afhints.c

奇趣公司比较新的qt/emd版本

  }


  FT_LOCAL_DEF( void )
  af_glyph_hints_save( AF_GlyphHints  hints,
                       FT_Outline*    outline )
  {
    AF_Point    point = hints->points;
    AF_Point    limit = point + hints->num_points;
    FT_Vector*  vec   = outline->points;
    char*       tag   = outline->tags;


    for ( ; point < limit; point++, vec++, tag++ )
    {
      vec->x = point->x;
      vec->y = point->y;

      if ( point->flags & AF_FLAG_CONIC )
        tag[0] = FT_CURVE_TAG_CONIC;
      else if ( point->flags & AF_FLAG_CUBIC )
        tag[0] = FT_CURVE_TAG_CUBIC;
      else
        tag[0] = FT_CURVE_TAG_ON;
    }
  }


  /****************************************************************
   *
   *                     EDGE POINT GRID-FITTING
   *
   ****************************************************************/


  FT_LOCAL_DEF( void )
  af_glyph_hints_align_edge_points( AF_GlyphHints  hints,
                                    AF_Dimension   dim )
  {
    AF_AxisHints  axis       = & hints->axis[dim];
    AF_Edge       edges      = axis->edges;
    AF_Edge       edge_limit = edges + axis->num_edges;
    AF_Edge       edge;


    for ( edge = edges; edge < edge_limit; edge++ )
    {
      /* move the points of each segment     */
      /* in each edge to the edge's position */
      AF_Segment  seg = edge->first;


      do
      {
        AF_Point  point = seg->first;


        for (;;)
        {
          if ( dim == AF_DIMENSION_HORZ )
          {
            point->x      = edge->pos;
            point->flags |= AF_FLAG_TOUCH_X;
          }
          else
          {
            point->y      = edge->pos;
            point->flags |= AF_FLAG_TOUCH_Y;
          }

          if ( point == seg->last )
            break;

          point = point->next;
        }

        seg = seg->edge_next;

      } while ( seg != edge->first );
    }
  }


  /****************************************************************
   *
   *                    STRONG POINT INTERPOLATION
   *
   ****************************************************************/


  /* hint the strong points -- this is equivalent to the TrueType `IP' */
  /* hinting instruction                                               */

  FT_LOCAL_DEF( void )
  af_glyph_hints_align_strong_points( AF_GlyphHints  hints,
                                      AF_Dimension   dim )
  {
    AF_Point      points      = hints->points;
    AF_Point      point_limit = points + hints->num_points;
    AF_AxisHints  axis        = &hints->axis[dim];
    AF_Edge       edges       = axis->edges;
    AF_Edge       edge_limit  = edges + axis->num_edges;
    AF_Flags      touch_flag;


    if ( dim == AF_DIMENSION_HORZ )
      touch_flag = AF_FLAG_TOUCH_X;
    else
      touch_flag  = AF_FLAG_TOUCH_Y;

    if ( edges < edge_limit )
    {
      AF_Point  point;
      AF_Edge   edge;


      for ( point = points; point < point_limit; point++ )
      {
        FT_Pos  u, ou, fu;  /* point position */
        FT_Pos  delta;


        if ( point->flags & touch_flag )
          continue;

        /* if this point is candidate to weak interpolation, we       */
        /* interpolate it after all strong points have been processed */

        if (  ( point->flags & AF_FLAG_WEAK_INTERPOLATION ) &&
             !( point->flags & AF_FLAG_INFLECTION )         )
          continue;

        if ( dim == AF_DIMENSION_VERT )
        {
          u  = point->fy;
          ou = point->oy;
        }
        else
        {
          u  = point->fx;
          ou = point->ox;
        }

        fu = u;

        /* is the point before the first edge? */
        edge  = edges;
        delta = edge->fpos - u;
        if ( delta >= 0 )
        {
          u = edge->pos - ( edge->opos - ou );
          goto Store_Point;
        }

        /* is the point after the last edge? */
        edge  = edge_limit - 1;
        delta = u - edge->fpos;
        if ( delta >= 0 )
        {
          u = edge->pos + ( ou - edge->opos );
          goto Store_Point;
        }

        {
          FT_UInt  min, max, mid;
          FT_Pos   fpos;


          /* find enclosing edges */
          min = 0;
          max = edge_limit - edges;

          while ( min < max )
          {
            mid  = ( max + min ) >> 1;
            edge = edges + mid;
            fpos = edge->fpos;

            if ( u < fpos )
              max = mid;
            else if ( u > fpos )
              min = mid + 1;
            else
            {
              /* we are on the edge */
              u = edge->pos;
              goto Store_Point;
            }
          }

          {
            AF_Edge  before = edges + min - 1;
            AF_Edge  after  = edges + min + 0;


            /* assert( before && after && before != after ) */
            if ( before->scale == 0 )
              before->scale = FT_DivFix( after->pos - before->pos,
                                         after->fpos - before->fpos );

            u = before->pos + FT_MulFix( fu - before->fpos,
                                         before->scale );
          }
        }

