ftstroke.c

奇趣公司比较新的qt/emd版本

          goto Exit;
      }

      /* process the corner */
      stroker->angle_out = stroker->subpath_angle;
      turn               = FT_Angle_Diff( stroker->angle_in,
                                          stroker->angle_out );

      /* no specific corner processing is required if the turn is 0 */
      if ( turn != 0 )
      {
        /* when we turn to the right, the inside side is 0 */
        inside_side = 0;

        /* otherwise, the inside side is 1 */
        if ( turn < 0 )
          inside_side = 1;

        error = ft_stroker_inside( stroker, inside_side );
        if ( error )
          goto Exit;

        /* process the outside side */
        error = ft_stroker_outside( stroker, 1 - inside_side );
        if ( error )
          goto Exit;
      }

      /* then end our two subpaths */
      ft_stroke_border_close( stroker->borders + 0, 1 );
      ft_stroke_border_close( stroker->borders + 1, 0 );
    }

  Exit:
    return error;
  }


  /* documentation is in ftstroke.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Stroker_GetBorderCounts( FT_Stroker        stroker,
                              FT_StrokerBorder  border,
                              FT_UInt          *anum_points,
                              FT_UInt          *anum_contours )
  {
    FT_UInt   num_points = 0, num_contours = 0;
    FT_Error  error;


    if ( !stroker || border > 1 )
    {
      error = FT_Err_Invalid_Argument;
      goto Exit;
    }

    error = ft_stroke_border_get_counts( stroker->borders + border,
                                         &num_points, &num_contours );
  Exit:
    if ( anum_points )
      *anum_points = num_points;

    if ( anum_contours )
      *anum_contours = num_contours;

    return error;
  }


  /* documentation is in ftstroke.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Stroker_GetCounts( FT_Stroker  stroker,
                        FT_UInt    *anum_points,
                        FT_UInt    *anum_contours )
  {
    FT_UInt   count1, count2, num_points   = 0;
    FT_UInt   count3, count4, num_contours = 0;
    FT_Error  error;


    error = ft_stroke_border_get_counts( stroker->borders + 0,
                                         &count1, &count2 );
    if ( error )
      goto Exit;

    error = ft_stroke_border_get_counts( stroker->borders + 1,
                                         &count3, &count4 );
    if ( error )
      goto Exit;

    num_points   = count1 + count3;
    num_contours = count2 + count4;

  Exit:
    *anum_points   = num_points;
    *anum_contours = num_contours;
    return error;
  }


  /* documentation is in ftstroke.h */

  FT_EXPORT_DEF( void )
  FT_Stroker_ExportBorder( FT_Stroker        stroker,
                           FT_StrokerBorder  border,
                           FT_Outline*       outline )
  {
    if ( border == FT_STROKER_BORDER_LEFT  ||
         border == FT_STROKER_BORDER_RIGHT )
    {
      FT_StrokeBorder  sborder = & stroker->borders[border];


      if ( sborder->valid )
        ft_stroke_border_export( sborder, outline );
    }
  }


  /* documentation is in ftstroke.h */

  FT_EXPORT_DEF( void )
  FT_Stroker_Export( FT_Stroker   stroker,
                     FT_Outline*  outline )
  {
    FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_LEFT, outline );
    FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_RIGHT, outline );
  }


  /* documentation is in ftstroke.h */

  /*
   *  The following is very similar to FT_Outline_Decompose, except
   *  that we do support opened paths, and do not scale the outline.
   */
  FT_EXPORT_DEF( FT_Error )
  FT_Stroker_ParseOutline( FT_Stroker   stroker,
                           FT_Outline*  outline,
                           FT_Bool      opened )
  {
    FT_Vector   v_last;
    FT_Vector   v_control;
    FT_Vector   v_start;

    FT_Vector*  point;
    FT_Vector*  limit;
    char*       tags;

    FT_Error    error;

