#ifndef OT_LAYOUT_GPOS_LIGATUREARRAY_HH

#define OT_LAYOUT_GPOS_LIGATUREARRAY_HH

namespace OT {

namespace Layout {

namespace GPOS_impl {

typedef AnchorMatrix LigatureAttach;    /* component-major--

                                         * in order of writing direction--,

                                         * mark-minor--

                                         * ordered by class--zero-based. */

/* Array of LigatureAttach tables ordered by LigatureCoverage Index */

struct LigatureArray : List16OfOffset16To<LigatureAttach>

{

  template <typename Iterator,

            hb_requires (hb_is_iterator (Iterator))>

  bool subset (hb_subset_context_t *c,

               Iterator             coverage,

               unsigned             class_count,

               const hb_map_t      *klass_mapping,

               hb_sorted_vector_t<hb_codepoint_t> &new_coverage /* OUT */) const

  {

    TRACE_SUBSET (this);

    const hb_map_t &glyph_map = c->plan->glyph_map_gsub;

    auto *out = c->serializer->start_embed (this);

    if (unlikely (!c->serializer->extend_min (out)))  return_trace (false);

    bool ret = false;

    for (const auto _ : + hb_zip (coverage, *this)

                        | hb_filter (glyph_map, hb_first))

    {

      const LigatureAttach& src = (this + _.second);

      bool non_empty = + hb_range (src.rows * class_count)

                       | hb_filter ([=] (unsigned index) { return klass_mapping->has (index % class_count); })

                       | hb_map ([&] (const unsigned index) { return !src.offset_is_null (index / class_count, index % class_count, class_count); })

                       | hb_any;

      if (!non_empty) continue;

      auto *matrix = out->serialize_append (c->serializer);

      if (unlikely (!matrix)) return_trace (false);

      auto indexes =

          + hb_range (src.rows * class_count)

          | hb_filter ([=] (unsigned index) { return klass_mapping->has (index % class_count); })

          ;

      ret |= matrix->serialize_subset (c,

               _.second,

               this,

               src.rows,

               indexes);

      hb_codepoint_t new_gid = glyph_map.get (_.first);

      new_coverage.push (new_gid);

    }

    return_trace (ret);

  }

};

}

}

}

#endif /* OT_LAYOUT_GPOS_LIGATUREARRAY_HH */