/*

 * Copyright © 2019  Adobe Inc.

 * Copyright © 2019  Ebrahim Byagowi

 *

 *  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.

 *

 * Adobe Author(s): Michiharu Ariza

 */

#ifndef HB_OT_VAR_GVAR_TABLE_HH

#define HB_OT_VAR_GVAR_TABLE_HH

#include "hb-decycler.hh"

#include "hb-open-type.hh"

#include "hb-ot-dual.hh"

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

/*

 * gvar -- Glyph Variation Table

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

 */

#define HB_OT_TAG_gvar HB_TAG('g','v','a','r')

#define HB_OT_TAG_GVAR HB_TAG('G','V','A','R')

struct hb_glyf_scratch_t

{

  // glyf

  contour_point_vector_t all_points;

  contour_point_vector_t comp_points;

  hb_decycler_t decycler;

  // gvar

  contour_point_vector_t orig_points;

  hb_vector_t<int> x_deltas;

  hb_vector_t<int> y_deltas;

  contour_point_vector_t deltas;

  hb_vector_t<unsigned int> shared_indices;

  hb_vector_t<unsigned int> private_indices;

};

namespace OT {

template <typename OffsetType>

struct glyph_variations_t

{

  // TODO: Move tuple_variations_t to outside of TupleVariationData

  using tuple_variations_t = typename TupleVariationData<OffsetType>::tuple_variations_t;

  using GlyphVariationData = TupleVariationData<OffsetType>;

  hb_vector_t<tuple_variations_t> glyph_variations;

  hb_vector_t<F2DOT14> compiled_shared_tuples;

  private:

  unsigned shared_tuples_count = 0;

  /* shared coords-> index map after instantiation */

  hb_hashmap_t<const hb_vector_t<F2DOT14>*, unsigned> shared_tuples_idx_map;

  hb_alloc_pool_t pool;

  public:

  unsigned compiled_shared_tuples_count () const

  { return shared_tuples_count; }

  unsigned compiled_byte_size () const

  {

    unsigned byte_size = 0;

    for (const auto& _ : glyph_variations)

      byte_size += _.get_compiled_byte_size ();

    return byte_size;

  }

  bool create_from_glyphs_var_data (unsigned axis_count,

                                    const hb_array_t<const F2DOT14> shared_tuples,

                                    const hb_subset_plan_t *plan,

                                    const hb_hashmap_t<hb_codepoint_t, hb_bytes_t>& new_gid_var_data_map)

  {

    if (unlikely (!glyph_variations.alloc_exact (plan->new_to_old_gid_list.length)))

      return false;

    auto it = hb_iter (plan->new_to_old_gid_list);

    for (auto &_ : it)

    {

      hb_codepoint_t new_gid = _.first;

      contour_point_vector_t *all_contour_points;

      if (!new_gid_var_data_map.has (new_gid) ||

          !plan->new_gid_contour_points_map.has (new_gid, &all_contour_points))

        return false;

      hb_bytes_t var_data = new_gid_var_data_map.get (new_gid);

      const GlyphVariationData* p = reinterpret_cast<const GlyphVariationData*> (var_data.arrayZ);

      typename GlyphVariationData::tuple_iterator_t iterator;

      tuple_variations_t tuple_vars;

      hb_vector_t<unsigned> shared_indices;

      /* in case variation data is empty, push an empty struct into the vector,

       * keep the vector in sync with the new_to_old_gid_list */

      if (!var_data || ! p->has_data () || !all_contour_points->length ||

          !GlyphVariationData::get_tuple_iterator (var_data, axis_count,

                                                   var_data.arrayZ,

                                                   shared_indices, &iterator))

      {

        glyph_variations.push (std::move (tuple_vars));

        continue;

      }

      bool is_composite_glyph = false;

      is_composite_glyph = plan->composite_new_gids.has (new_gid);

      if (!p->decompile_tuple_variations (all_contour_points->length, true /* is_gvar */,

                                          iterator, &(plan->axes_old_index_tag_map),

                                          shared_indices, shared_tuples,

                                          tuple_vars, /* OUT */

            &pool,

                                          is_composite_glyph))

        return false;

      glyph_variations.push (std::move (tuple_vars));

    }

    return !glyph_variations.in_error () && glyph_variations.length == plan->new_to_old_gid_list.length;

