src/hb-ot-layout-base-table.hh - third_party/harfbuzz - Git at Google

 /*
  * Copyright © 2016  Elie Roux <elie.roux@telecom-bretagne.eu>
  * Copyright © 2018  Google, Inc.
  * Copyright © 2018-2019  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.
  *
  * 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"

 namespace OT {

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

 struct BaseCoordFormat1
 {
   hb_position_t get_coord (hb_font_t *font, hb_direction_t direction) const
   {
     return HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_y (coordinate) : font->em_scale_x (coordinate);
   }

   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     return_trace (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 (hb_font_t *font, hb_direction_t direction) const
   {
     /* TODO */
     return HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_y (coordinate) : font->em_scale_x (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 */
   HBGlyphID16	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 HB_DIRECTION_IS_HORIZONTAL (direction)
 	 ? font->em_scale_y (coordinate) + device.get_y_delta (font, var_store)
 	 : font->em_scale_x (coordinate) + 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 */
   Offset16To<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
 {
   bool has_data () const { return u.format; }

   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 (font, direction);
     case 2: return u.format2.get_coord (font, direction);
     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
 {
   int cmp (hb_tag_t key) const { return tag.cmp (key); }

   bool has_data () const { return tag; }

   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 */
   Offset16To<BaseCoord>
 		minCoord;	/* Offset to BaseCoord table that defines
 				 * the minimum extent value, from beginning
 				 * of MinMax table (may be NULL) */
   Offset16To<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
   {
     const FeatMinMaxRecord &minMaxCoord = featMinMaxRecords.bsearch (feature_tag);
     if (minMaxCoord.has_data ())
       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:
   Offset16To<BaseCoord>
 		minCoord;	/* Offset to BaseCoord table that defines
 				 * minimum extent value, from the beginning
 				 * of MinMax table (may be NULL) */
   Offset16To<BaseCoord>
 		maxCoord;	/* Offset to BaseCoord table that defines
 				 * maximum extent value, from the beginning
 				 * of MinMax table (may be NULL) */
   SortedArray16Of<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 */
   Array16OfOffset16To<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
 {
   int cmp (hb_tag_t key) const { return baseLangSysTag.cmp (key); }

   bool has_data () const { return baseLangSysTag; }

   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 */
   Offset16To<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
   {
     const BaseLangSysRecord& record = baseLangSysRecords.bsearch (language_tag);
     return record.has_data () ? 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 has_data () 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:
   Offset16To<BaseValues>
 		baseValues;	/* Offset to BaseValues table, from beginning
 				 * of BaseScript table (may be NULL) */
   Offset16To<MinMax>
 		defaultMinMax;	/* Offset to MinMax table, from beginning of
 				 * BaseScript table (may be NULL) */
   SortedArray16Of<BaseLangSysRecord>
 		baseLangSysRecords;
 				/* Number of BaseLangSysRecords
 				 * defined — may be zero (0) */

   public:
   DEFINE_SIZE_ARRAY (6, baseLangSysRecords);
 };

 struct BaseScriptList;
 struct BaseScriptRecord
 {
   int cmp (hb_tag_t key) const { return baseScriptTag.cmp (key); }

   bool has_data () const { return baseScriptTag; }

   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 */
   Offset16To<BaseScript>
 		baseScript;	/* Offset to BaseScript table, from beginning
 				 * of BaseScriptList */

   public:
   DEFINE_SIZE_STATIC (6);
 };

 struct BaseScriptList
 {
   const BaseScript &get_base_script (hb_tag_t script) const
   {
     const BaseScriptRecord *record = &baseScriptRecords.bsearch (script);
     if (!record->has_data ()) record = &baseScriptRecords.bsearch (HB_TAG ('D','F','L','T'));
     return record->has_data () ? 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:
   SortedArray16Of<BaseScriptRecord>
 			baseScriptRecords;

   public:
   DEFINE_SIZE_ARRAY (2, baseScriptRecords);
 };

 struct Axis
 {
   bool get_baseline (hb_tag_t          baseline_tag,
 		     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.has_data ())
     {
       *coord = nullptr;
       return false;
     }

     if (likely (coord))
     {
       unsigned int tag_index = 0;
       if (!(this+baseTagList).bfind (baseline_tag, &tag_index))
       {
         *coord = nullptr;
         return false;
       }
       *coord = &base_script.get_base_coord (tag_index);
     }

