aflatin.c

奇趣公司比较新的qt/emd版本

        edge1->pos    = blue->fit;
        edge1->flags |= AF_EDGE_DONE;

        if ( edge2 && !edge2->blue_edge )
        {
          af_latin_align_linked_edge( hints, dim, edge1, edge2 );
          edge2->flags |= AF_EDGE_DONE;
        }

        if ( !anchor )
          anchor = edge;
      }
    }

    /* now we will align all stem edges, trying to maintain the */
    /* relative order of stems in the glyph                     */
    for ( edge = edges; edge < edge_limit; edge++ )
    {
      AF_Edge  edge2;


      if ( edge->flags & AF_EDGE_DONE )
        continue;

      /* skip all non-stem edges */
      edge2 = edge->link;
      if ( !edge2 )
      {
        has_serifs++;
        continue;
      }

      /* now align the stem */

      /* this should not happen, but it's better to be safe */
      if ( edge2->blue_edge )
      {
        AF_LOG(( "ASSERTION FAILED for edge %d\n", edge2-edges ));

        af_latin_align_linked_edge( hints, dim, edge2, edge );
        edge->flags |= AF_EDGE_DONE;
        continue;
      }

      if ( !anchor )
      {
        FT_Pos  org_len, org_center, cur_len;
        FT_Pos  cur_pos1, error1, error2, u_off, d_off;


        org_len = edge2->opos - edge->opos;
        cur_len = af_latin_compute_stem_width(
                    hints, dim, org_len,
                    (AF_Edge_Flags)edge->flags,
                    (AF_Edge_Flags)edge2->flags );
        if ( cur_len <= 64 )
          u_off = d_off = 32;
        else
        {
          u_off = 38;
          d_off = 26;
        }

        if ( cur_len < 96 )
        {
          org_center = edge->opos + ( org_len >> 1 );

          cur_pos1   = FT_PIX_ROUND( org_center );

          error1 = org_center - ( cur_pos1 - u_off );
          if ( error1 < 0 )
            error1 = -error1;

          error2 = org_center - ( cur_pos1 + d_off );
          if ( error2 < 0 )
            error2 = -error2;

          if ( error1 < error2 )
            cur_pos1 -= u_off;
          else
            cur_pos1 += d_off;

          edge->pos  = cur_pos1 - cur_len / 2;
          edge2->pos = edge->pos + cur_len;
        }
        else
          edge->pos = FT_PIX_ROUND( edge->opos );

        AF_LOG(( "ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f) "
                 "snapped to (%.2f) (%.2f)\n",
                 edge-edges, edge->opos / 64.0,
                 edge2-edges, edge2->opos / 64.0,
                 edge->pos / 64.0, edge2->pos / 64.0 ));
        anchor = edge;

        edge->flags |= AF_EDGE_DONE;

        af_latin_align_linked_edge( hints, dim, edge, edge2 );
      }
      else
      {
        FT_Pos  org_pos, org_len, org_center, cur_len;
        FT_Pos  cur_pos1, cur_pos2, delta1, delta2;


        org_pos    = anchor->pos + ( edge->opos - anchor->opos );
        org_len    = edge2->opos - edge->opos;
        org_center = org_pos + ( org_len >> 1 );

        cur_len = af_latin_compute_stem_width(
                   hints, dim, org_len,
                   (AF_Edge_Flags)edge->flags,
                   (AF_Edge_Flags)edge2->flags );

        if ( edge2->flags & AF_EDGE_DONE )
          edge->pos = edge2->pos - cur_len;

        else if ( cur_len < 96 )
        {
          FT_Pos  u_off, d_off;


          cur_pos1 = FT_PIX_ROUND( org_center );

          if (cur_len <= 64 )
            u_off = d_off = 32;
          else
          {
            u_off = 38;
            d_off = 26;
          }

          delta1 = org_center - ( cur_pos1 - u_off );
          if ( delta1 < 0 )
            delta1 = -delta1;

          delta2 = org_center - ( cur_pos1 + d_off );
          if ( delta2 < 0 )
            delta2 = -delta2;

          if ( delta1 < delta2 )
            cur_pos1 -= u_off;
          else
            cur_pos1 += d_off;

          edge->pos  = cur_pos1 - cur_len / 2;
          edge2->pos = cur_pos1 + cur_len / 2;