  }

  bool instantiate (const hb_subset_plan_t *plan)

  {

    unsigned count = plan->new_to_old_gid_list.length;

    bool iup_optimize = false;

    optimize_scratch_t scratch;

    iup_optimize = plan->flags & HB_SUBSET_FLAGS_OPTIMIZE_IUP_DELTAS;

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

    {

      hb_codepoint_t new_gid = plan->new_to_old_gid_list[i].first;

      contour_point_vector_t *all_points;

      if (!plan->new_gid_contour_points_map.has (new_gid, &all_points))

        return false;

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

      if (plan->has_avar2 && plan->avar2_reachable_ranges.get_population ())

  glyph_variations[i].cull_unreachable (plan->avar2_reachable_ranges);

      if (!glyph_variations[i].instantiate (plan->axes_location, plan->axes_triple_distances, scratch, &pool, all_points, iup_optimize))

        return false;

    }

    return true;

  }

  bool compile_bytes (const hb_map_t& axes_index_map,

                      const hb_map_t& axes_old_index_tag_map)

  {

    if (!compile_shared_tuples (axes_index_map, axes_old_index_tag_map))

      return false;

    for (tuple_variations_t& vars: glyph_variations)

      if (!vars.compile_bytes (axes_index_map, axes_old_index_tag_map,

                               true, /* use shared points*/

                               true,

                               &shared_tuples_idx_map,

             &pool))

        return false;

    return true;

  }

  bool compile_shared_tuples (const hb_map_t& axes_index_map,

                              const hb_map_t& axes_old_index_tag_map)

  {

    /* key is pointer to compiled_peak_coords inside each tuple, hashing

     * function will always deref pointers first */

    hb_hashmap_t<const hb_vector_t<F2DOT14>*, unsigned> coords_count_map;

    /* count the num of shared coords */

    for (tuple_variations_t& vars: glyph_variations)

    {

      for (tuple_delta_t& var : vars.tuple_vars)

      {

        if (!var.compile_coords (axes_index_map, axes_old_index_tag_map, &pool))

          return false;

        unsigned *count;

  unsigned hash = hb_hash (&var.compiled_peak_coords);

        if (coords_count_map.has_with_hash (&(var.compiled_peak_coords), hash, &count))

    (*count)++;

        else

          coords_count_map.set_with_hash (&(var.compiled_peak_coords), hash, 1);

      }

    }

    if (!coords_count_map || coords_count_map.in_error ())

      return false;

    /* add only those coords that are used more than once into the vector and sort */

    hb_vector_t<hb_pair_t<const hb_vector_t<F2DOT14>*, unsigned>> shared_coords {

      + hb_iter (coords_count_map)

      | hb_filter ([] (const hb_pair_t<const hb_vector_t<F2DOT14>*, unsigned>& p) { return p.second > 1; })

    };

    if (unlikely (shared_coords.in_error ())) return false;

    /* no shared tuples: no coords are used more than once */

    if (!shared_coords) return true;

    /* sorting based on the coords frequency first (high to low), then compare

     * the coords bytes */

    shared_coords.qsort (_cmp_coords);

    /* build shared_coords->idx map and shared tuples byte array */

    shared_tuples_count = hb_min (0xFFFu + 1, shared_coords.length);

    unsigned len = shared_tuples_count * (shared_coords[0].first->length);

    if (unlikely (!compiled_shared_tuples.alloc (len)))

      return false;

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

    {

      shared_tuples_idx_map.set (shared_coords[i].first, i);

      /* add a concat() in hb_vector_t? */

      for (auto c : shared_coords[i].first->iter ())

        compiled_shared_tuples.push (c);

    }

    return true;

  }

  static int _cmp_coords (const void *pa, const void *pb)

  {

    const hb_pair_t<hb_vector_t<F2DOT14> *, unsigned> *a = (const hb_pair_t<hb_vector_t<F2DOT14> *, unsigned> *) pa;

    const hb_pair_t<hb_vector_t<F2DOT14> *, unsigned> *b = (const hb_pair_t<hb_vector_t<F2DOT14> *, unsigned> *) pb;

    if (a->second != b->second)

      return b->second - a->second; // high to low

    return b->first->as_array().cmp (a->first->as_array ());

