topic Re: Get Rectangle Center Point in Visual LISP, AutoLISP and General Customization Forum

Get Rectangle Center Point

Anonymous — Thu, 08 Apr 2021 11:42:04 GMT

Hello, I need a function which "finds the center point of a rectangle" and also, store distance from center to width in a variable and distance from center to length in another variable. Thanks!

Re: Get Rectangle Center Point

ВeekeeCZ — Thu, 08 Apr 2021 11:49:10 GMT

A rectangle from a polyline? Or lines? Better post a dwg example.

And which would be the width and which length? Just general w<l?

Re: Get Rectangle Center Point

Anonymous — Thu, 08 Apr 2021 12:04:16 GMT

A Polyline rectangle. Any width and length.

I want to draw a circle with its center as rectangle center with below function. But circle radius shouldn't go outside rectangle. So I want to use distances from sides to limit radius size (if that's the right approach)!

(defun C:DRWCRC () (initget 1) (setq c (getpoint "\nChoose Center:")) (initget 7) (setq rad (getdist c "\nRadius Size:")) (command "circle" c rad) (princ) )

Re: Get Rectangle Center Point

ВeekeeCZ — Thu, 08 Apr 2021 12:17:13 GMT

Sure. Your func is not bad.. but this one is a bit better - less dependent on environment settings.

(vl-load-com)

(defun c:CircleInscribed ( / s e p d r)

  (if (setq s (ssget '((0 . "LWPOLYLINE"))))
    (repeat (setq i (sslength s))
      (setq e (ssname s (setq i (1- i))))
      (setq p (mapcar '/ (mapcar '+ (vlax-curve-getpointatparam e 0) (vlax-curve-getpointatparam e 2)) '(2 2)))
      (setq r (min (setq d (vlax-curve-getdistatparam e 1)) (- (vlax-curve-getdistatparam e 2) d)))
      (entmakex (list (cons 0 "CIRCLE") (cons 10 p) (cons 40 (/ r 2))))))
  (princ)
  )

If your rectangle is from 4 vertices (if else the routine fails), then parameter 0 is the first one, and +1 next one.

Re: Get Rectangle Center Point

Kent1Cooper — Thu, 08 Apr 2021 12:24:06 GMT

If you can count on always selecting an actually rectangular Polyline, and want the largest internal Circle drawn, something like this? [untested]:

(vl-load-com); in case needed

(defun C:CMR ; = Circle at Midpoint of Rectangle

(/ rec)

(setq

rec (car (entsel "\nRectangle to draw Circle in the middle of: "))

dim1 (/ (distance (vlax-curve-getStartPoint rec) (vlax-curve-getPointAtParam rec 1)) 2)

dim2 (/ (distance (vlax-curve-getPointAtParam rec 1) (vlax-curve-getPointAtParam rec 2)) 2)

); setq

(command "_.circle"

"_non"

(mapcar '/

(mapcar '+ (vlax-curve-getStartPoint rec) (vlax-curve-getPointAtParam rec 2))

'(2 2 2)

); mapcar /

(min dim1 dim2); radius

); command

(princ)

); defun

That leaves the distances you want in the 'dim1' and 'dim2' variables.

It could be made to verify that you selected a Polyline, that it's closed and with 4 vertices, and even check whether it's rectangular (I have code for that if you want).

Re: Get Rectangle Center Point

Anonymous — Thu, 08 Apr 2021 12:26:03 GMT

This is really good, Thanks! But I want to be able to draw it MAX (to the sides of rectangle) MIN (any size smaller)!

Re: Get Rectangle Center Point

Anonymous — Thu, 08 Apr 2021 12:26:52 GMT

Thanks! Same here, I want to be able to draw it MAX (to the sides of rectangle) MIN (any size smaller)!

Re: Get Rectangle Center Point

ВeekeeCZ — Thu, 08 Apr 2021 12:41:02 GMT

One routine for min and second for max?

