ftgrays.c

winNT技术操作系统,国外开放的原代码和LIUX一样

            if ( point < limit )
            {
              FT_Vector  vec;
              FT_Vector  v_middle;


              point++;
              tags++;
              tag = FT_CURVE_TAG( tags[0] );

              vec.x = SCALED( point->x );
              vec.y = SCALED( point->y );

              if ( tag == FT_CURVE_TAG_ON )
              {
                error = func_interface->conic_to( &v_control, &vec,
                                                  user );
                if ( error )
                  goto Exit;
                continue;
              }

              if ( tag != FT_CURVE_TAG_CONIC )
                goto Invalid_Outline;

              v_middle.x = ( v_control.x + vec.x ) / 2;
              v_middle.y = ( v_control.y + vec.y ) / 2;

              error = func_interface->conic_to( &v_control, &v_middle,
                                                user );
              if ( error )
                goto Exit;

              v_control = vec;
              goto Do_Conic;
            }

            error = func_interface->conic_to( &v_control, &v_start,
                                              user );
            goto Close;
          }

        default:  /* FT_CURVE_TAG_CUBIC */
          {
            FT_Vector  vec1, vec2;


            if ( point + 1 > limit                             ||
                 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC )
              goto Invalid_Outline;

            point += 2;
            tags  += 2;

            vec1.x = SCALED( point[-2].x );
            vec1.y = SCALED( point[-2].y );

            vec2.x = SCALED( point[-1].x );
            vec2.y = SCALED( point[-1].y );

            if ( point <= limit )
            {
              FT_Vector  vec;


              vec.x = SCALED( point->x );
              vec.y = SCALED( point->y );

              error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
              if ( error )
                goto Exit;
              continue;
            }

            error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
            goto Close;
          }
        }
      }

      /* close the contour with a line segment */
      error = func_interface->line_to( &v_start, user );

   Close:
      if ( error )
        goto Exit;

      first = last + 1;
    }

    return 0;

  Exit:
    return error;

  Invalid_Outline:
    return ErrRaster_Invalid_Outline;
  }

#endif /* _STANDALONE_ */


  typedef struct  TBand_
  {
    TPos  min, max;

  } TBand;


  static int
  gray_convert_glyph_inner( RAS_ARG )
  {
    static
    const FT_Outline_Funcs  func_interface =
    {
      (FT_Outline_MoveTo_Func) gray_move_to,
      (FT_Outline_LineTo_Func) gray_line_to,
      (FT_Outline_ConicTo_Func)gray_conic_to,
      (FT_Outline_CubicTo_Func)gray_cubic_to,
      0,
      0
    };

    volatile int  error = 0;

    if ( ft_setjmp( ras.jump_buffer ) == 0 )
    {
      error = FT_Outline_Decompose( &ras.outline, &func_interface, &ras );
      gray_record_cell( RAS_VAR );
    }
    else
    {
      error = ErrRaster_Memory_Overflow;
    }

    return error;
  }


  static int
  gray_convert_glyph( RAS_ARG )
  {
    TBand            bands[40];
    TBand* volatile  band;
    int volatile     n, num_bands;
    TPos volatile    min, max, max_y;
    FT_BBox*         clip;


    /* Set up state in the raster object */
    gray_compute_cbox( RAS_VAR );

    /* clip to target bitmap, exit if nothing to do */
    clip = &ras.clip_box;

    if ( ras.max_ex <= clip->xMin || ras.min_ex >= clip->xMax ||
         ras.max_ey <= clip->yMin || ras.min_ey >= clip->yMax )
      return 0;

    if ( ras.min_ex < clip->xMin ) ras.min_ex = clip->xMin;
    if ( ras.min_ey < clip->yMin ) ras.min_ey = clip->yMin;

    if ( ras.max_ex > clip->xMax ) ras.max_ex = clip->xMax;
    if ( ras.max_ey > clip->yMax ) ras.max_ey = clip->yMax;

    ras.count_ex = ras.max_ex - ras.min_ex;
    ras.count_ey = ras.max_ey - ras.min_ey;

    /* simple heuristic used to speed-up the bezier decomposition -- see */
    /* the code in gray_render_conic() and gray_render_cubic() for more  */
    /* details                                                           */
    ras.conic_level = 32;
    ras.cubic_level = 16;

