Delete objects that intersect a polyline

Hello guys, I've already asked that.. but I?m not able to find the post (maybe it has been deleted?)

Anyway Mr. Mac Lee answerd me that there are 2 methods.

1) slow, it interrogates every object and find if it intersect the plyne

2) fast, something using the Zoom

I've compiled the first one, but its very slow if i have a lot of ojects.

Can someone remind me about the second method? Thanks guys

The old code

(DEFUN cancella_cerchi (/)
 (SETQ 
    	i 0
       deleted (LIST)
       lista_polilinee (LIST)
 )
 (sel_polylines "Bordi")

 
 (REPEAT (LENGTH lista_polilinee)
   (setq n 0
         p_linea (NTH i lista_polilinee))
   (REPEAT (LENGTH lista_cerchi)
     (SETQ cerchio_obj (VLAX-ENAME->VLA-OBJECT (NTH n lista_cerchi)))
     (IF
       (/= (VLAX-INVOKE p_linea 'intersectwith cerchio_obj ACEXTENDNONE) nil)
        (PROGN (ENTDEL (NTH n lista_cerchi))
               (SETQ deleted (APPEND deleted (LIST (NTH n lista_cerchi))))
        )
     )
     (SETQ n (1+ n))
   )
   (SETQ del 0)
   (REPEAT (LENGTH deleted)
     (SETQ lista_cerchi (VL-REMOVE (NTH del deleted) lista_cerchi))
     (SETQ del (1+ del))
   )
   (SETQ i (1+ i))
   (entdel (VLAX-VLA-OBJECT->ENAME p_linea))
 )
 ;(prompt (length lista_cerchi))
)

EDIT:

Two methods spring to mind:

 

1) Slow but more robust:

Iterate over the set of all circles created.

Delete circles for which (vlax-invoke 'intersectwith acextendnone) is non-nil for any one polyline.

 

2) Quicker but less reliable:

Zoom to extents of polyline.

Obtain a Fence selection of circles using the polyline vertices for each polyline (ssget "_F" '((0 . "CIRCLE"))) [reference here].

Erase all entities in the selection.

Can someone remind me about the second method? Thanks guys

Just an example .

(setq s (car (entsel "\nSelect Polyline :")))
(vla-getboundingbox (vlax-ename->vla-object s) 'j 'k)
(vla-ZoomWindow (vlax-get-acad-object) j k)

Thanks, I've a little question about that.

Look at this short video: http://autode.sk/1My5bQW

When I created the hatch I save the polyline of the boundary, and I delete the object using the first metod.. The boundary isn't a perfect square..

The code you posted seems to work properly if the boundary is a rectangle.. Correct? Maybe I'm wrong, please let me know

Thanks, Dennis

See the methods suggested in this thread: http://www.theswamp.org/index.php?topic=50190.0

See the methods suggested in this thread: http://www.theswamp.org/index.php?topic=50190.0

Thanks Lee, it was hard to find it too many forums eheh

I'll try to post there the solution!

Thanks

EDIT: Solution

well, this is the solution!

(defun cdrs (key lst / pair rtn)
(while (setq pair (assoc key lst))
(setq rtn (cons (cdr pair) rtn)
lst (cdr (member pair lst))
)
)
(reverse rtn)
)

(setq vertici_pl (cdrs 10 (entget (car (entsel "\nSelect a polyline")))))
(defun c:cancella_cerchi_interni ( / e i n s x )
   (if (setq s (ssget "_CP" vertici_pl  '((0 . "CIRCLE"))))
       (progn
           (setq i 0
                 n (sslength s)
           )
           (repeat n
               (setq e (ssname s i)
                     ;x (cdr (assoc 0 (entget e)))
                     i (1+ i)
               )
               (entdel e)
           )
       )
   )
   (princ)
)

(defun c:cancella_cerchi_lungo_linea ( / e i n s x )
   (if (setq s (ssget "_F" (append vertici_pl (list (car vertici_pl)))  '((0 . "CIRCLE"))))
       (progn
           (setq i 0
                 n (sslength s)
           )
           (repeat n
               (setq e (ssname s i)
                     ;x (cdr (assoc 0 (entget e)))
                     i (1+ i)
               )
               (entdel e)
           )
       )
   )
   (princ)
)

1) delete only objects crossing a selection fence

2) delete everything inside and crossing the selection fence