aflatin.c

奇趣公司比较新的qt/emd版本

    {
      scale = scaler->x_scale;
      delta = scaler->x_delta;
    }
    else
    {
      scale = scaler->y_scale;
      delta = scaler->y_delta;
    }

    axis = &metrics->axis[dim];

    if ( axis->org_scale == scale && axis->org_delta == delta )
      return;

    axis->org_scale = scale;
    axis->org_delta = delta;

    /*
     * correct X and Y scale to optimize the alignment of the top of small
     * letters to the pixel grid
     */
    {
      AF_LatinAxis  Axis = &metrics->axis[AF_DIMENSION_VERT];
      AF_LatinBlue  blue = NULL;


      for ( nn = 0; nn < Axis->blue_count; nn++ )
      {
        if ( Axis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT )
        {
          blue = &Axis->blues[nn];
          break;
        }
      }

      if ( blue )
      {
        FT_Pos  scaled = FT_MulFix( blue->shoot.org, scaler->y_scale );
        FT_Pos  fitted = ( scaled + 40 ) & ~63;


        if ( scaled != fitted )
        {
          if ( dim == AF_DIMENSION_HORZ )
          {
            if ( fitted < scaled )
              scale -= scale / 50;  /* scale *= 0.98 */
          }
          else
          {
            scale = FT_MulDiv( scale, fitted, scaled );
          }
        }
      }
    }

    axis->scale = scale;
    axis->delta = delta;

    if ( dim == AF_DIMENSION_HORZ )
    {
      metrics->root.scaler.x_scale = scale;
      metrics->root.scaler.x_delta = delta;
    }
    else
    {
      metrics->root.scaler.y_scale = scale;
      metrics->root.scaler.y_delta = delta;
    }

    /* scale the standard widths */
    for ( nn = 0; nn < axis->width_count; nn++ )
    {
      AF_Width  width = axis->widths + nn;


      width->cur = FT_MulFix( width->org, scale );
      width->fit = width->cur;
    }

    /* an extra-light axis corresponds to a standard width that is */
    /* smaller than 0.75 pixels                                    */
    axis->extra_light = FT_MulFix( axis->standard_width, scale ) < 32 + 8;

    if ( dim == AF_DIMENSION_VERT )
    {
      /* scale the blue zones */
      for ( nn = 0; nn < axis->blue_count; nn++ )
      {
        AF_LatinBlue  blue = &axis->blues[nn];
        FT_Pos        dist;


        blue->ref.cur   = FT_MulFix( blue->ref.org, scale ) + delta;
        blue->ref.fit   = blue->ref.cur;
        blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
        blue->shoot.fit = blue->shoot.cur;
        blue->flags    &= ~AF_LATIN_BLUE_ACTIVE;

        /* a blue zone is only active if it is less than 3/4 pixels tall */
        dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
        if ( dist <= 48 && dist >= -48 )
        {
          FT_Pos  delta1, delta2;


          delta1 = blue->shoot.org - blue->ref.org;
          delta2 = delta1;
          if ( delta1 < 0 )
            delta2 = -delta2;

          delta2 = FT_MulFix( delta2, scale );

          if ( delta2 < 32 )
            delta2 = 0;
          else if ( delta2 < 64 )
            delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
          else
            delta2 = FT_PIX_ROUND( delta2 );

          if ( delta1 < 0 )
            delta2 = -delta2;

          blue->ref.fit   = FT_PIX_ROUND( blue->ref.cur );
          blue->shoot.fit = blue->ref.fit + delta2;

          blue->flags |= AF_LATIN_BLUE_ACTIVE;
        }
      }
    }
  }


  FT_LOCAL_DEF( void )
  af_latin_metrics_scale( AF_LatinMetrics  metrics,
                          AF_Scaler        scaler )
  {
    metrics->root.scaler.render_mode = scaler->render_mode;
    metrics->root.scaler.face        = scaler->face;

    af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
    af_latin_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  FT_LOCAL_DEF( FT_Error )
  af_latin_hints_compute_segments( AF_GlyphHints  hints,
                                   AF_Dimension   dim )
  {
    AF_AxisHints  axis          = &hints->axis[dim];
    FT_Memory     memory        = hints->memory;
    FT_Error      error         = AF_Err_Ok;
    AF_Segment    segment       = NULL;
    AF_SegmentRec seg0;
    AF_Point*     contour       = hints->contours;
    AF_Point*     contour_limit = contour + hints->num_contours;
    AF_Direction  major_dir, segment_dir;

#ifdef AF_HINT_METRICS
    AF_Point  min_point =  0;
    AF_Point  max_point =  0;
    FT_Pos    min_coord =  32000;
    FT_Pos    max_coord = -32000;
#endif


    FT_ZERO( &seg0 );
    seg0.score = 32000;
    seg0.flags = AF_EDGE_NORMAL;

    major_dir   = (AF_Direction)FT_ABS( axis->major_dir );
    segment_dir = major_dir;

    axis->num_segments = 0;

    /* set up (u,v) in each point */
    if ( dim == AF_DIMENSION_HORZ )
    {
      AF_Point  point = hints->points;
      AF_Point  limit = point + hints->num_points;


      for ( ; point < limit; point++ )
      {
        point->u = point->fx;
        point->v = point->fy;
      }
    }
    else
    {
      AF_Point  point = hints->points;
      AF_Point  limit = point + hints->num_points;


      for ( ; point < limit; point++ )
      {
        point->u = point->fy;
        point->v = point->fx;
      }
    }

