smooth.c

ucgui的矢量字库支持包,可以象windows一样使用truetype的字库了

               cell->x, cell->area, cell->cover );
    }
    fprintf(stderr, "\n" );
  }

#endif /* DEBUG_GRAYS */


  static void
  gray_hline( RAS_ARG_ TCoord  x,
                       TCoord  y,
                       TPos    area,
                       int     acount )
  {
    FT_Span*   span;
    int        count;
    int        coverage;


    /* compute the coverage line's coverage, depending on the    */
    /* outline fill rule                                         */
    /*                                                           */
    /* the coverage percentage is area/(PIXEL_BITS*PIXEL_BITS*2) */
    /*                                                           */
    coverage = (int)( area >> ( PIXEL_BITS * 2 + 1 - 8 ) );
                                                    /* use range 0..256 */
    if ( coverage < 0 )
      coverage = -coverage;

    if ( ras.outline.flags & FT_OUTLINE_EVEN_ODD_FILL )
    {
      coverage &= 511;

      if ( coverage > 256 )
        coverage = 512 - coverage;
      else if ( coverage == 256 )
        coverage = 255;
    }
    else
    {
      /* normal non-zero winding rule */
      if ( coverage >= 256 )
        coverage = 255;
    }

    y += (TCoord)ras.min_ey;
    x += (TCoord)ras.min_ex;

    if ( coverage )
    {
      /* see if we can add this span to the current list */
      count = ras.num_gray_spans;
      span  = ras.gray_spans + count - 1;
      if ( count > 0                          &&
           ras.span_y == y                    &&
           (int)span->x + span->len == (int)x &&
           span->coverage == coverage )
      {
        span->len = (unsigned short)( span->len + acount );
        return;
      }

      if ( ras.span_y != y || count >= FT_MAX_GRAY_SPANS )
      {
        if ( ras.render_span && count > 0 )
          ras.render_span( ras.span_y, count, ras.gray_spans,
                           ras.render_span_data );
        /* ras.render_span( span->y, ras.gray_spans, count ); */

#ifdef DEBUG_GRAYS

        if ( ras.span_y >= 0 )
        {
          int  n;


          fprintf( stderr, "y=%3d ", ras.span_y );
          span = ras.gray_spans;
          for ( n = 0; n < count; n++, span++ )
            fprintf( stderr, "[%d..%d]:%02x ",
                     span->x, span->x + span->len - 1, span->coverage );
          fprintf( stderr, "\n" );
        }

#endif /* DEBUG_GRAYS */

        ras.num_gray_spans = 0;
        ras.span_y         = y;

        count = 0;
        span  = ras.gray_spans;
      }
      else
        span++;

      /* add a gray span to the current list */
      span->x        = (short)x;
      span->len      = (unsigned short)acount;
      span->coverage = (unsigned char)coverage;
      ras.num_gray_spans++;
    }
  }


  static void
  gray_sweep( RAS_ARG_ const FT_Bitmap*  target )
  {
    TCoord  x, y, cover;
    TArea   area;
    PCell   start, cur, limit;

    FT_UNUSED( target );


    if ( ras.num_cells == 0 )
      return;

    cur   = ras.cells;
    limit = cur + ras.num_cells;

    cover              = 0;
    ras.span_y         = -1;
    ras.num_gray_spans = 0;

    for (;;)
    {
      start  = cur;
      y      = start->y;
      x      = start->x;

      area   = start->area;
      cover += start->cover;

      /* accumulate all start cells */
      for (;;)
      {
        ++cur;
        if ( cur >= limit || cur->y != start->y || cur->x != start->x )
          break;

        area  += cur->area;
        cover += cur->cover;
      }

      /* if the start cell has a non-null area, we must draw an */
      /* individual gray pixel there                            */
      if ( area && x >= 0 )
      {
        gray_hline( RAS_VAR_ x, y, cover * ( ONE_PIXEL * 2 ) - area, 1 );
        x++;
      }

      if ( x < 0 )
        x = 0;

      if ( cur < limit && start->y == cur->y )
      {
        /* draw a gray span between the start cell and the current one */
        if ( cur->x > x )
          gray_hline( RAS_VAR_ x, y,
                      cover * ( ONE_PIXEL * 2 ), cur->x - x );
      }
      else
      {
        /* draw a gray span until the end of the clipping region */
        if ( cover && x < ras.max_ex - ras.min_ex )
          gray_hline( RAS_VAR_ x, y,
                      cover * ( ONE_PIXEL * 2 ),
                      (int)( ras.max_ex - x - ras.min_ex ) );
        cover = 0;
      }

      if ( cur >= limit )
        break;
    }

    if ( ras.render_span && ras.num_gray_spans > 0 )
      ras.render_span( ras.span_y, ras.num_gray_spans,
                       ras.gray_spans, ras.render_span_data );

