sfobjs.c

下载来的一个看图软件的源代码

/***************************************************************************/
/*                                                                         */
/*  sfobjs.c                                                               */
/*                                                                         */
/*    SFNT object management (base).                                       */
/*                                                                         */
/*  Copyright 1996-2001, 2002, 2003 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 "ttcmap0.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



  /* convert a UTF-16 name entry to ASCII */
  static FT_String*
  tt_name_entry_ascii_from_utf16( TT_NameEntry  entry,
                                  FT_Memory     memory )
  {
    FT_String*  string;
    FT_UInt     len, code, n;
    FT_Byte*    read = (FT_Byte*)entry->string;


    len = (FT_UInt)entry->stringLength / 2;

    if ( FT_MEM_NEW_ARRAY( string, len + 1 ) )
      return NULL;

    for ( n = 0; n < len; n++ )
    {
      code = FT_NEXT_USHORT( read );
      if ( code < 32 || code > 127 )
        code = '?';

      string[n] = (char)code;
    }

    string[len] = 0;

    return string;
  }


  /* convert a UCS-4 name entry to ASCII */
  static FT_String*
  tt_name_entry_ascii_from_ucs4( TT_NameEntry  entry,
                                 FT_Memory     memory )
  {
    FT_String*  string;
    FT_UInt     len, code, n;
    FT_Byte*    read = (FT_Byte*)entry->string;


    len = (FT_UInt)entry->stringLength / 4;

    if ( FT_MEM_NEW_ARRAY( string, len + 1 ) )
      return NULL;

    for ( n = 0; n < len; n++ )
    {
      code = (FT_UInt)FT_NEXT_ULONG( read );
      if ( code < 32 || code > 127 )
        code = '?';

      string[n] = (char)code;
    }

    string[len] = 0;

    return string;
  }


  /* convert an Apple Roman or symbol name entry to ASCII */
  static FT_String*
  tt_name_entry_ascii_from_other( TT_NameEntry  entry,
                                  FT_Memory     memory )
  {
    FT_String*  string;
    FT_UInt     len, code, n;
    FT_Byte*    read = (FT_Byte*)entry->string;


    len = (FT_UInt)entry->stringLength;

    if ( FT_MEM_NEW_ARRAY( string, len + 1 ) )
      return NULL;

    for ( n = 0; n < len; n++ )
    {
      code = *read++;
      if ( code < 32 || code > 127 )
        code = '?';

      string[n] = (char)code;
    }

    string[len] = 0;

    return string;
  }


  typedef FT_String*  (*TT_NameEntry_ConvertFunc)( TT_NameEntry  entry,
                                                   FT_Memory     memory );


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_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*
  tt_face_get_name( TT_Face    face,
                    FT_UShort  nameid )
  {
    FT_Memory         memory = face->root.memory;
    FT_String*        result = NULL;
    FT_UShort         n;
    TT_NameEntryRec*  rec;
    FT_Int            found_apple   = -1;
    FT_Int            found_win     = -1;
    FT_Int            found_unicode = -1;

    TT_NameEntry_ConvertFunc  convert;


    rec = face->name_table.names;
    for ( n = 0; n < face->num_names; n++, rec++ )
    {
      /* According to the OpenType 1.3 specification, only Microsoft or  */
      /* Apple platform IDs might be used in the `name' table.  The      */
      /* `Unicode' platform is reserved for the `cmap' table, and the    */
      /* `Iso' one is deprecated.                                        */
      /*                                                                 */
      /* However, the Apple TrueType specification doesn't say the same  */
      /* thing and goes to suggest that all Unicode `name' table entries */
      /* should be coded in UTF-16 (in big-endian format I suppose).     */
      /*                                                                 */
      if ( rec->nameID == nameid && rec->stringLength > 0 )
      {
        switch ( rec->platformID )
        {
        case TT_PLATFORM_APPLE_UNICODE:
        case TT_PLATFORM_ISO:
          /* there is `languageID' to check there.  We should use this */
          /* field only as a last solution when nothing else is        */
          /* available.                                                */
          /*                                                           */
          found_unicode = n;
          break;

        case TT_PLATFORM_MACINTOSH:
          if ( rec->languageID == TT_MAC_LANGID_ENGLISH )
            found_apple = n;

          break;

        case TT_PLATFORM_MICROSOFT:
          /* we only take a non-English name when there is nothing */
          /* else available in the font                            */
          /*                                                       */
          if ( found_win == -1 || ( rec->languageID & 0x3FF ) == 0x009 )
          {
            switch ( rec->encodingID )
            {
            case TT_MS_ID_SYMBOL_CS:
            case TT_MS_ID_UNICODE_CS:
            case TT_MS_ID_UCS_4:
              found_win = n;
              break;

            default:
              ;
            }
          }
          break;

        default:
          ;
        }
      }
    }

    /* some fonts contain invalid Unicode or Macintosh formatted entries; */
    /* we will thus favor names encoded in Windows formats if available   */
    /*                                                                    */
    convert = NULL;
    if ( found_win >= 0 )
    {
      rec = face->name_table.names + found_win;
      switch ( rec->encodingID )
      {
      case TT_MS_ID_UNICODE_CS:
      case TT_MS_ID_SYMBOL_CS:
        convert = tt_name_entry_ascii_from_utf16;
        break;

      case TT_MS_ID_UCS_4:
        convert = tt_name_entry_ascii_from_ucs4;
        break;

      default:
        ;
      }
    }
    else if ( found_apple >= 0 )
    {
      rec     = face->name_table.names + found_apple;
      convert = tt_name_entry_ascii_from_other;
    }
    else if ( found_unicode >= 0 )
    {
      rec     = face->name_table.names + found_unicode;
      convert = tt_name_entry_ascii_from_utf16;
    }

    if ( rec && convert )
    {
      if ( rec->string == NULL )
      {
        FT_Error   error  = SFNT_Err_Ok;
        FT_Stream  stream = face->name_table.stream;

        FT_UNUSED( error );


        if ( FT_NEW_ARRAY  ( rec->string, rec->stringLength ) ||
             FT_STREAM_SEEK( rec->stringOffset )              ||
             FT_STREAM_READ( rec->string, rec->stringLength ) )
        {
          FT_FREE( rec->string );
          rec->stringLength = 0;
          result            = NULL;
          goto Exit;
        }
      }

      result = convert( rec, memory );
    }

  Exit:
    return result;
  }


  static FT_Encoding
  sfnt_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_MS_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_Service     sfnt;
    SFNT_HeaderRec   sfnt_header;

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


    sfnt = (SFNT_Service)face->sfnt;
    if ( !sfnt )
    {
      sfnt = (SFNT_Service)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_Service)
                        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_Service  sfnt = (SFNT_Service)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.                                                      */