src/hb-open-file-private.hh - third_party/harfbuzz - Git at Google

 /*
  * Copyright © 2007,2008,2009  Red Hat, Inc.
  * Copyright © 2012  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.
  *
  * Red Hat Author(s): Behdad Esfahbod
  * Google Author(s): Behdad Esfahbod
  */

 #ifndef HB_OPEN_FILE_PRIVATE_HH
 #define HB_OPEN_FILE_PRIVATE_HH

 #include "hb-open-type-private.hh"


 namespace OT {


 /*
  *
  * The OpenType Font File
  *
  */


 /*
  * Organization of an OpenType Font
  */

 struct OpenTypeFontFile;
 struct OffsetTable;
 struct TTCHeader;


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

   Tag		tag;		/* 4-byte identifier. */
   CheckSum	checkSum;	/* CheckSum for this table. */
   ULONG		offset;		/* Offset from beginning of TrueType font
 				 * file. */
   ULONG		length;		/* Length of this table. */
   public:
   DEFINE_SIZE_STATIC (16);
 } OpenTypeTable;

 typedef struct OffsetTable
 {
   friend struct OpenTypeFontFile;

   inline unsigned int get_table_count (void) const
   { return numTables; }
   inline const TableRecord& get_table (unsigned int i) const
   {
     if (unlikely (i >= numTables)) return Null(TableRecord);
     return tables[i];
   }
   inline unsigned int get_table_tags (unsigned int start_offset,
 				      unsigned int *table_count, /* IN/OUT */
 				      hb_tag_t     *table_tags /* OUT */) const
   {
     if (table_count)
     {
       if (start_offset >= numTables)
         *table_count = 0;
       else
         *table_count = MIN (*table_count, numTables - start_offset);

       const TableRecord *sub_tables = tables + start_offset;
       unsigned int count = *table_count;
       for (unsigned int i = 0; i < count; i++)
 	table_tags[i] = sub_tables[i].tag;
     }
     return numTables;
   }
   inline bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
   {
     Tag t;
     t.set (tag);
     unsigned int count = numTables;
     for (unsigned int i = 0; i < count; i++)
     {
       if (t == tables[i].tag)
       {
         if (table_index) *table_index = i;
         return true;
       }
     }
     if (table_index) *table_index = Index::NOT_FOUND_INDEX;
     return false;
   }
   inline const TableRecord& get_table_by_tag (hb_tag_t tag) const
   {
     unsigned int table_index;
     find_table_index (tag, &table_index);
     return get_table (table_index);
   }

   public:
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     return_trace (c->check_struct (this) && c->check_array (tables, TableRecord::static_size, numTables));
   }

   protected:
   Tag		sfnt_version;	/* '\0\001\0\00' if TrueType / 'OTTO' if CFF */
   USHORT	numTables;	/* Number of tables. */
   USHORT	searchRangeZ;	/* (Maximum power of 2 <= numTables) x 16 */
   USHORT	entrySelectorZ;	/* Log2(maximum power of 2 <= numTables). */
   USHORT	rangeShiftZ;	/* NumTables x 16-searchRange. */
   TableRecord	tables[VAR];	/* TableRecord entries. numTables items */
   public:
   DEFINE_SIZE_ARRAY (12, tables);
 } OpenTypeFontFace;


 /*
  * TrueType Collections
  */

 struct TTCHeaderVersion1
 {
   friend struct TTCHeader;

   inline unsigned int get_face_count (void) const { return table.len; }
   inline const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; }