     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.has_data ())
     {
       *min_coord = *max_coord = nullptr;
       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:
   Offset16To<SortedArray16Of<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 */
   Offset16To<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_tag_t        baseline_tag,
 		     hb_direction_t  direction,
 		     hb_tag_t        script_tag,
 		     hb_tag_t        language_tag,
 		     hb_position_t  *base) const
   {
     const BaseCoord *base_coord = nullptr;
     if (unlikely (!get_axis (direction).get_baseline (baseline_tag, script_tag, language_tag, &base_coord) ||
 		  !base_coord || !base_coord->has_data ()))
       return false;

     if (likely (base))
       *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,
 		    hb_direction_t  direction,
 		    hb_tag_t        script_tag,
 		    hb_tag_t        language_tag,
 		    hb_tag_t        feature_tag,
 		    hb_position_t  *min,
 		    hb_position_t  *max)
   {
     const BaseCoord *min_coord, *max_coord;
     if (!get_axis (direction).get_min_max (script_tag, language_tag, feature_tag,
 					   &min_coord, &max_coord))
       return false;

     const VariationStore &var_store = get_var_store ();
     if (likely (min && min_coord)) *min = min_coord->get_coord (font, var_store, direction);
     if (likely (max && max_coord)) *max = max_coord->get_coord (font, var_store, direction);
     return true;
   }

   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     return_trace (likely (c->check_struct (this) &&
 			  likely (version.major == 1) &&
 			  hAxis.sanitize (c, this) &&
 			  vAxis.sanitize (c, this) &&
 			  (version.to_int () < 0x00010001u || varStore.sanitize (c, this))));
   }

   protected:
   FixedVersion<>version;	/* Version of the BASE table */
   Offset16To<Axis>hAxis;		/* Offset to horizontal Axis table, from beginning
 				 * of BASE table (may be NULL) */
   Offset16To<Axis>vAxis;		/* Offset to vertical Axis table, from beginning
 				 * of BASE table (may be NULL) */
   Offset32To<VariationStore>
 		varStore;	/* Offset to the table of Item Variation
 				 * Store--from beginning of BASE
 				 * header (may be NULL).  Introduced
 				 * in version 0x00010001. */
   public:
   DEFINE_SIZE_MIN (8);
 };


 } /* namespace OT */


 #endif /* HB_OT_LAYOUT_BASE_TABLE_HH */
	/*
	* Copyright © 2016 Elie Roux <elie.roux@telecom-bretagne.eu>
	* Copyright © 2018 Google, Inc.
	* Copyright © 2018-2019 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.
	*
	* 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"

	namespace OT {

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

	struct BaseCoordFormat1
	{
	hb_position_t get_coord (hb_font_t *font, hb_direction_t direction) const
	{
	return HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_y (coordinate) : font->em_scale_x (coordinate);
	}

	bool sanitize (hb_sanitize_context_t *c) const
	{
	TRACE_SANITIZE (this);
	return_trace (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 (hb_font_t *font, hb_direction_t direction) const
	{
	/* TODO */
	return HB_DIRECTION_IS_HORIZONTAL (direction) ? font->em_scale_y (coordinate) : font->em_scale_x (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 */
	HBGlyphID16 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 HB_DIRECTION_IS_HORIZONTAL (direction)
	? font->em_scale_y (coordinate) + device.get_y_delta (font, var_store)
	: font->em_scale_x (coordinate) + 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 */
	Offset16To<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
	{
	bool has_data () const { return u.format; }

	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 (font, direction);
	case 2: return u.format2.get_coord (font, direction);
	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
	{
	int cmp (hb_tag_t key) const { return tag.cmp (key); }

	bool has_data () const { return tag; }

	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 */
	Offset16To<BaseCoord>
	minCoord; /* Offset to BaseCoord table that defines
	* the minimum extent value, from beginning
	* of MinMax table (may be NULL) */
	Offset16To<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
	{
	const FeatMinMaxRecord &minMaxCoord = featMinMaxRecords.bsearch (feature_tag);
	if (minMaxCoord.has_data ())
	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:
	Offset16To<BaseCoord>
	minCoord; /* Offset to BaseCoord table that defines
	* minimum extent value, from the beginning
	* of MinMax table (may be NULL) */
	Offset16To<BaseCoord>
	maxCoord; /* Offset to BaseCoord table that defines
	* maximum extent value, from the beginning
	* of MinMax table (may be NULL) */
	SortedArray16Of<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 */
	Array16OfOffset16To<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
	{
	int cmp (hb_tag_t key) const { return baseLangSysTag.cmp (key); }