  }

  template<typename Iterator,

           hb_requires (hb_is_iterator (Iterator))>

  bool serialize_glyph_var_data (hb_serialize_context_t *c,

                                 Iterator it,

                                 bool long_offset,

                                 unsigned num_glyphs,

                                 char* glyph_var_data_offsets /* OUT: glyph var data offsets array */) const

  {

    TRACE_SERIALIZE (this);

    if (long_offset)

    {

      ((HBUINT32 *) glyph_var_data_offsets)[0] = 0;

      glyph_var_data_offsets += 4;

    }

    else

    {

      ((HBUINT16 *) glyph_var_data_offsets)[0] = 0;

      glyph_var_data_offsets += 2;

    }

    unsigned glyph_offset = 0;

    hb_codepoint_t last_gid = 0;

    unsigned idx = 0;

    GlyphVariationData* cur_glyph = c->start_embed<GlyphVariationData> ();

    if (!cur_glyph) return_trace (false);

    for (auto &_ : it)

    {

      hb_codepoint_t gid = _.first;

      if (long_offset)

        for (; last_gid < gid; last_gid++)

          ((HBUINT32 *) glyph_var_data_offsets)[last_gid] = glyph_offset;

      else

        for (; last_gid < gid; last_gid++)

          ((HBUINT16 *) glyph_var_data_offsets)[last_gid] = glyph_offset / 2;

      if (idx >= glyph_variations.length) return_trace (false);

      if (!cur_glyph->serialize (c, true, glyph_variations[idx])) return_trace (false);

      GlyphVariationData* next_glyph = c->start_embed<GlyphVariationData> ();

      glyph_offset += (char *) next_glyph - (char *) cur_glyph;

      if (long_offset)

        ((HBUINT32 *) glyph_var_data_offsets)[gid] = glyph_offset;

      else

        ((HBUINT16 *) glyph_var_data_offsets)[gid] = glyph_offset / 2;

      last_gid++;

      idx++;

      cur_glyph = next_glyph;

    }

    if (long_offset)

      for (; last_gid < num_glyphs; last_gid++)

        ((HBUINT32 *) glyph_var_data_offsets)[last_gid] = glyph_offset;

    else

      for (; last_gid < num_glyphs; last_gid++)

        ((HBUINT16 *) glyph_var_data_offsets)[last_gid] = glyph_offset / 2;

    return_trace (true);

  }

};

template <typename T, typename Types>

struct gvar_GVAR

{

  using GlyphCountType = typename Types::HBUINT;

  using GlyphVariationData = TupleVariationData<GlyphCountType>;

  static constexpr unsigned glyph_count_max ()

  { return (1u << (8 * GlyphCountType::static_size)) - 1; }

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

  bool sanitize_shallow (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (c->check_struct (this) &&

      hb_barrier () &&

      (version.major == 1) &&

      sharedTuples.sanitize (c, this, axisCount * sharedTupleCount) &&

      (is_long_offset () ?

         c->check_array (get_long_offset_array (), c->get_num_glyphs () + 1) :

         c->check_array (get_short_offset_array (), c->get_num_glyphs () + 1)));

  }

  /* GlyphVariationData not sanitized here; must be checked while accessing each glyph variation data */

  bool sanitize (hb_sanitize_context_t *c) const

  { return sanitize_shallow (c); }

  bool decompile_glyph_variations (hb_subset_context_t *c,

                                   glyph_variations_t<GlyphCountType>& glyph_vars /* OUT */) const

  {

    hb_hashmap_t<hb_codepoint_t, hb_bytes_t> new_gid_var_data_map;

    auto it = hb_iter (c->plan->new_to_old_gid_list);

    if (it->first == 0 && !(c->plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE))

    {

      new_gid_var_data_map.set (0, hb_bytes_t ());

      it++;

    }

    for (auto &_ : it)

    {

      hb_codepoint_t new_gid = _.first;

      hb_codepoint_t old_gid = _.second;

      hb_bytes_t var_data_bytes = get_glyph_var_data_bytes (c->source_blob, glyphCountX, old_gid);

      new_gid_var_data_map.set (new_gid, var_data_bytes);

    }

    if (new_gid_var_data_map.in_error ()) return false;

    hb_array_t<const F2DOT14> shared_tuples = (this+sharedTuples).as_array ((unsigned) sharedTupleCount * (unsigned) axisCount);

    return glyph_vars.create_from_glyphs_var_data (axisCount, shared_tuples, c->plan, new_gid_var_data_map);

