ftoutln.c

超强的嵌入式GUI系统

    outline->flags ^= FT_OUTLINE_REVERSE_FILL;
  }


  /* documentation is in ftoutln.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Outline_Render( FT_Library         library,
                     FT_Outline*        outline,
                     FT_Raster_Params*  params )
  {
    FT_Error     error;
    FT_Bool      update = 0;
    FT_Renderer  renderer;
    FT_ListNode  node;


    if ( !library )
      return FT_Err_Invalid_Library_Handle;

    if ( !outline || !params )
      return FT_Err_Invalid_Argument;

    renderer = library->cur_renderer;
    node     = library->renderers.head;

    params->source = (void*)outline;

    error = FT_Err_Cannot_Render_Glyph;
    while ( renderer )
    {
      error = renderer->raster_render( renderer->raster, params );
      if ( !error || FT_ERROR_BASE( error ) != FT_Err_Cannot_Render_Glyph )
        break;

      /* FT_Err_Cannot_Render_Glyph is returned if the render mode   */
      /* is unsupported by the current renderer for this glyph image */
      /* format                                                      */

      /* now, look for another renderer that supports the same */
      /* format                                                */
      renderer = FT_Lookup_Renderer( library, FT_GLYPH_FORMAT_OUTLINE,
                                     &node );
      update   = 1;
    }

    /* if we changed the current renderer for the glyph image format */
    /* we need to select it as the next current one                  */
    if ( !error && update && renderer )
      FT_Set_Renderer( library, renderer, 0, 0 );

    return error;
  }


  /* documentation is in ftoutln.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Outline_Get_Bitmap( FT_Library        library,
                         FT_Outline*       outline,
                         const FT_Bitmap  *abitmap )
  {
    FT_Raster_Params  params;


    if ( !abitmap )
      return FT_Err_Invalid_Argument;

    /* other checks are delayed to FT_Outline_Render() */

    params.target = abitmap;
    params.flags  = 0;

    if ( abitmap->pixel_mode == FT_PIXEL_MODE_GRAY  ||
         abitmap->pixel_mode == FT_PIXEL_MODE_LCD   ||
         abitmap->pixel_mode == FT_PIXEL_MODE_LCD_V )
      params.flags |= FT_RASTER_FLAG_AA;

    return FT_Outline_Render( library, outline, &params );
  }


  /* documentation is in ftoutln.h */

  FT_EXPORT_DEF( void )
  FT_Vector_Transform( FT_Vector*        vector,
                       const FT_Matrix*  matrix )
  {
    FT_Pos xz, yz;


    if ( !vector || !matrix )
      return;

    xz = FT_MulFix( vector->x, matrix->xx ) +
         FT_MulFix( vector->y, matrix->xy );

    yz = FT_MulFix( vector->x, matrix->yx ) +
         FT_MulFix( vector->y, matrix->yy );

    vector->x = xz;
    vector->y = yz;
  }


  /* documentation is in ftoutln.h */

  FT_EXPORT_DEF( void )
  FT_Outline_Transform( const FT_Outline*  outline,
                        const FT_Matrix*   matrix )
  {
    FT_Vector*  vec;
    FT_Vector*  limit;


    if ( !outline || !matrix )
      return;

    vec   = outline->points;
    limit = vec + outline->n_points;

    for ( ; vec < limit; vec++ )
      FT_Vector_Transform( vec, matrix );
  }


#if 0

#define FT_OUTLINE_GET_CONTOUR( outline, c, first, last )  \
  do {                                                     \
    (first) = ( c > 0 ) ? (outline)->points +              \
                            (outline)->contours[c - 1] + 1 \
                        : (outline)->points;               \
    (last) = (outline)->points + (outline)->contours[c];   \
  } while ( 0 )


  /* Is a point in some contour?                     */
  /*                                                 */
  /* We treat every point of the contour as if it    */
  /* it were ON.  That is, we allow false positives, */
  /* but disallow false negatives.  (XXX really?)    */
  static FT_Bool
  ft_contour_has( FT_Outline*  outline,
                  FT_Short     c,
                  FT_Vector*   point )
  {
    FT_Vector*  first;
    FT_Vector*  last;
    FT_Vector*  a;
    FT_Vector*  b;
    FT_UInt     n = 0;


    FT_OUTLINE_GET_CONTOUR( outline, c, first, last );

    for ( a = first; a <= last; a++ )
    {
      FT_Pos  x;
      FT_Int  intersect;


      b = ( a == last ) ? first : a + 1;

      intersect = ( a->y - point->y ) ^ ( b->y - point->y );