#ifdef DEBUG_GRAYS

    {
      int       n;
      FT_Span*  span;


      fprintf( stderr, "y=%3d ", ras.span_y );
      span = ras.gray_spans;
      for ( n = 0; n < ras.num_gray_spans; n++, span++ )
        fprintf( stderr, "[%d..%d]:%02x ",
                 span->x, span->x + span->len - 1, span->coverage );
      fprintf( stderr, "\n" );
    }

#endif /* DEBUG_GRAYS */

  }


#ifdef _STANDALONE_

  /*************************************************************************/
  /*                                                                       */
  /*  The following function should only compile in stand_alone mode,      */
  /*  i.e., when building this component without the rest of FreeType.     */
  /*                                                                       */
  /*************************************************************************/

  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FT_Outline_Decompose                                               */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Walks over an outline's structure to decompose it into individual  */
  /*    segments and Bezier arcs.  This function is also able to emit      */
  /*    `move to' and `close to' operations to indicate the start and end  */
  /*    of new contours in the outline.                                    */
  /*                                                                       */
  /* <Input>                                                               */
  /*    outline        :: A pointer to the source target.                  */
  /*                                                                       */
  /*    func_interface :: A table of `emitters', i.e,. function pointers   */
  /*                      called during decomposition to indicate path     */
  /*                      operations.                                      */
  /*                                                                       */
  /*    user           :: A typeless pointer which is passed to each       */
  /*                      emitter during the decomposition.  It can be     */
  /*                      used to store the state during the               */
  /*                      decomposition.                                   */
  /*                                                                       */
  /* <Return>                                                              */
  /*    Error code.  0 means sucess.                                       */
  /*                                                                       */
  static
  int  FT_Outline_Decompose( const FT_Outline*        outline,
                             const FT_Outline_Funcs*  func_interface,
                             void*                    user )
  {
#undef SCALED
#if 0
#define SCALED( x )  ( ( (x) << shift ) - delta )
#else
#define SCALED( x )  (x)
#endif

    FT_Vector   v_last;
    FT_Vector   v_control;
    FT_Vector   v_start;

    FT_Vector*  point;
    FT_Vector*  limit;
    char*       tags;

    int   n;         /* index of contour in outline     */
    int   first;     /* index of first point in contour */
    int   error;
    char  tag;       /* current point's state           */

#if 0
    int   shift = func_interface->shift;
    TPos  delta = func_interface->delta;
#endif


    first = 0;

    for ( n = 0; n < outline->n_contours; n++ )
    {
      int  last;  /* index of last point in contour */


      last  = outline->contours[n];
      limit = outline->points + last;

      v_start = outline->points[first];
      v_last  = outline->points[last];

      v_start.x = SCALED( v_start.x ); v_start.y = SCALED( v_start.y );
      v_last.x  = SCALED( v_last.x );  v_last.y  = SCALED( v_last.y );

      v_control = v_start;

      point = outline->points + first;
      tags  = outline->tags  + first;
      tag   = FT_CURVE_TAG( tags[0] );

      /* A contour cannot start with a cubic control point! */
      if ( tag == FT_CURVE_TAG_CUBIC )
        goto Invalid_Outline;

      /* check first point to determine origin */
      if ( tag == FT_CURVE_TAG_CONIC )
      {
        /* first point is conic control.  Yes, this happens. */
        if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON )
        {
          /* start at last point if it is on the curve */
          v_start = v_last;
          limit--;
        }
        else
        {
          /* if both first and last points are conic,         */
          /* start at their middle and record its position    */
          /* for closure                                      */
          v_start.x = ( v_start.x + v_last.x ) / 2;
          v_start.y = ( v_start.y + v_last.y ) / 2;

          v_last = v_start;
        }
        point--;
        tags--;
      }

      error = func_interface->move_to( &v_start, user );
      if ( error )
        goto Exit;

      while ( point < limit )
      {
        point++;
        tags++;

        tag = FT_CURVE_TAG( tags[0] );
        switch ( tag )
        {
        case FT_CURVE_TAG_ON:  /* emit a single line_to */
          {
            FT_Vector  vec;


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

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

        case FT_CURVE_TAG_CONIC:  /* consume conic arcs */
          {
            v_control.x = SCALED( point->x );
            v_control.y = SCALED( point->y );

          Do_Conic:
            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
  {
    TPos  min, max;

  } TBand;


  static int
  gray_convert_glyph_inner( RAS_ARG )
  {
    static