... if yes, then find a MIN function and change it to MAX. As simple as that.

Re: Get Rectangle Center Point

Kent1Cooper — Thu, 08 Apr 2021 18:14:15 GMT

@Anonymous wrote:
.... I want to be able to draw it MAX (to the sides of rectangle) MIN (any size smaller)!

This should [untested] offer the MAXimum size that fits within the rectangle as the default, and accept any other size input from the User:

(vl-load-com); in case needed (defun C:CMR ; = Circle at Midpoint of Rectangle (/ rec rad) (setq rec (car (entsel "\nRectangle to draw Circle in the middle of: ")) dim1 (/ (distance (vlax-curve-getStartPoint rec) (vlax-curve-getPointAtParam rec 1)) 2) dim2 (/ (distance (vlax-curve-getPointAtParam rec 1) (vlax-curve-getPointAtParam rec 2)) 2) ); setq (initget 6); no zero, no negative (setq rad (cond ( (getdist (strcat "\nRadius of Circle <max. " (rtos (min dim1 dim2)); in current Units mode/precision ">: " ); strcat ); getdist ); User-input condition ((min dim1 dim2)); default on User Enter ); cond ); setq (command "_.circle" "_non" (mapcar '/ (mapcar '+ (vlax-curve-getStartPoint rec) (vlax-curve-getPointAtParam rec 2)) '(2 2 2) ); mapcar / rad ; radius ); command (princ) ); defun

It could be made to reject sizes larger than what fits in the rectangle, if that's needed.

Re: Get Rectangle Center Point

Anonymous — Thu, 08 Apr 2021 19:24:54 GMT

This is Perfect. Toast! 🍻😀

Re: Get Rectangle Center Point

hak_vz — Thu, 08 Apr 2021 19:32:06 GMT

(defun circle_in_rect ( min_max / *error* adoc take take2 e eo eco coords a b c d1 d2 m p q) (defun *error* ( msg ) (if (not (member msg '("Function cancelled" "quit / exit abort"))) (princ (strcat "\nError: " msg)) ) (setvar 'cmdecho 1) (princ) ) (defun take (amount lst / ret) (repeat amount (setq ret (cons (car lst) (take (1- amount) (cdr lst)))))) (defun take2 (lst) (take 2 lst)) (setq adoc (vla-get-activedocument (vlax-get-acad-object))) (vla-endundomark adoc) (vla-startundomark adoc) (setvar 'cmdecho 0) (while (setq e (car(entsel "\nSelect rectangle >"))) (setq eo (vlax-ename->vla-object e) co(vlax-get eo 'Coordinates)) (while co (setq coords (cons (take2 co) coords) co (cddr co))) (setq a (car coords) b (cadr coords) c (caddr coords) p (mapcar '*(mapcar '+ a b) '(0.5 0.5)) q (mapcar '*(mapcar '+ b c) '(0.5 0.5)) m (mapcar '*(mapcar '+ a c) '(0.5 0.5)) d1 (distance m p) d2 (distance m q) ) (if(eq min_max "<") (command "_.circle" "_non" m (car(vl-sort (list d1 d2) '<))) (command "_.circle" "_non" m (car(vl-sort (list d1 d2) '>))) ) ) (vla-endundomark adoc) (setvar 'cmdecho 1) (princ) ) (defun c:min_circle_in_rect nil (circle_in_rect "<")) (defun c:max_circle_in_rect nil (circle_in_rect ">")) (defun min_circle_in_rect nil (circle_in_rect "<")) (defun max_circle_in_rect nil (circle_in_rect ">"))

Re: Get Rectangle Center Point

Sea-Haven — Fri, 09 Apr 2021 00:17:35 GMT

Nice idea 4 options, for me add a overall (defun c:cinr then use a cond on pick. Need multi radio buttons.lsp. The button picked can be saved so next run just click OK.