  }

  template<typename Iterator,

           hb_requires (hb_is_iterator (Iterator))>

  bool serialize (hb_serialize_context_t *c,

                  const glyph_variations_t<GlyphCountType>& glyph_vars,

                  Iterator it,

                  unsigned axis_count,

                  unsigned num_glyphs,

                  bool force_long_offsets) const

  {

    TRACE_SERIALIZE (this);

    gvar_GVAR *out = c->allocate_min<gvar_GVAR> ();

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

    out->version.major = 1;

    out->version.minor = 0;

    out->axisCount = axis_count;

    out->glyphCountX = hb_min (glyph_count_max (), num_glyphs);

    unsigned glyph_var_data_size = glyph_vars.compiled_byte_size ();

    /* According to the spec: If the short format (Offset16) is used for offsets,

     * the value stored is the offset divided by 2, so the maximum data size should

     * be 2 * 0xFFFFu, which is 0x1FFFEu */

    bool long_offset = glyph_var_data_size > 0x1FFFEu || force_long_offsets;

    out->flags = long_offset ? 1 : 0;

    unsigned glyph_var_data_offsets_size = (long_offset ? 4 : 2) * (num_glyphs + 1);

    HBUINT8 *glyph_var_data_offsets = c->allocate_size<HBUINT8> (glyph_var_data_offsets_size, false);

    if (!glyph_var_data_offsets) return_trace (false);

    /* shared tuples */

    unsigned shared_tuple_count = glyph_vars.compiled_shared_tuples_count ();

    out->sharedTupleCount = shared_tuple_count;

    if (!shared_tuple_count)

      out->sharedTuples = (char *) glyph_var_data_offsets + glyph_var_data_offsets_size - (char *) out;

    else

    {

      hb_array_t<const F2DOT14> shared_tuples = glyph_vars.compiled_shared_tuples.as_array ().copy (c);

      if (!shared_tuples.arrayZ) return_trace (false);

      out->sharedTuples = (const char *) shared_tuples.arrayZ - (char *) out;

    }

    char *glyph_var_data = c->start_embed<char> ();

    if (!glyph_var_data) return_trace (false);

    out->dataZ = glyph_var_data - (char *) out;

    return_trace (glyph_vars.serialize_glyph_var_data (c, it, long_offset, num_glyphs,

                                                       (char *) glyph_var_data_offsets));

  }

  bool instantiate (hb_subset_context_t *c) const

  {

    TRACE_SUBSET (this);

    glyph_variations_t<GlyphCountType> glyph_vars;

    if (!decompile_glyph_variations (c, glyph_vars))

      return_trace (false);

    if (!glyph_vars.instantiate (c->plan)) return_trace (false);

    if (!glyph_vars.compile_bytes (c->plan->axes_index_map, c->plan->axes_old_index_tag_map))

      return_trace (false);

    unsigned axis_count = c->plan->axes_index_map.get_population ();

    unsigned num_glyphs = c->plan->num_output_glyphs ();

    auto it = hb_iter (c->plan->new_to_old_gid_list);

    bool force_long_offsets = false;

#ifdef HB_EXPERIMENTAL_API

    force_long_offsets = c->plan->flags & HB_SUBSET_FLAGS_IFTB_REQUIREMENTS;

#endif

    return_trace (serialize (c->serializer, glyph_vars, it, axis_count, num_glyphs, force_long_offsets));

  }

  bool subset (hb_subset_context_t *c) const

  {

    TRACE_SUBSET (this);

    if (c->plan->all_axes_pinned)

      return_trace (false);

    if (c->plan->normalized_coords)

      return_trace (instantiate (c));

    unsigned glyph_count = version.to_int () ? c->plan->source->get_num_glyphs () : 0;

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

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

    out->version.major = 1;

    out->version.minor = 0;

    out->axisCount = axisCount;

    out->sharedTupleCount = sharedTupleCount;

    unsigned int num_glyphs = c->plan->num_output_glyphs ();

    out->glyphCountX = hb_min (glyph_count_max (), num_glyphs);

