/*判
 
断曲线是否是样条*/
bool isSpline(tag_t cruve_tag)
{
	logical is_spline = 0;
	UF_EVAL_p_t evaluator;

	UF_CALL(UF_EVAL_initialize(cruve_tag, &evaluator));
	UF_CALL(UF_EVAL_is_spline(evaluator, &is_spline));
	UF_CALL(UF_EVAL_free(evaluator));

	return is_spline;
}

/*判断样条是否是2D维度*/
bool isSpline2D(tag_t cruve_tag)
{
	if (isSpline(cruve_tag))
	{
		/*获取几何对象的维度*/
		int dimensionality;//物体的维度
		double data[6];
		//如果dimensionality(维度) = UF_MODL_POINT,data[0 - 2] = 点的坐标
		//如果dimensionality(维度) = UF_MODL_LINEAR,data[0 - 2] = 直线上一点的坐标,data[3 - 5] = 直线的单位方向向量
		//如果dimensionality(维度) = UF_MODL_PLANAR,data[0 - 2] = 平面上一点的坐标,data[3 - 5] = 平面的单位法向量
		//如果dimensionality(维度) = UF_MODL_THREE_DIMENSIONAL,data[0 - 5] = 未使用
		
		UF_CALL(UF_MODL_ask_obj_dimensionality(cruve_tag, &dimensionality, data));

		if (UF_MODL_LINEAR == dimensionality || UF_MODL_PLANAR == dimensionality)
			return 1;
	}

	return 0;
}

/*判断样条是否近似线性（是否可转换成直线）*/
bool isSpline2DLinearSimilar(tag_t cruve_tag)
{
	if (isSpline2D(cruve_tag))
	{
		/*计算曲线的最大曲率数据 */
		double check_curva = 1 / 300.0;
		double range[4] = { 0,100,0,0 };//For curves: range[0]=umin, range[1]=umax.For surfaces: range[0-1]= umin & umax range[2-3]=vmin & vmax
		int curva_type = 0;//Not used for curve objects
		double max_curva[5];//O //For curve objects max_curva[0] = u ,max_curva[1-3]: 曲率最大的点坐标 ,max_curva[4]: 最大曲率
		int status;//0= max_curva[] is returned.1=constant curvature object encountered. only return the constant value in max_curva[4]
		UF_CALL(UF_MODL_ask_max_curvature(cruve_tag, range, curva_type, max_curva, &status));

		if (fabs(max_curva[4]) < check_curva)
			return 1;
	}

	return 0;
}