private void calcOffset()
{
var norm = HostUtils.GetHostNormal(this.NewFI);
var p0 = this.NewFI.LocationCurve().GetEndPoint(0);
var pOffset = this.OffsetLocLine.GetEndPoint(0);
var totalOffset = (pOffset - p0).DotProduct(norm);
double symbolOffset = LineBasedFamilyUtils.GetSymbolOffset(this.fs);
double profileOffset = LineBasedFamilyUtils.GetProfileOffset(this.fs);
double instanceOffset = totalOffset - symbolOffset - profileOffset;
this.NewFI.get_Parameter(BuiltInParameter.INSTANCE_FREE_HOST_OFFSET_PARAM).Set(instanceOffset);
}
