JDK14/Java14源码在线阅读

/*
 * Copyright © 2016 Elie Roux <elie.roux@telecom-bretagne.eu>
 * Copyright © 2018  Google, Inc.
 * Copyright © 2018  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.
 *
 * Google Author(s): Behdad Esfahbod
 */

#ifndef HB_OT_LAYOUT_BASE_TABLE_HH
#define HB_OT_LAYOUT_BASE_TABLE_HH

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

/* To be removed */
typedef hb_tag_t hb_ot_layout_baseline_t;

namespace OT {

/*
 * BASE -- Baseline
 * https://docs.microsoft.com/en-us/typography/opentype/spec/base
 */

struct BaseCoordFormat1
{
  hb_position_t get_coord () const { return coordinate; }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this)));
  }

  protected:
  HBUINT16      format;         /* Format identifier--format = 1 */
  FWORD         coordinate;     /* X or Y value, in design units */
  public:
  DEFINE_SIZE_STATIC (4);
};

struct BaseCoordFormat2
{
  hb_position_t get_coord () const
  {
    /* TODO */
    return coordinate;
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this));
  }

  protected:
  HBUINT16      format;         /* Format identifier--format = 2 */
  FWORD         coordinate;     /* X or Y value, in design units */
  GlyphID       referenceGlyph; /* Glyph ID of control glyph */
  HBUINT16      coordPoint;     /* Index of contour point on the
                                 * reference glyph */
  public:
  DEFINE_SIZE_STATIC (8);
};

struct BaseCoordFormat3
{
  hb_position_t get_coord (hb_font_t *font,
                           const VariationStore &var_store,
                           hb_direction_t direction) const
  {
    const Device &device = this+deviceTable;
    return coordinate + (HB_DIRECTION_IS_VERTICAL (direction) ?
                         device.get_y_delta (font, var_store) :
                         device.get_x_delta (font, var_store));
  }


  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
                          deviceTable.sanitize (c, this)));
  }

  protected:
  HBUINT16      format;         /* Format identifier--format = 3 */
  FWORD         coordinate;     /* X or Y value, in design units */
  OffsetTo<Device>
                deviceTable;    /* Offset to Device table for X or
                                 * Y value, from beginning of
                                 * BaseCoord table (may be NULL). */
  public:
  DEFINE_SIZE_STATIC (6);
};

struct BaseCoord
{
  hb_position_t get_coord (hb_font_t *font,
                           const VariationStore &var_store,
                           hb_direction_t direction) const
  {
    switch (u.format) {
    case 1: return u.format1.get_coord ();
    case 2: return u.format2.get_coord ();
    case 3: return u.format3.get_coord (font, var_store, direction);
    default:return 0;
    }
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    if (unlikely (!u.format.sanitize (c))) return_trace (false);
    switch (u.format) {
    case 1: return_trace (u.format1.sanitize (c));
    case 2: return_trace (u.format2.sanitize (c));
    case 3: return_trace (u.format3.sanitize (c));
    default:return_trace (false);
    }
  }

  protected:
  union {
    HBUINT16            format;
    BaseCoordFormat1    format1;
    BaseCoordFormat2    format2;
    BaseCoordFormat3    format3;
  } u;
  public:
  DEFINE_SIZE_UNION (2, format);
};

struct FeatMinMaxRecord
{
  static int cmp (const void *key_, const void *entry_)
  {
    hb_tag_t key = * (hb_tag_t *) key_;
    const FeatMinMaxRecord &entry = * (const FeatMinMaxRecord *) entry_;
    return key < (unsigned int) entry.tag ? -1 :
           key > (unsigned int) entry.tag ? 1 :
           0;
  }

  void get_min_max (const BaseCoord **min, const BaseCoord **max) const
  {
    if (likely (min)) *min = &(this+minCoord);
    if (likely (max)) *max = &(this+maxCoord);
  }

  bool sanitize (hb_sanitize_context_t *c, const void *base) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
                          minCoord.sanitize (c, this) &&
                          maxCoord.sanitize (c, this)));
  }

  protected:
  Tag           tag;            /* 4-byte feature identification tag--must
                                 * match feature tag in FeatureList */
  OffsetTo<BaseCoord>
                minCoord;       /* Offset to BaseCoord table that defines
                                 * the minimum extent value, from beginning
                                 * of MinMax table (may be NULL) */
  OffsetTo<BaseCoord>
                maxCoord;       /* Offset to BaseCoord table that defines
                                 * the maximum extent value, from beginning
                                 * of MinMax table (may be NULL) */
  public:
  DEFINE_SIZE_STATIC (8);

