ftview.c

freetype库的应用demo,里面包含freetype的很多实例

/****************************************************************************/
/*                                                                          */
/*  The FreeType project -- a free and portable quality TrueType renderer.  */
/*                                                                          */
/*  Copyright 1996-2000, 2003, 2004, 2005 by                                */
/*  D. Turner, R.Wilhelm, and W. Lemberg                                    */
/*                                                                          */
/*                                                                          */
/*  FTView - a simple font viewer.                                          */
/*                                                                          */
/*  This is a new version using the MiGS graphics subsystem for             */
/*  blitting and display.                                                   */
/*                                                                          */
/*  Press F1 when running this program to have a list of key-bindings       */
/*                                                                          */
/****************************************************************************/


#include "ftcommon.i"
#include <math.h>



  static FT_Error
  Render_GammaGrid( void )
  {
    int   g;
    int   yside  = 11;
    int   xside  = 10;
    int   levels = 17;
    int   gammas = 30;
    int   x_0    = (bit.width - levels*xside)/2;
    int   y_0    = (bit.rows  - gammas*(yside+1))/2;
    int   pitch  = bit.pitch;

    if ( pitch < 0 )
      pitch = -pitch;

    memset( bit.buffer, 100, pitch*bit.rows );

    grGotobitmap( &bit );

    for ( g = 1; g <= gammas; g += 1 )
    {
      double ggamma = g/10.0;
      char   temp[6];
      int    y = y_0 + (yside+1)*(g-1);
      int    nx, ny;

      unsigned char*  line = bit.buffer + y*bit.pitch;

      if ( bit.pitch < 0 )
        line -= bit.pitch*(bit.rows-1);

      line += x_0*3;

      grSetPixelMargin( x_0-32, y + (yside-8)/2 );
      grGotoxy( 0, 0 );

      sprintf( temp, "%.1f", ggamma );
      grWrite( temp );

      for ( ny = 0; ny < yside; ny++, line += bit.pitch )
      {
        unsigned char*  dst = line;

        for ( nx = 0; nx < levels; nx++, dst += 3 * xside )
        {
          double  p   = nx/(double)(levels - 1);
          int     gm  = (int)( 255.0 * pow( p, ggamma ) );

          memset( dst, gm, xside * 3 );
        }
      }
    }
    return 0;
  }


  static FT_Error
  Render_Stroke( int  first_index )
  {
    FT_F26Dot6     start_x, start_y, step_x, step_y, x, y;
    FTC_ScalerRec  scaler;
    FT_Stroker     stroker = NULL;
    int            i;
    grBitmap       bit3;


    start_x = 4;
    start_y = 16 + current_font.height;


    scaler.face_id = current_font.face_id;
    scaler.width   = current_font.width;
    scaler.height  = current_font.height;
    scaler.pixel   = 1;

    error = FTC_Manager_LookupSize( cache_manager, &scaler, &size );
    if ( error )
      goto Exit;

    error = FT_Stroker_New( size->face->memory, &stroker );
    if ( error )
      goto Exit;

    FT_Stroker_Set( stroker,
                    64,
                    FT_STROKER_LINECAP_ROUND,
                    FT_STROKER_LINEJOIN_ROUND,
                    0 );

    step_x = size->metrics.x_ppem + 4;
    step_y = ( size->metrics.height >> 6 ) + 4;

    x = start_x;
    y = start_y;

    i = first_index;
    i = first_index;

    while ( i < face->num_glyphs )
    {
      int           left, top, x_advance, y_advance, x_top, y_top;
      FT_GlyphSlot  slot = size->face->glyph;
      FT_Glyph      glyphp;

#if 0
      gindex = *(unsigned char*)p;
      if ( encoding == FT_ENCODING_NONE )
        gindex = get_glyph_index( gindex );
#endif
      error = FT_Load_Glyph( size->face, i, FT_LOAD_NO_BITMAP );
      if ( !error && slot->format == FT_GLYPH_FORMAT_OUTLINE )
      {
        FT_Glyph  glyphb;

        error = FT_Get_Glyph( slot, &glyphp );
        if ( error )
          goto Next;

        error = FT_Glyph_Stroke( &glyphp, stroker, 1 );
        if ( error )
        {
          FT_Done_Glyph( glyphp );
          goto Next;
        }

        error = glyph_to_bitmap( glyphp, &bit3, &left, &top,
                                 &x_advance, &y_advance, (FT_Pointer*)&glyphb );
        if ( !error )
        {
          /* now render the bitmap into the display surface */
          x_top = x + left;
          y_top = y - top;
          grBlitGlyphToBitmap( &bit, &bit3, x_top, y_top, fore_color );

