vla-intersectwith shortcoming

[john.uhden]

Although Land Desktop has a routine for labeling the elevation of polyline contours, it often misbehaves.  So naturally I wrote my own.  The object is to pick the polyline at the desired label point, extract the elevation, add the text aligned with the polyline, and break the polyline from one end of the text to the other.  Sadly, 2004 doesn't have background masking, and the boss despises wipeouts, thus we must break the polyline.

My method was to create an invisible circle, find the intersects, and use them as the two break points.

After some trial and error, I have found that the method does not work when the circle intersects one bulged segment twice.  Even the native TRIM command won't work.  If one of the intersections is with a straight polyline segment, it does work.

Has anyone else experienced this behavior?  Or maybe it was a bug that's been fixed since 2004.

[ronjonp · Accepted solution]

---

@cadffm wrote:

...

the last option is to create a new object and erase the old one.

I will try it in a newer version, if you are not faster with your test.

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@cadffm  In before me but same thought process. 🍻 

[john.uhden]

Tomorrow. Gotta get gas and get home.
Many thanks, Sebastian.

[cadffm · Accepted solution]

Cry

You can not remove the mask by this way (remove 90 45 63 441 & entmod), so in 2004 the only way is to re-create the Object.

In 2005-2021 it also not working by entmod, but you have vla-put-backgroundfill

Note:

You all saw and fix the issue in my basic sample code, but for beginners i post the edited code again.

(defun TEST (#90# #63# #45# / #el# #TEMP#) ;; TEST-> (TEST 3 9 1) or (TEST 1 4 1)
(while
(setq #el# (entget(car (nentsel "\nMtext wählen: "))))
;;================================================================
(if (assoc 90 #el#)
(setq #el# (subst (cons 90 #90#) (assoc 90 #el#) #el#))
(setq #el# (append #el# (list (cons 90 #90#))))
)
;;================================================================
(if (assoc 63 #el#)
(setq #el# (subst (cons 63 #63#) (assoc 63 #el#) #el#))
(setq #el# (append #el# (list (cons 63 #63#))))
)
;;================================================================
(if (assoc 45 #el#)
(setq #el# (subst (cons 45 #45#) (assoc 45 #el#) #el#))
(setq #el# (append #el# (list (cons 45 #45#)))) ;
)
;;================================================================
(entmod #el#)
)
)

[john.uhden]

I got it (removing backgroundfill via dxf).  Yes, you have to delete the original and make a new one, because entmoding it (to remove) does not work.

(foreach dxf '(-1 5 330 90 45 63 441)(setq ent (vl-remove (assoc dxf ent) ent)))
(entdel e) ;; chuck the original
(entmake ent) ;; make a new one

I have no idea what the 441 code is for. 

Of course the original ent should include its xdata so that it is recreated.

[ronjonp]

@john.uhden  

From the docs:

441	Transparency of background fill color (not implemented)

You see the post HERE? That solution worked for me.