text: /*
   * Copyright © 2018  Ebrahim Byagowi
   * Copyright © 2020  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): Calder Kitagawa
   */
  
  #ifndef HB_OT_COLOR_COLR_TABLE_HH
  #define HB_OT_COLOR_COLR_TABLE_HH
  
  #include "hb-open-type.hh"
  
  /*
   * COLR -- Color
   * https://docs.microsoft.com/en-us/typography/opentype/spec/colr
   */
  #define HB_OT_TAG_COLR HB_TAG('C','O','L','R')
  
  
  namespace OT {
  
  
  struct LayerRecord
  {
    operator hb_ot_color_layer_t () const { return {glyphId, colorIdx}; }
  
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (c->check_struct (this));
    }
  
    public:
    HBGlyphID	glyphId;	/* Glyph ID of layer glyph */
    Index		colorIdx;	/* Index value to use with a
  				 * selected color palette.
  				 * An index value of 0xFFFF
  				 * is a special case indicating
  				 * that the text foreground
  				 * color (defined by a
  				 * higher-level client) should
  				 * be used and shall not be
  				 * treated as actual index
  				 * into CPAL ColorRecord array. */
    public:
    DEFINE_SIZE_STATIC (4);
  };
  
  struct BaseGlyphRecord
  {
    int cmp (hb_codepoint_t g) const
    { return g < glyphId ? -1 : g > glyphId ? 1 : 0; }
  
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (likely (c->check_struct (this)));
    }
  
    public:
    HBGlyphID	glyphId;	/* Glyph ID of reference glyph */
    HBUINT16	firstLayerIdx;	/* Index (from beginning of
  				 * the Layer Records) to the
  				 * layer record. There will be
  				 * numLayers consecutive entries
  				 * for this base glyph. */
    HBUINT16	numLayers;	/* Number of color layers
  				 * associated with this glyph */
    public:
    DEFINE_SIZE_STATIC (6);
  };
  
  struct COLR
  {
    static constexpr hb_tag_t tableTag = HB_OT_TAG_COLR;
  
    bool has_data () const { return numBaseGlyphs; }
  
    unsigned int get_glyph_layers (hb_codepoint_t       glyph,
  				 unsigned int         start_offset,
  				 unsigned int        *count, /* IN/OUT.  May be NULL. */
  				 hb_ot_color_layer_t *layers /* OUT.     May be NULL. */) const
    {
      const BaseGlyphRecord &record = (this+baseGlyphsZ).bsearch (numBaseGlyphs, glyph);
  
      hb_array_t<const LayerRecord> all_layers = (this+layersZ).as_array (numLayers);
      hb_array_t<const LayerRecord> glyph_layers = all_layers.sub_array (record.firstLayerIdx,
  								       record.numLayers);
      if (count)
      {
        + glyph_layers.sub_array (start_offset, count)
        | hb_sink (hb_array (layers, *count))
        ;
      }
      return glyph_layers.length;
    }
  
    struct accelerator_t
    {
      accelerator_t () {}
      ~accelerator_t () { fini (); }
  
      void init (hb_face_t *face)
      { colr = hb_sanitize_context_t ().reference_table<COLR> (face); }
  
      void fini () { this->colr.destroy (); }
  
      bool is_valid () { return colr.get_blob ()->length; }
  
      void closure_glyphs (hb_codepoint_t glyph,
  			 hb_set_t *related_ids /* OUT */) const
      { colr->closure_glyphs (glyph, related_ids); }
  
      private:
      hb_blob_ptr_t<COLR> colr;
    };
  
    void closure_glyphs (hb_codepoint_t glyph,
  		       hb_set_t *related_ids /* OUT */) const
    {
      const BaseGlyphRecord *record = get_base_glyph_record (glyph);
      if (!record) return;
  
      auto glyph_layers = (this+layersZ).as_array (numLayers).sub_array (record->firstLayerIdx,
  								       record->numLayers);
      if (!glyph_layers.length) return;
      related_ids->add_array (&glyph_layers[0].glyphId, glyph_layers.length, LayerRecord::min_size);
    }
  
