src/hb-ot-var-fvar-table.hh - third_party/harfbuzz - Git at Google

 /*
  * 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_FVAR_TABLE_HH
 #define HB_OT_VAR_FVAR_TABLE_HH

 #include "hb-open-type.hh"

 /*
  * fvar -- Font Variations
  * https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
  */

 #define HB_OT_TAG_fvar HB_TAG('f','v','a','r')


 namespace OT {


 struct InstanceRecord
 {
   inline bool sanitize (hb_sanitize_context_t *c, unsigned int axis_count) const
   {
     TRACE_SANITIZE (this);
     return_trace (c->check_struct (this) &&
 		  c->check_array (coordinatesZ.arrayZ, axis_count));
   }

   protected:
   NameID	subfamilyNameID;/* The name ID for entries in the 'name' table
 				 * that provide subfamily names for this instance. */
   HBUINT16	reserved;	/* Reserved for future use — set to 0. */
   UnsizedArrayOf<Fixed>
 		coordinatesZ;	/* The coordinates array for this instance. */
   //NameID	postScriptNameIDX;/*Optional. The name ID for entries in the 'name'
   //				  * table that provide PostScript names for this
   //				  * instance. */

   public:
   DEFINE_SIZE_ARRAY (4, coordinatesZ);
 };

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

   public:
   Tag		axisTag;	/* Tag identifying the design variation for the axis. */
   Fixed		minValue;	/* The minimum coordinate value for the axis. */
   Fixed		defaultValue;	/* The default coordinate value for the axis. */
   Fixed		maxValue;	/* The maximum coordinate value for the axis. */
   HBUINT16	reserved;	/* Reserved for future use — set to 0. */
   NameID	axisNameID;	/* The name ID for entries in the 'name' table that
 				 * provide a display name for this axis. */

   public:
   DEFINE_SIZE_STATIC (20);
 };

 struct fvar
 {
   static const hb_tag_t tableTag	= HB_OT_TAG_fvar;

   inline bool has_data (void) const { return version.to_int (); }

   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     return_trace (version.sanitize (c) &&
 		  likely (version.major == 1) &&
 		  c->check_struct (this) &&
 		  instanceSize >= axisCount * 4 + 4 &&
 		  axisSize <= 1024 && /* Arbitrary, just to simplify overflow checks. */
 		  instanceSize <= 1024 && /* Arbitrary, just to simplify overflow checks. */
 		  c->check_range (this, things) &&
 		  c->check_range (&StructAtOffset<char> (this, things),
 				  axisCount * axisSize + instanceCount * instanceSize));
   }

   inline unsigned int get_axis_count (void) const
   { return axisCount; }

   inline bool get_axis (unsigned int index, hb_ot_var_axis_t *info) const
   {
     if (unlikely (index >= axisCount))
       return false;

     if (info)
     {
       const AxisRecord &axis = get_axes ()[index];
       info->tag = axis.axisTag;
       info->name_id =  axis.axisNameID;
       info->default_value = axis.defaultValue / 65536.;
       /* Ensure order, to simplify client math. */
       info->min_value = MIN<float> (info->default_value, axis.minValue / 65536.);
       info->max_value = MAX<float> (info->default_value, axis.maxValue / 65536.);
     }

     return true;
   }

   inline unsigned int get_axis_infos (unsigned int      start_offset,
 				      unsigned int     *axes_count /* IN/OUT */,
 				      hb_ot_var_axis_t *axes_array /* OUT */) const
   {
     if (axes_count)
     {
       unsigned int count = axisCount;
       start_offset = MIN (start_offset, count);

       count -= start_offset;
       axes_array += start_offset;

       count = MIN (count, *axes_count);
       *axes_count = count;

       for (unsigned int i = 0; i < count; i++)
 	get_axis (start_offset + i, axes_array + i);
     }
     return axisCount;
   }

   inline bool find_axis (hb_tag_t tag, unsigned int *index, hb_ot_var_axis_t *info) const
   {
     const AxisRecord *axes = get_axes ();
     unsigned int count = get_axis_count ();
     for (unsigned int i = 0; i < count; i++)
       if (axes[i].axisTag == tag)
       {
         if (index)
 	  *index = i;
 	return get_axis (i, info);
       }
     if (index)
       *index = HB_OT_VAR_NO_AXIS_INDEX;
     return false;
   }

