Adjusts the columns of nodes within the unfixedLayer to reduce the number of "bends" between the unfixedLayer and its adjacent layers. The direction argument indicates which of the adjacent layers should be taken into consideration when reducing the number of bends. The "weighted bend" between a node U and a node V connected by link L is calculated by abs((U.column + L.portFromColOffset) - (V.column + L.portToColOffset)) * LinkStraightenWeight(L) The LinkStraightenWeight attempts to give higher priority to links between "artificial" nodes; i.e., long links in the final layout will be straighter. The idea is to iterate the ShiftBendStraighten and adjacentExchangeBendStraighten methods until no improvements are made.

protected virtual bool BendStraighten( 
   int unfixedLayer,
   int direction
)