code: public void markConstrainedEdge( TriangulationPoint p, TriangulationPoint q )
      {
          if( ( q == points[0] && p == points[1] ) || ( q == points[1] && p == points[0] ) )
          {
              cEdge[2] = true;
          }
          else if( ( q == points[0] && p == points[2] ) || ( q == points[2] && p == points[0] ) )
          {
              cEdge[1] = true;
          }
          else if( ( q == points[1] && p == points[2] ) || ( q == points[2] && p == points[1] ) )
          {
              cEdge[0] = true;
          }
      }
docs: Mark edge as constrained