ftstring.c

freetype库的应用demo,里面包含freetype的很多实例

    num_glyphs = expect = 0;
    while ( *p )
    {
      in_code = *p++ ;

      if ( in_code >= 0xC0 )
      {
        if ( in_code < 0xE0 )           /*  U+0080 - U+07FF   */
        {
          expect = 1;
          codepoint = in_code & 0x1F;
        }
        else if ( in_code < 0xF0 )      /*  U+0800 - U+FFFF   */
        {
          expect = 2;
          codepoint = in_code & 0x0F;
        }
        else if ( in_code < 0xF8 )      /* U+10000 - U+10FFFF */
        {
          expect = 3;
          codepoint = in_code & 0x07;
        }
        continue;
      }
      else if ( in_code >= 0x80 )
      {
        --expect;

        if ( expect >= 0 )
        {
          codepoint <<= 6;
          codepoint  += in_code & 0x3F;
        }
        if ( expect >  0 )
          continue;

        expect = 0;
      }
      else                              /* ASCII, U+0000 - U+007F */
        codepoint = in_code;

      if ( encoding )
        glyph_index = FT_Get_Char_Index( face, codepoint );
      else
        glyph_index = codepoint;

      glyph->glyph_index = glyph_index;
      glyph++;
      num_glyphs++;
      if ( num_glyphs >= MAX_GLYPHS )
        break;
    }
  }


  static void
  reset_transform( void )
  {
    double    angle   = Rotation * 3.14159 / 64.0;
    FT_Fixed  cosinus = (FT_Fixed)( cos( angle ) * 65536.0 );
    FT_Fixed  sinus   = (FT_Fixed)( sin( angle ) * 65536.0 );


    transform       = ( angle != 0 );
    trans_matrix.xx = cosinus;
    trans_matrix.yx = sinus;
    trans_matrix.xy = -sinus;
    trans_matrix.yy = cosinus;
  }


/****************************************************************************/
/****************************************************************************/
/****************************************************************************/
/****                                                                    ****/
/****                     E V E N T   H A N D L I N G                    ****/
/****                                                                    ****/
/****************************************************************************/
/****************************************************************************/
/****************************************************************************/


  static void
  Help( void )
  {
    grEvent  dummy_event;


    clear_display();
    grGotoxy( 0, 0 );
    grSetMargin( 2, 1 );
    grGotobitmap( &bit );

    grWriteln("FreeType String Viewer - part of the FreeType test suite" );
    grLn();
    grWriteln("This program is used to display a string of text using" );
    grWriteln("the new convenience API of the FreeType 2 library.");
    grLn();
    grWriteln("Use the following keys :");
    grLn();
    grWriteln("  F1 or ?   : display this help screen" );
    grWriteln("  a         : toggle anti-aliasing" );
    grWriteln("  f         : toggle forced auto-hinting" );
    grWriteln("  h         : toggle outline hinting" );
    grWriteln("  k         : toggle kerning" );
    grWriteln("  g         : toggle gamma correction" );
    grLn();
    grWriteln("  Up        : increase pointsize by 1 unit" );
    grWriteln("  Down      : decrease pointsize by 1 unit" );
    grWriteln("  Page Up   : increase pointsize by 10 units" );
    grWriteln("  Page Down : decrease pointsize by 10 units" );
    grLn();
    grWriteln("  Right     : rotate counter-clockwise" );
    grWriteln("  Left      : rotate clockwise" );
    grWriteln("  F7        : big rotate counter-clockwise");
    grWriteln("  F8        : big rotate clockwise");
    grLn();
    grWriteln("  F9        : decrease gamma by 0.1" );
    grWriteln("  F10       : increase gamma by 0.1" );
    grLn();
    grWriteln("press any key to exit this help screen");

    grRefreshSurface( surface );
    grListenSurface( surface, gr_event_key, &dummy_event );
  }


  static int
  Process_Event( grEvent*  event )
  {
    int  i;


    switch ( event->key )
    {
    case grKeyEsc:            /* ESC or q */
    case grKEY( 'q' ):
      return 0;

    case grKEY( 'f' ):
      autohint = !autohint;
      new_header = autohint ? (char *)"forced auto-hinting is now on"
                            : (char *)"forced auto-hinting is now off";
      return 1;

    case grKEY( 'k' ):
      kerning = ( kerning + 1 ) % 3;
      new_header =
        kerning == 2
          ? (char *)"kerning and side bearing correction is now active"
          : kerning == 1 ? (char *)"kerning is now active"
                         : (char *)"kerning is now ignored";
      return 1;

