/*

 * 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_MVAR_TABLE_HH

#define HB_OT_VAR_MVAR_TABLE_HH

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

namespace OT {

struct VariationValueRecord

{

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (c->check_struct (this));

  }

  bool subset (hb_subset_context_t *c,

               const hb_map_t& varidx_map) const

  {

    TRACE_SUBSET (this);

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

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

    hb_codepoint_t *new_idx;

    return_trace (c->serializer->check_assign (out->varIdx,

                                               (varidx_map.has (varIdx, &new_idx)) ? *new_idx : HB_OT_LAYOUT_NO_VARIATIONS_INDEX,

                                               HB_SERIALIZE_ERROR_INT_OVERFLOW));

  }

  public:

  Tag   valueTag; /* Four-byte tag identifying a font-wide measure. */

  VarIdx  varIdx;   /* Outer/inner index into ItemVariationStore item. */

  public:

  DEFINE_SIZE_STATIC (8);

};

/*

 * MVAR -- Metrics Variations

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

 */

#define HB_OT_TAG_MVAR HB_TAG('M','V','A','R')

struct MVAR

{

  static constexpr hb_tag_t tableTag = HB_OT_TAG_MVAR;

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (version.sanitize (c) &&

      hb_barrier () &&

      likely (version.major == 1) &&

      c->check_struct (this) &&

      hb_barrier () &&

      valueRecordSize >= VariationValueRecord::static_size &&

      varStore.sanitize (c, this) &&

      c->check_range (valuesZ.arrayZ,

          valueRecordCount,

          valueRecordSize));

  }

  bool subset (hb_subset_context_t *c) const

  {

    TRACE_SUBSET (this);

#ifdef HB_NO_VAR

    return_trace (false);

#endif

    if (c->plan->all_axes_pinned)

      return_trace (false);

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

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

    out->version = version;

    out->reserved = reserved;

    out->valueRecordSize = valueRecordSize;

    out->valueRecordCount = valueRecordCount;

    item_variations_t item_vars;

    const ItemVariationStore& src_var_store = this+varStore;

    if (!item_vars.instantiate (src_var_store, c->plan))

      return_trace (false);

    /* serialize varstore */

    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);

    /* serialize value records array */

    unsigned value_rec_count = valueRecordCount;

    const VariationValueRecord *record = reinterpret_cast<const VariationValueRecord*> (valuesZ.arrayZ);

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

    {

      if (!record->subset (c, item_vars.get_varidx_map ())) return_trace (false);

      record++;

    }

    return_trace (true);

  }

  float get_var (hb_tag_t tag,

     const int *coords, unsigned int coord_count) const

  {

    const VariationValueRecord *record;

    record = (VariationValueRecord *) hb_bsearch (tag,

              (const VariationValueRecord *)

                (const HBUINT8 *) valuesZ,

              valueRecordCount, valueRecordSize,

              tag_compare);

    if (!record)

      return 0.;

    return (this+varStore).get_delta (record->varIdx, coords, coord_count);

  }

protected:

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

  {

    const hb_tag_t *a = (const hb_tag_t *) pa;

    const Tag *b = (const Tag *) pb;

    return b->cmp (*a);

  }

  protected:

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

         * initially set to 0x00010000u */

  HBUINT16  reserved; /* Not used; set to 0. */

  HBUINT16  valueRecordSize;/* The size in bytes of each value record —

         * must be greater than zero. */

  HBUINT16  valueRecordCount;/* The number of value records — may be zero. */

  Offset16To<ItemVariationStore>

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

  UnsizedArrayOf<HBUINT8>

    valuesZ;  /* Array of value records. The records must be

         * in binary order of their valueTag field. */

  public:

  DEFINE_SIZE_ARRAY (12, valuesZ);

};

} /* namespace OT */

#define HB_ADD_MVAR_VAR(tag, field) \

       c->serializer->check_assign (table->field, \

            roundf (table->field + \

              MVAR.get_var (tag, \

                c->plan->normalized_coords.arrayZ, \

                c->plan->normalized_coords.length)), \

            HB_SERIALIZE_ERROR_INT_OVERFLOW)

#endif /* HB_OT_VAR_MVAR_TABLE_HH */