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

 /*
  * Copyright © 2018  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): Garret Rieger
  */

 #ifndef HB_OT_HDMX_TABLE_HH
 #define HB_OT_HDMX_TABLE_HH

 #include "hb-open-type.hh"

 /*
  * hdmx -- Horizontal Device Metrics
  * https://docs.microsoft.com/en-us/typography/opentype/spec/hdmx
  */
 #define HB_OT_TAG_hdmx HB_TAG('h','d','m','x')


 namespace OT {


 struct DeviceRecord
 {
   struct SubsetView
   {
     const DeviceRecord *source_device_record;
     unsigned int sizeDeviceRecord;
     hb_subset_plan_t *subset_plan;

     void init (const DeviceRecord *source_device_record,
 	       unsigned int sizeDeviceRecord,
 	       hb_subset_plan_t   *subset_plan)
     {
       this->source_device_record = source_device_record;
       this->sizeDeviceRecord = sizeDeviceRecord;
       this->subset_plan = subset_plan;
     }

     unsigned int len () const
     { return this->subset_plan->num_output_glyphs (); }

     const HBUINT8* operator [] (unsigned int new_gid) const
     {
       if (unlikely (new_gid >= len ())) return nullptr;

       hb_codepoint_t old_gid;
       if (!this->subset_plan->old_gid_for_new_gid (new_gid, &old_gid))
         return &Null(HBUINT8);

       if (old_gid >= sizeDeviceRecord - DeviceRecord::min_size)
         return nullptr;
       return &(this->source_device_record->widthsZ[old_gid]);
     }
   };

   static unsigned int get_size (unsigned int count)
   { return hb_ceil_to_4 (min_size + count * HBUINT8::static_size); }

   bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)
   {
     TRACE_SERIALIZE (this);

     unsigned int size = get_size (subset_view.len ());
     if (unlikely (!c->allocate_size<DeviceRecord> (size)))
     {
       DEBUG_MSG(SUBSET, nullptr, "Couldn't allocate enough space for DeviceRecord: %d.",
 		 size);
       return_trace (false);
     }

     this->pixelSize.set (subset_view.source_device_record->pixelSize);
     this->maxWidth.set (subset_view.source_device_record->maxWidth);

     for (unsigned int i = 0; i < subset_view.len (); i++)
     {
       const HBUINT8 *width = subset_view[i];
       if (!width)
       {
 	DEBUG_MSG(SUBSET, nullptr, "HDMX width for new gid %d is missing.", i);
 	return_trace (false);
       }
       widthsZ[i].set (*width);
     }

     return_trace (true);
   }

   bool sanitize (hb_sanitize_context_t *c, unsigned int sizeDeviceRecord) const
   {
     TRACE_SANITIZE (this);
     return_trace (likely (c->check_struct (this) &&
 			  c->check_range (this, sizeDeviceRecord)));
   }

   HBUINT8			pixelSize;	/* Pixel size for following widths (as ppem). */
   HBUINT8			maxWidth;	/* Maximum width. */
   UnsizedArrayOf<HBUINT8>	widthsZ;	/* Array of widths (numGlyphs is from the 'maxp' table). */
   public:
   DEFINE_SIZE_ARRAY (2, widthsZ);
 };


 struct hdmx
 {
   static constexpr hb_tag_t tableTag = HB_OT_TAG_hdmx;

   unsigned int get_size () const
   { return min_size + numRecords * sizeDeviceRecord; }

   const DeviceRecord& operator [] (unsigned int i) const
   {
     /* XXX Null(DeviceRecord) is NOT safe as it's num-glyphs lengthed.
      * https://github.com/harfbuzz/harfbuzz/issues/1300 */
     if (unlikely (i >= numRecords)) return Null (DeviceRecord);
     return StructAtOffset<DeviceRecord> (&this->firstDeviceRecord, i * sizeDeviceRecord);
   }

   bool serialize (hb_serialize_context_t *c, const hdmx *source_hdmx, hb_subset_plan_t *plan)
   {
     TRACE_SERIALIZE (this);

     if (unlikely (!c->extend_min ((*this))))  return_trace (false);

     this->version.set (source_hdmx->version);
     this->numRecords.set (source_hdmx->numRecords);
     this->sizeDeviceRecord.set (DeviceRecord::get_size (plan->num_output_glyphs ()));

     for (unsigned int i = 0; i < source_hdmx->numRecords; i++)
     {
       DeviceRecord::SubsetView subset_view;
       subset_view.init (&(*source_hdmx)[i], source_hdmx->sizeDeviceRecord, plan);