   inline int normalize_axis_value (unsigned int axis_index, float v) const
   {
     hb_ot_var_axis_t axis;
     if (!get_axis (axis_index, &axis))
       return 0;

     v = MAX (MIN (v, axis.max_value), axis.min_value); /* Clamp. */

     if (v == axis.default_value)
       return 0;
     else if (v < axis.default_value)
       v = (v - axis.default_value) / (axis.default_value - axis.min_value);
     else
       v = (v - axis.default_value) / (axis.max_value - axis.default_value);
     return (int) (v * 16384.f + (v >= 0.f ? .5f : -.5f));
   }

   protected:
   inline const AxisRecord * get_axes (void) const
   { return &StructAtOffset<AxisRecord> (this, things); }

   inline const InstanceRecord * get_instances (void) const
   { return &StructAtOffset<InstanceRecord> (get_axes () + axisCount, 0); }

   protected:
   FixedVersion<>version;	/* Version of the fvar table
 				 * initially set to 0x00010000u */
   Offset16	things;		/* Offset in bytes from the beginning of the table
 				 * to the start of the AxisRecord array. */
   HBUINT16	reserved;	/* This field is permanently reserved. Set to 2. */
   HBUINT16	axisCount;	/* The number of variation axes in the font (the
 				 * number of records in the axes array). */
   HBUINT16	axisSize;	/* The size in bytes of each VariationAxisRecord —
 				 * set to 20 (0x0014) for this version. */
   HBUINT16	instanceCount;	/* The number of named instances defined in the font
 				 * (the number of records in the instances array). */
   HBUINT16	instanceSize;	/* The size in bytes of each InstanceRecord — set
 				 * to either axisCount * sizeof(Fixed) + 4, or to
 				 * axisCount * sizeof(Fixed) + 6. */

   public:
   DEFINE_SIZE_STATIC (16);
 };

 } /* namespace OT */


 #endif /* HB_OT_VAR_FVAR_TABLE_HH */
	/*
	* 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_FVAR_TABLE_HH
	#define HB_OT_VAR_FVAR_TABLE_HH

	#include "hb-open-type.hh"

	/*
	* fvar -- Font Variations
	* https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
	*/

	#define HB_OT_TAG_fvar HB_TAG('f','v','a','r')


	namespace OT {


	struct InstanceRecord
	{
	inline bool sanitize (hb_sanitize_context_t *c, unsigned int axis_count) const
	{
	TRACE_SANITIZE (this);
	return_trace (c->check_struct (this) &&
	c->check_array (coordinatesZ.arrayZ, axis_count));
	}

	protected:
	NameID subfamilyNameID;/* The name ID for entries in the 'name' table
	* that provide subfamily names for this instance. */
	HBUINT16 reserved; /* Reserved for future use — set to 0. */
	UnsizedArrayOf<Fixed>
	coordinatesZ; /* The coordinates array for this instance. */
	//NameID postScriptNameIDX;/*Optional. The name ID for entries in the 'name'
	// * table that provide PostScript names for this
	// * instance. */

	public:
	DEFINE_SIZE_ARRAY (4, coordinatesZ);
	};

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

	public:
	Tag axisTag; /* Tag identifying the design variation for the axis. */
	Fixed minValue; /* The minimum coordinate value for the axis. */
	Fixed defaultValue; /* The default coordinate value for the axis. */
	Fixed maxValue; /* The maximum coordinate value for the axis. */
	HBUINT16 reserved; /* Reserved for future use — set to 0. */
	NameID axisNameID; /* The name ID for entries in the 'name' table that
	* provide a display name for this axis. */

	public:
	DEFINE_SIZE_STATIC (20);
	};

	struct fvar
	{
	static const hb_tag_t tableTag = HB_OT_TAG_fvar;

