sfobjs.c

一个Xpdf应用的例子

/***************************************************************************/
/*                                                                         */
/*  sfobjs.c                                                               */
/*                                                                         */
/*    SFNT object management (base).                                       */
/*                                                                         */
/*  Copyright 1996-2001 by                                                 */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include "sfobjs.h"
#include "ttload.h"
#include FT_INTERNAL_SFNT_H
#include FT_INTERNAL_POSTSCRIPT_NAMES_H
#include FT_TRUETYPE_IDS_H
#include FT_TRUETYPE_TAGS_H

#include "sferrors.h"


  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_sfobjs


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Get_Name                                                           */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Returns a given ENGLISH name record in ASCII.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face   :: A handle to the source face object.                      */
  /*                                                                       */
  /*    nameid :: The name id of the name record to return.                */
  /*                                                                       */
  /* <Return>                                                              */
  /*    Character string.  NULL if no name is present.                     */
  /*                                                                       */
  static FT_String*
  Get_Name( TT_Face    face,
            FT_UShort  nameid )
  {
    FT_Memory    memory = face->root.memory;
    FT_UShort    n;
    TT_NameRec*  rec;
    FT_Bool      wide_chars    = 1;
    FT_Int       found_apple   = -1;
    FT_Int       found_win     = -1;
    FT_Int       found_unicode = -1;
    FT_Int       found;


    rec = face->name_table.names;
    for ( n = 0; n < face->name_table.numNameRecords; n++, rec++ )
    {
      if ( rec->nameID == nameid && rec->string )
      {
        switch ( rec->platformID )
        {
          case TT_PLATFORM_APPLE_UNICODE:
            {
              found_unicode = n;
              break;
            }
            
          case TT_PLATFORM_MACINTOSH:
            {
              if ( rec->languageID == TT_MAC_ID_ROMAN )
                found_apple = n;
              
              break;
            }
            
          case TT_PLATFORM_MICROSOFT:
            {
              if (  rec->encodingID <= TT_MS_ID_UNICODE_CS &&
                   (rec->languageID & 0x3FF) == 0x009      )
              {
                found_win = n;
              }
              break;
            }
          
          default:
            ;
        }
      }
    }

    /* some fonts contain invalid Unicode or Macintosh formatted entries */
    /* we will thus favor name encoded in Windows formats when they're   */
    /* available..                                                       */
    /*                                                                   */
    found = found_win;
    if ( found < 0 )
    {
      found = found_apple;
      if ( found_apple < 0 )
        found = found_unicode;
      else
        wide_chars = 0;
    }

    /* found a Unicode name */
    if ( found >= 0 )
    {
      FT_String*  string;
      FT_UInt     len;

      rec = face->name_table.names + found;
      if ( wide_chars )
      {
        FT_UInt   m;


        len = (FT_UInt)rec->stringLength / 2;
        if ( MEM_Alloc( string, len + 1 ) )
          return NULL;

        for ( m = 0; m < len; m ++ )
          string[m] = rec->string[2 * m + 1];
      }
      else
      {
        len = rec->stringLength;
        if ( MEM_Alloc( string, len + 1 ) )
          return NULL;

        MEM_Copy( string, rec->string, len );
      }

      string[len] = '\0';
      return string;
    }

    return NULL;
  }


  static FT_Encoding
  find_encoding( int  platform_id,
                 int  encoding_id )
  {
    typedef struct  TEncoding
    {
      int          platform_id;
      int          encoding_id;
      FT_Encoding  encoding;

    } TEncoding;

    static
    const TEncoding  tt_encodings[] =
    {
      { TT_PLATFORM_ISO,           -1,                  ft_encoding_unicode },

      { TT_PLATFORM_APPLE_UNICODE, -1,                  ft_encoding_unicode },

      { TT_PLATFORM_MACINTOSH,     TT_MAC_ID_ROMAN,     ft_encoding_apple_roman },

      { TT_PLATFORM_MICROSOFT,     TT_MS_ID_SYMBOL_CS,  ft_encoding_symbol },
      { TT_PLATFORM_MICROSOFT,     TT_MS_ID_UCS_4,      ft_encoding_unicode },
      { TT_PLATFORM_MICROSOFT,     TT_MS_ID_UNICODE_CS, ft_encoding_unicode },
      { TT_PLATFORM_MICROSOFT,     TT_MS_ID_SJIS,       ft_encoding_sjis },
      { TT_PLATFORM_MICROSOFT,     TT_MS_ID_GB2312,     ft_encoding_gb2312 },
      { TT_PLATFORM_MICROSOFT,     TT_MS_ID_BIG_5,      ft_encoding_big5 },
      { TT_PLATFORM_MICROSOFT,     TT_MS_ID_WANSUNG,    ft_encoding_wansung },
      { TT_PLATFORM_MICROSOFT,     TT_MS_ID_JOHAB,      ft_encoding_johab }
    };

    const TEncoding  *cur, *limit;


