pshalgo.c

winNT技术操作系统,国外开放的原代码和LIUX一样

    if ( ax < 0 )
      ax = -ax;
    if ( ay < 0 )
      ay = -ay;
    d_in = ax + ay;

    ax = x_out;
    if ( ax < 0 )
      ax = -ax;
    ay = y_out;
    if ( ay < 0 )
      ay = -ay;
    d_out = ax + ay;

    ax = x_out + x_in;
    if ( ax < 0 )
      ax = -ax;
    ay = y_out + y_in;
    if ( ay < 0 )
      ay = -ay;
    d_corner = ax + ay;

    return ( d_in + d_out - d_corner ) < ( d_corner >> 4 );
  }

  static FT_Int
  psh_corner_orientation( FT_Pos  in_x,
                          FT_Pos  in_y,
                          FT_Pos  out_x,
                          FT_Pos  out_y )
  {
    FT_Int  result;


    /* deal with the trivial cases quickly */
    if ( in_y == 0 )
    {
      if ( in_x >= 0 )
        result = out_y;
      else
        result = -out_y;
    }
    else if ( in_x == 0 )
    {
      if ( in_y >= 0 )
        result = -out_x;
      else
        result = out_x;
    }
    else if ( out_y == 0 )
    {
      if ( out_x >= 0 )
        result = in_y;
      else
        result = -in_y;
    }
    else if ( out_x == 0 )
    {
      if ( out_y >= 0 )
        result = -in_x;
      else
        result =  in_x;
    }
    else /* general case */
    {
      long long  delta = (long long)in_x * out_y - (long long)in_y * out_x;

      if ( delta == 0 )
        result = 0;
      else
        result = 1 - 2 * ( delta < 0 );
    }

    return result;
  }

#endif /* !1 */


#ifdef COMPUTE_INFLEXS

  /* compute all inflex points in a given glyph */
  static void
  psh_glyph_compute_inflections( PSH_Glyph  glyph )
  {
    FT_UInt  n;


    for ( n = 0; n < glyph->num_contours; n++ )
    {
      PSH_Point  first, start, end, before, after;
      FT_Pos     in_x, in_y, out_x, out_y;
      FT_Int     orient_prev, orient_cur;
      FT_Int     finished = 0;


      /* we need at least 4 points to create an inflection point */
      if ( glyph->contours[n].count < 4 )
        continue;

      /* compute first segment in contour */
      first = glyph->contours[n].start;

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

        in_x = end->org_u - start->org_u;
        in_y = end->org_v - start->org_v;

      } while ( in_x == 0 && in_y == 0 );

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

          out_x = start->org_u - before->org_u;
          out_y = start->org_v - before->org_v;

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

        orient_prev = psh_corner_orientation( in_x, in_y, out_x, out_y );

      } while ( orient_prev == 0 );

      first = start;
      in_x  = out_x;
      in_y  = out_y;

      /* 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;

            out_x = after->org_u - end->org_u;
            out_y = after->org_v - end->org_v;

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

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

        } while ( orient_cur == 0 );

        if ( ( orient_cur ^ orient_prev ) < 0 )
        {
          do
          {
            psh_point_set_inflex( start );
            start = start->next;
          }
          while ( start != end );

          psh_point_set_inflex( start );
        }

        start       = end;
        end         = after;
        orient_prev = orient_cur;
        in_x        = out_x;
        in_y        = out_y;

      } while ( !finished );

    Skip:
      ;
    }
  }

#endif /* COMPUTE_INFLEXS */


  static void
  psh_glyph_done( PSH_Glyph  glyph )
  {
    FT_Memory  memory = glyph->memory;


    psh_hint_table_done( &glyph->hint_tables[1], memory );
    psh_hint_table_done( &glyph->hint_tables[0], memory );

    FT_FREE( glyph->points );
    FT_FREE( glyph->contours );

    glyph->num_points   = 0;
    glyph->num_contours = 0;

    glyph->memory = 0;
  }


  static int
  psh_compute_dir( FT_Pos  dx,
                   FT_Pos  dy )
  {
    FT_Pos  ax, ay;
    int     result = PSH_DIR_NONE;


    ax = ( dx >= 0 ) ? dx : -dx;
    ay = ( dy >= 0 ) ? dy : -dy;

    if ( ay * 12 < ax )
    {
      /* |dy| <<< |dx|  means a near-horizontal segment */
      result = ( dx >= 0 ) ? PSH_DIR_RIGHT : PSH_DIR_LEFT;
    }
    else if ( ax * 12 < ay )
    {
      /* |dx| <<< |dy|  means a near-vertical segment */
      result = ( dy >= 0 ) ? PSH_DIR_UP : PSH_DIR_DOWN;
    }

    return result;
  }


  /* load outline point coordinates into hinter glyph */
  static void
  psh_glyph_load_points( PSH_Glyph  glyph,
                         FT_Int     dimension )
  {
    FT_Vector*  vec   = glyph->outline->points;
    PSH_Point   point = glyph->points;
    FT_UInt     count = glyph->num_points;


    for ( ; count > 0; count--, point++, vec++ )
    {
      point->flags2 = 0;
      point->hint   = NULL;
      if ( dimension == 0 )
      {
        point->org_u = vec->x;
        point->org_v = vec->y;
      }
      else
      {
        point->org_u = vec->y;
        point->org_v = vec->x;
      }