      /* a and b are on the same side */
      if ( intersect >= 0 )
      {
        if ( intersect == 0 && a->y == point->y )
        {
          if ( ( a->x <= point->x && b->x >= point->x ) ||
               ( a->x >= point->x && b->x <= point->x ) )
            return 1;
        }

        continue;
      }

      x = a->x + ( b->x - a->x ) * (point->y - a->y ) / ( b->y - a->y );

      if ( x < point->x )
        n++;
      else if ( x == point->x )
        return 1;
    }

    return ( n % 2 );
  }


  static FT_Bool
  ft_contour_enclosed( FT_Outline*  outline,
                       FT_UShort    c )
  {
    FT_Vector*  first;
    FT_Vector*  last;
    FT_Short    i;


    FT_OUTLINE_GET_CONTOUR( outline, c, first, last );

    for ( i = 0; i < outline->n_contours; i++ )
    {
      if ( i != c && ft_contour_has( outline, i, first ) )
      {
        FT_Vector*  pt;


        for ( pt = first + 1; pt <= last; pt++ )
          if ( !ft_contour_has( outline, i, pt ) )
            return 0;

        return 1;
      }
    }

    return 0;
  }


  /* This version differs from the public one in that each */
  /* part (contour not enclosed in another contour) of the */
  /* outline is checked for orientation.  This is          */
  /* necessary for some buggy CJK fonts.                   */
  static FT_Orientation
  ft_outline_get_orientation( FT_Outline*  outline )
  {
    FT_Short        i;
    FT_Vector*      first;
    FT_Vector*      last;
    FT_Orientation  orient = FT_ORIENTATION_NONE;


    first = outline->points;
    for ( i = 0; i < outline->n_contours; i++, first = last + 1 )
    {
      FT_Vector*  point;
      FT_Vector*  xmin_point;
      FT_Pos      xmin;


      last = outline->points + outline->contours[i];

      /* skip degenerate contours */
      if ( last < first + 2 )
        continue;

      if ( ft_contour_enclosed( outline, i ) )
        continue;

      xmin       = first->x;
      xmin_point = first;

      for ( point = first + 1; point <= last; point++ )
      {
        if ( point->x < xmin )
        {
          xmin       = point->x;
          xmin_point = point;
        }
      }

      /* check the orientation of the contour */
      {
        FT_Vector*      prev;
        FT_Vector*      next;
        FT_Orientation  o;


        prev = ( xmin_point == first ) ? last : xmin_point - 1;
        next = ( xmin_point == last ) ? first : xmin_point + 1;

        if ( FT_Atan2( prev->x - xmin_point->x, prev->y - xmin_point->y ) >
             FT_Atan2( next->x - xmin_point->x, next->y - xmin_point->y ) )
          o = FT_ORIENTATION_POSTSCRIPT;
        else
          o = FT_ORIENTATION_TRUETYPE;

        if ( orient == FT_ORIENTATION_NONE )
          orient = o;
        else if ( orient != o )
          return FT_ORIENTATION_NONE;
      }
    }

    return orient;
  }

#endif /* 0 */


  /* documentation is in ftoutln.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Outline_Embolden( FT_Outline*  outline,
                       FT_Pos       strength )
  {
    FT_Vector*  points;
    FT_Vector   v_prev, v_first, v_next, v_cur;
    FT_Angle    rotate, angle_in, angle_out;
    FT_Int      c, n, first;
    FT_Int      orientation;


    if ( !outline )
      return FT_Err_Invalid_Argument;

    strength /= 2;
    if ( strength == 0 )
      return FT_Err_Ok;

    orientation = FT_Outline_Get_Orientation( outline );
    if ( orientation == FT_ORIENTATION_NONE )
    {
      if ( outline->n_contours )
        return FT_Err_Invalid_Argument;
      else
        return FT_Err_Ok;
    }

    if ( orientation == FT_ORIENTATION_TRUETYPE )
      rotate = -FT_ANGLE_PI2;
    else
      rotate = FT_ANGLE_PI2;

    points = outline->points;

    first = 0;
    for ( c = 0; c < outline->n_contours; c++ )
    {
      int  last = outline->contours[c];


      v_first = points[first];
      v_prev  = points[last];
      v_cur   = v_first;

      for ( n = first; n <= last; n++ )
      {
        FT_Vector  in, out;
        FT_Angle   angle_diff;
        FT_Pos     d;
        FT_Fixed   scale;


        if ( n < last )
          v_next = points[n + 1];
        else
          v_next = v_first;

        /* compute the in and out vectors */
        in.x = v_cur.x - v_prev.x;
        in.y = v_cur.y - v_prev.y;

        out.x = v_next.x - v_cur.x;
        out.y = v_next.y - v_cur.y;

        angle_in   = FT_Atan2( in.x, in.y );
        angle_out  = FT_Atan2( out.x, out.y );
        angle_diff = FT_Angle_Diff( angle_in, angle_out );
        scale      = FT_Cos( angle_diff / 2 );

        if ( scale < 0x4000L && scale > -0x4000L )
          in.x = in.y = 0;
        else
        {
          d = FT_DivFix( strength, scale );