    /* do each contour separately */
    for ( ; contour < contour_limit; contour++ )
    {
      AF_Point  point   =  contour[0];
      AF_Point  last    =  point->prev;
      int       on_edge =  0;
      FT_Pos    min_pos =  32000;  /* minimum segment pos != min_coord */
      FT_Pos    max_pos = -32000;  /* maximum segment pos != max_coord */
      FT_Bool   passed;


#ifdef AF_HINT_METRICS
      if ( point->u < min_coord )
      {
        min_coord = point->u;
        min_point = point;
      }
      if ( point->u > max_coord )
      {
        max_coord = point->u;
        max_point = point;
      }
#endif

      if ( point == last )  /* skip singletons -- just in case */
        continue;

      if ( FT_ABS( last->out_dir )  == major_dir &&
           FT_ABS( point->out_dir ) == major_dir )
      {
        /* we are already on an edge, try to locate its start */
        last = point;

        for (;;)
        {
          point = point->prev;
          if ( FT_ABS( point->out_dir ) != major_dir )
          {
            point = point->next;
            break;
          }
          if ( point == last )
            break;
        }
      }

      last   = point;
      passed = 0;

      for (;;)
      {
        FT_Pos  u, v;


        if ( on_edge )
        {
          u = point->u;
          if ( u < min_pos )
            min_pos = u;
          if ( u > max_pos )
            max_pos = u;

          if ( point->out_dir != segment_dir || point == last )
          {
            /* we are just leaving an edge; record a new segment! */
            segment->last = point;
            segment->pos  = (FT_Short)( ( min_pos + max_pos ) >> 1 );

            /* a segment is round if either its first or last point */
            /* is a control point                                   */
            if ( ( segment->first->flags | point->flags ) &
                   AF_FLAG_CONTROL                        )
              segment->flags |= AF_EDGE_ROUND;

            /* compute segment size */
            min_pos = max_pos = point->v;

            v = segment->first->v;
            if ( v < min_pos )
              min_pos = v;
            if ( v > max_pos )
              max_pos = v;

            segment->min_coord = (FT_Short)min_pos;
            segment->max_coord = (FT_Short)max_pos;
            segment->height    = (FT_Short)( segment->max_coord -
                                             segment->min_coord );

            on_edge = 0;
            segment = NULL;
            /* fallthrough */
          }
        }

        /* now exit if we are at the start/end point */
        if ( point == last )
        {
          if ( passed )
            break;
          passed = 1;
        }

        if ( !on_edge && FT_ABS( point->out_dir ) == major_dir )
        {
          /* this is the start of a new segment! */
          segment_dir = (AF_Direction)point->out_dir;

          /* clear all segment fields */
          error = af_axis_hints_new_segment( axis, memory, &segment );
          if ( error )
            goto Exit;

          segment[0]        = seg0;
          segment->dir      = (FT_Char)segment_dir;
          min_pos = max_pos = point->u;
          segment->first    = point;
          segment->last     = point;
          segment->contour  = contour;
          on_edge           = 1;

#ifdef AF_HINT_METRICS
          if ( point == max_point )
            max_point = 0;

          if ( point == min_point )
            min_point = 0;
#endif
        }

        point = point->next;
      }

    } /* contours */


    /* now slightly increase the height of segments when this makes */
    /* sense -- this is used to better detect and ignore serifs     */
    {
      AF_Segment  segments     = axis->segments;
      AF_Segment  segments_end = segments + axis->num_segments;


      for ( segment = segments; segment < segments_end; segment++ )
      {
        AF_Point  first   = segment->first;
        AF_Point  last    = segment->last;
        FT_Pos    first_v = first->v;
        FT_Pos    last_v  = last->v;


        if ( first == last )
          continue;

        if ( first_v < last_v )
        {
          AF_Point  p;


          p = first->prev;
          if ( p->v < first_v )
            segment->height = (FT_Short)( segment->height +
                                          ( ( first_v - p->v ) >> 1 ) );

          p = last->next;
          if ( p->v > last_v )
            segment->height = (FT_Short)( segment->height +
                                          ( ( p->v - last_v ) >> 1 ) );
        }
        else
        {
          AF_Point  p;


          p = first->prev;
          if ( p->v > first_v )
            segment->height = (FT_Short)( segment->height +
                                          ( ( p->v - first_v ) >> 1 ) );

          p = last->next;
          if ( p->v < last_v )
            segment->height = (FT_Short)( segment->height +
                                          ( ( last_v - p->v ) >> 1 ) );
        }
      }
    }

#ifdef AF_HINT_METRICS
    /* we need to ensure that there are edges on the left-most and  */
    /* right-most points of the glyph in order to hint the metrics; */
    /* we do this by inserting fake segments when needed            */

    if ( dim == AF_DIMENSION_HORZ )
    {
      AF_Point  point       = hints->points;
      AF_Point  point_limit = point + hints->num_points;

      FT_Pos    min_pos =  32000;
      FT_Pos    max_pos = -32000;


      min_point = 0;
      max_point = 0;

      /* compute minimum and maximum points */
      for ( ; point < point_limit; point++ )
      {
        FT_Pos  x = point->fx;


        if ( x < min_pos )
        {
          min_pos   = x;
          min_point = point;
        }
        if ( x > max_pos )
        {
          max_pos   = x;
          max_point = point;
        }
      }

      /* insert minimum segment */
      if ( min_point )
      {
        /* clear all segment fields */
        error = af_axis_hints_new_segment( axis, memory, &segment );
        if ( error )
          goto Exit;

        segment[0]     = seg0;
        segment->dir   = segment_dir;
        segment->first = min_point;
        segment->last  = min_point;
        segment->pos   = min_pos;

        segment = NULL;