Calling all Gurus: Here is an easy one

[jack.frahm]

Command: L
LINE Specify first point: _from Base point: <Offset>: .06

Specify next point or [Undo]: _from Base point: <Offset>: .06


How would I make the above series of commands one easy LISP routine? I would like to create a LISP routine that would allow the drawing of a line that starts offset at .xx from user input.

Thanks in advance,
Jack

[paulmcz]

... offset 0.06, OK, but at what angle from the base point?

Command: L
LINE Specify first point: _from Base point: <Offset>: .06

Specify next point or [Undo]: _from Base point: <Offset>: .06


How would I make the above series of commands one easy LISP routine? I would like to create a LISP routine that would allow the drawing of a line that starts offset at .xx from user input.

Thanks in advance,
Jack

[rkmcswain]

Command: L
LINE Specify first point: _from Base point: <Offset>: .06

Specify next point or [Undo]: _from Base point: <Offset>: .06


How would I make the above series of commands one easy LISP routine? I would like to create a LISP routine that would allow the drawing of a line that starts offset at .xx from user input.

Thanks in advance,
Jack

Something like this?

 (defun c:myline	(/ p1)
   (command "._line"
 	   (polar (setq p1 (getpoint "\nSpecify first point: "))
 		  (* 0.5 pi)
 		  0.06
 	   )
 	   (polar (getpoint p1 "\nSpecify next point: ")
 		  (* 0.5 pi)
 		  0.06
 	   )
 	   ""
   )
   (princ)
 )

You will have to modify the angle to suit your needs. Currently it's 90°

[CAB2k]

Here are some more options:

 (defun c:myline        (/ p1)
   (if (and (setq p1 (getpoint "\nSpecify first point: "))
            (setq p2 (getpoint p1 "\nSpecify next point: ")))
     (command "._line"
           (polar p1 (* 0.5 pi) 0.06)
           (polar p2 (* 0.5 pi) 0.06)
           ""
     )
   )
   (princ)
 )

(defun c:myline (/ p1)
   (if (and (setq p1 (getpoint "\nSpecify first point: "))
            (setq p2 (getpoint p1 "\nSpecify next point: ")))
     (command "._line" p1 p2 ""
              "_.move" "L" "" p1 (polar p1 (* 0.5 pi) 0.06) ""
             )
   )
   (princ)
)

[kennet.sjoberg]

Hi Jack, have fun

(defun c:parl ( / Pkt1 ) ;; *Offset*

  (defun parl_err (msg / ask )
    (princ "\nUser [Esc]. " )
    (if (not *Offset* ) (setq *Offset* 0 ) ( ) )
    (setq *error* OldErr )
    (setq ask (getreal (strcat "New Offset <" (rtos *Offset* 2 2 )"> or Enter ? : " )) )
    (if ask (setq *Offset* ask ) (setq *Offset* *Offset* ) )
    (drawl)
  )

  (defun drawl ( / OldErr Pkt2 )
    (setq OldErr *error* *error* parl_err )
    (initget 65 )
    (if (not *Offset* ) (while (not (setq *Offset* (getdist "Digitize the distance or enter a real : " )))) ( ) )
    (princ (strcat "\nPresent Offset is " (rtos *Offset* 2 2 ) ", use [Esc] to change.\n" ) )
    (if (not Pkt1 ) (while (not (setq Pkt1 (getpoint "Start point: ")))) )
    (while (not (setq Pkt2 (getpoint "End point: "))) )
    (command "._line" 
      (polar Pkt1 (+ (angle Pkt1 Pkt2 ) (/ PI 2 )) *Offset* )
      (polar Pkt2 (+ (angle Pkt1 Pkt2 ) (/ PI 2 )) *Offset* )
      ""
    )
    (setq *error* OldErr )
  )

  (drawl)
  (princ)
)

paulmcz, the line is parallel to the 2 points
rkmcswain, what happens when You draw a vertical line ?
ab2draft, what happens when You draw a vertical line ?
ab2draft, what happens again when You draw a vertical line ?

: ) Happy Computing !

kennet

[CAB2k]

kennet,
sorry I did not test the code, just offering options for limited error checking.

How about one that repeats until enter is pressed and you may change the offset as in your code, sort of like your code .

(defun c:myline (/ p1 p2 ang)
  ;; remembers changed offset
  ;; press ENTER to quit
  ;;  press O to change offset
  ;;  to offset to the opposit direction pick points in reverse order
  ;;  or enter a negative offset
  (setq off|set (cond (off|set) (0.06)); default
        p1 t
  ) 
  (while
    (and
      (not
        (while (and p1 (/= (type p1) 'list))
          (initget "Offset")
          (setq p1 (getpoint
                     (strcat "\nPick first point or [Offset] to change: "
                             (rtos off|set))))
          (if (= p1 "Offset")
            (while (not (setq off|set (getdist "\nEnter new offset distance: ")))))
        )
      )
      (and p1
           (setq p2 (getpoint p1 "\nSpecify next point: "))
           (setq ang (- (angle p1 p2) (* 0.5 pi))
                 p1  (polar p1 ang off|set)
                 p2  (polar p2 ang off|set)
           )
           (not (command "._line" p1 p2 ""))
           (setq p1 T)
      )
    )
  )
  (princ)
)

[rkmcswain]

rkmcswain, what happens when You draw a vertical line ?
kennet

Same thing it does when you draw a line at any other angle. Both line endpoints are 0.06 units away, at 90°, from the two picked points, just what the code tells it to do, unless I'm missing something.

[kennet.sjoberg]

Same thing it does when you draw a line at any other angle . . unless I'm missing something.

Yes rkmcswain, my routine always draw the line offset and parallel,
Your routine draws the line parallel 0 dislocated when vertical.

: ) Happy Computing !

kennet

[rkmcswain]

Yes rkmcswain, my routine always draw the line offset and parallel,
Your routine draws the line parallel 0 dislocated when vertical.
kennet

That's great, but the original post never specified an angle from which the offset points should be offset.

...allow the drawing of a line that starts offset at .xx from user input

My last comment on the first post indicated to the OP that the angle might have to be modified by the OP, possibly at run time.

[kennet.sjoberg]

mmm..rkmcswain, In Your opinion You are totally right,

That's great, but the original post never specified an angle from which the offset points should be offset.

But for me is an offset distance always perpendicular to a line or curve,
or in AutoCAD terms "Offsetting creates a new object whose shape parallels the shape of a selected object."
and in our case an fictitious line through two points.

: ) Happy Computing !

kennet