          FT_Done_Glyph( glyphb );
          FT_Done_Glyph( glyphp );

          x += x_advance + 1;

          if ( x + size->metrics.x_ppem > bit.width )
          {
            x  = start_x;
            y += step_y;

            if ( y >= bit.rows )
              goto Exit;
          }
        }
        else
          FT_Done_Glyph( glyphp );

        if ( error )
          goto Next;
      }
      else
      {
      Next:
        Fail++;
      }

      i++;
    }

  Exit:
    if ( stroker )
      FT_Stroker_Done( stroker );

    return error;
  }


  /* most code is copied from Render_Stroke */
  static FT_Error
  Render_Embolden( int  first_index )
  {
    FT_F26Dot6     start_x, start_y, step_x, step_y, x, y;
    FTC_ScalerRec  scaler;
    int            i;
    grBitmap       bit3;


    start_x = 4;
    start_y = 16 + current_font.height;


    scaler.face_id = current_font.face_id;
    scaler.width   = current_font.width;
    scaler.height  = current_font.height;
    scaler.pixel   = 1;

    error = FTC_Manager_LookupSize( cache_manager, &scaler, &size );
    if ( error )
      goto Exit;

    step_x = size->metrics.x_ppem + 4;
    step_y = ( size->metrics.height >> 6 ) + 4;

    x = start_x;
    y = start_y;

    i = first_index;
    i = first_index;

    while ( i < face->num_glyphs )
    {
      int           left, top, x_advance, y_advance, x_top, y_top;
      FT_GlyphSlot  slot = size->face->glyph;
      FT_Glyph      glyphp;

#if 0
      gindex = *(unsigned char*)p;
      if ( encoding == FT_ENCODING_NONE )
        gindex = get_glyph_index( gindex );
#endif
      error = FT_Load_Glyph( size->face, i, FT_LOAD_DEFAULT );
      if ( !error )
      {
        FT_Glyph  glyphb;


        FT_GlyphSlot_Embolden( slot );
        error = FT_Get_Glyph( slot, &glyphp );
        if ( error )
          goto Next;

        error = glyph_to_bitmap( glyphp, &bit3, &left, &top,
                                 &x_advance, &y_advance,
                                 (FT_Pointer*)&glyphb );
        if ( !error )
        {
          /* now render the bitmap into the display surface */
          x_top = x + left;
          y_top = y - top;
          grBlitGlyphToBitmap( &bit, &bit3, x_top, y_top, fore_color );

          FT_Done_Glyph( glyphb );
          FT_Done_Glyph( glyphp );

          x += x_advance + 1;

          if ( x + size->metrics.x_ppem > bit.width )
          {
            x  = start_x;
            y += step_y;

            if ( y >= bit.rows )
              goto Exit;
          }
        }
        else
          FT_Done_Glyph( glyphp );

        if ( error )
          goto Next;
      }
      else
      {
      Next:
        Fail++;
      }

      i++;
    }

  Exit:
    return error;
  }


  static FT_Error
  Render_All( int  first_index )
  {
    FT_F26Dot6     start_x, start_y, step_x, step_y, x, y;
    FTC_ScalerRec  scaler;
    FT_Pointer     glyf;
    int            i;
    grBitmap       bit3;


    start_x = 4;
    start_y = 16 + current_font.height;

    scaler.face_id = current_font.face_id;
    scaler.width   = current_font.width;
    scaler.height  = current_font.height;
    scaler.pixel   = 1;

    error = FTC_Manager_LookupSize( cache_manager, &scaler, &size );
    if ( error )
    {
      /* probably a non-existent bitmap font size */
      return error;
    }

    step_x = size->metrics.x_ppem + 4;
    step_y = ( size->metrics.height >> 6 ) + 4;

    x = start_x;
    y = start_y;

    i = first_index;

#if 0
    while ( i < first_index + 1 )
#else
    while ( i < num_indices )
#endif
    {
      int  x_top, y_top, left, top, x_advance, y_advance;


      error = get_glyph_bitmap( i, &bit3, &left, &top,
                                &x_advance, &y_advance, &glyf );
      if ( !error )
      {
        /* now render the bitmap into the display surface */
        x_top = x + left;
        y_top = y - top;
        grBlitGlyphToBitmap( &bit, &bit3, x_top, y_top, fore_color );

        if ( glyf )
          done_glyph_bitmap( glyf );

        x += x_advance + 1;

        if ( x + size->metrics.x_ppem > bit.width )
        {
          x  = start_x;
          y += step_y;

          if ( y >= bit.rows )
            return FT_Err_Ok;
        }
      }
      else
        Fail++;