          FT_Vector_From_Polar( &in, d, angle_in + angle_diff / 2 - rotate );
        }

        outline->points[n].x = v_cur.x + strength + in.x;
        outline->points[n].y = v_cur.y + strength + in.y;

        v_prev = v_cur;
        v_cur  = v_next;
      }

      first = last + 1;
    }

    return FT_Err_Ok;
  }


  /* documentation is in ftoutln.h */

  FT_EXPORT_DEF( FT_Orientation )
  FT_Outline_Get_Orientation( FT_Outline*  outline )
  {
    FT_Pos      xmin       = 32768L;
    FT_Pos      xmin_ymin  = 32768L;
    FT_Pos      xmin_ymax  = -32768L;
    FT_Vector*  xmin_first = NULL;
    FT_Vector*  xmin_last  = NULL;

    short*      contour;

    FT_Vector*  first;
    FT_Vector*  last;
    FT_Vector*  prev;
    FT_Vector*  point;

    int             i;
    FT_Pos          ray_y[3];
    FT_Orientation  result[3];


    if ( !outline || outline->n_points <= 0 )
      return FT_ORIENTATION_TRUETYPE;

    /* We use the nonzero winding rule to find the orientation.       */
    /* Since glyph outlines behave much more `regular' than arbitrary */
    /* cubic or quadratic curves, this test deals with the polygon    */
    /* only which is spanned up by the control points.                */

    first = outline->points;
    for ( contour = outline->contours;
          contour < outline->contours + outline->n_contours;
          contour++, first = last + 1 )
    {
      FT_Pos  contour_xmin = 32768L;
      FT_Pos  contour_xmax = -32768L;
      FT_Pos  contour_ymin = 32768L;
      FT_Pos  contour_ymax = -32768L;


      last = outline->points + *contour;

      /* skip degenerate contours */
      if ( last < first + 2 )
        continue;

      for ( point = first; point <= last; ++point )
      {
        if ( point->x < contour_xmin )
          contour_xmin = point->x;

        if ( point->x > contour_xmax )
          contour_xmax = point->x;

        if ( point->y < contour_ymin )
          contour_ymin = point->y;

        if ( point->y > contour_ymax )
          contour_ymax = point->y;
      }

      if ( contour_xmin < xmin          &&
           contour_xmin != contour_xmax &&
           contour_ymin != contour_ymax )
      {
        xmin       = contour_xmin;
        xmin_ymin  = contour_ymin;
        xmin_ymax  = contour_ymax;
        xmin_first = first;
        xmin_last  = last;
      }
    }

    if ( xmin == 32768 )
      return FT_ORIENTATION_TRUETYPE;

    ray_y[0] = ( xmin_ymin * 3 + xmin_ymax     ) >> 2;
    ray_y[1] = ( xmin_ymin     + xmin_ymax     ) >> 1;
    ray_y[2] = ( xmin_ymin     + xmin_ymax * 3 ) >> 2;

    for ( i = 0; i < 3; i++ )
    {
      FT_Pos      left_x;
      FT_Pos      right_x;
      FT_Vector*  left1;
      FT_Vector*  left2;
      FT_Vector*  right1;
      FT_Vector*  right2;


    RedoRay:
      left_x  = 32768L;
      right_x = -32768L;

      left1 = left2 = right1 = right2 = NULL;

      prev = xmin_last;
      for ( point = xmin_first; point <= xmin_last; prev = point, ++point )
      {
        FT_Pos  tmp_x;


        if ( point->y == ray_y[i] || prev->y == ray_y[i] )
        {
          ray_y[i]++;
          goto RedoRay;
        }

        if ( ( point->y < ray_y[i] && prev->y < ray_y[i] ) ||
             ( point->y > ray_y[i] && prev->y > ray_y[i] ) )
          continue;

        tmp_x = FT_MulDiv( point->x - prev->x,
                           ray_y[i] - prev->y,
                           point->y - prev->y ) + prev->x;

        if ( tmp_x < left_x )
        {
          left_x = tmp_x;
          left1  = prev;
          left2  = point;
        }

        if ( tmp_x > right_x )
        {
          right_x = tmp_x;
          right1  = prev;
          right2  = point;
        }
      }

      if ( left1 && right1 )
      {
        if ( left1->y < left2->y && right1->y > right2->y )
          result[i] = FT_ORIENTATION_TRUETYPE;
        else if ( left1->y > left2->y && right1->y < right2->y )
          result[i] = FT_ORIENTATION_POSTSCRIPT;
        else
          result[i] = FT_ORIENTATION_NONE;
      }
    }

    if ( result[0] != FT_ORIENTATION_NONE                     &&
         ( result[0] == result[1] || result[0] == result[2] ) )
      return result[0];

    if ( result[1] != FT_ORIENTATION_NONE && result[1] == result[2] )
      return result[1];

    return FT_ORIENTATION_TRUETYPE;
  }


/* END */