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (likely (c->check_struct (this) &&
  			  (this+baseGlyphsZ).sanitize (c, numBaseGlyphs) &&
  			  (this+layersZ).sanitize (c, numLayers)));
    }
  
    template<typename BaseIterator, typename LayerIterator,
  	   hb_requires (hb_is_iterator (BaseIterator)),
  	   hb_requires (hb_is_iterator (LayerIterator))>
    bool serialize (hb_serialize_context_t *c,
  		  unsigned version,
  		  BaseIterator base_it,
  		  LayerIterator layer_it)
    {
      TRACE_SERIALIZE (this);
      if (unlikely (base_it.len () != layer_it.len ()))
        return_trace (false);
  
      if (unlikely (!c->extend_min (this))) return_trace (false);
      this->version = version;
      numLayers = 0;
      numBaseGlyphs = base_it.len ();
      baseGlyphsZ = COLR::min_size;
      layersZ = COLR::min_size + numBaseGlyphs * BaseGlyphRecord::min_size;
  
      for (const hb_item_type<BaseIterator>& _ : + base_it.iter ())
      {
        auto* record = c->embed (_);
        if (unlikely (!record)) return_trace (false);
        record->firstLayerIdx = numLayers;
        numLayers += record->numLayers;
      }
  
      for (const hb_item_type<LayerIterator>& _ : + layer_it.iter ())
        _.as_array ().copy (c);
  
      return_trace (true);
    }
  
    const BaseGlyphRecord* get_base_glyph_record (hb_codepoint_t gid) const
    {
      if ((unsigned int) gid == 0) // Ignore notdef.
        return nullptr;
      const BaseGlyphRecord* record = &(this+baseGlyphsZ).bsearch (numBaseGlyphs, (unsigned int) gid);
      if ((record && (hb_codepoint_t) record->glyphId != gid))
        record = nullptr;
      return record;
    }
  
    bool subset (hb_subset_context_t *c) const
    {
      TRACE_SUBSET (this);
  
      const hb_map_t &reverse_glyph_map = *c->plan->reverse_glyph_map;
  
      auto base_it =
      + hb_range (c->plan->num_output_glyphs ())
      | hb_map_retains_sorting ([&](hb_codepoint_t new_gid)
  			      {
  				hb_codepoint_t old_gid = reverse_glyph_map.get (new_gid);
  
  				const BaseGlyphRecord* old_record = get_base_glyph_record (old_gid);
  				if (unlikely (!old_record))
  				  return hb_pair_t<bool, BaseGlyphRecord> (false, Null (BaseGlyphRecord));
  
  				BaseGlyphRecord new_record;
  				new_record.glyphId = new_gid;
  				new_record.numLayers = old_record->numLayers;
  				return hb_pair_t<bool, BaseGlyphRecord> (true, new_record);
  			      })
      | hb_filter (hb_first)
      | hb_map_retains_sorting (hb_second)
      ;
  
      auto layer_it =
      + hb_range (c->plan->num_output_glyphs ())
      | hb_map (reverse_glyph_map)
      | hb_map_retains_sorting ([&](hb_codepoint_t old_gid)
  			      {
  				const BaseGlyphRecord* old_record = get_base_glyph_record (old_gid);
  				hb_vector_t<LayerRecord> out_layers;
  
  				if (unlikely (!old_record ||
  					      old_record->firstLayerIdx >= numLayers ||
  					      old_record->firstLayerIdx + old_record->numLayers > numLayers))
  				  return hb_pair_t<bool, hb_vector_t<LayerRecord>> (false, out_layers);
  
  				auto layers = (this+layersZ).as_array (numLayers).sub_array (old_record->firstLayerIdx,
  											     old_record->numLayers);
  				out_layers.resize (layers.length);
  				for (unsigned int i = 0; i < layers.length; i++) {
  				  out_layers[i] = layers[i];
  				  hb_codepoint_t new_gid = 0;
  				  if (unlikely (!c->plan->new_gid_for_old_gid (out_layers[i].glyphId, &new_gid)))
  				    return hb_pair_t<bool, hb_vector_t<LayerRecord>> (false, out_layers);
  				  out_layers[i].glyphId = new_gid;
  				}
  
  				return hb_pair_t<bool, hb_vector_t<LayerRecord>> (true, out_layers);
  			      })
      | hb_filter (hb_first)
      | hb_map_retains_sorting (hb_second)
      ;
  
      if (unlikely (!base_it || !layer_it || base_it.len () != layer_it.len ()))
        return_trace (false);
  
      COLR *colr_prime = c->serializer->start_embed<COLR> ();
      return_trace (colr_prime->serialize (c->serializer, version, base_it, layer_it));
    }
  
    protected:
    HBUINT16	version;	/* Table version number (starts at 0). */
    HBUINT16	numBaseGlyphs;	/* Number of Base Glyph Records. */
    LNNOffsetTo<SortedUnsizedArrayOf<BaseGlyphRecord>>
  		baseGlyphsZ;	/* Offset to Base Glyph records. */
    LNNOffsetTo<UnsizedArrayOf<LayerRecord>>
  		layersZ;	/* Offset to Layer Records. */
    HBUINT16	numLayers;	/* Number of Layer Records. */
    public:
    DEFINE_SIZE_STATIC (14);
  };
  
  } /* namespace OT */
  
  
  #endif /* HB_OT_COLOR_COLR_TABLE_HH */
  