/*

 * Copyright © 2017  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

 */

#ifndef HB_OT_VAR_HVAR_TABLE_HH

#define HB_OT_VAR_HVAR_TABLE_HH

#include "hb-ot-layout-common.hh"

#include "hb-ot-var-common.hh"

namespace OT {

struct index_map_subset_plan_t

{

  enum index_map_index_t {

    ADV_INDEX,

    LSB_INDEX,  /* dual as TSB */

    RSB_INDEX,  /* dual as BSB */

    VORG_INDEX

  };

  void init (const DeltaSetIndexMap  *index_map,

       hb_inc_bimap_t      &outer_map,

       hb_vector_t<hb_set_t *> &inner_sets,

       const hb_subset_plan_t  *plan,

       bool bypass_empty = true)

  {

    map_count = 0;

    full_map_count = plan->new_to_old_gid_list.length ?

         plan->new_to_old_gid_list.tail ().first + 1 : 0;

    /* Only the advance mapping may be dropped in favor of implicit

     * glyph-id indexing (for the others a null offset means no deltas),

     * and only when the source was map-less too, preserving its form. */

    can_drop_to_implicit = !bypass_empty && !index_map;

    max_inners.init ();

    output_map.init ();

    if (bypass_empty && (!index_map || !index_map->get_map_count ())) return;

    unsigned int  last_val = (unsigned int)-1;

    hb_codepoint_t  last_gid = HB_CODEPOINT_INVALID;

    max_inners.resize (inner_sets.length);

    for (unsigned i = 0; i < inner_sets.length; i++) max_inners[i] = 0;

    /* Search backwards for a map value different from the last map value */

    auto &new_to_old_gid_list = plan->new_to_old_gid_list;

    unsigned count = new_to_old_gid_list.length;

    if (!index_map)

    {

      map_count = new_to_old_gid_list.tail ().first + 1;

    }

    else

    {

      for (unsigned j = count; j; j--)

      {

        hb_codepoint_t gid = new_to_old_gid_list.arrayZ[j - 1].first;

        hb_codepoint_t old_gid = new_to_old_gid_list.arrayZ[j - 1].second;

        unsigned int v = index_map->map (old_gid);

        if (last_gid == HB_CODEPOINT_INVALID)

        {

    last_val = v;

    last_gid = gid;

    continue;

        }

        if (v != last_val)

    break;

        last_gid = gid;

      }

      if (unlikely (last_gid == (hb_codepoint_t)-1)) return;

      map_count = last_gid + 1;

    }

    for (auto _ : plan->new_to_old_gid_list)

    {

      hb_codepoint_t gid = _.first;

      if (gid >= map_count) break;

      hb_codepoint_t old_gid = _.second;

      unsigned int v = index_map ? index_map->map (old_gid): old_gid;

      unsigned int outer = v >> 16;

      unsigned int inner = v & 0xFFFF;

      outer_map.add (outer);

      if (inner > max_inners[outer]) max_inners[outer] = inner;

      if (outer >= inner_sets.length) return;

      inner_sets[outer]->add (inner);

    }

  }

  void fini ()

  {

    max_inners.fini ();

    output_map.fini ();

  }

  void remap (const DeltaSetIndexMap *input_map,

        const hb_inc_bimap_t &outer_map,

        const hb_vector_t<hb_inc_bimap_t> &inner_maps,

        const hb_subset_plan_t *plan)

  {

    outer_bit_count = 1;

    inner_bit_count = 1;

    for (unsigned int i = 0; i < max_inners.length; i++)

    {

      if (inner_maps[i].get_population () == 0) continue;

      unsigned int bit_count = (max_inners[i]==0)? 1: hb_bit_storage (inner_maps[i][max_inners[i]]);

      if (bit_count > inner_bit_count) inner_bit_count = bit_count;

    }

    if (unlikely (!output_map.resize (map_count))) return;

    for (const auto &_ : plan->new_to_old_gid_list)

    {

      hb_codepoint_t new_gid = _.first;

      hb_codepoint_t old_gid = _.second;

      if (unlikely (new_gid >= map_count)) break;

      uint32_t v = input_map? input_map->map (old_gid) : old_gid;

      unsigned outer = v >> 16;

      unsigned new_outer = outer_map[outer];

      unsigned bit_count = (new_outer == 0) ? 1 : hb_bit_storage (new_outer);

      outer_bit_count = hb_max (bit_count, outer_bit_count);

      output_map.arrayZ[new_gid] = (new_outer << 16) | (inner_maps[outer][v & 0xFFFF]);