    case grKEY( 'a' ):
      antialias  = !antialias;
      new_header = antialias ? (char *)"anti-aliasing is now on"
                             : (char *)"anti-aliasing is now off";
      return 1;

    case grKEY( 'b' ):
#if 0
      use_sbits  = !use_sbits;
      new_header = use_sbits
                     ? (char *)"embedded bitmaps are now used when available"
                     : (char *)"embedded bitmaps are now ignored";
#else
      new_header = (char *)"embedded bitmaps can't be rotated/transformed";
#endif
      return 1;

    case grKEY( 'n' ):
    case grKEY( 'p' ):
      return (int)event->key;

    case grKEY( 'h' ):
      hinted     = !hinted;
      new_header = hinted ? (char *)"glyph hinting is now active"
                          : (char *)"glyph hinting is now ignored";
      break;

    case grKEY( 'g' ):
      use_gamma = !use_gamma;
      new_header = use_gamma ? (char *)"gamma correction is now on"
                             : (char *)"gamma correction is now off";
      return 1;

    case grKeyF1:
    case grKEY( '?' ):
      Help();
      return 1;

#if 0
    case grKeyF3: i =  16; goto Do_Rotate;
    case grKeyF4: i = -16; goto Do_Rotate;
    case grKeyF5: i =   1; goto Do_Rotate;
    case grKeyF6: i =  -1; goto Do_Rotate;
#endif

    case grKeyPageUp:   i =  10; goto Do_Scale;
    case grKeyPageDown: i = -10; goto Do_Scale;
    case grKeyUp:       i =   1; goto Do_Scale;
    case grKeyDown:     i =  -1; goto Do_Scale;

    case grKeyLeft:  i =  -1; goto Do_Rotate;
    case grKeyRight: i =   1; goto Do_Rotate;
    case grKeyF7:    i = -10; goto Do_Rotate;
    case grKeyF8:    i =  10; goto Do_Rotate;

    case grKeyF9 : if (gamma_value > 0.1f) gamma_value -= 0.1f; goto Do_Gamma_Set;
    case grKeyF10:                         gamma_value += 0.1f; goto Do_Gamma_Set;
    default:
      ;
    }
    return 1;

  Do_Rotate:
    Rotation = ( Rotation + i ) & 127;
    return 1;

  Do_Gamma_Set:
  {
    static char header_buffer[64];

    sprintf(header_buffer, "gamma is %.1f", gamma_value);
    new_header = header_buffer;
    init_gamma();
    return 1;
  }

  Do_Scale:
    ptsize += i;
    if ( ptsize < 1 )         ptsize = 1;
    if ( ptsize > MAXPTSIZE ) ptsize = MAXPTSIZE;
    return 1;

#if 0
  Do_Glyph:
    Num += i;
    if ( Num < 0 )           Num = 0;
    if ( Num >= num_glyphs ) Num = num_glyphs - 1;
    return 1;
#endif
  }


/****************************************************************************/
/****************************************************************************/
/****************************************************************************/
/****                                                                    ****/
/****                       M A I N   P R O G R A M                      ****/
/****                                                                    ****/
/****************************************************************************/
/****************************************************************************/
/****************************************************************************/


  static void
  usage( char*  execname )
  {
    fprintf( stderr,  "\n" );
    fprintf( stderr,  "ftstring: string viewer -- part of the FreeType project\n" );
    fprintf( stderr,  "-------------------------------------------------------\n" );
    fprintf( stderr,  "\n" );
    fprintf( stderr,  "Usage: %s [options below] ppem fontname[.ttf|.ttc] ...\n",
             execname );
    fprintf( stderr,  "\n" );
    fprintf( stderr,  "  -e enc      specify encoding tag (default: unic)\n" );
    fprintf( stderr,  "  -r R        use resolution R dpi (default: 72 dpi)\n" );
    fprintf( stderr,  "  -m message  message to display\n" );
    fprintf( stderr,  "\n" );

    exit( 1 );
  }


  int
  main( int     argc,
        char**  argv )
  {
    int     i, old_ptsize, orig_ptsize, file;
    int     first_glyph = 0;
    int     XisSetup = 0;
    char    filename[128 + 4];
    char    alt_filename[128 + 4];
    char*   execname;
    int     option;
    int     file_loaded;
    PGlyph  glyph;

    grEvent   event;


    execname = ft_basename( argv[0] );

    while ( 1 )
    {
      option = getopt( argc, argv, "e:m:r:" );

      if ( option == -1 )
        break;

      switch ( option )
      {
      case 'e':
        encoding = (FT_Encoding)make_tag( optarg );
        break;

      case 'r':
        res = atoi( optarg );
        if ( res < 1 )
          usage( execname );
        break;

      case 'm':
        if ( argc < 3 )
          usage( execname );
        Text = optarg;
        break;

      default:
        usage( execname );
        break;
      }
    }

    argc -= optind;
    argv += optind;

    if ( argc <= 1 )
      usage( execname );

    if ( sscanf( argv[0], "%d", &orig_ptsize ) != 1 )
      orig_ptsize = 64;

    file = 1;