    /* avar2 partial instancing: cull tuple variations whose region falls

     * outside the reachable old-space final-coord ranges. Rewritten glyph

     * data is cached per new gid; untouched glyphs are copied verbatim. */

    hb_vector_t<hb_vector_t<char>> culled_vars;

    hb_set_t culled_gids;

    if (c->plan->has_avar2 && c->plan->avar2_reachable_ranges.get_population ())

    {

      hb_array_t<const F2DOT14> shared_tuples_array =

    (this+sharedTuples).as_array ((unsigned) sharedTupleCount * (unsigned) axisCount);

      if (unlikely (!culled_vars.resize (num_glyphs))) return_trace (false);

      auto cull_it = hb_iter (c->plan->new_to_old_gid_list);

      if (cull_it->first == 0 && !(c->plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE))

  cull_it++;

      for (auto &_ : cull_it)

      {

  hb_bytes_t var_data_bytes = get_glyph_var_data_bytes (c->source_blob, glyph_count, _.second);

  if (var_data_bytes.length < GlyphVariationData::min_size) continue;

  bool changed = false;

  if (unlikely (!var_data_bytes.as<GlyphVariationData> ()

          ->cull_tuple_variations (var_data_bytes, axisCount,

                 shared_tuples_array,

                 &c->plan->axes_old_index_tag_map,

                 c->plan->avar2_reachable_ranges,

                 culled_vars[_.first], &changed)))

    return_trace (false);

  if (changed) culled_gids.add (_.first);

      }

      if (unlikely (culled_gids.in_error ())) return_trace (false);

    }

    auto it = hb_iter (c->plan->new_to_old_gid_list);

    if (it->first == 0 && !(c->plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE))

      it++;

    unsigned subset_data_size = 0;

    unsigned padding_size = 0;

    for (auto &_ : it)

    {

      hb_codepoint_t old_gid = _.second;

      unsigned glyph_data_size = culled_gids.has (_.first)

         ? culled_vars[_.first].length

         : get_glyph_var_data_bytes (c->source_blob, glyph_count, old_gid).length;

      if (glyph_data_size % 2)

      {

        glyph_data_size++;

        padding_size++;

      }

      if (unlikely (hb_unsigned_add_overflows (subset_data_size, glyph_data_size, &subset_data_size)))

  return_trace (false);

    }

    /* According to the spec: If the short format (Offset16) is used for offsets,

     * the value stored is the offset divided by 2, so the maximum data size should

     * be 2 * 0xFFFFu, which is 0x1FFFEu */

    bool long_offset = subset_data_size > 0x1FFFEu;

#ifdef HB_EXPERIMENTAL_API

    long_offset = long_offset || (c->plan->flags & HB_SUBSET_FLAGS_IFTB_REQUIREMENTS);

#endif

    out->flags = long_offset ? 1 : 0;

    unsigned subset_offsets_size = (long_offset ? 4 : 2) * (num_glyphs + 1);

    HBUINT8 *subset_offsets = c->serializer->allocate_size<HBUINT8> (subset_offsets_size, false);

    if (!subset_offsets) return_trace (false);

    /* shared tuples */

    if (!sharedTupleCount || !sharedTuples)

      out->sharedTuples = (char *) subset_offsets + subset_offsets_size - (char *) out;

    else

    {

      unsigned int shared_tuple_size = F2DOT14::static_size * axisCount * sharedTupleCount;

      F2DOT14 *tuples = c->serializer->allocate_size<F2DOT14> (shared_tuple_size);

      if (!tuples) return_trace (false);

      out->sharedTuples = (char *) tuples - (char *) out;

      hb_memcpy (tuples, this+sharedTuples, shared_tuple_size);

    }

    /* This ordering relative to the shared tuples array, which puts the glyphVariationData

       last in the table, is required when HB_SUBSET_FLAGS_IFTB_REQUIREMENTS is set */

    if (long_offset)

      subset_data_size -= padding_size;

    char *subset_data = c->serializer->allocate_size<char> (subset_data_size, false);

    if (!subset_data) return_trace (false);

    out->dataZ = subset_data - (char *) out;

    if (long_offset)

    {

      ((HBUINT32 *) subset_offsets)[0] = 0;

      subset_offsets += 4;

    }

    else

    {

      ((HBUINT16 *) subset_offsets)[0] = 0;

      subset_offsets += 2;

