# File vtk/tk/vtkTkRenderWidget.rb, line 366
  def Zoom(x,y)
    if @CurrentRenderer

      renderer = @CurrentRenderer
      camera = @CurrentCamera

      zoomFactor = 1.02**(0.5*(@LastY - y))
      @CurrentZoom = @CurrentZoom * zoomFactor

      if camera.GetParallelProjection != 0
        parallelScale = camera.GetParallelScale/zoomFactor
        camera.SetParallelScale(parallelScale)
      else
        camera.Dolly(zoomFactor)
        renderer.ResetCameraClippingRange
      end

      @LastX = x
      @LastY = y

      self.Render
    end
  end