再发两曲线求交点函数(终结版)!

mkhsj928

(defun test(/ m_ent1 m_ent2 m_jdtab)
(setq m_ent1 (car (entsel "\n请选择第一条曲线: ")))
(setq m_ent2 (car (entsel "\n请选择第二条曲线: ")))
(setq m_jdtab (m_IntersectWith m_ent1 m_ent2))
(princ"\n交点表: ")(princ m_jdtab)
(princ)
) (defun m_IntersectWith(m_ent1 m_ent2 / m_obj1 m_obj2 m_objcopy1 m_objcopy2 m_jdtab m_jdtab1 i)
;;适用对象: Line、Polyline、LWPolyline、Circle、Arc、Ellipse、3dPolyline、Spline
;;支持求空间虚交点，但Z坐标始终为0.0，要求Z坐标，请用(vlax-curve-getClosestPointToProjection)函数
(setq m_obj1 (vlax-ename->vla-object m_ent1))
(setq m_obj2 (vlax-ename->vla-object m_ent2))

(setq m_objcopy1 (vla-copy m_obj1));;复制第一条曲线实体
(setq m_objcopy2 (vla-copy m_obj2));;复制第二条曲线实体

(setq m_objcopy1 (m_ShadowToXY m_objcopy1));;得到投影实体
(setq m_objcopy2 (m_ShadowToXY m_objcopy2));;得到投影实体


(setq m_jdtab1 (vla-intersectwith m_objcopy1 m_objcopy2 acExtendnone));;得到交点集

(if (> (vlax-safearray-get-u-bound (vlax-variant-value m_jdtab1) 1) 1);;判断有无交点
(progn
(setq m_jdtab1 (vlax-safearray->list (vlax-variant-value m_jdtab1)));;safearray数组转换为list表
(setq i 0)
(repeat (/ (length m_jdtab1) 3)
(setq m_jd (list (nth i m_jdtab1) (nth (+ 1 i) m_jdtab1) (nth (+ 2 i) m_jdtab1)));;取得一个交点
(setq m_jdtab (cons m_jd m_jdtab));;构造交点表（(第一个交点) (第二个交点)。。。）
(setq i (+ 3 i))
)
)
(princ"\n两曲线无交点!")
)

(vla-delete m_objcopy1);;删除复制的第一条曲线实体
(vla-delete m_objcopy2);;删除复制的第二条曲线实体

(setq m_jdtab m_jdtab);;返回交点表，无交点返回nil
) (defun m_ShadowToXY(m_obj / m_objname m_pts m_pts1 i)
;;对曲线实体m_obj创建一个投影至xy平面的曲线实体，即对曲线实体上每个控制点的z坐标值置为0.0
;;输入曲线实体(vla对象)
;;返回投影实体(vla对象)
(setq m_objname (vla-get-objectname m_obj));;取得实体的类型名称
(m_princ "\nObjectName：" m_objname)
(cond
((= "AcDbSpline" m_objname);;样条曲线(Spline)
(setq i 0)
(setq m_pts (vlax-variant-value (vla-get-fitpoints m_obj)));;取得样条曲线的拟合点
(setq m_pts1 (vlax-variant-value (vla-get-controlpoints m_obj)));;取得样条曲线的控制点
(repeat (vla-get-numberoffitpoints m_obj);;循环
(vlax-safearray-put-element m_pts (+ i 2) 0.0);;改变每个拟合点的z值为0.0
(setq i (+ i 3))
)
(vla-put-fitpoints m_obj m_pts);;更改曲线拟合点属性 (setq i 0)

(repeat (vla-get-numberofcontrolpoints m_obj);;循环
(vlax-safearray-put-element m_pts1 (+ i 2) 0.0);;改变每个控制点的z值为0.0
(setq i (+ i 3))
)
(vla-put-controlpoints m_obj m_pts1);;更改曲线控制点属性
)

((= "AcDb3dPolyline" m_objname);;三维多段线(3dpolyline)
(setq i 0)
(setq m_pts (vlax-variant-value (vla-get-coordinates m_obj)));;取得3维多段线的控制点
(repeat (/ (length (vlax-safearray->list m_pts)) 3)
(vlax-safearray-put-element m_pts (+ i 2) 0.0)
(setq i (+ i 3))
)
(vla-put-coordinates m_obj m_pts)
)

((= "AcDbLine" m_objname);;直线(line)
(setq i 0)
(setq m_pts (vlax-variant-value (vla-get-startpoint m_obj)));;取得直线的起点座标
(setq m_pts1 (vlax-variant-value (vla-get-endpoint m_obj)));;取得直线的端点座标
(vlax-safearray-put-element m_pts 2 0.0);;改变起点座标z值为0.0
(vlax-safearray-put-element m_pts1 2 0.0)
(vla-put-startpoint m_obj m_pts)
(vla-put-endpoint m_obj m_pts1)
) ((or (= "AcDbCircle" m_objname);;园(circle)
(= "AcDbArc" m_objname);;圆弧(arc)
(= "AcDbEllipse" m_objname);;椭圆及椭圆弧(ellipse)
)
(setq m_pts (vlax-variant-value (vla-get-center m_obj)));;取得中心点座标
(vlax-safearray-put-element m_pts 2 0.0);;改变中心点座标z值为0.0
(vla-put-center m_obj m_pts)
)

((or (= "AcDbPolyline" m_objname);;多段线(polyline、lwpolyline)
(= "AcDb2dPolyline" m_objname);;拟合的2维多段线(polyline、lwpolyline)
)
(vla-put-elevation m_obj 0.0);;改变标高值为0.0
)
)
(setq m_obj m_obj)
)
呵呵，这应该差不多了吧！

cqnj023

好

mkhsj928

注意：(m_princ "\nObjectName：" m_objname)是本人测试时用的，没意义。(m_princ msg var)是自己定义的显示函数，目的是不想输入两个princ！使用时请删掉！

wmz

只是我有一个问题,如果一条曲线多次通过另一条曲线时就形成了两个以上的交点,该如何求这多个交点坐标呢?

yjrun

试试看

meflying

这样投影对SPLINE是有误差的

mkhsj928

meflying 版主太厉害了啊！我正要问问这个问题呢，在Lisp里面有什么更好的办法吗？

无痕

用move压平如何？

mkhsj928

wmz发表于2004-8-15 12:22:00只是我有一个问题,如果一条曲线多次通过另一条曲线时就形成了两个以上的交点,该如何求这多个交点坐标呢?

IntersectWith函数求出的就是所有交点组成的表！

mkhsj928

无痕发表于2004-8-17 21:46:00用move压平如何？

请问具体怎么做？