kc3-lang/harfbuzz/src/OT/Layout/GPOS/PairPosFormat1.hh

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• Hash : 192d264a
  Author :
  Date : 2025-03-25T13:32:01
  

  [subset] remove divisions when computing the cost of binary search
  

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• src/OT/Layout/GPOS/PairPosFormat1.hh

• #ifndef OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH
  #define OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH
  
  #include "PairSet.hh"
  
  namespace OT {
  namespace Layout {
  namespace GPOS_impl {
  
  
  template <typename Types>
  struct PairPosFormat1_3
  {
    using PairSet = GPOS_impl::PairSet<Types>;
    using PairValueRecord = GPOS_impl::PairValueRecord<Types>;
  
    protected:
    HBUINT16      format;                 /* Format identifier--format = 1 */
    typename Types::template OffsetTo<Coverage>
                  coverage;               /* Offset to Coverage table--from
                                           * beginning of subtable */
    ValueFormat   valueFormat[2];         /* [0] Defines the types of data in
                                           * ValueRecord1--for the first glyph
                                           * in the pair--may be zero (0) */
                                          /* [1] Defines the types of data in
                                           * ValueRecord2--for the second glyph
                                           * in the pair--may be zero (0) */
    Array16Of<typename Types::template OffsetTo<PairSet>>
                  pairSet;                /* Array of PairSet tables
                                           * ordered by Coverage Index */
    public:
    DEFINE_SIZE_ARRAY (8 + Types::size, pairSet);
  
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
  
      if (!c->check_struct (this)) return_trace (false);
      hb_barrier ();
  
      unsigned int len1 = valueFormat[0].get_len ();
      unsigned int len2 = valueFormat[1].get_len ();
      typename PairSet::sanitize_closure_t closure =
      {
        valueFormat,
        len1,
        PairSet::get_size (len1, len2)
      };
  
      return_trace (coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
    }
  
    bool intersects (const hb_set_t *glyphs) const
    {
      auto &cov = this+coverage;
  
      if (pairSet.len > glyphs->get_population () * hb_bit_storage ((unsigned) pairSet.len))
      {
        for (hb_codepoint_t g : glyphs->iter())
        {
  	unsigned i = cov.get_coverage (g);
  	if ((this+pairSet[i]).intersects (glyphs, valueFormat))
  	  return true;
        }
        return false;
      }
  
      return
      + hb_zip (cov, pairSet)
      | hb_filter (*glyphs, hb_first)
      | hb_map (hb_second)
      | hb_map ([glyphs, this] (const typename Types::template OffsetTo<PairSet> &_)
                { return (this+_).intersects (glyphs, valueFormat); })
      | hb_any
      ;
    }
  
    void closure_lookups (hb_closure_lookups_context_t *c) const {}
    void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
    {
      if ((!valueFormat[0].has_device ()) && (!valueFormat[1].has_device ())) return;
  
      auto it =
      + hb_zip (this+coverage, pairSet)
      | hb_filter (c->glyph_set, hb_first)
      | hb_map (hb_second)
      ;
  
      if (!it) return;
      + it
      | hb_map (hb_add (this))
      | hb_apply ([&] (const PairSet& _) { _.collect_variation_indices (c, valueFormat); })
      ;
    }
  
    void collect_glyphs (hb_collect_glyphs_context_t *c) const
    {
      if (unlikely (!(this+coverage).collect_coverage (c->input))) return;
      unsigned int count = pairSet.len;
      for (unsigned int i = 0; i < count; i++)
        (this+pairSet[i]).collect_glyphs (c, valueFormat);
    }
  
    const Coverage &get_coverage () const { return this+coverage; }
  
    unsigned cache_cost () const
    {
      return (this+coverage).cost ();
    }
    static void * cache_func (void *p, hb_ot_lookup_cache_op_t op)
    {
      switch (op)
      {
        case hb_ot_lookup_cache_op_t::CREATE:
        {
  	hb_ot_lookup_cache_t *cache = (hb_ot_lookup_cache_t *) hb_malloc (sizeof (hb_ot_lookup_cache_t));
  	if (likely (cache))
  	  cache->clear ();
  	return cache;
        }
        case hb_ot_lookup_cache_op_t::ENTER:
  	return (void *) true;
        case hb_ot_lookup_cache_op_t::LEAVE:
  	return nullptr;
        case hb_ot_lookup_cache_op_t::DESTROY:
        {
  	hb_ot_lookup_cache_t *cache = (hb_ot_lookup_cache_t *) p;
  	hb_free (cache);
  	return nullptr;
        }
      }
      return nullptr;
    }
  
    bool apply_cached (hb_ot_apply_context_t *c) const { return _apply (c, true); }
    bool apply (hb_ot_apply_context_t *c) const { return _apply (c, false); }
    bool _apply (hb_ot_apply_context_t *c, bool cached) const
    {
      TRACE_APPLY (this);
  
      hb_buffer_t *buffer = c->buffer;
  
