	}
    
    	/* Form for this syllable. */
    	last_form = join ? USE_FINA : USE_ISOL;
    	for (unsigned int i = start; i < end; i++)
    	  info[i].mask = (info[i].mask & other_masks) | masks[last_form];
    
    	break;
        }
    
        last_start = start;
      }
    }
    
    static void
    setup_syllables_use (const hb_ot_shape_plan_t *plan,
    		     hb_font_t *font HB_UNUSED,
    		     hb_buffer_t *buffer)
    {
      find_syllables_use (buffer);
      foreach_syllable (buffer, start, end)
        buffer->unsafe_to_break (start, end);
      setup_rphf_mask (plan, buffer);
      setup_topographical_masks (plan, buffer);
    }
    
    static void
    record_rphf_use (const hb_ot_shape_plan_t *plan,
    		 hb_font_t *font HB_UNUSED,
    		 hb_buffer_t *buffer)
    {
      const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
    
      hb_mask_t mask = use_plan->rphf_mask;
      if (!mask) return;
      hb_glyph_info_t *info = buffer->info;
    
      foreach_syllable (buffer, start, end)
      {
        /* Mark a substituted repha as USE_R. */
        for (unsigned int i = start; i < end && (info[i].mask & mask); i++)
          if (_hb_glyph_info_substituted (&info[i]))
          {
    	info[i].use_category() = USE_R;
    	break;
          }
      }
    }
    
    static void
    record_pref_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
    		 hb_font_t *font HB_UNUSED,
    		 hb_buffer_t *buffer)
    {
      hb_glyph_info_t *info = buffer->info;
    
      foreach_syllable (buffer, start, end)
      {
        /* Mark a substituted pref as VPre, as they behave the same way. */
        for (unsigned int i = start; i < end; i++)
          if (_hb_glyph_info_substituted (&info[i]))
          {
    	info[i].use_category() = USE_VPre;
    	break;
          }
      }
    }
    
    static inline bool
    is_halant_use (const hb_glyph_info_t &info)
    {
      return (info.use_category() == USE_H || info.use_category() == USE_HVM) &&
    	 !_hb_glyph_info_ligated (&info);
    }
    
    static void
    reorder_syllable_use (hb_buffer_t *buffer, unsigned int start, unsigned int end)
    {
      use_syllable_type_t syllable_type = (use_syllable_type_t) (buffer->info[start].syllable() & 0x0F);
      /* Only a few syllable types need reordering. */
      if (unlikely (!(FLAG_UNSAFE (syllable_type) &
    		  (FLAG (use_virama_terminated_cluster) |
    		   FLAG (use_sakot_terminated_cluster) |
    		   FLAG (use_standard_cluster) |
    		   FLAG (use_broken_cluster) |
    		   0))))
        return;
    
      hb_glyph_info_t *info = buffer->info;
    
    #define POST_BASE_FLAGS64 (FLAG64 (USE_FAbv) | \
    			   FLAG64 (USE_FBlw) | \
    			   FLAG64 (USE_FPst) | \
    			   FLAG64 (USE_MAbv) | \
    			   FLAG64 (USE_MBlw) | \
    			   FLAG64 (USE_MPst) | \
    			   FLAG64 (USE_MPre) | \
    			   FLAG64 (USE_VAbv) | \
    			   FLAG64 (USE_VBlw) | \
    			   FLAG64 (USE_VPst) | \
    			   FLAG64 (USE_VPre) | \
    			   FLAG64 (USE_VMAbv) | \
    			   FLAG64 (USE_VMBlw) | \
    			   FLAG64 (USE_VMPst) | \
    			   FLAG64 (USE_VMPre))
    
      /* Move things forward. */
      if (info[start].use_category() == USE_R && end - start > 1)
      {
        /* Got a repha.  Reorder it towards the end, but before the first post-base
         * glyph. */
        for (unsigned int i = start + 1; i < end; i++)
        {
          bool is_post_base_glyph = (FLAG64_UNSAFE (info[i].use_category()) & POST_BASE_FLAGS64) ||
    				is_halant_use (info[i]);
          if (is_post_base_glyph || i == end - 1)
          {
    	/* If we hit a post-base glyph, move before it; otherwise move to the
    	 * end. Shift things in between backward. */
    
    	if (is_post_base_glyph)
    	  i--;
    
    	buffer->merge_clusters (start, i + 1);
    	hb_glyph_info_t t = info[start];
    	memmove (&info[start], &info[start + 1], (i - start) * sizeof (info[0]));
    	info[i] = t;
    
    	break;
          }
        }
      }
    
      /* Move things back. */
      unsigned int j = start;
      for (unsigned int i = start; i < end; i++)
      {
        uint32_t flag = FLAG_UNSAFE (info[i].use_category());
        if (is_halant_use (info[i]))
        {
          /* If we hit a halant, move after it; otherwise move to the beginning, and
           * shift things in between forward. */
          j = i + 1;
        }
        else if (((flag) & (FLAG (USE_VPre) | FLAG (USE_VMPre))) &&
    	     /* Only move the first component of a MultipleSubst. */
    	     0 == _hb_glyph_info_get_lig_comp (&info[i]) &&
    	     j < i)
        {
          buffer->merge_clusters (j, i + 1);
          hb_glyph_info_t t = info[i];
          memmove (&info[j + 1], &info[j], (i - j) * sizeof (info[0]));
          info[j] = t;
        }
      }
    }
    
    static void
    reorder_use (const hb_ot_shape_plan_t *plan,
    	     hb_font_t *font,
    	     hb_buffer_t *buffer)
    {
      if (buffer->message (font, "start reordering USE"))
      {
        hb_syllabic_insert_dotted_circles (font, buffer,
    				       use_broken_cluster,
    				       USE_B,
    				       USE_R);
    
        foreach_syllable (buffer, start, end)
          reorder_syllable_use (buffer, start, end);
    
        (void) buffer->message (font, "end reordering USE");
      }
    
      HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
    }
    
    
    static void
    preprocess_text_use (const hb_ot_shape_plan_t *plan,
    		     hb_buffer_t              *buffer,
    		     hb_font_t                *font)
    {
      _hb_preprocess_text_vowel_constraints (plan, buffer, font);
    }
    
    static bool
    compose_use (const hb_ot_shape_normalize_context_t *c,
    	     hb_codepoint_t  a,
    	     hb_codepoint_t  b,
    	     hb_codepoint_t *ab)
    {
      /* Avoid recomposing split matras. */
      if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
        return false;
    
      return (bool)c->unicode->compose (a, b, ab);
    }
    
    
    const hb_ot_complex_shaper_t _hb_ot_complex_shaper_use =
    {
      collect_features_use,
      nullptr, /* override_features */
      data_create_use,
      data_destroy_use,
      preprocess_text_use,
      nullptr, /* postprocess_glyphs */
      HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
      nullptr, /* decompose */
      compose_use,
      setup_masks_use,
      HB_TAG_NONE, /* gpos_tag */
      nullptr, /* reorder_marks */
      HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
      false, /* fallback_position */
    };
    
    
    #endif