       if (!c->start_embed<DeviceRecord> ()->serialize (c, subset_view))
 	return_trace (false);
     }

     return_trace (true);
   }

   static size_t get_subsetted_size (const hdmx *source_hdmx, hb_subset_plan_t *plan)
   {
     return min_size + source_hdmx->numRecords * DeviceRecord::get_size (plan->num_output_glyphs ());
   }

   bool subset (hb_subset_plan_t *plan) const
   {
     size_t dest_size = get_subsetted_size (this, plan);
     hdmx *dest = (hdmx *) malloc (dest_size);
     if (unlikely (!dest))
     {
       DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for hdmx subset output.", (unsigned long) dest_size);
       return false;
     }

     hb_serialize_context_t c (dest, dest_size);
     hdmx *hdmx_prime = c.start_serialize<hdmx> ();
     if (!hdmx_prime || !hdmx_prime->serialize (&c, this, plan))
     {
       free (dest);
       DEBUG_MSG(SUBSET, nullptr, "Failed to serialize write new hdmx.");
       return false;
     }
     c.end_serialize ();

     hb_blob_t *hdmx_prime_blob = hb_blob_create ((const char *) dest,
 						 dest_size,
 						 HB_MEMORY_MODE_READONLY,
 						 dest,
 						 free);
     bool result = plan->add_table (HB_OT_TAG_hdmx, hdmx_prime_blob);
     hb_blob_destroy (hdmx_prime_blob);

     return result;
   }

   bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     return_trace (c->check_struct (this) &&
 		  !hb_unsigned_mul_overflows (numRecords, sizeDeviceRecord) &&
 		  sizeDeviceRecord >= DeviceRecord::min_size &&
 		  c->check_range (this, get_size ()));
   }

   protected:
   HBUINT16		version;		/* Table version number (0) */
   HBUINT16		numRecords;		/* Number of device records. */
   HBUINT32		sizeDeviceRecord;	/* Size of a device record, 32-bit aligned. */
   DeviceRecord		firstDeviceRecord;	/* Array of device records. */
   public:
   DEFINE_SIZE_MIN (8);
 };

 } /* namespace OT */


 #endif /* HB_OT_HDMX_TABLE_HH */
	/*
	* Copyright © 2018 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): Garret Rieger
	*/

	#ifndef HB_OT_HDMX_TABLE_HH
	#define HB_OT_HDMX_TABLE_HH

	#include "hb-open-type.hh"

	/*
	* hdmx -- Horizontal Device Metrics
	* https://docs.microsoft.com/en-us/typography/opentype/spec/hdmx
	*/
	#define HB_OT_TAG_hdmx HB_TAG('h','d','m','x')


	namespace OT {


	struct DeviceRecord
	{
	struct SubsetView
	{
	const DeviceRecord *source_device_record;
	unsigned int sizeDeviceRecord;
	hb_subset_plan_t *subset_plan;

	void init (const DeviceRecord *source_device_record,
	unsigned int sizeDeviceRecord,
	hb_subset_plan_t *subset_plan)
	{
	this->source_device_record = source_device_record;
	this->sizeDeviceRecord = sizeDeviceRecord;
	this->subset_plan = subset_plan;
	}

	unsigned int len () const
	{ return this->subset_plan->num_output_glyphs (); }

	const HBUINT8* operator [] (unsigned int new_gid) const
	{
	if (unlikely (new_gid >= len ())) return nullptr;

	hb_codepoint_t old_gid;
	if (!this->subset_plan->old_gid_for_new_gid (new_gid, &old_gid))
	return &Null(HBUINT8);

	if (old_gid >= sizeDeviceRecord - DeviceRecord::min_size)
	return nullptr;
	return &(this->source_device_record->widthsZ[old_gid]);
	}
	};

	static unsigned int get_size (unsigned int count)
	{ return hb_ceil_to_4 (min_size + count * HBUINT8::static_size); }

	bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)
	{
	TRACE_SERIALIZE (this);

	unsigned int size = get_size (subset_view.len ());
	if (unlikely (!c->allocate_size<DeviceRecord> (size)))
	{
	DEBUG_MSG(SUBSET, nullptr, "Couldn't allocate enough space for DeviceRecord: %d.",
	size);
	return_trace (false);
	}

	this->pixelSize.set (subset_view.source_device_record->pixelSize);
	this->maxWidth.set (subset_view.source_device_record->maxWidth);

	for (unsigned int i = 0; i < subset_view.len (); i++)
	{
	const HBUINT8 *width = subset_view[i];
	if (!width)
	{
	DEBUG_MSG(SUBSET, nullptr, "HDMX width for new gid %d is missing.", i);
	return_trace (false);
	}
	widthsZ[i].set (*width);
	}

	return_trace (true);
	}

	bool sanitize (hb_sanitize_context_t *c, unsigned int sizeDeviceRecord) const
	{
	TRACE_SANITIZE (this);
	return_trace (likely (c->check_struct (this) &&
	c->check_range (this, sizeDeviceRecord)));
	}

