/// <summary>
/// 添加关节。将新控制点添加到控制点列表中，并更新前面的样条曲线。
/// </summary>
/// <param name="spline">上一条样条曲线</param>
/// <param name="point">当前点</param>
public void AddJoint(SplineCurves spline, Vector3 point)
{
//前一根样条曲线不为null，所以更新前一根样条曲线的控制点列表，同时更新当前样条曲线的控制点列表。
if (spline != null)
{
//前一根样条曲线是第1根样条曲线，更新它的Pk+1和Pk+2点
if (spline.First)
{
origin = spline.origin;
start = spline.start;
end = point;
destination = point;
GenerateSamplePoint();
return;
}
//前一根样条曲线不是第1根样条曲线，仅更新它的Pk+2点
else
{
spline.destination = point;
spline.GenerateSamplePoint();
origin = spline.start;
start = spline.end;
end = point;
destination = point;
GenerateSamplePoint();
}
}
//前一根样条曲线spline为null，说明控制点列表中只有一个点，所以4个控制点样同。
else
{
origin = point;
start = point;
end = point;
destination = point;
First = true;
}
}