};

struct MinMax
{
  void get_min_max (hb_tag_t          feature_tag,
                           const BaseCoord **min,
                           const BaseCoord **max) const
  {
    /* TODO Replace hb_bsearch() with .bsearch(). */
    const FeatMinMaxRecord *minMaxCoord = (const FeatMinMaxRecord *)
                                          hb_bsearch (&feature_tag, featMinMaxRecords.arrayZ,
                                                      featMinMaxRecords.len,
                                                      FeatMinMaxRecord::static_size,
                                                      FeatMinMaxRecord::cmp);
    if (minMaxCoord)
      minMaxCoord->get_min_max (min, max);
    else
    {
      if (likely (min)) *min = &(this+minCoord);
      if (likely (max)) *max = &(this+maxCoord);
    }
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
                          minCoord.sanitize (c, this) &&
                          maxCoord.sanitize (c, this) &&
                          featMinMaxRecords.sanitize (c, this)));
  }

  protected:
  OffsetTo<BaseCoord>
                minCoord;       /* Offset to BaseCoord table that defines
                                 * minimum extent value, from the beginning
                                 * of MinMax table (may be NULL) */
  OffsetTo<BaseCoord>
                maxCoord;       /* Offset to BaseCoord table that defines
                                 * maximum extent value, from the beginning
                                 * of MinMax table (may be NULL) */
  SortedArrayOf<FeatMinMaxRecord>
                featMinMaxRecords;
                                /* Array of FeatMinMaxRecords, in alphabetical
                                 * order by featureTableTag */
  public:
  DEFINE_SIZE_ARRAY (6, featMinMaxRecords);
};

struct BaseValues
{
  const BaseCoord &get_base_coord (int baseline_tag_index) const
  {
    if (baseline_tag_index == -1) baseline_tag_index = defaultIndex;
    return this+baseCoords[baseline_tag_index];
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
                          baseCoords.sanitize (c, this)));
  }

  protected:
  Index         defaultIndex;   /* Index number of default baseline for this
                                 * script — equals index position of baseline tag
                                 * in baselineTags array of the BaseTagList */
  OffsetArrayOf<BaseCoord>
                baseCoords;     /* Number of BaseCoord tables defined — should equal
                                 * baseTagCount in the BaseTagList
                                 *
                                 * Array of offsets to BaseCoord tables, from beginning of
                                 * BaseValues table — order matches baselineTags array in
                                 * the BaseTagList */
  public:
  DEFINE_SIZE_ARRAY (4, baseCoords);
};

struct BaseLangSysRecord
{
  static int cmp (const void *key_, const void *entry_)
  {
    hb_tag_t key = * (hb_tag_t *) key_;
    const BaseLangSysRecord &entry = * (const BaseLangSysRecord *) entry_;
    return key < (unsigned int) entry.baseLangSysTag ? -1 :
           key > (unsigned int) entry.baseLangSysTag ? 1 :
           0;
  }

  const MinMax &get_min_max () const
  { return this+minMax; }

  bool sanitize (hb_sanitize_context_t *c, const void *base) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
                          minMax.sanitize (c, this)));
  }

  protected:
  Tag           baseLangSysTag; /* 4-byte language system identification tag */
  OffsetTo<MinMax>
                minMax;         /* Offset to MinMax table, from beginning
                                 * of BaseScript table */
  public:
  DEFINE_SIZE_STATIC (6);
};

struct BaseScript
{
  const MinMax &get_min_max (hb_tag_t language_tag) const
  {
    /* TODO Replace hb_bsearch() with .bsearch(). */
    const BaseLangSysRecord* record = (const BaseLangSysRecord *)
                                      hb_bsearch (&language_tag, baseLangSysRecords.arrayZ,
                                                  baseLangSysRecords.len,
                                                  BaseLangSysRecord::static_size,
                                                  BaseLangSysRecord::cmp);
    return record ? record->get_min_max () : this+defaultMinMax;
  }

  const BaseCoord &get_base_coord (int baseline_tag_index) const
  { return (this+baseValues).get_base_coord (baseline_tag_index); }

  bool is_empty () const { return !baseValues; }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
                          baseValues.sanitize (c, this) &&
                          defaultMinMax.sanitize (c, this) &&
                          baseLangSysRecords.sanitize (c, this)));
  }

  protected:
  OffsetTo<BaseValues>
                baseValues;     /* Offset to BaseValues table, from beginning
                                 * of BaseScript table (may be NULL) */
  OffsetTo<MinMax>
                defaultMinMax;  /* Offset to MinMax table, from beginning of
                                 * BaseScript table (may be NULL) */
  SortedArrayOf<BaseLangSysRecord>
                baseLangSysRecords;
                                /* Number of BaseLangSysRecords
                                 * defined — may be zero (0) */

  public:
  DEFINE_SIZE_ARRAY (6, baseLangSysRecords);
};

