Unity点到线段的最短距离

    /// <summary>
    /// 计算点到线段的最短距离
    /// </summary>
    /// <param name="point"></param>
    /// <param name="lineStart"></param>
    /// <param name="lineEnd"></param>
    /// <returns></returns>
    public static float DistancePointLine(Vector3 point, Vector3 lineStart, Vector3 lineEnd)
    {
        Vector3 rhs = point - lineStart;
        Vector3 vector3 = lineEnd - lineStart;
        float magnitude = vector3.magnitude;
        Vector3 lhs = vector3;
        if ((double) magnitude > 9.99999997475243E-07)
            lhs /= magnitude;
        float num = Mathf.Clamp(Vector3.Dot(lhs, rhs), 0.0f, magnitude);
        Vector3 v3 = lineStart + lhs * num;
        return Vector3.Magnitude (v3 - point);
    }