    FT_Int   n;         /* index of contour in outline     */
    FT_UInt  first;     /* index of first point in contour */
    FT_Int   tag;       /* current point's state           */


    if ( !outline || !stroker )
      return FT_Err_Invalid_Argument;

    FT_Stroker_Rewind( stroker );

    first = 0;

    for ( n = 0; n < outline->n_contours; n++ )
    {
      FT_UInt  last;  /* index of last point in contour */


      last  = outline->contours[n];
      limit = outline->points + last;

      /* skip empty points; we don't stroke these */
      if ( last <= first )
      {
        first = last + 1;
        continue;
      }

      v_start = outline->points[first];
      v_last  = outline->points[last];

      v_control = v_start;

      point = outline->points + first;
      tags  = outline->tags  + first;
      tag   = FT_CURVE_TAG( tags[0] );

      /* A contour cannot start with a cubic control point! */
      if ( tag == FT_CURVE_TAG_CUBIC )
        goto Invalid_Outline;

      /* check first point to determine origin */
      if ( tag == FT_CURVE_TAG_CONIC )
      {
        /* First point is conic control.  Yes, this happens. */
        if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON )
        {
          /* start at last point if it is on the curve */
          v_start = v_last;
          limit--;
        }
        else
        {
          /* if both first and last points are conic,         */
          /* start at their middle and record its position    */
          /* for closure                                      */
          v_start.x = ( v_start.x + v_last.x ) / 2;
          v_start.y = ( v_start.y + v_last.y ) / 2;

          v_last = v_start;
        }
        point--;
        tags--;
      }

      error = FT_Stroker_BeginSubPath( stroker, &v_start, opened );
      if ( error )
        goto Exit;

      while ( point < limit )
      {
        point++;
        tags++;

        tag = FT_CURVE_TAG( tags[0] );
        switch ( tag )
        {
        case FT_CURVE_TAG_ON:  /* emit a single line_to */
          {
            FT_Vector  vec;


            vec.x = point->x;
            vec.y = point->y;

            error = FT_Stroker_LineTo( stroker, &vec );
            if ( error )
              goto Exit;
            continue;
          }

        case FT_CURVE_TAG_CONIC:  /* consume conic arcs */
          v_control.x = point->x;
          v_control.y = point->y;

        Do_Conic:
          if ( point < limit )
          {
            FT_Vector  vec;
            FT_Vector  v_middle;


            point++;
            tags++;
            tag = FT_CURVE_TAG( tags[0] );

            vec = point[0];

            if ( tag == FT_CURVE_TAG_ON )
            {
              error = FT_Stroker_ConicTo( stroker, &v_control, &vec );
              if ( error )
                goto Exit;
              continue;
            }

            if ( tag != FT_CURVE_TAG_CONIC )
              goto Invalid_Outline;

            v_middle.x = ( v_control.x + vec.x ) / 2;
            v_middle.y = ( v_control.y + vec.y ) / 2;

            error = FT_Stroker_ConicTo( stroker, &v_control, &v_middle );
            if ( error )
              goto Exit;

            v_control = vec;
            goto Do_Conic;
          }

          error = FT_Stroker_ConicTo( stroker, &v_control, &v_start );
          goto Close;

        default:  /* FT_CURVE_TAG_CUBIC */
          {
            FT_Vector  vec1, vec2;


            if ( point + 1 > limit                             ||
                 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC )
              goto Invalid_Outline;

            point += 2;
            tags  += 2;

            vec1 = point[-2];
            vec2 = point[-1];

            if ( point <= limit )
            {
              FT_Vector  vec;


              vec = point[0];

              error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &vec );
              if ( error )
                goto Exit;
              continue;
            }

            error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &v_start );
            goto Close;
          }
        }
      }

    Close:
      if ( error )
        goto Exit;

      error = FT_Stroker_EndSubPath( stroker );
      if ( error )
        goto Exit;

      first = last + 1;
    }

    return 0;

  Exit:
    return error;

