afhints.c

奇趣公司比较新的qt/emd版本

          do
          {
            end   = after;
            after = after->next;
            if ( after == first )
              finished = 1;

            out_x = after->fx - end->fx;
            out_y = after->fy - end->fy;

          } while ( out_x == 0 && out_y == 0 );

          orient_cur = ft_corner_orientation( in_x, in_y, out_x, out_y );

        } while ( orient_cur == 0 );

        if ( ( orient_prev + orient_cur ) == 0 )
        {
          /* we have an inflection point here */
          do
          {
            start->flags |= AF_FLAG_INFLECTION;
            start = start->next;

          } while ( start != end );

          start->flags |= AF_FLAG_INFLECTION;
        }

        start = end;
        end   = after;

        orient_prev = orient_cur;
        in_x        = out_x;
        in_y        = out_y;

      } while ( !finished );

    Skip:
      ;
    }
  }

#else /* old code */

  static void
  af_glyph_hints_compute_inflections( AF_GlyphHints  hints )
  {
    AF_Point*  contour       = hints->contours;
    AF_Point*  contour_limit = contour + hints->num_contours;


    /* do each contour separately */
    for ( ; contour < contour_limit; contour++ )
    {
      AF_Point  point = contour[0];
      AF_Point  first = point;
      AF_Point  start = point;
      AF_Point  end   = point;
      AF_Point  before;
      AF_Point  after;
      AF_Angle  angle_in, angle_seg, angle_out;
      AF_Angle  diff_in, diff_out;
      FT_Int    finished = 0;


      /* compute first segment in contour */
      first = point;

      start = end = first;
      do
      {
        end = end->next;
        if ( end == first )
          goto Skip;

      } while ( end->fx == first->fx && end->fy == first->fy );

      angle_seg = af_angle_atan( end->fx - start->fx,
                                 end->fy - start->fy );

      /* extend the segment start whenever possible */
      before = start;
      do
      {
        do
        {
          start  = before;
          before = before->prev;
          if ( before == first )
            goto Skip;

        } while ( before->fx == start->fx && before->fy == start->fy );

        angle_in = af_angle_atan( start->fx - before->fx,
                                  start->fy - before->fy );

      } while ( angle_in == angle_seg );

      first = start;

      AF_ANGLE_DIFF( diff_in, angle_in, angle_seg );

      /* now, process all segments in the contour */
      do
      {
        /* first, extend current segment's end whenever possible */
        after = end;
        do
        {
          do
          {
            end   = after;
            after = after->next;
            if ( after == first )
              finished = 1;

          } while ( end->fx == after->fx && end->fy == after->fy );

          angle_out = af_angle_atan( after->fx - end->fx,
                                     after->fy - end->fy );

        } while ( angle_out == angle_seg );

        AF_ANGLE_DIFF( diff_out, angle_seg, angle_out );

        if ( ( diff_in ^ diff_out ) < 0 )
        {
          /* diff_in and diff_out have different signs, we have */
          /* inflection points here...                          */
          do
          {
            start->flags |= AF_FLAG_INFLECTION;
            start = start->next;

          } while ( start != end );

          start->flags |= AF_FLAG_INFLECTION;
        }

        start     = end;
        end       = after;
        angle_seg = angle_out;
        diff_in   = diff_out;

      } while ( !finished );

    Skip:
      ;
    }
  }

#endif /* old code */


  FT_LOCAL_DEF( void )
  af_glyph_hints_init( AF_GlyphHints  hints,
                       FT_Memory      memory )
  {
    FT_ZERO( hints );
    hints->memory = memory;
  }


  FT_LOCAL_DEF( void )
  af_glyph_hints_done( AF_GlyphHints  hints )
  {
    if ( hints && hints->memory )
    {
      FT_Memory  memory = hints->memory;
      int        dim;


      /*
       *  note that we don't need to free the segment and edge
       *  buffers, since they are really within the hints->points array
       */
      for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
      {
        AF_AxisHints  axis = &hints->axis[dim];


        axis->num_segments = 0;
        axis->max_segments = 0;
        FT_FREE( axis->segments );

        axis->num_edges    = 0;
        axis->max_edges    = 0;
        FT_FREE( axis->edges );
      }

      FT_FREE( hints->contours );
      hints->max_contours = 0;
      hints->num_contours = 0;

      FT_FREE( hints->points );
      hints->num_points = 0;
      hints->max_points = 0;

      hints->memory = NULL;
    }
  }


  FT_LOCAL_DEF( void )
  af_glyph_hints_rescale( AF_GlyphHints     hints,
                          AF_ScriptMetrics  metrics )
  {
    hints->metrics      = metrics;
    hints->scaler_flags = metrics->scaler.flags;
  }


  FT_LOCAL_DEF( FT_Error )
  af_glyph_hints_reload( AF_GlyphHints  hints,
                         FT_Outline*    outline )
  {
    FT_Error   error   = AF_Err_Ok;
    AF_Point   points;
    FT_UInt    old_max, new_max;
    FT_Fixed   x_scale = hints->x_scale;
    FT_Fixed   y_scale = hints->y_scale;
    FT_Pos     x_delta = hints->x_delta;
    FT_Pos     y_delta = hints->y_delta;
    FT_Memory  memory  = hints->memory;


    hints->num_points   = 0;
    hints->num_contours = 0;

    hints->axis[0].num_segments = 0;
    hints->axis[0].num_edges    = 0;
    hints->axis[1].num_segments = 0;
    hints->axis[1].num_edges    = 0;

