Give Line direction clock wise

[avinash00002002]

Hi!

I need help that I have select a line at any direction it always give me clockwise direction p1 and p2 point.

Avinash

[komondormrex]

check the following

(defun c:mark_line_ends (/ line_object line_mid_point delta_x_y delta_x_y line_start line_end) 
	(setq line_object (vlax-ename->vla-object (car (entsel "\nPick line: ")))
	      line_mid_point (polar (vlax-get line_object 'startpoint) (vla-get-angle line_object) (* 0.5 (vla-get-length line_object)))  
	      delta_x_y (mapcar '- (vlax-get line_object 'startpoint)  (vlax-get line_object 'endpoint) '(0 0))
	)
  	(if (< (abs (car delta_x_y)) 1e-9)
	  (setq line_angle (* 1.5 pi)) 
	  (setq line_angle (atan (apply '/ (reverse delta_x_y))))
	)
  	(mapcar '(lambda (text line_point) (vla-addtext (vla-get-block (vla-get-activelayout (vla-get-activedocument (vlax-get-acad-object))))
				       		       text
					    	       (vlax-3d-point line_point)
					     	       25
					   )
		 )
		'("P1" "P2")
		 (list
	   	 	(polar (setq line_start (polar line_mid_point (+ pi line_angle) (* 0.5 (vla-get-length line_object)))) (- (+ pi line_angle) (* 0.5 pi)) 25)
	         	(polar (setq line_end (polar line_mid_point line_angle (* 0.5 (vla-get-length line_object)))) (+ line_angle (* 0.5 pi)) 25)
		 )
	)
        (vlax-put line_object 'startpoint line_start)
  	(vlax-put line_object 'endpoint line_end)
	(princ)
)

updated_2

[avinash00002002]

Thanks for your prompt reply, it works now text  p1 and p2, How to get define p1 and p2 from this routine

[Kent1Cooper]

---

@avinash00002002 wrote:

I want to achieve that I need p1 point at the left side and p2 point is right side for identify cut at p1 point has left side and if cut at point p2 then it identify right side always.

---

I don't understand what relationship this has to "clock wise" in the Topic heading, and Message 1's "...always give me clockwise direction."

[komondormrex]

if you need to change end points of a line according to marking check update_2 in message 21.

[autoid374ceb4990]

avinash00002002:

Please explain  "identify cut at p1 point has left side and if cut at point p2 then it identify right side"

[Kent1Cooper]

If what you want is to have whichever end is farther to the left put into a variable called p1, and whichever end is farther to the right put into a variable called p2, no matter which direction the Line was drawn, try this [in simplest terms, minimally tested]:

(defun C:LLtoR ; = Line endpoints ordered from Left to Right
  (/ lin endsLtoR)
  (setq
    lin (car (entsel "\nSelect Line for endpoint ordering: "))
    endsLtoR
      (vl-sort (list (getpropertyvalue lin "StartPoint") (getpropertyvalue lin "EndPoint"))
        '(lambda (a b) (< (car a) (car b)))
      ); sort
    p1 (car endsLtoR)
    p2 (cadr endsLtoR)
  ); setq
  (prin1)
)

If a Line is vertical [neither end is to the left or right of the other], its start point will be p1 and its end point will be p2.  But it could be made to, for example, put whichever end is lower into p1 and whichever end is higher into p2, or to differentiate by some other standard.

[Sea-Haven · Accepted solution]

One of the things I often do is pick a line near and end this does not change the line direction but does swap P1 and P2 so they go away from P1. Is this maybe what you want.

like others need some visual clues, a dwg or an image.

[Moshe-A]

@Sea-Haven,

Well done! after 6 experts and 26:30 hours you are winning my the gold medal, i take off my hat 😀
@john.uhden where are you? we need your Wisdom here 🙏

[Sea-Haven]

Thank you.

Waiting for @avinash00002002 to provide clear information.

[avinash00002002]

Yes, Please find sample drawing.

I have a angle bracing, in that bracing have some cuts, I want to identify that cuts if upper left cut find than some symbol name and so on.

[avinash00002002]

missed out attachment

[Sea-Haven]

What you want is the "Chamfer" command, plus say a trim then draw the object provided easy. Just have a front end asking relevant questions. Ran out of time today.

(if (not AH:getvalsm (load "Multi getvals.lsp")))
(setq ans (AH:getvalsm (list "Enter values " "length " 5 4 "1000" "Height" 5 4 "45" "Circle radius " 5 4 "8.75"
"Circle offset " 5 4 "25" "top offset " 5 4  "4" "Chamfer edge " 5 4 "10")))

Will not be back for a few days, if you had posted the dwg at 1st post would have had a solution around post 2-3. 

[Kent1Cooper]

---

@avinash00002002 wrote:

.... it always give me clockwise direction p1 and p2 point.

---

I still don't understand what you mean by "clockwise" in this context.  In your sample drawing, the direction from P1 to P2 is clockwise in relation to the overall outline, but P3 to P4 is counterclockwise.  Likewise, P7 to P8 is clockwise, but P5 to P6 is counterclockwise.  And AutoCAD doesn't have any way of knowing that those independent Lines make a closed outline, so it can't determine clockwise vs. counterclockwise directions around it.

Also:  Is the sample drawing what you are starting with, or the desired end result?  If it's what you're starting with, what should be the end result?  If it's the end result, what did you start with?

[If it's an end result, and if it started as a rectangle, then CHAMFER is probably what you want, as suggested.  And if the outline were a Polyline instead of independent Lines, CHAMFER can do that to all four corners at once, by selecting the Polyline anywhere -- no separate selections of adjacent edges for each corner.  Also, if it were a Polyline, AutoCAD could determine which direction around it is clockwise, though maybe that would not matter if Chamfer does the job.]