      i++;
    }

    return FT_Err_Ok;
  }


  static FT_Error
  Render_Text( int  first_index )
  {
    FT_F26Dot6     start_x, start_y, step_x, step_y, x, y;
    FTC_ScalerRec  scaler;
    FT_Pointer     glyf;
    int            i;
    grBitmap       bit3;

    const unsigned char*  p;


    start_x = 4;
    start_y = 16 + current_font.height;

    scaler.face_id = current_font.face_id;
    scaler.width   = current_font.width;
    scaler.height  = current_font.height;
    scaler.pixel   = 1;

    error = FTC_Manager_LookupSize( cache_manager, &scaler, &size );
    if ( error )
    {
      /* probably a non-existent bitmap font size */
      return error;
    }

    step_x = size->metrics.x_ppem + 4;
    step_y = ( size->metrics.height >> 6 ) + 4;

    x = start_x;
    y = start_y;

    i = first_index;
    p = Text;
    while ( i > 0 && *p )
    {
      p++;
      i--;
    }

    while ( *p )
    {
      int      left, top, x_advance, y_advance, x_top, y_top;
      FT_UInt  gindex;


      gindex = *(unsigned char*)p;
      if ( encoding == FT_ENCODING_NONE )
        gindex = get_glyph_index( gindex );

      /* if a cmap is active, `get_glyph_bitmap' will convert the */
      /* char code in `gindex' to a real glyph index              */
      error = get_glyph_bitmap( gindex, &bit3, &left, &top,
                                &x_advance, &y_advance, &glyf );
      if ( !error )
      {
        /* now render the bitmap into the display surface */
        x_top = x + left;
        y_top = y - top;
        grBlitGlyphToBitmap( &bit, &bit3, x_top, y_top, fore_color );

        if ( glyf )
          done_glyph_bitmap( glyf );

        x += x_advance + 1;

        if ( x + size->metrics.x_ppem > bit.width )
        {
          x  = start_x;
          y += step_y;

          if ( y >= bit.rows )
            return FT_Err_Ok;
        }
      }
      else
        Fail++;

      p++;
    }

    return FT_Err_Ok;
  }


  static FT_Error
  Render_Waterfall( int  first_size )
  {
    FT_F26Dot6  start_x, start_y, step_x, step_y, x, y;
    FT_Pointer  glyf;
    int         pt_size, max_size = 100000;
    grBitmap    bit3;

    unsigned char         text[256];
    const unsigned char*  p;


    start_x = 4;
    start_y = 16;

    pt_size = first_size;

    {
      error = FTC_Manager_LookupFace( cache_manager, current_font.face_id, &face );
      if ( error )
      {
        /* can't access the font file. do not render anything */
        fprintf( stderr, "can't access font file %p\n", current_font.face_id );
        return 0;
      }

      if ( !FT_IS_SCALABLE( face ) )
      {
        int  i;


        max_size = 0;
        for ( i = 0; i < face->num_fixed_sizes; i++ )
          if ( face->available_sizes[i].height >= max_size )
            max_size = face->available_sizes[i].height;
      }
    }

    for (;;)
    {
      FTC_ScalerRec  scaler;


      sprintf( (char*)text,
                "%d: the quick brown fox jumps over the lazy dog "
                "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789", pt_size );

      p = text;

      set_current_pointsize( pt_size );

      if ( pt_size > max_size )
        break;
      pt_size++;

      scaler.face_id = current_font.face_id;
      scaler.width   = current_font.width;
      scaler.height  = current_font.height;
      scaler.pixel   = 1;

      error = FTC_Manager_LookupSize( cache_manager, &scaler, &size );
      if ( error )
      {
        /* probably a non-existent bitmap font size */
        continue;
      }

      step_x = size->metrics.x_ppem + 4;
      step_y = ( size->metrics.height >> 6 ) + 1;

      x = start_x;
      y = start_y + ( size->metrics.ascender >> 6 );

      start_y += step_y;

      if ( y >= bit.rows )
        break;

      while ( *p )
      {
        int      left, top, x_advance, y_advance, x_top, y_top;
        FT_UInt  gindex;


        gindex = *(unsigned char*)p;
        if ( encoding == FT_ENCODING_NONE )
          gindex = get_glyph_index( gindex );

        /* if a cmap is active, `get_glyph_bitmap' will convert the */
        /* char code in `gindex' to a real glyph index              */
        error = get_glyph_bitmap( gindex, &bit3, &left, &top,
                                  &x_advance, &y_advance, &glyf );
        if ( !error )
        {
          /* now render the bitmap into the display surface */
          x_top = x + left;
          y_top = y - top;
          grBlitGlyphToBitmap( &bit, &bit3, x_top, y_top, fore_color );

          if ( glyf )
            done_glyph_bitmap( glyf );