    /* first of all, reallocate the contours array when necessary */
    new_max = (FT_UInt)outline->n_contours;
    old_max = hints->max_contours;
    if ( new_max > old_max )
    {
      new_max = ( new_max + 3 ) & ~3;

      if ( FT_RENEW_ARRAY( hints->contours, old_max, new_max ) )
        goto Exit;

      hints->max_contours = new_max;
    }

    /*
     *  then reallocate the points arrays if necessary --
     *  note that we reserve two additional point positions, used to
     *  hint metrics appropriately
     */
    new_max = (FT_UInt)( outline->n_points + 2 );
    old_max = hints->max_points;
    if ( new_max > old_max )
    {
      new_max = ( new_max + 2 + 7 ) & ~7;

      if ( FT_RENEW_ARRAY( hints->points, old_max, new_max ) )
        goto Exit;

      hints->max_points = new_max;
    }

    hints->num_points   = outline->n_points;
    hints->num_contours = outline->n_contours;

    /* We can't rely on the value of `FT_Outline.flags' to know the fill   */
    /* direction used for a glyph, given that some fonts are broken (e.g., */
    /* the Arphic ones).  We thus recompute it each time we need to.       */
    /*                                                                     */
    hints->axis[AF_DIMENSION_HORZ].major_dir = AF_DIR_UP;
    hints->axis[AF_DIMENSION_VERT].major_dir = AF_DIR_LEFT;

    if ( FT_Outline_Get_Orientation( outline ) == FT_ORIENTATION_POSTSCRIPT )
    {
      hints->axis[AF_DIMENSION_HORZ].major_dir = AF_DIR_DOWN;
      hints->axis[AF_DIMENSION_VERT].major_dir = AF_DIR_RIGHT;
    }

    hints->x_scale = x_scale;
    hints->y_scale = y_scale;
    hints->x_delta = x_delta;
    hints->y_delta = y_delta;

    hints->xmin_delta = 0;
    hints->xmax_delta = 0;

    points = hints->points;
    if ( hints->num_points == 0 )
      goto Exit;

    {
      AF_Point  point;
      AF_Point  point_limit = points + hints->num_points;


      /* compute coordinates & Bezier flags */
      {
        FT_Vector*  vec = outline->points;
        char*       tag = outline->tags;


        for ( point = points; point < point_limit; point++, vec++, tag++ )
        {
          point->fx = (FT_Short)vec->x;
          point->fy = (FT_Short)vec->y;
          point->ox = point->x = FT_MulFix( vec->x, x_scale ) + x_delta;
          point->oy = point->y = FT_MulFix( vec->y, y_scale ) + y_delta;

          switch ( FT_CURVE_TAG( *tag ) )
          {
          case FT_CURVE_TAG_CONIC:
            point->flags = AF_FLAG_CONIC;
            break;
          case FT_CURVE_TAG_CUBIC:
            point->flags = AF_FLAG_CUBIC;
            break;
          default:
            point->flags = 0;
          }
        }
      }

      /* compute `next' and `prev' */
      {
        FT_Int    contour_index;
        AF_Point  prev;
        AF_Point  first;
        AF_Point  end;


        contour_index = 0;

        first = points;
        end   = points + outline->contours[0];
        prev  = end;

        for ( point = points; point < point_limit; point++ )
        {
          point->prev = prev;
          if ( point < end )
          {
            point->next = point + 1;
            prev        = point;
          }
          else
          {
            point->next = first;
            contour_index++;
            if ( point + 1 < point_limit )
            {
              end   = points + outline->contours[contour_index];
              first = point + 1;
              prev  = end;
            }
          }
        }
      }

      /* set-up the contours array */
      {
        AF_Point*  contour       = hints->contours;
        AF_Point*  contour_limit = contour + hints->num_contours;
        short*     end           = outline->contours;
        short      idx           = 0;


        for ( ; contour < contour_limit; contour++, end++ )
        {
          contour[0] = points + idx;
          idx        = (short)( end[0] + 1 );
        }
      }

      /* compute directions of in & out vectors */
      {
        for ( point = points; point < point_limit; point++ )
        {
          AF_Point  prev;
          AF_Point  next;
          FT_Pos    in_x, in_y, out_x, out_y;


          prev   = point->prev;
          in_x   = point->fx - prev->fx;
          in_y   = point->fy - prev->fy;

          point->in_dir = (FT_Char)af_direction_compute( in_x, in_y );

          next   = point->next;
          out_x  = next->fx - point->fx;
          out_y  = next->fy - point->fy;

          point->out_dir = (FT_Char)af_direction_compute( out_x, out_y );

          if ( point->flags & ( AF_FLAG_CONIC | AF_FLAG_CUBIC ) )
          {
          Is_Weak_Point:
            point->flags |= AF_FLAG_WEAK_INTERPOLATION;
          }
          else if ( point->out_dir == point->in_dir )
          {

#if 1

            if ( point->out_dir != AF_DIR_NONE )
              goto Is_Weak_Point;

            if ( ft_corner_is_flat( in_x, in_y, out_x, out_y ) )
              goto Is_Weak_Point;

#else /* old code */

            AF_Angle  angle_in, angle_out, delta;


            if ( point->out_dir != AF_DIR_NONE )
              goto Is_Weak_Point;

            angle_in  = af_angle_atan( in_x, in_y );
            angle_out = af_angle_atan( out_x, out_y );

            AF_ANGLE_DIFF( delta, angle_in, angle_out );

            if ( delta < 2 && delta > -2 )
              goto Is_Weak_Point;

#endif /* old code */

          }
          else if ( point->in_dir == -point->out_dir )
            goto Is_Weak_Point;
        }
      }
    }

    /* compute inflection points */
    af_glyph_hints_compute_inflections( hints );

  Exit:
    return error;