	bool has_data () const { return baseLangSysTag; }

	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 */
	Offset16To<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
	{
	const BaseLangSysRecord& record = baseLangSysRecords.bsearch (language_tag);
	return record.has_data () ? 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 has_data () 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:
	Offset16To<BaseValues>
	baseValues; /* Offset to BaseValues table, from beginning
	* of BaseScript table (may be NULL) */
	Offset16To<MinMax>
	defaultMinMax; /* Offset to MinMax table, from beginning of
	* BaseScript table (may be NULL) */
	SortedArray16Of<BaseLangSysRecord>
	baseLangSysRecords;
	/* Number of BaseLangSysRecords
	* defined — may be zero (0) */

	public:
	DEFINE_SIZE_ARRAY (6, baseLangSysRecords);
	};

	struct BaseScriptList;
	struct BaseScriptRecord
	{
	int cmp (hb_tag_t key) const { return baseScriptTag.cmp (key); }

	bool has_data () const { return baseScriptTag; }

	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 */
	Offset16To<BaseScript>
	baseScript; /* Offset to BaseScript table, from beginning
	* of BaseScriptList */

	public:
	DEFINE_SIZE_STATIC (6);
	};

	struct BaseScriptList
	{
	const BaseScript &get_base_script (hb_tag_t script) const
	{
	const BaseScriptRecord *record = &baseScriptRecords.bsearch (script);
	if (!record->has_data ()) record = &baseScriptRecords.bsearch (HB_TAG ('D','F','L','T'));
	return record->has_data () ? 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:
	SortedArray16Of<BaseScriptRecord>
	baseScriptRecords;

	public:
	DEFINE_SIZE_ARRAY (2, baseScriptRecords);
	};

	struct Axis
	{
	bool get_baseline (hb_tag_t baseline_tag,
	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.has_data ())
	{
	*coord = nullptr;
	return false;
	}

	if (likely (coord))
	{
	unsigned int tag_index = 0;
	if (!(this+baseTagList).bfind (baseline_tag, &tag_index))
	{
	*coord = nullptr;
	return false;
	}
	*coord = &base_script.get_base_coord (tag_index);
	}

	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.has_data ())
	{
	min_coord = max_coord = nullptr;
	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:
	Offset16To<SortedArray16Of<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 */
	Offset16To<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_tag_t baseline_tag,
	hb_direction_t direction,
	hb_tag_t script_tag,
	hb_tag_t language_tag,
	hb_position_t *base) const
	{
	const BaseCoord *base_coord = nullptr;
	if (unlikely (!get_axis (direction).get_baseline (baseline_tag, script_tag, language_tag, &base_coord) \|\|
	!base_coord \|\| !base_coord->has_data ()))
	return false;

	if (likely (base))
	*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,
	hb_direction_t direction,
	hb_tag_t script_tag,
	hb_tag_t language_tag,
	hb_tag_t feature_tag,
	hb_position_t *min,
	hb_position_t *max)
	{
	const BaseCoord min_coord, max_coord;
	if (!get_axis (direction).get_min_max (script_tag, language_tag, feature_tag,
	&min_coord, &max_coord))
	return false;

	const VariationStore &var_store = get_var_store ();
	if (likely (min && min_coord)) *min = min_coord->get_coord (font, var_store, direction);
	if (likely (max && max_coord)) *max = max_coord->get_coord (font, var_store, direction);
	return true;
	}

	bool sanitize (hb_sanitize_context_t *c) const
	{
	TRACE_SANITIZE (this);
	return_trace (likely (c->check_struct (this) &&
	likely (version.major == 1) &&
	hAxis.sanitize (c, this) &&
	vAxis.sanitize (c, this) &&
	(version.to_int () < 0x00010001u \|\| varStore.sanitize (c, this))));
	}

	protected:
	FixedVersion<>version; /* Version of the BASE table */
	Offset16To<Axis>hAxis; /* Offset to horizontal Axis table, from beginning
	* of BASE table (may be NULL) */
	Offset16To<Axis>vAxis; /* Offset to vertical Axis table, from beginning
	* of BASE table (may be NULL) */
	Offset32To<VariationStore>
	varStore; /* Offset to the table of Item Variation
	* Store--from beginning of BASE
	* header (may be NULL). Introduced
	* in version 0x00010001. */
	public:
	DEFINE_SIZE_MIN (8);
	};


	} /* namespace OT */


	#endif /* HB_OT_LAYOUT_BASE_TABLE_HH */