    {
      int level = 0;


      if ( ras.count_ex > 24 || ras.count_ey > 24 )
        level++;
      if ( ras.count_ex > 120 || ras.count_ey > 120 )
        level++;

      ras.conic_level <<= level;
      ras.cubic_level <<= level;
    }

    /* setup vertical bands */
    num_bands = (int)( ( ras.max_ey - ras.min_ey ) / ras.band_size );
    if ( num_bands == 0 )  num_bands = 1;
    if ( num_bands >= 39 ) num_bands = 39;

    ras.band_shoot = 0;

    min   = ras.min_ey;
    max_y = ras.max_ey;

    for ( n = 0; n < num_bands; n++, min = max )
    {
      max = min + ras.band_size;
      if ( n == num_bands - 1 || max > max_y )
        max = max_y;

      bands[0].min = min;
      bands[0].max = max;
      band         = bands;

      while ( band >= bands )
      {
        TPos  bottom, top, middle;
        int   error;

        {
          PCell  cells_max;
          int    yindex;
          long   cell_start, cell_end, cell_mod;


          ras.ycells = (PCell*)ras.buffer;
          ras.ycount = band->max - band->min;

          cell_start = sizeof ( PCell ) * ras.ycount;
          cell_mod   = cell_start % sizeof ( TCell );
          if ( cell_mod > 0 )
            cell_start += sizeof ( TCell ) - cell_mod;

          cell_end  = ras.buffer_size;
          cell_end -= cell_end % sizeof( TCell );

          cells_max = (PCell)( (char*)ras.buffer + cell_end );
          ras.cells = (PCell)( (char*)ras.buffer + cell_start );
          if ( ras.cells >= cells_max )
            goto ReduceBands;

          ras.max_cells = cells_max - ras.cells;
          if ( ras.max_cells < 2 )
            goto ReduceBands;

          for ( yindex = 0; yindex < ras.ycount; yindex++ )
            ras.ycells[yindex] = NULL;
        }

        ras.num_cells = 0;
        ras.invalid   = 1;
        ras.min_ey    = band->min;
        ras.max_ey    = band->max;
        ras.count_ey  = band->max - band->min;

        error = gray_convert_glyph_inner( RAS_VAR );

        if ( !error )
        {
          gray_sweep( RAS_VAR_ &ras.target );
          band--;
          continue;
        }
        else if ( error != ErrRaster_Memory_Overflow )
          return 1;

      ReduceBands:
        /* render pool overflow; we will reduce the render band by half */
        bottom = band->min;
        top    = band->max;
        middle = bottom + ( ( top - bottom ) >> 1 );

        /* This is too complex for a single scanline; there must */
        /* be some problems.                                     */
        if ( middle == bottom )
        {
#ifdef DEBUG_GRAYS
          fprintf( stderr, "Rotten glyph!\n" );
#endif
          return 1;
        }

        if ( bottom-top >= ras.band_size )
          ras.band_shoot++;

        band[1].min = bottom;
        band[1].max = middle;
        band[0].min = middle;
        band[0].max = top;
        band++;
      }
    }

    if ( ras.band_shoot > 8 && ras.band_size > 16 )
      ras.band_size = ras.band_size / 2;

    return 0;
  }


  static int
  gray_raster_render( PRaster                  raster,
                      const FT_Raster_Params*  params )
  {
    const FT_Outline*  outline    = (const FT_Outline*)params->source;
    const FT_Bitmap*   target_map = params->target;
    PWorker            worker;


    if ( !raster || !raster->buffer || !raster->buffer_size )
      return ErrRaster_Invalid_Argument;

    /* return immediately if the outline is empty */
    if ( outline->n_points == 0 || outline->n_contours <= 0 )
      return 0;

    if ( !outline || !outline->contours || !outline->points )
      return ErrRaster_Invalid_Outline;

    if ( outline->n_points !=
           outline->contours[outline->n_contours - 1] + 1 )
      return ErrRaster_Invalid_Outline;

    worker = raster->worker;

    /* if direct mode is not set, we must have a target bitmap */
    if ( ( params->flags & FT_RASTER_FLAG_DIRECT ) == 0 )
    {
      if ( !target_map )
        return ErrRaster_Invalid_Argument;