          AF_LOG(( "STEM: %d (opos=%.2f) to %d (opos=%.2f) "
                   "snapped to (%.2f) and (%.2f)\n",
                   edge-edges, edge->opos / 64.0,
                   edge2-edges, edge2->opos / 64.0,
                   edge->pos / 64.0, edge2->pos / 64.0 ));
        }
        else
        {
          org_pos    = anchor->pos + ( edge->opos - anchor->opos );
          org_len    = edge2->opos - edge->opos;
          org_center = org_pos + ( org_len >> 1 );

          cur_len    = af_latin_compute_stem_width(
                         hints, dim, org_len,
                         (AF_Edge_Flags)edge->flags,
                         (AF_Edge_Flags)edge2->flags );

          cur_pos1   = FT_PIX_ROUND( org_pos );
          delta1     = cur_pos1 + ( cur_len >> 1 ) - org_center;
          if ( delta1 < 0 )
            delta1 = -delta1;

          cur_pos2   = FT_PIX_ROUND( org_pos + org_len ) - cur_len;
          delta2     = cur_pos2 + ( cur_len >> 1 ) - org_center;
          if ( delta2 < 0 )
            delta2 = -delta2;

          edge->pos  = ( delta1 < delta2 ) ? cur_pos1 : cur_pos2;
          edge2->pos = edge->pos + cur_len;

          AF_LOG(( "STEM: %d (opos=%.2f) to %d (opos=%.2f) "
                   "snapped to (%.2f) and (%.2f)\n",
                   edge-edges, edge->opos / 64.0,
                   edge2-edges, edge2->opos / 64.0,
                   edge->pos / 64.0, edge2->pos / 64.0 ));
        }

        edge->flags  |= AF_EDGE_DONE;
        edge2->flags |= AF_EDGE_DONE;

        if ( edge > edges && edge->pos < edge[-1].pos )
        {
          AF_LOG(( "BOUND: %d (pos=%.2f) to (%.2f)\n",
                   edge-edges, edge->pos / 64.0, edge[-1].pos / 64.0 ));
          edge->pos = edge[-1].pos;
        }
      }
    }

    /* make sure that lowercase m's maintain their symmetry */

    /* In general, lowercase m's have six vertical edges if they are sans */
    /* serif, or twelve if they are with serifs.  This implementation is  */
    /* based on that assumption, and seems to work very well with most    */
    /* faces.  However, if for a certain face this assumption is not      */
    /* true, the m is just rendered like before.  In addition, any stem   */
    /* correction will only be applied to symmetrical glyphs (even if the */
    /* glyph is not an m), so the potential for unwanted distortion is    */
    /* relatively low.                                                    */

    /* We don't handle horizontal edges since we can't easily assure that */
    /* the third (lowest) stem aligns with the base line; it might end up */
    /* one pixel higher or lower.                                         */

    n_edges = edge_limit - edges;
    if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
    {
      AF_Edge  edge1, edge2, edge3;
      FT_Pos   dist1, dist2, span, delta;


      if ( n_edges == 6 )
      {
        edge1 = edges;
        edge2 = edges + 2;
        edge3 = edges + 4;
      }
      else
      {
        edge1 = edges + 1;
        edge2 = edges + 5;
        edge3 = edges + 9;
      }

      dist1 = edge2->opos - edge1->opos;
      dist2 = edge3->opos - edge2->opos;

      span = dist1 - dist2;
      if ( span < 0 )
        span = -span;

      if ( span < 8 )
      {
        delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
        edge3->pos -= delta;
        if ( edge3->link )
          edge3->link->pos -= delta;

        /* move the serifs along with the stem */
        if ( n_edges == 12 )
        {
          ( edges + 8 )->pos -= delta;
          ( edges + 11 )->pos -= delta;
        }

        edge3->flags |= AF_EDGE_DONE;
        if ( edge3->link )
          edge3->link->flags |= AF_EDGE_DONE;
      }
    }

    if ( has_serifs || !anchor )
    {
      /*
       *  now hint the remaining edges (serifs and single) in order
       *  to complete our processing
       */
      for ( edge = edges; edge < edge_limit; edge++ )
      {
        FT_Pos  delta;


        if ( edge->flags & AF_EDGE_DONE )
          continue;

        delta = 1000;

        if ( edge->serif )
        {
          delta = edge->serif->opos - edge->opos;
          if ( delta < 0 )
            delta = -delta;
        }

