Rotating in segments

[TunzaGibbo]

Hi All

 

Is it possible in Autolisp to insert a block (In this case it's a line) then pick a point (this point defines the centre of an imaginary circle) once the point is picked I would like to move the cursor 360 deg around the point. Like drawing the imaginary point but as the cursor moves through the imaginary 8/45 deg segments the block (Line) will rotate as the cursor moves through each segment. So as the cursor moves around the centre point the line will rotate 8 times (45 deg for each segment. Once I decide the required rotation i would then click the mouse to accept.

I hope you can understand all that

 

Regards

[dlanorh]

Hi All

 

Is it possible in Autolisp to insert a block (In this case it's a line) then pick a point (this point defines the centre of an imaginary circle) once the point is picked I would like to move the cursor 360 deg around the point. Like drawing the imaginary point but as the cursor moves through the imaginary 8/45 deg segments the block (Line) will rotate as the cursor moves through each segment. So as the cursor moves around the centre point the line will rotate 8 times (45 deg for each segment. Once I decide the required rotation i would then click the mouse to accept.

I hope you can understand all that

 

Regards

 

 

Sounds like you need (grread) although i'm not certain it will do what you want in the order you want it.

 

 

Demo code to draw a line per to a curve

;;; Draw perpendicular line
;;; Alan J. Thompson, 10.15.09
(defun c:LPer (/ #Ent #Read)
 (and
   (setq #Ent (car (entsel "\nSelect curve: ")))
   (vl-position (cdr (assoc 0 (entget #Ent))) '("LWPOLYLINE" "ARC" "LINE" "CIRCLE" "ELLIPSE"))
   (while (not (eq 25 (car (setq #Read (grread T 15 0)))))
     (princ "\rSpecify point for line: ")
     (redraw)
     (if (vl-consp (cadr #Read))
       (grdraw (vlax-curve-getclosestpointto #Ent (trans (cadr #Read) 1 0) T)
               (trans (cadr #Read) 1 0)
               1
       ) ;_ grdraw
     ) ;_ if
     (if (eq 3 (car #Read))
       (entmake (list '(0 . "LINE")
                      (cons 10 (vlax-curve-getclosestpointto #Ent (trans (cadr #Read) 1 0) T))
                      (cons 11 (trans (cadr #Read) 1 0))
                ) ;_ list
       ) ;_ entmake
     ) ;_ if
   ) ;_ while
 ) ;_ and
 (redraw)
 (princ)
) ;_ defun

Draw any arc, circle, ellipse or polyline, load the lisp then type "lper". Move the cursor around. The red line is always per to selected object. If you left click it will draw a line from the point clicked per to the selected object.

 

 

Or my dynamic Angle and Distance

 

(defun c:DAD (/  pt pos dms)
 (and (setq pt (getpoint "\nSpecify base point: "))
   (while (eq 5 (car (setq pos (grread T 15 0))))
     (redraw)
     (grdraw pt (cadr pos) 1 1)
     (setq dms (strcat "Angle : " (angtos (angle pt (cadr pos)) 1 4) "   Distance : " (rtos (distance pt (cadr pos)) 2 3)))
     (princ (strcat "\r" dms "       "))
     (grtext -1 dms)
   );end_while
 );end_and
 (redraw)
 (princ)
);end_defun

 

 

Angle is displayed in Degrees minutes and seconds but its easy to change

Edited May 20, 2018 by dlanorh
added code

[hanhphuc]

segment? 'polar snap' 45d?

(setq [b]a[/b] (angle p1 p2))
([color="blue"] polar[/color] p1 (- [b]a[/b] ([color="blue"][b]rem[/b][/color] [b]a[/b] (* 0.25 pi))) (distance p1 p2) )

 

or dynamic block?

[Cad64]

Why don't you use Polar Tracking? https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2016/ENU/AutoCAD-Core/files/GUID-7EC3C63D-EA4E-4E65-A676-C3A3627E3F19-htm.html

 

Just enable it, set the angle of rotation for 45, or whatever increment you want, then use the rotate command as you normally would. As you move your cursor around the base point it will snap to the angle you specified.

 

Also, when you insert a block, if you enable "specify rotation on screen", you can rotate the block around its insertion point using the polar tracking angle you specified.

[BIGAL]

The other way would be say insert line at 0 angle then hit space bar repeatedly to rotate press enter to accept. Obviously a lisp.

[TunzaGibbo]

Thanks Big Al Sounds Straight forward I'll give it a go and let you know

 

Tony