#ifdef DEBUG_HINTER
      point->org_x = vec->x;
      point->org_y = vec->y;
#endif

    }
  }


  /* save hinted point coordinates back to outline */
  static void
  psh_glyph_save_points( PSH_Glyph  glyph,
                         FT_Int     dimension )
  {
    FT_UInt     n;
    PSH_Point   point = glyph->points;
    FT_Vector*  vec   = glyph->outline->points;
    char*       tags  = glyph->outline->tags;


    for ( n = 0; n < glyph->num_points; n++ )
    {
      if ( dimension == 0 )
        vec[n].x = point->cur_u;
      else
        vec[n].y = point->cur_u;

      if ( psh_point_is_strong( point ) )
        tags[n] |= (char)( ( dimension == 0 ) ? 32 : 64 );

#ifdef DEBUG_HINTER

      if ( dimension == 0 )
      {
        point->cur_x   = point->cur_u;
        point->flags_x = point->flags2 | point->flags;
      }
      else
      {
        point->cur_y   = point->cur_u;
        point->flags_y = point->flags2 | point->flags;
      }

#endif

      point++;
    }
  }


  static FT_Error
  psh_glyph_init( PSH_Glyph    glyph,
                  FT_Outline*  outline,
                  PS_Hints     ps_hints,
                  PSH_Globals  globals )
  {
    FT_Error   error;
    FT_Memory  memory;


    /* clear all fields */
    FT_MEM_ZERO( glyph, sizeof ( *glyph ) );

    memory = glyph->memory = globals->memory;

    /* allocate and setup points + contours arrays */
    if ( FT_NEW_ARRAY( glyph->points,   outline->n_points   ) ||
         FT_NEW_ARRAY( glyph->contours, outline->n_contours ) )
      goto Exit;

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

    {
      FT_UInt      first = 0, next, n;
      PSH_Point    points  = glyph->points;
      PSH_Contour  contour = glyph->contours;


      for ( n = 0; n < glyph->num_contours; n++ )
      {
        FT_Int     count;
        PSH_Point  point;


        next  = outline->contours[n] + 1;
        count = next - first;

        contour->start = points + first;
        contour->count = (FT_UInt)count;

        if ( count > 0 )
        {
          point = points + first;

          point->prev    = points + next - 1;
          point->contour = contour;

          for ( ; count > 1; count-- )
          {
            point[0].next = point + 1;
            point[1].prev = point;
            point++;
            point->contour = contour;
          }
          point->next = points + first;
        }

        contour++;
        first = next;
      }
    }

    {
      PSH_Point   points = glyph->points;
      PSH_Point   point  = points;
      FT_Vector*  vec    = outline->points;
      FT_UInt     n;


      for ( n = 0; n < glyph->num_points; n++, point++ )
      {
        FT_Int  n_prev = (FT_Int)( point->prev - points );
        FT_Int  n_next = (FT_Int)( point->next - points );
        FT_Pos  dxi, dyi, dxo, dyo;


        if ( !( outline->tags[n] & FT_CURVE_TAG_ON ) )
          point->flags = PSH_POINT_OFF;

        dxi = vec[n].x - vec[n_prev].x;
        dyi = vec[n].y - vec[n_prev].y;

        point->dir_in = (FT_Char)psh_compute_dir( dxi, dyi );

        dxo = vec[n_next].x - vec[n].x;
        dyo = vec[n_next].y - vec[n].y;

        point->dir_out = (FT_Char)psh_compute_dir( dxo, dyo );

        /* detect smooth points */
        if ( point->flags & PSH_POINT_OFF )
          point->flags |= PSH_POINT_SMOOTH;

        else if ( point->dir_in == point->dir_out )
        {
          if ( point->dir_out != PSH_DIR_NONE           ||
               psh_corner_is_flat( dxi, dyi, dxo, dyo ) )
            point->flags |= PSH_POINT_SMOOTH;
        }
      }
    }

    glyph->outline = outline;
    glyph->globals = globals;

#ifdef COMPUTE_INFLEXS
    psh_glyph_load_points( glyph, 0 );
    psh_glyph_compute_inflections( glyph );
#endif /* COMPUTE_INFLEXS */

    /* now deal with hints tables */
    error = psh_hint_table_init( &glyph->hint_tables [0],
                                 &ps_hints->dimension[0].hints,
                                 &ps_hints->dimension[0].masks,
                                 &ps_hints->dimension[0].counters,
                                 memory );
    if ( error )
      goto Exit;

    error = psh_hint_table_init( &glyph->hint_tables [1],
                                 &ps_hints->dimension[1].hints,
                                 &ps_hints->dimension[1].masks,
                                 &ps_hints->dimension[1].counters,
                                 memory );
    if ( error )
      goto Exit;

  Exit:
    return error;
  }


  /* compute all extrema in a glyph for a given dimension */
  static void
  psh_glyph_compute_extrema( PSH_Glyph  glyph )
  {
    FT_UInt  n;