    }

  }

  bool remap_after_instantiation (const hb_subset_plan_t *plan,

                                  const hb_map_t& varidx_map)

  {

    /* recalculate bit_count after remapping */

    outer_bit_count = 1;

    inner_bit_count = 1;

    for (const auto &_ : plan->new_to_old_gid_list)

    {

      hb_codepoint_t new_gid = _.first;

      if (unlikely (new_gid >= map_count)) break;

      uint32_t v = output_map.arrayZ[new_gid];

      uint32_t *new_varidx;

      if (!varidx_map.has (v, &new_varidx))

        return false;

      output_map.arrayZ[new_gid] = *new_varidx;

      unsigned outer = (*new_varidx) >> 16;

      unsigned bit_count = (outer == 0) ? 1 : hb_bit_storage (outer);

      outer_bit_count = hb_max (bit_count, outer_bit_count);

      unsigned inner = (*new_varidx) & 0xFFFF;

      bit_count = (inner == 0) ? 1 : hb_bit_storage (inner);

      inner_bit_count = hb_max (bit_count, inner_bit_count);

    }

    return true;

  }

  unsigned int get_inner_bit_count () const { return inner_bit_count; }

  unsigned int get_width ()           const { return ((outer_bit_count + inner_bit_count + 7) / 8); }

  unsigned int get_map_count ()       const { return map_count; }

  size_t get_size () const

  {

    if (!map_count) return 0;

    return hb_unsigned_mul_add_saturate (get_width (), map_count,

           DeltaSetIndexMap::min_size);

  }

  bool is_identity () const

  {

    if (!output_map) return true;

    /* An advance map whose entries are the identity over every output

     * glyph is equivalent to implicit glyph-id indexing; drop it.  A

     * truncated map doesn't qualify: glyphs past its end share its last

     * value, not their own ids. */

    if (!can_drop_to_implicit || map_count != full_map_count) return false;

    for (unsigned i = 0; i < map_count; i++)

      if (output_map.arrayZ[i] != i) return false;

    return true;

  }

  hb_array_t<const uint32_t> get_output_map () const { return output_map.as_array (); }

  protected:

  unsigned int map_count;

  unsigned int full_map_count;

  bool can_drop_to_implicit;

  hb_vector_t<unsigned int> max_inners;

  unsigned int outer_bit_count;

  unsigned int inner_bit_count;

  hb_vector_t<uint32_t> output_map;

};

struct hvarvvar_subset_plan_t

{

  hvarvvar_subset_plan_t() : inner_maps (), index_map_plans () {}

  ~hvarvvar_subset_plan_t() { fini (); }

  void init (const hb_array_t<const DeltaSetIndexMap *> &index_maps,

       const ItemVariationStore &_var_store,

       const hb_subset_plan_t *plan)

  {

    index_map_plans.resize (index_maps.length);

    var_store = &_var_store;

    inner_sets.resize (var_store->get_sub_table_count ());

    for (unsigned int i = 0; i < inner_sets.length; i++)

      inner_sets[i] = hb_set_create ();

    adv_set = hb_set_create ();

    inner_maps.resize (var_store->get_sub_table_count ());

    if (unlikely (!index_map_plans.length || !inner_sets.length || !inner_maps.length)) return;

    bool retain_adv_map = false;

    index_map_plans[0].init (index_maps[0], outer_map, inner_sets, plan, false);

    if (!index_maps[0])

    {

      retain_adv_map = plan->flags & HB_SUBSET_FLAGS_RETAIN_GIDS;

      outer_map.add (0);

      for (hb_codepoint_t old_gid : plan->glyphset()->iter())

        inner_sets[0]->add (old_gid);

      hb_set_union (adv_set, inner_sets[0]);

    }

    for (unsigned int i = 1; i < index_maps.length; i++)

      index_map_plans[i].init (index_maps[i], outer_map, inner_sets, plan);

    outer_map.sort ();

    if (retain_adv_map)

    {

      for (const auto &_ : plan->new_to_old_gid_list)

      {

        hb_codepoint_t old_gid = _.second;

  inner_maps[0].add (old_gid);

      }

    }

    else

    {

      inner_maps[0].add_set (adv_set);

      hb_set_subtract (inner_sets[0], adv_set);

      inner_maps[0].add_set (inner_sets[0]);

    }

    for (unsigned int i = 1; i < inner_maps.length; i++)

      inner_maps[i].add_set (inner_sets[i]);

    for (unsigned int i = 0; i < index_maps.length; i++)

      index_map_plans[i].remap (index_maps[i], outer_map, inner_maps, plan);

