LISP Routine to Draw Walkways?

[Anonymous]

I do a lot of repetitive tasks in my daily drawings and I’d like to make life easier!  I was researching how I could write a lisp to draw a walkway path for a roof.  I came across a couple of interesting posts but couldn’t follow the code because of my lack of understanding the language.  Can anyone help point me in a direction that I could learn the language?

So what I do is draw a 30” x 30” square (using the rectangle command).  Then copy it so there is a 2” gap between them.  Then I go back and hatch them with a dot hatch scaled to 96.  What I’d like to do is type a command and it would draw the walkways for me and hatch them if possible.  The problem is the last one is a custom cut size depending on the length of the walkway run?

Now I know I can draw a line, draw the square, hatch the square, array it on the path with set distance between items, then fix the last one so it looks the way I want it to, and then delete the line.  But why do all that when I have a program that allows me to customize it to be done for me? 

Any help would be greatly appreciated and I’m looking to learn so I can create more on my own and maybe someday help somebody new like me!   Thanks in Advance!

Also I've attached a sketch of what I am kind of looking for?

[devitg]

Please upload in ACAD  2007 or early version

[Anonymous]

I believe I did this right?  Let me know if it doesn't work.  I've drawn in the walkway pads for location and I'm hopeful I've explained it well enough to understand my intent?

[devitg]

Michael , you did it rigth, a DWG serve as source to make a LISP.

I full understand your need.

Let me see the DWG , to know if I need further info.

Thanks.

[Kent1Cooper]

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@Anonymous wrote:

.... I was researching how I could write a lisp to draw a walkway path for a roof. ....

So what I do is draw a 30” x 30” square (using the rectangle command).  Then copy it so there is a 2” gap between them.  Then I go back and hatch them with a dot hatch scaled to 96.  What I’d like to do is type a command and it would draw the walkways for me and hatch them if possible.  The problem is the last one is a custom cut size depending on the length of the walkway run?

....

---

I draw those too, sometimes, so I can use such a thing.  Give this a try:

(defun C:RWW ; = Roof Walk-Way
  (/ *error* pt1 pt2 len ang angl angr len qua pad)
  (defun *error* (errmsg)
    (if (not (wcmatch errmsg "Function cancelled,quit / exit abort,console break"))
      (princ (strcat "\nError: " errmsg))
    ); end if
    (setvar 'snapbase snapb)
    (setvar 'osmode osm)
    (setvar 'blipmode blipm)
    (command "_.undo" "_end")
    (setvar 'cmdecho cmde)
    (princ)
  ); end defun - *error*
  (setq
    cmde (getvar 'cmdecho)
    osm (getvar 'osmode)
    blipm (getvar 'blipmode)
    snapb (getvar 'snapbase)
  ); setq
  (setvar 'cmdecho 0)
  (command "_.undo" "_begin")
  (setq
    pt1 (getpoint "\nOne end of walkway center-line [including end gaps]: ")
    pt2 (getpoint pt1 "\nOther end: ")
    ang (angle pt1 pt2)
    angl (+ ang (/ pi 2)); leftward from path direction
    angr (- ang (/ pi 2)); rightward
    pt1 (polar pt1 ang 2); replace w/ starting edge of first pad [after 1st gap]
    len (distance pt1 pt2); including one gap per pad
    qua (fix (/ len 32)); quantity of full-size squares
    inc 0
  ); setq
  (setvar 'snapbase (reverse (cdr (reverse pt1))))
    ; for consistent Hatch positioning [must be XY only]
  (setvar 'osmode 0)
  (setvar 'blipmode 0)
  (command
    "_.pline"
      (polar pt1 angr 15)
      (polar (getvar 'lastpoint) ang 30)
      (polar (getvar 'lastpoint) angl 30)
      (polar pt1 angl 15)
      "_close"
    "_.hatch" "dots" 96 (angtos ang) "_last" ""
  ); command
  (setq
    pad (ssget "_P"); Polyline square
    pad (ssadd (entlast) pad); Hatch
  ); setq
  (repeat (1- qua)
    (command "_.copy" pad "" pt1 (polar pt1 ang (* 32 (setq inc (1+ inc)))))
  ); repeat
  (setq
    pt1 (polar pt1 ang (* qua 32))
    pt2 (polar pt2 (+ ang pi) 2)
  ); setq
  (setvar 'snapbase (reverse (cdr (reverse pt1)))); again
  (if (> (- len (* qua 32) 2) 0); partial pad yet to draw
    (command ; then
      "_.pline"
        (polar pt1 angr 15)
        (polar pt2 angr 15)
        (polar pt2 angl 15)
        (polar pt1 angl 15)
        "_close"
      "_.hatch" "dots" 96 (angtos ang) "_last" ""
    ); command
  ); if
  (setvar 'snapbase snapb)
  (setvar 'osmode osm)
  (setvar 'blipmode blipm)
  (command "_.undo" "_end")
  (setvar 'cmdecho cmde)
  (princ)
); defun

Limited testing, but it seems to work.  It could perhaps also use Layer controls, and some other little stuff.  Consider also whether to use a Block for the full-size pad, and Minsert to put the full-size ones in [big memory-saver!] -- I may convert it to that approach for my own use, later.