    }

    unsigned int glyph_offset = 0;

    hb_codepoint_t last = 0;

    it = hb_iter (c->plan->new_to_old_gid_list);

    if (it->first == 0 && !(c->plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE))

      it++;

    for (auto &_ : it)

    {

      hb_codepoint_t gid = _.first;

      hb_codepoint_t old_gid = _.second;

      if (long_offset)

  for (; last < gid; last++)

    ((HBUINT32 *) subset_offsets)[last] = glyph_offset;

      else

  for (; last < gid; last++)

    ((HBUINT16 *) subset_offsets)[last] = glyph_offset / 2;

      hb_bytes_t var_data_bytes = culled_gids.has (gid)

          ? hb_bytes_t (culled_vars[gid].arrayZ,

            culled_vars[gid].length)

          : get_glyph_var_data_bytes (c->source_blob,

                    glyph_count,

                    old_gid);

      hb_memcpy (subset_data, var_data_bytes.arrayZ, var_data_bytes.length);

      unsigned glyph_data_size = var_data_bytes.length;

      subset_data += glyph_data_size;

      glyph_offset += glyph_data_size;

      if (!long_offset && (glyph_data_size % 2))

      {

        *subset_data = 0;

        subset_data++;

        glyph_offset++;

      }

      if (long_offset)

  ((HBUINT32 *) subset_offsets)[gid] = glyph_offset;

      else

  ((HBUINT16 *) subset_offsets)[gid] = glyph_offset / 2;

      last++; // Skip over gid

    }

    if (long_offset)

      for (; last < num_glyphs; last++)

  ((HBUINT32 *) subset_offsets)[last] = glyph_offset;

    else

      for (; last < num_glyphs; last++)

  ((HBUINT16 *) subset_offsets)[last] = glyph_offset / 2;

    return_trace (true);

  }

  protected:

  const hb_bytes_t get_glyph_var_data_bytes (hb_blob_t *blob,

               unsigned glyph_count,

               hb_codepoint_t glyph) const

  {

    unsigned start_offset = get_offset (glyph_count, glyph);

    unsigned end_offset = get_offset (glyph_count, glyph+1);

    if (unlikely (end_offset < start_offset)) return hb_bytes_t ();

    unsigned length = end_offset - start_offset;

    hb_bytes_t var_data = blob->as_bytes ().sub_array (((unsigned) dataZ) + start_offset, length);

    return likely (var_data.length >= GlyphVariationData::min_size) ? var_data : hb_bytes_t ();

  }

  bool is_long_offset () const { return flags & 1; }

  unsigned get_offset (unsigned glyph_count, unsigned i) const

  {

    if (unlikely (i > glyph_count)) return 0;

    hb_barrier ();

    return is_long_offset () ? get_long_offset_array ()[i] : get_short_offset_array ()[i] * 2;

  }

  const HBUINT32 * get_long_offset_array () const { return (const HBUINT32 *) &offsetZ; }

  const HBUINT16 *get_short_offset_array () const { return (const HBUINT16 *) &offsetZ; }

  public:

  struct accelerator_t

  {

    hb_scalar_cache_t *create_cache () const

    {

      return hb_scalar_cache_t::create (hb_min ((unsigned) table->sharedTupleCount,

            +TupleVariationHeader::max_shared_tuple_count));

    }

    static void destroy_cache (hb_scalar_cache_t *cache)

    {

      hb_scalar_cache_t::destroy (cache);

    }

    bool has_data () const { return table->has_data (); }

    accelerator_t (hb_face_t *face)

    {

      table = hb_sanitize_context_t ().reference_table<gvar_GVAR> (face, T::tableTag);

      /* If sanitize failed, set glyphCount to 0. */

      glyphCount = table->version.to_int () ? face->get_num_glyphs () : 0;

    }

    ~accelerator_t () { table.destroy (); }

    private:

    static float infer_delta (const hb_array_t<contour_point_t> points,

            const hb_array_t<contour_point_t> deltas,

            unsigned int target, unsigned int prev, unsigned int next,

            float contour_point_t::*m)