      /* nothing to do */
      if ( !target_map->width || !target_map->rows )
        return 0;

      if ( !target_map->buffer )
        return ErrRaster_Invalid_Argument;
    }

    /* this version does not support monochrome rendering */
    if ( !( params->flags & FT_RASTER_FLAG_AA ) )
      return ErrRaster_Invalid_Mode;

    /* compute clipping box */
    if ( ( params->flags & FT_RASTER_FLAG_DIRECT ) == 0 )
    {
      /* compute clip box from target pixmap */
      ras.clip_box.xMin = 0;
      ras.clip_box.yMin = 0;
      ras.clip_box.xMax = target_map->width;
      ras.clip_box.yMax = target_map->rows;
    }
    else if ( params->flags & FT_RASTER_FLAG_CLIP )
    {
      ras.clip_box = params->clip_box;
    }
    else
    {
      ras.clip_box.xMin = -32768L;
      ras.clip_box.yMin = -32768L;
      ras.clip_box.xMax =  32767L;
      ras.clip_box.yMax =  32767L;
    }

    gray_init_cells( worker, raster->buffer, raster->buffer_size );

    ras.outline   = *outline;
    ras.num_cells = 0;
    ras.invalid   = 1;
    ras.band_size = raster->band_size;
    ras.num_gray_spans = 0;

    if ( target_map )
      ras.target = *target_map;

    ras.render_span      = (FT_Raster_Span_Func)gray_render_span;
    ras.render_span_data = &ras;

    if ( params->flags & FT_RASTER_FLAG_DIRECT )
    {
      ras.render_span      = (FT_Raster_Span_Func)params->gray_spans;
      ras.render_span_data = params->user;
    }

    return gray_convert_glyph( worker );
  }


  /**** RASTER OBJECT CREATION: In standalone mode, we simply use *****/
  /****                         a static object.                  *****/

#ifdef _STANDALONE_

  static int
  gray_raster_new( void*       memory,
                   FT_Raster*  araster )
  {
    static TRaster  the_raster;

    FT_UNUSED( memory );


    *araster = (FT_Raster)&the_raster;
    FT_MEM_ZERO( &the_raster, sizeof ( the_raster ) );

    return 0;
  }


  static void
  gray_raster_done( FT_Raster  raster )
  {
    /* nothing */
    FT_UNUSED( raster );
  }

#else /* _STANDALONE_ */

  static int
  gray_raster_new( FT_Memory   memory,
                   FT_Raster*  araster )
  {
    FT_Error  error;
    PRaster   raster;


    *araster = 0;
    if ( !FT_ALLOC( raster, sizeof ( TRaster ) ) )
    {
      raster->memory = memory;
      *araster = (FT_Raster)raster;
    }

    return error;
  }


  static void
  gray_raster_done( FT_Raster  raster )
  {
    FT_Memory  memory = (FT_Memory)((PRaster)raster)->memory;


    FT_FREE( raster );
  }

#endif /* _STANDALONE_ */


  static void
  gray_raster_reset( FT_Raster  raster,
                     char*      pool_base,
                     long       pool_size )
  {
    PRaster  rast = (PRaster)raster;


    if ( raster )
    {
      if ( pool_base && pool_size >= (long)sizeof ( TWorker ) + 2048 )
      {
        PWorker  worker = (PWorker)pool_base;


        rast->worker      = worker;
        rast->buffer      = pool_base +
                              ( ( sizeof ( TWorker ) + sizeof ( TCell ) - 1 ) &
                                ~( sizeof ( TCell ) - 1 ) );
        rast->buffer_size = (long)( ( pool_base + pool_size ) -
                                    (char*)rast->buffer ) &
                                      ~( sizeof ( TCell ) - 1 );
        rast->band_size   = (int)( rast->buffer_size /
                                     ( sizeof ( TCell ) * 8 ) );
      }
      else
      {
        rast->buffer      = NULL;
        rast->buffer_size = 0;
        rast->worker      = NULL;
      }
    }
  }


  const FT_Raster_Funcs  ft_grays_raster =
  {
    FT_GLYPH_FORMAT_OUTLINE,

    (FT_Raster_New_Func)     gray_raster_new,
    (FT_Raster_Reset_Func)   gray_raster_reset,
    (FT_Raster_Set_Mode_Func)0,
    (FT_Raster_Render_Func)  gray_raster_render,
    (FT_Raster_Done_Func)    gray_raster_done
  };


/* END */