        if ( delta < 64 + 16 )
        {
          af_latin_align_serif_edge( hints, edge->serif, edge );
          AF_LOG(( "SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f) "
                   "aligned to (%.2f)\n",
                   edge-edges, edge->opos / 64.0,
                   edge->serif - edges, edge->serif->opos / 64.0,
                   edge->pos / 64.0 ));
        }
        else if ( !anchor )
        {
          AF_LOG(( "SERIF_ANCHOR: edge %d (opos=%.2f) snapped to (%.2f)\n",
                   edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
          edge->pos = FT_PIX_ROUND( edge->opos );
          anchor    = edge;
        }
        else
        {
          AF_Edge  before, after;


          for ( before = edge - 1; before >= edges; before-- )
            if ( before->flags & AF_EDGE_DONE )
              break;

          for ( after = edge + 1; after < edge_limit; after++ )
            if ( after->flags & AF_EDGE_DONE )
              break;

          if ( before >= edges && before < edge   &&
               after < edge_limit && after > edge )
            edge->pos = before->pos +
                          FT_MulDiv( edge->opos - before->opos,
                                     after->pos - before->pos,
                                     after->opos - before->opos );
          else
            edge->pos = anchor->pos +
                          FT_PIX_ROUND( edge->opos - anchor->opos );

          AF_LOG(( "SERIF_LINK: edge %d (opos=%.2f) snapped to (%.2f)\n",
                   edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
        }

        edge->flags |= AF_EDGE_DONE;

        if ( edge > edges && edge->pos < edge[-1].pos )
          edge->pos = edge[-1].pos;

        if ( edge + 1 < edge_limit        &&
             edge[1].flags & AF_EDGE_DONE &&
             edge->pos > edge[1].pos      )
          edge->pos = edge[1].pos;
      }
    }
  }


  static FT_Error
  af_latin_hints_apply( AF_GlyphHints    hints,
                        FT_Outline*      outline,
                        AF_LatinMetrics  metrics )
  {
    FT_Error  error;
    int       dim;


    error = af_glyph_hints_reload( hints, outline );
    if ( error )
      goto Exit;

    /* analyze glyph outline */
#ifdef AF_USE_WARPER
    if ( metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT ||
         AF_HINTS_DO_HORIZONTAL( hints ) )
#else
    if ( AF_HINTS_DO_HORIZONTAL( hints ) )
#endif
    {
      error = af_latin_hints_detect_features( hints, AF_DIMENSION_HORZ );
      if ( error )
        goto Exit;
    }

    if ( AF_HINTS_DO_VERTICAL( hints ) )
    {
      error = af_latin_hints_detect_features( hints, AF_DIMENSION_VERT );
      if ( error )
        goto Exit;

      af_latin_hints_compute_blue_edges( hints, metrics );
    }

    /* grid-fit the outline */
    for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
    {
#ifdef AF_USE_WARPER
      if ( ( dim == AF_DIMENSION_HORZ &&
             metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT ) )
      {
        AF_WarperRec  warper;
        FT_Fixed      scale;
        FT_Pos        delta;


        af_warper_compute( &warper, hints, dim, &scale, &delta );
        af_glyph_hints_scale_dim( hints, dim, scale, delta );
        continue;
      }
#endif

      if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
           ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
      {
        af_latin_hint_edges( hints, (AF_Dimension)dim );
        af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim );
        af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
        af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
      }
    }
    af_glyph_hints_save( hints, outline );

  Exit:
    return error;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****              L A T I N   S C R I P T   C L A S S              *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  static const AF_Script_UniRangeRec  af_latin_uniranges[] =
  {
    { 32,  127 },    /* XXX: TODO: Add new Unicode ranges here! */
    { 160, 255 },
    { 0,   0 }
  };


  FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec
  af_latin_script_class =
  {
    AF_SCRIPT_LATIN,
    af_latin_uniranges,

    sizeof( AF_LatinMetricsRec ),

    (AF_Script_InitMetricsFunc) af_latin_metrics_init,
    (AF_Script_ScaleMetricsFunc)af_latin_metrics_scale,
    (AF_Script_DoneMetricsFunc) NULL,

    (AF_Script_InitHintsFunc)   af_latin_hints_init,
    (AF_Script_ApplyHintsFunc)  af_latin_hints_apply
  };


/* END */