Function to calculate Mtext Justification based on Rotation

[Tsuky]

@CivilTechSource

Quote

I suppose the next to improve it is add offset, or a settings menu?

It's easy to do that.

I have make a more robust filter for mtext (with your exemple, adjust if necessary) 

(defun q_ang (alpha / )
  (cond
    ((not (eq (rem alpha (* 1.5 pi)) alpha)) 4)
    ((not (eq (rem alpha pi) alpha)) 3)
    ((not (eq (rem alpha (* 0.5 pi)) alpha)) 2)
    (T 1)
  )
)
(defun c:wow ( / ss ent dxf_ent ptlst n pt_cen dir_ang tmp ofst n rot)
  (princ "\nSelect closed polylines")
  (setq ss (ssget "_+.:E:S" '((0 . "LWPOLYLINE") (90 . 4) (-4 . "&") (70 . 1))))
  (cond
    (ss
      (initget 4)
      (setq
        ent (ssname ss 0)
        dxf_ent (entget ent)
        ptlst (mapcar 'cdr (vl-remove-if-not '(lambda (x) (= (car x) 10)) dxf_ent))
        n (float (length ptlst))
        pt_cen (list (/ (apply '+ (mapcar 'car ptlst)) n) (/ (apply '+ (mapcar 'cadr ptlst)) n))
        dir_ang (mapcar 'q_ang (mapcar '(lambda (x) (angle pt_cen x)) ptlst))
        tmp (* (distance pt_cen (car ptlst)) 0.25)
        ofst (getdist (car ptlst) (strcat "\nOffset for text <" (rtos (getvar "TEXTSIZE")) ">?: "))
      )
      (if (not ofst) (setq ofst (getvar "TEXTSIZE")))
      (mapcar
        '(lambda (p d / j po)
          (setq qsel (ssget "_C" (mapcar '- p (list tmp tmp 0.0)) (mapcar '+ p (list tmp tmp 0.0)) '((0 . "MTEXT") (8 . "-LE-E-External Levels") (7 . "LE Standard (No Height)"))))
          (cond
            (qsel
              (repeat (setq n (sslength qsel))
                (setq
                  ent (ssname qsel (setq n (1- n)))
                  dxf_ent (entget ent)
                  rot (cdr (assoc 50 dxf_ent))
                )
                (if (eq d 1) (if (zerop rot) (setq j 9 po (polar p (* 0.5 pi) ofst)) (setq j 7 po (polar p 0.0 ofst))))
                (if (eq d 2) (if (zerop rot) (setq j 7 po (polar p (* 0.5 pi) ofst)) (setq j 1 po (polar p pi ofst))))
                (if (eq d 3) (if (zerop rot) (setq j 1 po (polar p (* 1.5 pi) ofst)) (setq j 7 po (polar p pi ofst))))
                (if (eq d 4) (if (zerop rot) (setq j 3 po (polar p (* 1.5 pi) ofst)) (setq j 1 po (polar p 0.0 ofst))))
                (setq dxf_ent (subst (cons 10 po) (assoc 10 dxf_ent) dxf_ent))
                (setq dxf_ent (subst (cons 71 j) (assoc 71 dxf_ent) dxf_ent))
                (entmod dxf_ent)
              )
            )
          )
        )
        ptlst dir_ang
      )
    )
  )
  (prin1)
)

 

[GLAVCVS]

One step further could be to increase or decrease the size of the MTEXT objects.
This could be done dynamically, giving meaning to the cursor movement: when it moves in a certain direction, it not only determines the justification but also, as it moves farther away, it gradually increases the size step by step.
In my opinion, this is an interesting idea that deserves to be explored.