struct BaseScriptList;
struct BaseScriptRecord
{
  static int cmp (const void *key_, const void *entry_)
  {
    hb_tag_t key = * (hb_tag_t *) key_;
    const BaseScriptRecord &entry = * (const BaseScriptRecord *) entry_;
    return key < (unsigned int) entry.baseScriptTag ? -1 :
           key > (unsigned int) entry.baseScriptTag ? 1 :
           0;
  }

  const BaseScript &get_base_script (const BaseScriptList *list) const
  { return list+baseScript; }

  bool sanitize (hb_sanitize_context_t *c, const void *base) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
                          baseScript.sanitize (c, base)));
  }

  protected:
  Tag           baseScriptTag;  /* 4-byte script identification tag */
  OffsetTo<BaseScript>
                baseScript;     /* Offset to BaseScript table, from beginning
                                 * of BaseScriptList */

  public:
  DEFINE_SIZE_STATIC (6);
};

struct BaseScriptList
{
  const BaseScriptRecord *find_record (hb_tag_t script) const
  {
    /* TODO Replace hb_bsearch() with .bsearch(). */
    return (const BaseScriptRecord *) hb_bsearch (&script, baseScriptRecords.arrayZ,
                                                  baseScriptRecords.len,
                                                  BaseScriptRecord::static_size,
                                                  BaseScriptRecord::cmp);
  }

  /* TODO: Or client should handle fallback? */
  const BaseScript &get_base_script (hb_tag_t script) const
  {
    const BaseScriptRecord *record = find_record (script);
    if (!record) record = find_record ((hb_script_t) HB_TAG ('D','F','L','T'));

    return record ? record->get_base_script (this) : Null (BaseScript);
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (c->check_struct (this) &&
                  baseScriptRecords.sanitize (c, this));
  }

  protected:
  SortedArrayOf<BaseScriptRecord>
                        baseScriptRecords;

  public:
  DEFINE_SIZE_ARRAY (2, baseScriptRecords);
};

struct Axis
{
  bool get_baseline (hb_ot_layout_baseline_t   baseline,
                            hb_tag_t                  script_tag,
                            hb_tag_t                  language_tag,
                            const BaseCoord         **coord) const
  {
    const BaseScript &base_script = (this+baseScriptList).get_base_script (script_tag);
    if (base_script.is_empty ()) return false;

    if (likely (coord)) *coord = &base_script.get_base_coord ((this+baseTagList).bsearch (baseline));

    return true;
  }

  bool get_min_max (hb_tag_t          script_tag,
                    hb_tag_t          language_tag,
                    hb_tag_t          feature_tag,
                    const BaseCoord **min_coord,
                    const BaseCoord **max_coord) const
  {
    const BaseScript &base_script = (this+baseScriptList).get_base_script (script_tag);
    if (base_script.is_empty ()) return false;

    base_script.get_min_max (language_tag).get_min_max (feature_tag, min_coord, max_coord);

    return true;
  }

  bool sanitize (hb_sanitize_context_t *c) const
  {
    TRACE_SANITIZE (this);
    return_trace (likely (c->check_struct (this) &&
                          (this+baseTagList).sanitize (c) &&
                          (this+baseScriptList).sanitize (c)));
  }

  protected:
  OffsetTo<SortedArrayOf<Tag> >
                baseTagList;    /* Offset to BaseTagList table, from beginning
                                 * of Axis table (may be NULL)
                                 * Array of 4-byte baseline identification tags — must
                                 * be in alphabetical order */
  OffsetTo<BaseScriptList>
                baseScriptList; /* Offset to BaseScriptList table, from beginning
                                 * of Axis table
                                 * Array of BaseScriptRecords, in alphabetical order
                                 * by baseScriptTag */

  public:
  DEFINE_SIZE_STATIC (4);
};

struct BASE
{
  static constexpr hb_tag_t tableTag = HB_OT_TAG_BASE;

  const Axis &get_axis (hb_direction_t direction) const
  { return HB_DIRECTION_IS_VERTICAL (direction) ? this+vAxis : this+hAxis; }

  const VariationStore &get_var_store () const
  { return version.to_int () < 0x00010001u ? Null (VariationStore) : this+varStore; }

  bool get_baseline (hb_font_t               *font,
                     hb_ot_layout_baseline_t  baseline,
                     hb_direction_t           direction,
                     hb_tag_t                 script_tag,
                     hb_tag_t                 language_tag,
                     hb_position_t           *base) const
  {
    const BaseCoord *base_coord;
    if (!get_axis (direction).get_baseline (baseline, script_tag, language_tag, &base_coord))
      return false;

    if (likely (base && base_coord)) *base = base_coord->get_coord (font,
                                                                    get_var_store (),
                                                                    direction);
    return true;
  }

  /* TODO: Expose this separately sometime? */
  bool get_min_max (hb_font_t      *font,

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