	HBUINT8 pixelSize; /* Pixel size for following widths (as ppem). */
	HBUINT8 maxWidth; /* Maximum width. */
	UnsizedArrayOf<HBUINT8> widthsZ; /* Array of widths (numGlyphs is from the 'maxp' table). */
	public:
	DEFINE_SIZE_ARRAY (2, widthsZ);
	};


	struct hdmx
	{
	static constexpr hb_tag_t tableTag = HB_OT_TAG_hdmx;

	unsigned int get_size () const
	{ return min_size + numRecords * sizeDeviceRecord; }

	const DeviceRecord& operator [] (unsigned int i) const
	{
	/* XXX Null(DeviceRecord) is NOT safe as it's num-glyphs lengthed.
	* https://github.com/harfbuzz/harfbuzz/issues/1300 */
	if (unlikely (i >= numRecords)) return Null (DeviceRecord);
	return StructAtOffset<DeviceRecord> (&this->firstDeviceRecord, i * sizeDeviceRecord);
	}

	bool serialize (hb_serialize_context_t c, const hdmx source_hdmx, hb_subset_plan_t *plan)
	{
	TRACE_SERIALIZE (this);

	if (unlikely (!c->extend_min ((*this)))) return_trace (false);

	this->version.set (source_hdmx->version);
	this->numRecords.set (source_hdmx->numRecords);
	this->sizeDeviceRecord.set (DeviceRecord::get_size (plan->num_output_glyphs ()));

	for (unsigned int i = 0; i < source_hdmx->numRecords; i++)
	{
	DeviceRecord::SubsetView subset_view;
	subset_view.init (&(*source_hdmx)[i], source_hdmx->sizeDeviceRecord, plan);

	if (!c->start_embed<DeviceRecord> ()->serialize (c, subset_view))
	return_trace (false);
	}

	return_trace (true);
	}

	static size_t get_subsetted_size (const hdmx source_hdmx, hb_subset_plan_t plan)
	{
	return min_size + source_hdmx->numRecords * DeviceRecord::get_size (plan->num_output_glyphs ());
	}

	bool subset (hb_subset_plan_t *plan) const
	{
	size_t dest_size = get_subsetted_size (this, plan);
	hdmx dest = (hdmx ) malloc (dest_size);
	if (unlikely (!dest))
	{
	DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for hdmx subset output.", (unsigned long) dest_size);
	return false;
	}

	hb_serialize_context_t c (dest, dest_size);
	hdmx *hdmx_prime = c.start_serialize<hdmx> ();
	if (!hdmx_prime \|\| !hdmx_prime->serialize (&c, this, plan))
	{
	free (dest);
	DEBUG_MSG(SUBSET, nullptr, "Failed to serialize write new hdmx.");
	return false;
	}
	c.end_serialize ();

	hb_blob_t hdmx_prime_blob = hb_blob_create ((const char ) dest,
	dest_size,
	HB_MEMORY_MODE_READONLY,
	dest,
	free);
	bool result = plan->add_table (HB_OT_TAG_hdmx, hdmx_prime_blob);
	hb_blob_destroy (hdmx_prime_blob);

	return result;
	}

	bool sanitize (hb_sanitize_context_t *c) const
	{
	TRACE_SANITIZE (this);
	return_trace (c->check_struct (this) &&
	!hb_unsigned_mul_overflows (numRecords, sizeDeviceRecord) &&
	sizeDeviceRecord >= DeviceRecord::min_size &&
	c->check_range (this, get_size ()));
	}

	protected:
	HBUINT16 version; /* Table version number (0) */
	HBUINT16 numRecords; /* Number of device records. */
	HBUINT32 sizeDeviceRecord; /* Size of a device record, 32-bit aligned. */
	DeviceRecord firstDeviceRecord; /* Array of device records. */
	public:
	DEFINE_SIZE_MIN (8);
	};

	} /* namespace OT */


	#endif /* HB_OT_HDMX_TABLE_HH */