   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     return_trace (table.sanitize (c, this));
   }

   protected:
   Tag		ttcTag;		/* TrueType Collection ID string: 'ttcf' */
   FixedVersion<>version;	/* Version of the TTC Header (1.0),
 				 * 0x00010000u */
   ArrayOf<LOffsetTo<OffsetTable>, ULONG>
 		table;		/* Array of offsets to the OffsetTable for each font
 				 * from the beginning of the file */
   public:
   DEFINE_SIZE_ARRAY (12, table);
 };

 struct TTCHeader
 {
   friend struct OpenTypeFontFile;

   private:

   inline unsigned int get_face_count (void) const
   {
     switch (u.header.version.major) {
     case 2: /* version 2 is compatible with version 1 */
     case 1: return u.version1.get_face_count ();
     default:return 0;
     }
   }
   inline const OpenTypeFontFace& get_face (unsigned int i) const
   {
     switch (u.header.version.major) {
     case 2: /* version 2 is compatible with version 1 */
     case 1: return u.version1.get_face (i);
     default:return Null(OpenTypeFontFace);
     }
   }

   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     if (unlikely (!u.header.version.sanitize (c))) return_trace (false);
     switch (u.header.version.major) {
     case 2: /* version 2 is compatible with version 1 */
     case 1: return_trace (u.version1.sanitize (c));
     default:return_trace (true);
     }
   }

   protected:
   union {
   struct {
   Tag		ttcTag;		/* TrueType Collection ID string: 'ttcf' */
   FixedVersion<>version;	/* Version of the TTC Header (1.0 or 2.0),
 				 * 0x00010000u or 0x00020000u */
   }			header;
   TTCHeaderVersion1	version1;
   } u;
 };


 /*
  * OpenType Font File
  */

 struct OpenTypeFontFile
 {
   static const hb_tag_t tableTag	= HB_TAG ('_','_','_','_'); /* Sanitizer needs this. */

   static const hb_tag_t CFFTag		= HB_TAG ('O','T','T','O'); /* OpenType with Postscript outlines */
   static const hb_tag_t TrueTypeTag	= HB_TAG ( 0 , 1 , 0 , 0 ); /* OpenType with TrueType outlines */
   static const hb_tag_t TTCTag		= HB_TAG ('t','t','c','f'); /* TrueType Collection */
   static const hb_tag_t TrueTag		= HB_TAG ('t','r','u','e'); /* Obsolete Apple TrueType */
   static const hb_tag_t Typ1Tag		= HB_TAG ('t','y','p','1'); /* Obsolete Apple Type1 font in SFNT container */

   inline hb_tag_t get_tag (void) const { return u.tag; }

   inline unsigned int get_face_count (void) const
   {
     switch (u.tag) {
     case CFFTag:	/* All the non-collection tags */
     case TrueTag:
     case Typ1Tag:
     case TrueTypeTag:	return 1;
     case TTCTag:	return u.ttcHeader.get_face_count ();
     default:		return 0;
     }
   }
   inline const OpenTypeFontFace& get_face (unsigned int i) const
   {
     switch (u.tag) {
     /* Note: for non-collection SFNT data we ignore index.  This is because
      * Apple dfont container is a container of SFNT's.  So each SFNT is a
      * non-TTC, but the index is more than zero. */
     case CFFTag:	/* All the non-collection tags */
     case TrueTag:
     case Typ1Tag:
     case TrueTypeTag:	return u.fontFace;
     case TTCTag:	return u.ttcHeader.get_face (i);
     default:		return Null(OpenTypeFontFace);
     }
   }

   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     if (unlikely (!u.tag.sanitize (c))) return_trace (false);
     switch (u.tag) {
     case CFFTag:	/* All the non-collection tags */
     case TrueTag:
     case Typ1Tag:
     case TrueTypeTag:	return_trace (u.fontFace.sanitize (c));
     case TTCTag:	return_trace (u.ttcHeader.sanitize (c));
     default:		return_trace (true);
     }
   }

   protected:
   union {
   Tag			tag;		/* 4-byte identifier. */
   OpenTypeFontFace	fontFace;
   TTCHeader		ttcHeader;
   } u;
   public:
   DEFINE_SIZE_UNION (4, tag);
 };


 } /* namespace OT */


 #endif /* HB_OPEN_FILE_PRIVATE_HH */
	/*
	* Copyright © 2007,2008,2009 Red Hat, Inc.
	* Copyright © 2012 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.
	*
	* Red Hat Author(s): Behdad Esfahbod
	* Google Author(s): Behdad Esfahbod
	*/