    {

      float target_val = points.arrayZ[target].*m;

      float prev_val = points.arrayZ[prev].*m;

      float next_val = points.arrayZ[next].*m;

      float prev_delta =  deltas.arrayZ[prev].*m;

      float next_delta =  deltas.arrayZ[next].*m;

      if (prev_val == next_val)

  return (prev_delta == next_delta) ? prev_delta : 0.f;

      else if (target_val <= hb_min (prev_val, next_val))

  return (prev_val < next_val) ? prev_delta : next_delta;

      else if (target_val >= hb_max (prev_val, next_val))

  return (prev_val > next_val) ? prev_delta : next_delta;

      /* linear interpolation */

      float r = (target_val - prev_val) / (next_val - prev_val);

      return prev_delta + r * (next_delta - prev_delta);

    }

    static unsigned int next_index (unsigned int i, unsigned int start, unsigned int end)

    { return (i >= end) ? start : (i + 1); }

#ifndef HB_OPTIMIZE_SIZE

    template <bool is_x>

#endif

    static bool decompile_deltas_add_to_points (const HBUINT8 *&p /* IN/OUT */,

            hb_array_t<contour_point_t> points,

            float scalar,

            const HBUINT8 *end,

            unsigned start

#ifdef HB_OPTIMIZE_SIZE

            , bool is_x

#endif

            )

    {

      unsigned i = 0;

      unsigned count = points.length;

      while (i < count)

      {

  if (unlikely (p + 1 > end)) return false;

  unsigned control = *p++;

  unsigned run_count = (control & TupleValues::VALUE_RUN_COUNT_MASK) + 1;

  unsigned stop = i + run_count;

  if (unlikely (stop > count)) return false;

  unsigned skip = i < start ? hb_min (start - i, run_count) : 0;

  i += skip;

  switch (control & TupleValues::VALUES_SIZE_MASK)

  {

    case TupleValues::VALUES_ARE_ZEROS:

      i = stop;

      break;

    case TupleValues::VALUES_ARE_WORDS:

    {

      if (unlikely (p + run_count * HBINT16::static_size > end)) return false;

      p += skip * HBINT16::static_size;

      const auto *pp = (const HBINT16 *) p;

      for (; i < stop; i++)

      {

        float v = *pp++ * scalar;

        if (is_x) points.arrayZ[i].x += v;

        else points.arrayZ[i].y += v;

      }

      p = (const HBUINT8 *) pp;

    }

    break;

    case TupleValues::VALUES_ARE_LONGS:

    {

      if (unlikely (p + run_count * HBINT32::static_size > end)) return false;

      p += skip * HBINT32::static_size;

      const auto *pp = (const HBINT32 *) p;

      for (; i < stop; i++)

      {

        float v = *pp++ * scalar;

        if (is_x) points.arrayZ[i].x += v;

        else points.arrayZ[i].y += v;

      }

      p = (const HBUINT8 *) pp;

    }

    break;

    case TupleValues::VALUES_ARE_BYTES:

    {

      if (unlikely (p + run_count > end)) return false;

      p += skip * HBINT8::static_size;

      const auto *pp = (const HBINT8 *) p;

      for (; i < stop; i++)

      {

        float v = *pp++ * scalar;

        if (is_x) points.arrayZ[i].x += v;

        else points.arrayZ[i].y += v;

      }

      p = (const HBUINT8 *) pp;

    }

    break;

  }

      }

      return true;

    }

Unexecuted instantiation: bool OT::gvar_GVAR<OT::gvar, OT::Layout::SmallTypes>::accelerator_t::decompile_deltas_add_to_points<true>(OT::NumType<true, unsigned char, 1u> const*&, hb_array_t<contour_point_t>, float, OT::NumType<true, unsigned char, 1u> const*, unsigned int)

Unexecuted instantiation: bool OT::gvar_GVAR<OT::gvar, OT::Layout::SmallTypes>::accelerator_t::decompile_deltas_add_to_points<false>(OT::NumType<true, unsigned char, 1u> const*&, hb_array_t<contour_point_t>, float, OT::NumType<true, unsigned char, 1u> const*, unsigned int)

    public:

    bool apply_deltas_to_points (hb_codepoint_t glyph,

         hb_array_t<const int> coords,

         const hb_array_t<contour_point_t> points,

         hb_glyf_scratch_t &scratch,

         hb_scalar_cache_t *gvar_cache = nullptr,

         bool phantom_only = false,

         int64_t *budget = nullptr) const

    {

      if (unlikely (glyph >= glyphCount)) return true;

      hb_scalar_cache_t *scalar_cache = gvar_cache ?

