aflatin.c

智能设备中PDF阅读器的源码！用于windows mobile2003或者WM5以上

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

    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_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

    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;

            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->dir      = (FT_Char)segment_dir;
          segment->flags    = AF_EDGE_NORMAL;
          min_pos = max_pos = point->u;
          segment->first    = point;
          segment->last     = point;
          segment->contour  = contour;
          segment->score    = 32000;
          segment->len      = 0;
          segment->link     = NULL;
          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 */

#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->dir   = segment_dir;
        segment->flags = AF_EDGE_NORMAL;
        segment->first = min_point;
        segment->last  = min_point;
        segment->pos   = min_pos;
        segment->score = 32000;
        segment->len   = 0;
        segment->link  = NULL;

        segment = NULL;
      }

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

        segment->dir   = segment_dir;
        segment->flags = AF_EDGE_NORMAL;
        segment->first = max_point;
        segment->last  = max_point;
        segment->pos   = max_pos;
        segment->score = 32000;
        segment->len   = 0;
        segment->link  = NULL;

        segment = NULL;
      }
    }
#endif /* AF_HINT_METRICS */

  Exit:
    return error;
  }


  FT_LOCAL_DEF( void )
  af_latin_hints_link_segments( AF_GlyphHints  hints,
                                AF_Dimension   dim )
  {
    AF_AxisHints  axis          = &hints->axis[dim];
    AF_Segment    segments      = axis->segments;
    AF_Segment    segment_limit = segments + axis->num_segments;
    AF_Direction  major_dir     = axis->major_dir;
    FT_Pos        len_threshold, len_score;
    AF_Segment    seg1, seg2;


    len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
    if ( len_threshold == 0 )
      len_threshold = 1;

    len_score = AF_LATIN_CONSTANT( hints->metrics, 3000 );

    /* now compare each segment to the others */
    for ( seg1 = segments; seg1 < segment_limit; seg1++ )
    {
      /* the fake segments are introduced to hint the metrics -- */
      /* we must never link them to anything                     */
      if ( seg1->first == seg1->last || seg1->dir != major_dir )
        continue;

      for ( seg2 = segments; seg2 < segment_limit; seg2++ )
        if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
        {
          FT_Pos  pos1 = seg1->pos;
          FT_Pos  pos2 = seg2->pos;
          FT_Pos  dist = pos2 - pos1;


          if ( dist < 0 )
            continue;

          {
            FT_Pos  min = seg1->min_coord;
            FT_Pos  max = seg1->max_coord;
            FT_Pos  len, score;


            if ( min < seg2->min_coord )
              min = seg2->min_coord;

            if ( max > seg2->max_coord )
              max = seg2->max_coord;

            len = max - min;
            if ( len >= len_threshold )
            {
              score = dist + len_score / len;

              if ( score < seg1->score )
              {
                seg1->score = score;
                seg1->link  = seg2;
              }

              if ( score < seg2->score )
              {
                seg2->score = score;
                seg2->link  = seg1;
              }
            }
          }
        }
    }

    /* now, compute the `serif' segments */
    for ( seg1 = segments; seg1 < segment_limit; seg1++ )
    {
      seg2 = seg1->link;

      if ( seg2 )
      {
        seg2->num_linked++;
        if ( seg2->link != seg1 )
        {
          seg1->link  = 0;
          seg1->serif = seg2->link;
        }
      }
    }
  }


  FT_LOCAL_DEF( FT_Error )
  af_latin_hints_compute_edges( AF_GlyphHints  hints,
                                AF_Dimension   dim )
  {
    AF_AxisHints  axis   = &hints->axis[dim];
    FT_Error      error  = AF_Err_Ok;
    FT_Memory     memory = hints->memory;
    AF_LatinAxis  laxis  = &((AF_LatinMetrics)hints->metrics)->axis[dim];

    AF_Segment    segments      = axis->segments;
    AF_Segment    segment_limit = segments + axis->num_segments;
    AF_Segment    seg;

    AF_Direction  up_dir;
    FT_Fixed      scale;
    FT_Pos        edge_distance_threshold;


    axis->num_edges = 0;

    scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
                                         : hints->y_scale;

    up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP
                                          : AF_DIR_RIGHT;

    /*********************************************************************/
    /*                                                                   */
    /* We will begin by generating a sorted table of edges for the       */
    /* current direction.  To do so, we simply scan each segment and try */
    /* to find an edge in our table that corresponds to its position.    */
    /*                                                                   */
    /* If no edge is found, we create and insert a new edge in the       */
    /* sorted table.  Otherwise, we simply add the segment to the edge's */
    /* list which will be processed in the second step to compute the    */
    /* edge's properties.                                                */
    /*                                                                   */
    /* Note that the edges table is sorted along the segment/edge        */
    /* position.                                                         */
    /*                                                                   */
    /*********************************************************************/

    edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
                                         scale );
    if ( edge_distance_threshold > 64 / 4 )
      edge_distance_threshold = 64 / 4;

    edge_distance_threshold = FT_DivFix( edge_distance_threshold,
                                         scale );

    for ( seg = segments; seg < segment_limit; seg++ )
    {
      AF_Edge  found = 0;
      FT_Int   ee;


      /* look for an edge corresponding to the segment */
      for ( ee = 0; ee < axis->num_edges; ee++ )
      {
        AF_Edge  edge = axis->edges + ee;
        FT_Pos   dist;


        dist = seg->pos - edge->fpos;
        if ( dist < 0 )
          dist = -dist;

        if ( dist < edge_distance_threshold )
        {
          found = edge;
          break;
        }
      }

      if ( !found )
      {
        AF_Edge   edge;