Segment of a polygon

I am struggling on coming up with a way to determine which segment of
a polygon is picked by clicking on the segment. My end goal is to put
rectangles along a selected segment at a certain spacing. Could
someone give me a kick in the right direction. Thanks.

--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein

 

You mean like this? The segments are 0 based, so the first one is 0, second
is 1, etc.

(setq obj (vlax-ename->vla-object (car (entsel "Select pline: "))))
(setq pt (vlax-curve-getClosestPointTo obj (getpoint "Select point: ")))
(setq param (vlax-curve-getparamatpoint obj pt))
(setq seg# (fix param))

Then with help of the other vlax-curve- functions your spacing portion
should be a snap.

HTH,
Lord knows you've helped me a lot over the years ;-)
Jeff

 

Jeff,

Those dog gone curve functions. Thanks, I believe that is the "kick"
I needed.
I'll give them a go.

Thanks a bunch,

--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein

 

Hi Ken,

Haven't seen you around much these days.
Hope all is well.

I picked this up from someone in this group,
just don't remember who.

(setq point (cadr (entsel "\nselect an object: ")))

(nth 2 (car (ssnamex (ssget point))))


Just alternative to Jeff's suggestion.

 

Hi Ken,

You might want to compare what you have so far with John Uhden's SegmentPts function.
It does exactly what you want. It's been posted here quite a few times. I'm sure all
flavors are not the same. But of course the methods are what would be of interest.

I'll post what I have if you can't find it. Or maybe the author will grace us with
his presence... We miss you, John. ;-)

Regards
Joe Burke

 

Hey Jason,

Yeah I don't get to do much with Acad customization anymore. Seems
I've built all the custom tools we need. :-( Been diving into some
SQL and heading into VB and CNC stuff. It all comes back to Acad
though. Visual Basic is pretty cool. Thanks to this NG I've been
able to pick up on it a little. I have an idea that here shortly I'll
be living in the VBA NG.

Thanks for the help. I'm putting together a few tools for drawing CNC
milling operations. Got stuck on the very first one.

Thanks again.

--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein

 

Joe,

This is what I have so far: <grin>

(defun Horz_D315_32mm ()
(princ)
)

I did a quick search through OE didn't come up with anything. I'll do
some gooooogling. I look forward to comparing.......using John's
function.

Thanks

--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein

 

Ken,

Good work so far... ;-)

Google search would find John's function, but don't bother. Here's what I have. As I
said, it may not be what John posted most recently. But it does demonstrate how to
use the vlax-curve functions to solve the problem.

Joe Burke

;returns a list of two 3D points, the end points of the segment picked
;argument: ENT as returned by entsel
;works with lines, arcs and all types of plines
;by John Uhden - revised 9/28/02
(defun SegmentPts (ent / e pnt vobj Name param1 param2 p1 p2)
;(vl-load-com)
(and
(setq e (car ent))
(= (type e) 'ENAME)
(setq pnt (cadr ent))
(listp pnt)
(not (atom (cdr pnt)))
(vl-every (function (lambda (x)(= (type x) 'REAL))) pnt)
(setq vobj (vlax-ename->vla-object (car ent)))
(setq pnt (trans (cadr ent) 1 0))
(setq pnt (vlax-curve-getClosestPointTo vobj pnt))
(setq Name (vla-get-ObjectName vobj))
(cond
((vl-position Name '("AcDbArc" "AcDbLine"))
(setq p1 (vlax-curve-getStartPoint vobj))
(setq p2 (vlax-curve-getEndPoint vobj))
)
((wcmatch (strcase Name) "*POLYLINE")
(setq param1 (vlax-curve-getParamAtPoint vobj pnt))
(setq param1 (fix param1))
(setq param2 (1+ param1))
(if (equal param1 (vlax-curve-getStartParam vobj) 1e-10)
(setq p1 (vlax-curve-getStartPoint vobj))
(setq p1 (vlax-curve-getPointAtParam vobj param1))
)
(if (equal param2 (vlax-curve-getEndParam vobj) 1e-10)
(setq p2 (vlax-curve-getEndPoint vobj))
(setq p2 (vlax-curve-getPointAtParam vobj param2))
)
)
(T (prompt (strcat "\nHaven't figured out a(n) " Name " yet.")))
)
p1 p2
)
(list p1 p2)
) ;end

 

Hey thanks Joe. That is exactly what I was looking to do.

BTW feel free to use, modify, and distribute my function.


Thanks again.

--
Ken Alexander
Acad2004
Windows XP

"We can't solve problems by using the same kind
of thinking we used when we created them."
--Albert Einstein

 

Ken,

It's a small repayment for your GetNumber function back around January of this year.
That solved a bunch of problems on my end.

Joe