  #ifndef HB_NO_OT_LAYOUT_LOOKUP_CACHE
      hb_ot_lookup_cache_t *cache = cached ? (hb_ot_lookup_cache_t *) c->lookup_accel->cache : nullptr;
      unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint, cache);
  #else
      unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint);
  #endif
      if (index == NOT_COVERED) return_trace (false);
  
      hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
      skippy_iter.reset_fast (buffer->idx);
      unsigned unsafe_to;
      if (unlikely (!skippy_iter.next (&unsafe_to)))
      {
        buffer->unsafe_to_concat (buffer->idx, unsafe_to);
        return_trace (false);
      }
  
      return_trace ((this+pairSet[index]).apply (c, valueFormat, skippy_iter.idx));
    }
  
    bool subset (hb_subset_context_t *c) const
    {
      TRACE_SUBSET (this);
  
      const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
      const hb_map_t &glyph_map = *c->plan->glyph_map;
  
      auto *out = c->serializer->start_embed (*this);
      if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
      out->format = format;
  
      hb_pair_t<unsigned, unsigned> newFormats = hb_pair (valueFormat[0], valueFormat[1]);
  
      if (c->plan->normalized_coords)
      {
        /* all device flags will be dropped when full instancing, no need to strip
         * hints, also do not strip emtpy cause we don't compute the new default
         * value during stripping */
        newFormats = compute_effective_value_formats (glyphset, false, false, &c->plan->layout_variation_idx_delta_map);
      }
      /* do not strip hints for VF */
      else if (c->plan->flags & HB_SUBSET_FLAGS_NO_HINTING)
      {
        hb_blob_t* blob = hb_face_reference_table (c->plan->source, HB_TAG ('f','v','a','r'));
        bool has_fvar = (blob != hb_blob_get_empty ());
        hb_blob_destroy (blob);
  
        bool strip = !has_fvar;
        /* special case: strip hints when a VF has no GDEF varstore after
         * subsetting*/
        if (has_fvar && !c->plan->has_gdef_varstore)
          strip = true;
        newFormats = compute_effective_value_formats (glyphset, strip, true);
      }
  
      out->valueFormat[0] = newFormats.first;
      out->valueFormat[1] = newFormats.second;
  
      hb_sorted_vector_t<hb_codepoint_t> new_coverage;
  
      + hb_zip (this+coverage, pairSet)
      | hb_filter (glyphset, hb_first)
      | hb_filter ([this, c, out] (const typename Types::template OffsetTo<PairSet>& _)
                   {
                     auto snap = c->serializer->snapshot ();
                     auto *o = out->pairSet.serialize_append (c->serializer);
                     if (unlikely (!o)) return false;
                     bool ret = o->serialize_subset (c, _, this, valueFormat, out->valueFormat);
                     if (!ret)
                     {
                       out->pairSet.pop ();
                       c->serializer->revert (snap);
                     }
                     return ret;
                   },
                   hb_second)
      | hb_map (hb_first)
      | hb_map (glyph_map)
      | hb_sink (new_coverage)
      ;
  
      out->coverage.serialize_serialize (c->serializer, new_coverage.iter ());
  
      return_trace (bool (new_coverage));
    }
  
  
    hb_pair_t<unsigned, unsigned> compute_effective_value_formats (const hb_set_t& glyphset,
                                                                   bool strip_hints, bool strip_empty,
                                                                   const hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> *varidx_delta_map = nullptr) const
    {
      unsigned record_size = PairSet::get_size (valueFormat);
  
      unsigned format1 = 0;
      unsigned format2 = 0;
      for (const auto & _ :
  	  + hb_zip (this+coverage, pairSet)
  	  | hb_filter (glyphset, hb_first)
  	  | hb_map (hb_second)
  	)
      {
        const PairSet& set = (this + _);
        const PairValueRecord *record = &set.firstPairValueRecord;
  
        unsigned count = set.len;
        for (unsigned i = 0; i < count; i++)
        {
          if (record->intersects (glyphset))
          {
            format1 = format1 | valueFormat[0].get_effective_format (record->get_values_1 (), strip_hints, strip_empty, &set, varidx_delta_map);
            format2 = format2 | valueFormat[1].get_effective_format (record->get_values_2 (valueFormat[0]), strip_hints, strip_empty, &set, varidx_delta_map);
          }
          record = &StructAtOffset<const PairValueRecord> (record, record_size);
        }
  
        if (format1 == valueFormat[0] && format2 == valueFormat[1])
          break;
      }
  
      return hb_pair (format1, format2);
    }
  };
  
  
  }
  }
  }
  
  #endif  // OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH
  

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