      Store_Point:
        /* save the point position */
        if ( dim == AF_DIMENSION_HORZ )
          point->x = u;
        else
          point->y = u;

        point->flags |= touch_flag;
      }
    }
  }


  /****************************************************************
   *
   *                    WEAK POINT INTERPOLATION
   *
   ****************************************************************/


  static void
  af_iup_shift( AF_Point  p1,
                AF_Point  p2,
                AF_Point  ref )
  {
    AF_Point  p;
    FT_Pos    delta = ref->u - ref->v;


    for ( p = p1; p < ref; p++ )
      p->u = p->v + delta;

    for ( p = ref + 1; p <= p2; p++ )
      p->u = p->v + delta;
  }


  static void
  af_iup_interp( AF_Point  p1,
                 AF_Point  p2,
                 AF_Point  ref1,
                 AF_Point  ref2 )
  {
    AF_Point  p;
    FT_Pos    u;
    FT_Pos    v1 = ref1->v;
    FT_Pos    v2 = ref2->v;
    FT_Pos    d1 = ref1->u - v1;
    FT_Pos    d2 = ref2->u - v2;


    if ( p1 > p2 )
      return;

    if ( v1 == v2 )
    {
      for ( p = p1; p <= p2; p++ )
      {
        u = p->v;

        if ( u <= v1 )
          u += d1;
        else
          u += d2;

        p->u = u;
      }
      return;
    }

    if ( v1 < v2 )
    {
      for ( p = p1; p <= p2; p++ )
      {
        u = p->v;

        if ( u <= v1 )
          u += d1;
        else if ( u >= v2 )
          u += d2;
        else
          u = ref1->u + FT_MulDiv( u - v1, ref2->u - ref1->u, v2 - v1 );

        p->u = u;
      }
    }
    else
    {
      for ( p = p1; p <= p2; p++ )
      {
        u = p->v;

        if ( u <= v2 )
          u += d2;
        else if ( u >= v1 )
          u += d1;
        else
          u = ref1->u + FT_MulDiv( u - v1, ref2->u - ref1->u, v2 - v1 );

        p->u = u;
      }
    }
  }


  FT_LOCAL_DEF( void )
  af_glyph_hints_align_weak_points( AF_GlyphHints  hints,
                                    AF_Dimension   dim )
  {
    AF_Point   points        = hints->points;
    AF_Point   point_limit   = points + hints->num_points;
    AF_Point*  contour       = hints->contours;
    AF_Point*  contour_limit = contour + hints->num_contours;
    AF_Flags   touch_flag;
    AF_Point   point;
    AF_Point   end_point;
    AF_Point   first_point;


    /* PASS 1: Move segment points to edge positions */

    if ( dim == AF_DIMENSION_HORZ )
    {
      touch_flag = AF_FLAG_TOUCH_X;

      for ( point = points; point < point_limit; point++ )
      {
        point->u = point->x;
        point->v = point->ox;
      }
    }
    else
    {
      touch_flag = AF_FLAG_TOUCH_Y;

      for ( point = points; point < point_limit; point++ )
      {
        point->u = point->y;
        point->v = point->oy;
      }
    }

    point = points;

    for ( ; contour < contour_limit; contour++ )
    {
      point       = *contour;
      end_point   = point->prev;
      first_point = point;

      while ( point <= end_point && !( point->flags & touch_flag ) )
        point++;

      if ( point <= end_point )
      {
        AF_Point  first_touched = point;
        AF_Point  cur_touched   = point;


        point++;
        while ( point <= end_point )
        {
          if ( point->flags & touch_flag )
          {
            /* we found two successive touched points; we interpolate */
            /* all contour points between them                        */
            af_iup_interp( cur_touched + 1, point - 1,
                           cur_touched, point );
            cur_touched = point;
          }
          point++;
        }

        if ( cur_touched == first_touched )
        {
          /* this is a special case: only one point was touched in the */
          /* contour; we thus simply shift the whole contour           */
          af_iup_shift( first_point, end_point, cur_touched );
        }
        else
        {
          /* now interpolate after the last touched point to the end */
          /* of the contour                                          */
          af_iup_interp( cur_touched + 1, end_point,
                         cur_touched, first_touched );

          /* if the first contour point isn't touched, interpolate */
          /* from the contour start to the first touched point     */
          if ( first_touched > points )
            af_iup_interp( first_point, first_touched - 1,
                           cur_touched, first_touched );
        }
      }
    }

    /* now save the interpolated values back to x/y */
    if ( dim == AF_DIMENSION_HORZ )
    {
      for ( point = points; point < point_limit; point++ )
        point->x = point->u;
    }
    else
    {
      for ( point = points; point < point_limit; point++ )
        point->y = point->u;
    }
  }


#ifdef AF_USE_WARPER

  FT_LOCAL_DEF( void )
  af_glyph_hints_scale_dim( AF_GlyphHints  hints,
                            AF_Dimension   dim,
                            FT_Fixed       scale,
                            FT_Pos         delta )
  {
    AF_Point  points       = hints->points;
    AF_Point  points_limit = points + hints->num_points;
    AF_Point  point;


    if ( dim == AF_DIMENSION_HORZ )
    {
      for ( point = points; point < points_limit; point++ )
        point->x = FT_MulFix( point->fx, scale ) + delta;
    }
    else
    {
      for ( point = points; point < points_limit; point++ )
        point->y = FT_MulFix( point->fy, scale ) + delta;
    }
  }

#endif /* AF_USE_WARPER */

/* END */