	#ifndef HB_OPEN_FILE_PRIVATE_HH
	#define HB_OPEN_FILE_PRIVATE_HH

	#include "hb-open-type-private.hh"


	namespace OT {


	/*
	*
	* The OpenType Font File
	*
	*/


	/*
	* Organization of an OpenType Font
	*/

	struct OpenTypeFontFile;
	struct OffsetTable;
	struct TTCHeader;


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

	Tag tag; /* 4-byte identifier. */
	CheckSum checkSum; /* CheckSum for this table. */
	ULONG offset; /* Offset from beginning of TrueType font
	* file. */
	ULONG length; /* Length of this table. */
	public:
	DEFINE_SIZE_STATIC (16);
	} OpenTypeTable;

	typedef struct OffsetTable
	{
	friend struct OpenTypeFontFile;

	inline unsigned int get_table_count (void) const
	{ return numTables; }
	inline const TableRecord& get_table (unsigned int i) const
	{
	if (unlikely (i >= numTables)) return Null(TableRecord);
	return tables[i];
	}
	inline unsigned int get_table_tags (unsigned int start_offset,
	unsigned int table_count, / IN/OUT */
	hb_tag_t table_tags / OUT */) const
	{
	if (table_count)
	{
	if (start_offset >= numTables)
	*table_count = 0;
	else
	table_count = MIN (table_count, numTables - start_offset);

	const TableRecord *sub_tables = tables + start_offset;
	unsigned int count = *table_count;
	for (unsigned int i = 0; i < count; i++)
	table_tags[i] = sub_tables[i].tag;
	}
	return numTables;
	}
	inline bool find_table_index (hb_tag_t tag, unsigned int *table_index) const
	{
	Tag t;
	t.set (tag);
	unsigned int count = numTables;
	for (unsigned int i = 0; i < count; i++)
	{
	if (t == tables[i].tag)
	{
	if (table_index) *table_index = i;
	return true;
	}
	}
	if (table_index) *table_index = Index::NOT_FOUND_INDEX;
	return false;
	}
	inline const TableRecord& get_table_by_tag (hb_tag_t tag) const
	{
	unsigned int table_index;
	find_table_index (tag, &table_index);
	return get_table (table_index);
	}

	public:
	inline bool sanitize (hb_sanitize_context_t *c) const
	{
	TRACE_SANITIZE (this);
	return_trace (c->check_struct (this) && c->check_array (tables, TableRecord::static_size, numTables));
	}

	protected:
	Tag sfnt_version; /* '\0\001\0\00' if TrueType / 'OTTO' if CFF */
	USHORT numTables; /* Number of tables. */
	USHORT searchRangeZ; /* (Maximum power of 2 <= numTables) x 16 */
	USHORT entrySelectorZ; /* Log2(maximum power of 2 <= numTables). */
	USHORT rangeShiftZ; /* NumTables x 16-searchRange. */
	TableRecord tables[VAR]; /* TableRecord entries. numTables items */
	public:
	DEFINE_SIZE_ARRAY (12, tables);
	} OpenTypeFontFace;


	/*
	* TrueType Collections
	*/

	struct TTCHeaderVersion1
	{
	friend struct TTCHeader;

	inline unsigned int get_face_count (void) const { return table.len; }
	inline const OpenTypeFontFace& get_face (unsigned int i) const { return this+table[i]; }

	inline bool sanitize (hb_sanitize_context_t *c) const
	{
	TRACE_SANITIZE (this);
	return_trace (table.sanitize (c, this));
	}

	protected:
	Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
	FixedVersion<>version; /* Version of the TTC Header (1.0),
	* 0x00010000u */
	ArrayOf<LOffsetTo<OffsetTable>, ULONG>
	table; /* Array of offsets to the OffsetTable for each font
	* from the beginning of the file */
	public:
	DEFINE_SIZE_ARRAY (12, table);
	};

