code: func (v *ViewPort) Center(x, y int) {
  	if x < 0 || y < 0 || x >= v.limx || y >= v.limy || v.v == nil {
  		return
  	}
  	v.viewx = x - (v.width / 2)
  	v.viewy = y - (v.height / 2)
  	v.ValidateView()
  }
docs: // Center centers the point, if possible, in the View.