If the overall run length is up to 4" longer than a series of full pads, it leaves a gap at the end of that whole more-than-2" leftover space -- otherwise in the case of exactly 4" overage, it would be a 2" gap after the last pad, a zero-length "pad" and the final 2" gap.  Some possible compensation could be made for that, if that's not good [shorten the first pad, too, or something].

[Anonymous]

Just a little testing but this worked great! I did change it so that the hatch pattern would show on my hatch layer. I understood a good portion of your code and am constantly amazed at how guys like you can just throw something together like this!

[Kent1Cooper]

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@Anonymous wrote:
Just a little testing but this worked great! I did change it so that the hatch pattern would show on my hatch layer. I understood a good portion of your code and am constantly amazed at how guys like you can just throw something together like this!

---

I'm glad it works for you, but here's the MINSERTing version I speculated about before.  It uses less memory, and it's detectably faster for paths of any length.  Also, it handles System Variable settings in a collective sort of way, and correctly handles a total path length shorter than one full pad, for short connecting bits, which the previous version didn't.  [And the previous one didn't have a completely correct localized variables list.]

;;  RoofWalkWay.lsp [command name: RWW]
;;  To draw a straight-run Roof WalkWay of 30" square pads and 2" gaps
;;    between them and at ends of specified run.  Minserts full pad(s) if any,
;;    and draws final partial pad separately if needed.
;;  Kent Cooper, last edited 7 January 2014

(defun C:RWW ; = Roof Walk-Way
  (/ *error* cmde svnames svvals pt1 pt2 ang angl angr len qua)
  (defun *error* (errmsg)
    (if (not (wcmatch errmsg "Function cancelled,quit / exit abort,console break"))
      (prompt (strcat "\nError: " errmsg))
    ); end if
    (mapcar 'setvar svnames svvals)
    (command "_.undo" "_end")
    (setvar 'cmdecho cmde)
    (princ)
  ); end defun - *error*
  (setq
    cmde (getvar 'cmdecho)
      ; separate from others so changing others can be inside Undo begin/end
    svnames '(osmode blipmode snapbase)
    svvals (mapcar 'getvar svnames)
  ); setq
  (setvar 'cmdecho 0); suppress following, before changing other SysVars
  (command "_.undo" "_begin")
  (setq
    pt1 (getpoint "\nOne end of walkway center-line [including end gaps]: ")
    pt2 (getpoint pt1 "\nOther end: ")
    ang (angle pt1 pt2)
    angl (+ ang (/ pi 2)); leftward from path direction
    angr (- ang (/ pi 2)); rightward
    pt1 (polar pt1 ang 2); replace w/ starting edge of first pad [after 1st gap]
    len (distance pt1 pt2); including one gap per pad
    qua (fix (/ len 32)); quantity of full-size squares
  ); setq
  (mapcar 'setvar svnames (list 0 0 (reverse (cdr (reverse pt1)))))
    ; Osnap & Blips off,
    ; snapbase for symmetrical Hatch positioning [must be XY only]
  (if (not (tblsearch "block" "RoofWalkWayPad"))
    (command ; then -- make Block [at 0-degree orientation]
      "_.pline"
        (polar pt1 (* pi 1.5) 15)
        (polar (getvar 'lastpoint) 0 30)
        (polar (getvar 'lastpoint) (/ pi 2) 30)
        (polar pt1 (/ pi 2) 15)
        "_close"
      "_.hatch" "dots" 96 0 "_last" ""
      "_.block" "RoofWalkWayPad" pt1 "_previous" "_last" ""
    ); command
  ); if
  (if (> qua 0) ; at least one full pad
    (command "_.minsert" "RoofWalkWayPad" pt1 "" "" (angtos ang) 1 qua 32)
  ); if
  (setq
    pt1 (polar pt1 ang (* qua 32))
      ; for possible partial end pad, after full pads & gaps
    pt2 (polar pt2 (+ ang pi) 2); back off for final end gap
  ); setq
  (setvar 'snapbase (reverse (cdr (reverse pt1)))); again
  (if (> (- len (* qua 32) 2) 0); partial pad yet to draw
    (command ; then
      "_.pline"
        (polar pt1 angr 15)
        (polar pt2 angr 15)
        (polar pt2 angl 15)
        (polar pt1 angl 15)
        "_close"
      "_.hatch" "dots" 96 (angtos ang) "_last" ""
    ); command
  ); if
  (mapcar 'setvar svnames svvals)
  (command "_.undo" "_end")
  (setvar 'cmdecho cmde)
  (princ)
); defun

 Again, add your own Layer control.