  Invalid_Outline:
    return FT_Err_Invalid_Outline;
  }


  extern const FT_Glyph_Class  ft_outline_glyph_class;


  /* documentation is in ftstroke.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Glyph_Stroke( FT_Glyph    *pglyph,
                   FT_Stroker   stroker,
                   FT_Bool      destroy )
  {
    FT_Error  error = FT_Err_Invalid_Argument;
    FT_Glyph  glyph = NULL;


    if ( pglyph == NULL )
      goto Exit;

    glyph = *pglyph;
    if ( glyph == NULL || glyph->clazz != &ft_outline_glyph_class )
      goto Exit;

    {
      FT_Glyph  copy;


      error = FT_Glyph_Copy( glyph, &copy );
      if ( error )
        goto Exit;

      glyph = copy;
    }

    {
      FT_OutlineGlyph  oglyph  = (FT_OutlineGlyph) glyph;
      FT_Outline*      outline = &oglyph->outline;
      FT_UInt          num_points, num_contours;


      error = FT_Stroker_ParseOutline( stroker, outline, 0 );
      if ( error )
        goto Fail;

      (void)FT_Stroker_GetCounts( stroker, &num_points, &num_contours );

      FT_Outline_Done( glyph->library, outline );

      error = FT_Outline_New( glyph->library,
                              num_points, num_contours, outline );
      if ( error )
        goto Fail;

      outline->n_points   = 0;
      outline->n_contours = 0;

      FT_Stroker_Export( stroker, outline );
    }

    if ( destroy )
      FT_Done_Glyph( *pglyph );

    *pglyph = glyph;
    goto Exit;

  Fail:
    FT_Done_Glyph( glyph );
    glyph = NULL;

    if ( !destroy )
      *pglyph = NULL;

  Exit:
    return error;
  }


  /* documentation is in ftstroke.h */

  FT_EXPORT_DEF( FT_Error )
  FT_Glyph_StrokeBorder( FT_Glyph    *pglyph,
                         FT_Stroker   stroker,
                         FT_Bool      inside,
                         FT_Bool      destroy )
  {
    FT_Error  error = FT_Err_Invalid_Argument;
    FT_Glyph  glyph = NULL;


    if ( pglyph == NULL )
      goto Exit;

    glyph = *pglyph;
    if ( glyph == NULL || glyph->clazz != &ft_outline_glyph_class )
      goto Exit;

    {
      FT_Glyph  copy;


      error = FT_Glyph_Copy( glyph, &copy );
      if ( error )
        goto Exit;

      glyph = copy;
    }

    {
      FT_OutlineGlyph   oglyph  = (FT_OutlineGlyph) glyph;
      FT_StrokerBorder  border;
      FT_Outline*       outline = &oglyph->outline;
      FT_UInt           num_points, num_contours;


      border = FT_Outline_GetOutsideBorder( outline );
      if ( inside )
      {
        if ( border == FT_STROKER_BORDER_LEFT )
          border = FT_STROKER_BORDER_RIGHT;
        else
          border = FT_STROKER_BORDER_LEFT;
      }

      error = FT_Stroker_ParseOutline( stroker, outline, 0 );
      if ( error )
        goto Fail;

      (void)FT_Stroker_GetBorderCounts( stroker, border,
                                        &num_points, &num_contours );

      FT_Outline_Done( glyph->library, outline );

      error = FT_Outline_New( glyph->library,
                              num_points,
                              num_contours,
                              outline );
      if ( error )
        goto Fail;

      outline->n_points   = 0;
      outline->n_contours = 0;

      FT_Stroker_ExportBorder( stroker, border, outline );
    }

    if ( destroy )
      FT_Done_Glyph( *pglyph );

    *pglyph = glyph;
    goto Exit;

  Fail:
    FT_Done_Glyph( glyph );
    glyph = NULL;

    if ( !destroy )
      *pglyph = NULL;

  Exit:
    return error;
  }


/* END */