    cur   = tt_encodings;
    limit = cur + sizeof ( tt_encodings ) / sizeof ( tt_encodings[0] );

    for ( ; cur < limit; cur++ )
    {
      if ( cur->platform_id == platform_id )
      {
        if ( cur->encoding_id == encoding_id ||
             cur->encoding_id == -1          )
          return cur->encoding;
      }
    }

    return ft_encoding_none;
  }


  FT_LOCAL_DEF FT_Error
  SFNT_Init_Face( FT_Stream      stream,
                  TT_Face        face,
                  FT_Int         face_index,
                  FT_Int         num_params,
                  FT_Parameter*  params )
  {
    FT_Error            error;
    FT_Library          library = face->root.driver->root.library;
    SFNT_Interface*     sfnt;
    SFNT_Header         sfnt_header;

    /* for now, parameters are unused */
    FT_UNUSED( num_params );
    FT_UNUSED( params );

    sfnt = (SFNT_Interface*)face->sfnt;
    if ( !sfnt )
    {
      sfnt = (SFNT_Interface*)FT_Get_Module_Interface( library, "sfnt" );
      if ( !sfnt )
      {
        error = SFNT_Err_Invalid_File_Format;
        goto Exit;
      }

      face->sfnt       = sfnt;
      face->goto_table = sfnt->goto_table;
    }

    if ( !face->psnames )
    {
      face->psnames = (PSNames_Interface*)
                       FT_Get_Module_Interface( library, "psnames" );
    }

    /* check that we have a valid TrueType file */
    error = sfnt->load_sfnt_header( face, stream, face_index, &sfnt_header );
    if ( error )
      goto Exit;

    face->format_tag = sfnt_header.format_tag;
    face->num_tables = sfnt_header.num_tables;

    /* Load font directory */
    error = sfnt->load_directory( face, stream, &sfnt_header );
    if ( error )
      goto Exit;

    face->root.num_faces = face->ttc_header.count;
    if ( face->root.num_faces < 1 )
      face->root.num_faces = 1;

  Exit:
    return error;
  }


#undef  LOAD_
#define LOAD_( x )  ( ( error = sfnt->load_##x( face, stream ) ) \
                      != SFNT_Err_Ok )


  FT_LOCAL_DEF FT_Error
  SFNT_Load_Face( FT_Stream      stream,
                  TT_Face        face,
                  FT_Int         face_index,
                  FT_Int         num_params,
                  FT_Parameter*  params )
  {
    FT_Error         error;
    FT_Bool          has_outline;
    FT_Bool          is_apple_sbit;

    SFNT_Interface*  sfnt = (SFNT_Interface*)face->sfnt;

    FT_UNUSED( face_index );
    FT_UNUSED( num_params );
    FT_UNUSED( params );


    /* Load tables */

    /* We now support two SFNT-based bitmapped font formats.  They */
    /* are recognized easily as they do not include a `glyf'       */
    /* table.                                                      */
    /*                                                             */
    /* The first format comes from Apple, and uses a table named   */
    /* `bhed' instead of `head' to store the font header (using    */
    /* the same format).  It also doesn't include horizontal and   */
    /* vertical metrics tables (i.e. `hhea' and `vhea' tables are  */
    /* missing).                                                   */
    /*                                                             */
    /* The other format comes from Microsoft, and is used with     */
    /* WinCE/PocketPC.  It looks like a standard TTF, except that  */
    /* it doesn't contain outlines.                                */
    /*                                                             */

    /* do we have outlines in there? */
    has_outline   = FT_BOOL( ( TT_LookUp_Table( face, TTAG_glyf ) != 0 ) ||
                             ( TT_LookUp_Table( face, TTAG_CFF  ) != 0 ) );
    is_apple_sbit = 0;

#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS

    /* if this font doesn't contain outlines, we try to load */
    /* a `bhed' table                                        */
    if ( !has_outline )
      is_apple_sbit = FT_BOOL( !LOAD_( bitmap_header ) );

#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */

    /* load the font header (`head' table) if this isn't an Apple */
    /* sbit font file                                             */
    if ( !is_apple_sbit && LOAD_( header ) )
      goto Exit;

    /* the following tables are often not present in embedded TrueType */
    /* fonts within PDF documents, so don't check for them.            */
    (void)LOAD_( max_profile );
    (void)LOAD_( charmaps );
      
    /* the following tables are optional in PCL fonts -- */
    /* don't check for errors                            */
    (void)LOAD_( names );
    (void)LOAD_( psnames );

    /* do not load the metrics headers and tables if this is an Apple */
    /* sbit font file                                                 */
    if ( !is_apple_sbit )
    {
      /* load the `hhea' and `hmtx' tables at once */
      error = sfnt->load_metrics( face, stream, 0 );
      if ( error )
        goto Exit;

      /* try to load the `vhea' and `vmtx' tables at once */
      error = sfnt->load_metrics( face, stream, 1 );
      if ( error )
        goto Exit;

      if ( LOAD_( os2 ) )
        goto Exit;
    }