  }

  /* remap */

  bool remap_index_map_plans (const hb_subset_plan_t *plan,

                              const hb_map_t& varidx_map)

  {

    for (unsigned i = 0; i < index_map_plans.length; i++)

      if (!index_map_plans[i].remap_after_instantiation (plan, varidx_map))

        return false;

    return true;

  }

  void fini ()

  {

    for (unsigned int i = 0; i < inner_sets.length; i++)

      hb_set_destroy (inner_sets[i]);

    hb_set_destroy (adv_set);

    inner_maps.fini ();

    index_map_plans.fini ();

  }

  hb_inc_bimap_t outer_map;

  hb_vector_t<hb_inc_bimap_t> inner_maps;

  hb_vector_t<index_map_subset_plan_t> index_map_plans;

  const ItemVariationStore *var_store;

  protected:

  hb_vector_t<hb_set_t *> inner_sets;

  hb_set_t *adv_set;

};

/*

 * HVAR -- Horizontal Metrics Variations

 * https://docs.microsoft.com/en-us/typography/opentype/spec/hvar

 * VVAR -- Vertical Metrics Variations

 * https://docs.microsoft.com/en-us/typography/opentype/spec/vvar

 */

#define HB_OT_TAG_HVAR HB_TAG('H','V','A','R')

#define HB_OT_TAG_VVAR HB_TAG('V','V','A','R')

struct HVARVVAR

{

  static constexpr hb_tag_t HVARTag = HB_OT_TAG_HVAR;

  static constexpr hb_tag_t VVARTag = HB_OT_TAG_VVAR;

  bool has_data () const { return version.major != 0; }

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (version.sanitize (c) &&

      hb_barrier () &&

      likely (version.major == 1) &&

      varStore.sanitize (c, this) &&

      advMap.sanitize (c, this) &&

      lsbMap.sanitize (c, this) &&

      rsbMap.sanitize (c, this));

  }

  const ItemVariationStore& get_var_store () const

  { return this+varStore; }

  void listup_index_maps (hb_vector_t<const DeltaSetIndexMap *> &index_maps) const

  {

    if (advMap) index_maps.push (&(this+advMap));

    else index_maps.push (nullptr);

    if (lsbMap) index_maps.push (&(this+lsbMap));

    else index_maps.push (nullptr);

    if (rsbMap) index_maps.push (&(this+rsbMap));

    else index_maps.push (nullptr);

  }

  bool serialize_index_maps (hb_serialize_context_t *c,

           const hb_array_t<index_map_subset_plan_t> &im_plans)

  {

    TRACE_SERIALIZE (this);

    if (im_plans[index_map_subset_plan_t::ADV_INDEX].is_identity ())

      advMap = 0;

    else if (unlikely (!advMap.serialize_serialize (c, im_plans[index_map_subset_plan_t::ADV_INDEX])))

      return_trace (false);

    if (im_plans[index_map_subset_plan_t::LSB_INDEX].is_identity ())

      lsbMap = 0;

    else if (unlikely (!lsbMap.serialize_serialize (c, im_plans[index_map_subset_plan_t::LSB_INDEX])))

      return_trace (false);

    if (im_plans[index_map_subset_plan_t::RSB_INDEX].is_identity ())

      rsbMap = 0;

    else if (unlikely (!rsbMap.serialize_serialize (c, im_plans[index_map_subset_plan_t::RSB_INDEX])))

      return_trace (false);

    return_trace (true);

  }

  template <typename T>

  bool _subset (hb_subset_context_t *c) const

  {

    TRACE_SUBSET (this);

    if (c->plan->all_axes_pinned)

      return_trace (false);

    hvarvvar_subset_plan_t  hvar_plan;

    hb_vector_t<const DeltaSetIndexMap *>

        index_maps;

    ((T*)this)->listup_index_maps (index_maps);

    hvar_plan.init (index_maps.as_array (), this+varStore, c->plan);

    T *out = c->serializer->allocate_min<T> ();

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

    out->version.major = 1;

    out->version.minor = 0;

    if (c->plan->normalized_coords)

    {

      item_variations_t item_vars;

      if (!item_vars.instantiate (this+varStore, c->plan,

                                  advMap == 0 ? false : true,

                                  false, /* use_no_variation_idx = false */

                                  hvar_plan.inner_maps.as_array ()))

        return_trace (false);

      if (!out->varStore.serialize_serialize (c->serializer,

                                              item_vars.has_long_word (),

                                              c->plan->axis_tags,

                                              item_vars.get_region_list (),

                                              item_vars.get_vardata_encodings ()))

        return_trace (false);

