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)
)