          gvar_cache :

          (hb_scalar_cache_t *) &Null(hb_scalar_cache_t);

      hb_bytes_t var_data_bytes = table->get_glyph_var_data_bytes (table.get_blob (), glyphCount, glyph);

      if (!var_data_bytes.as<GlyphVariationData> ()->has_data ()) return true;

      auto &shared_indices = scratch.shared_indices;

      shared_indices.clear ();

      typename GlyphVariationData::tuple_iterator_t iterator;

      if (!GlyphVariationData::get_tuple_iterator (var_data_bytes, table->axisCount,

               var_data_bytes.arrayZ,

               shared_indices, &iterator))

  return true; /* so isn't applied at all */

      bool any_private_points = false;

      bool private_points_checked = false;

      /* Save original points for inferred delta calculation */

      auto &orig_points_vec = scratch.orig_points;

      orig_points_vec.clear (); // Populated lazily

      auto orig_points = orig_points_vec.as_array ();

      /* flag is used to indicate referenced point */

      auto &deltas_vec = scratch.deltas;

      deltas_vec.clear (); // Populated lazily

      auto deltas = deltas_vec.as_array ();

      unsigned num_coords = table->axisCount;

      hb_array_t<const F2DOT14> shared_tuples = (table+table->sharedTuples).as_array (table->sharedTupleCount * num_coords);

      auto &private_indices = scratch.private_indices;

      auto &x_deltas = scratch.x_deltas;

      auto &y_deltas = scratch.y_deltas;

      unsigned count = points.length;

      bool flush = false;

      do

      {

  float scalar = iterator.current_tuple->calculate_scalar (coords, num_coords, shared_tuples,

                 scalar_cache);

  if (scalar == 0.f) continue;

  if (budget &&

      unlikely (!hb_budget_spend (*budget, HB_BUDGET_1,

           phantom_only && count >= 4 ? 4 : count)))

    return false;

  if (!private_points_checked)

  {

    auto scan = iterator;

    do

    {

      if (scan.current_tuple->has_private_points ())

      {

        any_private_points = true;

        break;

      }

    } while (scan.move_to_next ());

    private_points_checked = true;

  }

  const HBUINT8 *p = iterator.get_serialized_data ();

  unsigned int length = iterator.current_tuple->get_data_size ();

  if (unlikely (!iterator.var_data_bytes.check_range (p, length)))

    return false;

  if (!deltas)

  {

    if (unlikely (!deltas_vec.resize_dirty  (count))) return false;

    deltas = deltas_vec.as_array ();

    hb_memset (deltas.arrayZ + (phantom_only ? count - 4 : 0), 0,

         (phantom_only ? 4 : count) * sizeof (deltas[0]));

  }

  const HBUINT8 *end = p + length;

  bool has_private_points = iterator.current_tuple->has_private_points ();

  if (has_private_points &&

      !GlyphVariationData::decompile_points (p, private_indices, end))

    return false;

  const hb_array_t<unsigned int> &indices = has_private_points ? private_indices : shared_indices;

  bool apply_to_all = (indices.length == 0);

  unsigned num_deltas = apply_to_all ? points.length : indices.length;

  unsigned start_deltas = (apply_to_all && phantom_only && num_deltas >= 4 ? num_deltas - 4 : 0);

  if (apply_to_all && !any_private_points)

  {

#ifdef HB_OPTIMIZE_SIZE

    if (unlikely (!decompile_deltas_add_to_points (p, points, scalar, end, start_deltas, true))) return false;

    if (unlikely (!decompile_deltas_add_to_points (p, points, scalar, end, start_deltas, false))) return false;

#else

    if (unlikely (!decompile_deltas_add_to_points<true> (p, points, scalar, end, start_deltas))) return false;

    if (unlikely (!decompile_deltas_add_to_points<false> (p, points, scalar, end, start_deltas))) return false;

#endif

    continue;

  }

  if (unlikely (!x_deltas.resize_dirty  (num_deltas))) return false;

  if (unlikely (!GlyphVariationData::decompile_deltas (p, x_deltas, end, false, start_deltas))) return false;

  if (unlikely (!y_deltas.resize_dirty  (num_deltas))) return false;

  if (unlikely (!GlyphVariationData::decompile_deltas (p, y_deltas, end, false, start_deltas))) return false;