;; 上班后书也看不进去，写个程序玩玩，也是不久前写的曲线断
;; 开的继续。其中有几处不足，当然所提出的不足在论坛上都有
;; 过讨论，大家可以搜索下，可能有答案也可能没有，有兴趣的
;; 参与下完善不足。积极参与者提议斑竹给与奖励

;; 为方便网友使用，附件系Vla方法"打断"圆的编译文件，

;; 两实体的交点，本函数没有过滤重合交点。在过滤重合点问题上
;; LUCAS曾经用 member 写过 ，但使用中发现达不到要求

(defun ea:ints (e1 e2 / pts ipts)
  (setq	ipts (vlax-variant-value
	       (vla-intersectwith
		 e1
		 e2
		 acExtendNone
	       )
	     )
  )
  (if (> (vlax-safearray-get-u-bound ipts 1) 0);是否有交点
    (progn
      (setq ipts
	     (vlax-safearray->list ipts)
      )
      (while (> (length ipts) 0)
	(setq pts (cons	(list (car ipts)
			      (cadr ipts)
			      (caddr ipts)
			)
			pts
		  );此处可以在添加时判断是否有重合点
	)
	(setq ipts (cdddr ipts))
      )
    )
  )
  pts					;也可以在这里单独去除重合点
)
;;基于实体的点的排序函数，就是有一系列点是在曲线实体上或外部，基于这个曲线实体，
;;从开始点到结束点排序这些点。结果是这些点依据实体的开始点开始排升序。
;;本函数用的是不去除重合点，实际中可能某些情况下要去除重合点
;;比如下面断开圆的应用中
(defun ea:SortPointOnCurve (points curve / pl1)
  (setq	pl1 (mapcar '(lambda (x /)
		       (vlax-curve-getparamatpoint
			 curve
			 (vlax-curve-getclosestpointto curve x)
		       )
		     )
		    points
	    )
  )
  (mapcar '(lambda (n) (nth n points))
            (vl-sort-i pl1 '<)	  
  )
)
;;
;;"断开"园的程序
;;
;; 使用了 Vla 方法 和 Entmake
;|

AddArc Method
 
Creates an arc given the center, radius, start angle, and end angle of the arc.

Signature 

RetVal = object.AddArc(Center, Radius, StartAngle, EndAngle)

StartAngle, EndAngle   Double; input-only

                       The start and end angles, in radians, defining the arc.
                       A start angle greater than an end angle defines a
                       counterclockwise arc. 
|;
;; Vla 方法
(defun c:BrkCr (/ line ssc thisdrawing modelspace intp cenpt lcen r)
  (if (and (setq line (entsel "\n选择线: "))
	   (progn
	     (princ "\n选择园.....")
	     T
	   )
	   (setq ssc (ssget '((0 . "circle"))))
      )
    (progn
      (setq thisdrawing	(vla-get-activedocument (vlax-get-acad-object))
	    modelspace	(vla-get-modelspace thisdrawing)
      )
      ;; ssget 后马上处理的话可以使用 ActiveSelectionSet 省去转换实体一步
      (vlax-for	circle (vla-get-activeselectionset thisdrawing)
	;;本处没有去除重合点，可能造成程序失败
	(setq intp  (ea:SortPointOnCurve
		      (ea:ints (vlax-ename->vla-object (car line))
			       circle
		      )
		      circle
		    )
	      ;;注意：当有很多交点时就要先用[点集沿曲线排序]函数对交点排序
	      intp  (append intp
			    (list (car intp))
		    )			;闭合圆
	      cenpt (vla-get-center circle) ;center point , variant
	      lcen  (vlax-safearray->list (vlax-variant-value cenpt))
					;Lisp 点
	      r	    (vla-get-radius circle) ;半径
	)
	(vla-delete circle)		;删除圆
					;循环一段段生成圆弧
	                                ;只要两个交点时才可以
	(while (and (> (length intp) 1)
		    (not (equal	(angle lcen (car intp))
				(angle lcen (cadr intp))
				0.001
			 )
		    )
	       )			;交点中没有过滤，这里就要加判断
	    (vla-addarc
	      modelspace
	      cenpt
	      r
	      (angle lcen (car intp))
	      (angle lcen (cadr intp))
	    )
					;此处 startangle endangle 是不能相等的
					;相等了就是 Circle 了
	  (setq intp (cdr intp))
	)
      )
    )
  )
  (princ)
)
;; 混合方法 生成 Arc 用 Entmake 方法 
(defun c:test1 (/ line circle clst intp cenpt ssc n)
  (if (and (setq line (entsel "\n选择线: "))
	   (progn
	     (princ "\n选择园.....")
	     T
	   )
	   (setq ssc (ssget '((0 . "circle"))))
      )
    (progn
      (setq n	0
	    ssl	(sslength ssc)
      )
      (repeat ssl
	(setq circle (ssname ssc n))
	(setq intp  (ea:SortPointOnCurve
		      (ea:ints (vlax-ename->vla-object (car line))
			       (vlax-ename->vla-object circle)
		      )
		      (vlax-ename->vla-object circle)
		    )
	      clst  (entget circle)
	      intp  (append intp
			    (list (car intp))
		    )
	      cenpt (cdr (assoc 10 clst))
	)
	(entdel circle)
	(while (and (> (length intp) 1)
		    (not (equal	(angle cenpt (car intp))
				(angle cenpt (cadr intp))
				0.001
			 )
		    )
	       )
	  ;;entmake 方法
	  (entmake (list '(0 . "ARC")
			 '(100 . "AcDbEntity")
			 '(100 . "AcDbCircle")
			 (assoc 10 clst)
			 (assoc 40 clst)
			 '(100 . "AcDbArc")
			 (cons 50 (angle cenpt (car intp)))
			 (cons 51 (angle cenpt (cadr intp)))
		   )
	  )
	  (setq intp (cdr intp))
	)
	(setq n (1+ n))
      )
    )
  )
  (princ)
)