	struct TTCHeader
	{
	friend struct OpenTypeFontFile;

	private:

	inline unsigned int get_face_count (void) const
	{
	switch (u.header.version.major) {
	case 2: /* version 2 is compatible with version 1 */
	case 1: return u.version1.get_face_count ();
	default:return 0;
	}
	}
	inline const OpenTypeFontFace& get_face (unsigned int i) const
	{
	switch (u.header.version.major) {
	case 2: /* version 2 is compatible with version 1 */
	case 1: return u.version1.get_face (i);
	default:return Null(OpenTypeFontFace);
	}
	}

	inline bool sanitize (hb_sanitize_context_t *c) const
	{
	TRACE_SANITIZE (this);
	if (unlikely (!u.header.version.sanitize (c))) return_trace (false);
	switch (u.header.version.major) {
	case 2: /* version 2 is compatible with version 1 */
	case 1: return_trace (u.version1.sanitize (c));
	default:return_trace (true);
	}
	}

	protected:
	union {
	struct {
	Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
	FixedVersion<>version; /* Version of the TTC Header (1.0 or 2.0),
	* 0x00010000u or 0x00020000u */
	} header;
	TTCHeaderVersion1 version1;
	} u;
	};


	/*
	* OpenType Font File
	*/

	struct OpenTypeFontFile
	{
	static const hb_tag_t tableTag = HB_TAG ('_','_','_','_'); /* Sanitizer needs this. */

	static const hb_tag_t CFFTag = HB_TAG ('O','T','T','O'); /* OpenType with Postscript outlines */
	static const hb_tag_t TrueTypeTag = HB_TAG ( 0 , 1 , 0 , 0 ); /* OpenType with TrueType outlines */
	static const hb_tag_t TTCTag = HB_TAG ('t','t','c','f'); /* TrueType Collection */
	static const hb_tag_t TrueTag = HB_TAG ('t','r','u','e'); /* Obsolete Apple TrueType */
	static const hb_tag_t Typ1Tag = HB_TAG ('t','y','p','1'); /* Obsolete Apple Type1 font in SFNT container */

	inline hb_tag_t get_tag (void) const { return u.tag; }

	inline unsigned int get_face_count (void) const
	{
	switch (u.tag) {
	case CFFTag: /* All the non-collection tags */
	case TrueTag:
	case Typ1Tag:
	case TrueTypeTag: return 1;
	case TTCTag: return u.ttcHeader.get_face_count ();
	default: return 0;
	}
	}
	inline const OpenTypeFontFace& get_face (unsigned int i) const
	{
	switch (u.tag) {
	/* Note: for non-collection SFNT data we ignore index. This is because
	* Apple dfont container is a container of SFNT's. So each SFNT is a
	* non-TTC, but the index is more than zero. */
	case CFFTag: /* All the non-collection tags */
	case TrueTag:
	case Typ1Tag:
	case TrueTypeTag: return u.fontFace;
	case TTCTag: return u.ttcHeader.get_face (i);
	default: return Null(OpenTypeFontFace);
	}
	}

	inline bool sanitize (hb_sanitize_context_t *c) const
	{
	TRACE_SANITIZE (this);
	if (unlikely (!u.tag.sanitize (c))) return_trace (false);
	switch (u.tag) {
	case CFFTag: /* All the non-collection tags */
	case TrueTag:
	case Typ1Tag:
	case TrueTypeTag: return_trace (u.fontFace.sanitize (c));
	case TTCTag: return_trace (u.ttcHeader.sanitize (c));
	default: return_trace (true);
	}
	}

	protected:
	union {
	Tag tag; /* 4-byte identifier. */
	OpenTypeFontFace fontFace;
	TTCHeader ttcHeader;
	} u;
	public:
	DEFINE_SIZE_UNION (4, tag);
	};


	} /* namespace OT */


	#endif /* HB_OPEN_FILE_PRIVATE_HH */