    /* Initialize engine */
    error = FT_Init_FreeType( &library );
    if ( error )
      PanicZ( "Could not initialize FreeType library" );

  NewFile:
    ptsize      = orig_ptsize;
    hinted      = 1;
    file_loaded = 0;

#ifndef macintosh
    i = strlen( argv[file] );
    while ( i > 0 && argv[file][i] != '\\' && argv[file][i] != '/' )
    {
      if ( argv[file][i] == '.' )
        i = 0;
      i--;
    }
#endif

    filename[128] = '\0';
    alt_filename[128] = '\0';

    strncpy( filename, argv[file], 128 );
    strncpy( alt_filename, argv[file], 128 );

    /* first, try to load the glyph name as-is */
    error = FT_New_Face( library, filename, 0, &face );
    if ( !error )
      goto Success;

#ifndef macintosh
    if ( i >= 0 )
    {
      strncpy( filename + strlen( filename ), ".ttf", 4 );
      strncpy( alt_filename + strlen( alt_filename ), ".ttc", 4 );
    }
#endif

    /* if it didn't work, try to add ".ttf" at the end */
    error = FT_New_Face( library, filename, 0, &face );
    if ( error )
      goto Display_Font;

  Success:
    init_gamma();

    /* prepare the text to be rendered */
    prepare_text( (unsigned char*)Text );

    file_loaded++;

    reset_scale( ptsize );

  Display_Font:
    /* initialise graphics if needed */
    if ( !XisSetup )
    {
      XisSetup = 1;
      init_display();
    }

    grSetTitle( surface, "FreeType String Viewer - press F1 for help" );
    old_ptsize = ptsize;

    if ( file_loaded >= 1 )
    {
      Fail = 0;
      Num  = first_glyph;

      if ( Num >= num_glyphs )
        Num = num_glyphs - 1;

      if ( Num < 0 )
        Num = 0;
    }

    for ( ;; )
    {
      int  key;

      clear_display();

      if ( file_loaded >= 1 )
      {
        /* layout & render string */
        {
          reset_transform();
          layout_glyphs();
          if (use_gamma)
            draw_gamma_ramp();
          render_string( bit.width/2, bit.rows/2 );
        }

        sprintf( Header, "%s %s (file %s)",
                         face->family_name,
                         face->style_name,
                         ft_basename( filename ) );

        if (!new_header)
          new_header = Header;

        grWriteCellString( &bit, 0, 0, new_header, fore_color );
        new_header = 0;

        sprintf( Header, "at %d points, rotation = %d",
                         ptsize,
                         Rotation );
      }
      else
      {
        sprintf( Header, "`%s' is not a font file or could not be opened",
                         ft_basename(filename) );
      }

      grWriteCellString( &bit, 0, 8, Header, fore_color );
      grRefreshSurface( surface );

      grListenSurface( surface, 0, &event );
      if ( !( key = Process_Event( &event ) ) )
        goto Fin;

      if ( key == 'n' )
      {
        if ( file_loaded >= 1 )
          FT_Done_Face( face );

        if ( file < argc - 1 )
          file++;

        goto NewFile;
      }

      if ( key == 'p' )
      {
        if ( file_loaded >= 1 )
          FT_Done_Face( face );

        if ( file > 1 )
          file--;

        goto NewFile;
      }

      if ( ptsize != old_ptsize )
      {
        reset_scale( ptsize );

        old_ptsize = ptsize;
      }
    }

  Fin:
    glyph = glyphs;
    for ( i = 0; i < MAX_GLYPHS; i++, glyph++ )
      if ( glyph->image )
        FT_Done_Glyph( glyph->image );

    FT_Done_Face    ( face    );
    FT_Done_FreeType( library );

#if 0
    grDoneSurface( surface );
    grDone();
#endif
    printf( "Execution completed successfully.\n" );
    printf( "Fails = %d\n", Fail );

    exit( 0 );      /* for safety reasons */
    return 0;       /* never reached */
  }


/* End */