      /* if varstore is optimized, remap output_map */

      if (advMap)

      {

        if (!hvar_plan.remap_index_map_plans (c->plan, item_vars.get_varidx_map ()))

          return_trace (false);

      }

    }

    else

    {

      /* avar2 partial instancing: cull unreachable regions. */

      hb_set_t dead_regions;

      if (c->plan->has_avar2)

  hvar_plan.var_store->collect_dead_regions (c->plan->axes_old_index_tag_map,

               c->plan->avar2_reachable_ranges,

               dead_regions);

      if (unlikely (!out->varStore

        .serialize_serialize (c->serializer,

            hvar_plan.var_store,

            hvar_plan.inner_maps.as_array (),

            dead_regions.get_population () ? &dead_regions : nullptr)))

      return_trace (false);

    }

    return_trace (out->T::serialize_index_maps (c->serializer,

            hvar_plan.index_map_plans.as_array ()));

  }

Unexecuted instantiation: bool OT::HVARVVAR::_subset<OT::HVAR>(hb_subset_context_t*) const

Unexecuted instantiation: bool OT::HVARVVAR::_subset<OT::VVAR>(hb_subset_context_t*) const

  HB_ALWAYS_INLINE

  float get_advance_delta_unscaled (hb_codepoint_t  glyph,

            const int *coords, unsigned int coord_count,

            hb_scalar_cache_t *store_cache = nullptr) const

  {

    uint32_t varidx = (this+advMap).map (glyph);

    return (this+varStore).get_delta (varidx,

              coords, coord_count,

              store_cache);

  }

  public:

  FixedVersion<>version;  /* Version of the metrics variation table

         * initially set to 0x00010000u */

  Offset32To<ItemVariationStore>

    varStore; /* Offset to item variation store table. */

  Offset32To<DeltaSetIndexMap>

    advMap;   /* Offset to advance var-idx mapping. */

  Offset32To<DeltaSetIndexMap>

    lsbMap;   /* Offset to lsb/tsb var-idx mapping. */

  Offset32To<DeltaSetIndexMap>

    rsbMap;   /* Offset to rsb/bsb var-idx mapping. */

  public:

  DEFINE_SIZE_STATIC (20);

};

struct HVAR : HVARVVAR {

  static constexpr hb_tag_t tableTag = HB_OT_TAG_HVAR;

  bool subset (hb_subset_context_t *c) const { return HVARVVAR::_subset<HVAR> (c); }

};

struct VVAR : HVARVVAR {

  static constexpr hb_tag_t tableTag = HB_OT_TAG_VVAR;

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (static_cast<const HVARVVAR *> (this)->sanitize (c) &&

      vorgMap.sanitize (c, this));

  }

  void listup_index_maps (hb_vector_t<const DeltaSetIndexMap *> &index_maps) const

  {

    HVARVVAR::listup_index_maps (index_maps);

    if (vorgMap) index_maps.push (&(this+vorgMap));

    else index_maps.push (nullptr);

  }

  bool serialize_index_maps (hb_serialize_context_t *c,

           const hb_array_t<index_map_subset_plan_t> &im_plans)

  {

    TRACE_SERIALIZE (this);

    if (unlikely (!HVARVVAR::serialize_index_maps (c, im_plans)))

      return_trace (false);

    if (!im_plans[index_map_subset_plan_t::VORG_INDEX].get_map_count ())

      vorgMap = 0;

    else if (unlikely (!vorgMap.serialize_serialize (c, im_plans[index_map_subset_plan_t::VORG_INDEX])))

      return_trace (false);

    return_trace (true);

  }

  bool subset (hb_subset_context_t *c) const { return HVARVVAR::_subset<VVAR> (c); }

  HB_ALWAYS_INLINE

  float get_vorg_delta_unscaled (hb_codepoint_t glyph,

         const int *coords, unsigned int coord_count,

         hb_scalar_cache_t *store_cache = nullptr) const

  {

    if (!vorgMap) return 0.f;

    uint32_t varidx = (this+vorgMap).map (glyph);

    return (this+varStore).get_delta (varidx,

              coords, coord_count,

              store_cache);

  }

  protected:

  Offset32To<DeltaSetIndexMap>

    vorgMap;  /* Offset to vertical-origin var-idx mapping. */

  public:

  DEFINE_SIZE_STATIC (24);

};

} /* namespace OT */

#endif /* HB_OT_VAR_HVAR_TABLE_HH */