	inline bool has_data (void) const { return version.to_int (); }

	inline bool sanitize (hb_sanitize_context_t *c) const
	{
	TRACE_SANITIZE (this);
	return_trace (version.sanitize (c) &&
	likely (version.major == 1) &&
	c->check_struct (this) &&
	instanceSize >= axisCount * 4 + 4 &&
	axisSize <= 1024 && /* Arbitrary, just to simplify overflow checks. */
	instanceSize <= 1024 && /* Arbitrary, just to simplify overflow checks. */
	c->check_range (this, things) &&
	c->check_range (&StructAtOffset<char> (this, things),
	axisCount * axisSize + instanceCount * instanceSize));
	}

	inline unsigned int get_axis_count (void) const
	{ return axisCount; }

	inline bool get_axis (unsigned int index, hb_ot_var_axis_t *info) const
	{
	if (unlikely (index >= axisCount))
	return false;

	if (info)
	{
	const AxisRecord &axis = get_axes ()[index];
	info->tag = axis.axisTag;
	info->name_id = axis.axisNameID;
	info->default_value = axis.defaultValue / 65536.;
	/* Ensure order, to simplify client math. */
	info->min_value = MIN<float> (info->default_value, axis.minValue / 65536.);
	info->max_value = MAX<float> (info->default_value, axis.maxValue / 65536.);
	}

	return true;
	}

	inline unsigned int get_axis_infos (unsigned int start_offset,
	unsigned int axes_count / IN/OUT */,
	hb_ot_var_axis_t axes_array / OUT */) const
	{
	if (axes_count)
	{
	unsigned int count = axisCount;
	start_offset = MIN (start_offset, count);

	count -= start_offset;
	axes_array += start_offset;

	count = MIN (count, *axes_count);
	*axes_count = count;

	for (unsigned int i = 0; i < count; i++)
	get_axis (start_offset + i, axes_array + i);
	}
	return axisCount;
	}

	inline bool find_axis (hb_tag_t tag, unsigned int index, hb_ot_var_axis_t info) const
	{
	const AxisRecord *axes = get_axes ();
	unsigned int count = get_axis_count ();
	for (unsigned int i = 0; i < count; i++)
	if (axes[i].axisTag == tag)
	{
	if (index)
	*index = i;
	return get_axis (i, info);
	}
	if (index)
	*index = HB_OT_VAR_NO_AXIS_INDEX;
	return false;
	}

	inline int normalize_axis_value (unsigned int axis_index, float v) const
	{
	hb_ot_var_axis_t axis;
	if (!get_axis (axis_index, &axis))
	return 0;

	v = MAX (MIN (v, axis.max_value), axis.min_value); /* Clamp. */

	if (v == axis.default_value)
	return 0;
	else if (v < axis.default_value)
	v = (v - axis.default_value) / (axis.default_value - axis.min_value);
	else
	v = (v - axis.default_value) / (axis.max_value - axis.default_value);
	return (int) (v * 16384.f + (v >= 0.f ? .5f : -.5f));
	}

	protected:
	inline const AxisRecord * get_axes (void) const
	{ return &StructAtOffset<AxisRecord> (this, things); }

	inline const InstanceRecord * get_instances (void) const
	{ return &StructAtOffset<InstanceRecord> (get_axes () + axisCount, 0); }

	protected:
	FixedVersion<>version; /* Version of the fvar table
	* initially set to 0x00010000u */
	Offset16 things; /* Offset in bytes from the beginning of the table
	* to the start of the AxisRecord array. */
	HBUINT16 reserved; /* This field is permanently reserved. Set to 2. */
	HBUINT16 axisCount; /* The number of variation axes in the font (the
	* number of records in the axes array). */
	HBUINT16 axisSize; /* The size in bytes of each VariationAxisRecord —
	* set to 20 (0x0014) for this version. */
	HBUINT16 instanceCount; /* The number of named instances defined in the font
	* (the number of records in the instances array). */
	HBUINT16 instanceSize; /* The size in bytes of each InstanceRecord — set
	* to either axisCount * sizeof(Fixed) + 4, or to
	* axisCount * sizeof(Fixed) + 6. */

	public:
	DEFINE_SIZE_STATIC (16);
	};

	} /* namespace OT */


	#endif /* HB_OT_VAR_FVAR_TABLE_HH */