Topic: bounding box along direction

[domenicomaria]

it's not perfect,
(because it doesn't analyze curves but only segments),

LM:ent->pts builds approximations for curves, so it's better than you think

... curves converted into segments ...
I have seen the point list that it makes...
and I have seen how It works (very well)
... however It Is an approximation ...
 however it Is more than enough, for what i need

[domenicomaria]

Please post your sample DWG.

how did you do ? as dexus ?

[Marc'Antonio Alessi]

See replay #1 and #11... 

[Stefan]

Here is an exact solution for polylines.
It is a mathematical solution, no entity is changed at all.

Code - Auto/Visual Lisp: [Select]

1. (defun _rot (p a)
2.   (list
3.     (- (* (car p) (cos a)) (* (cadr p) (sin a)))
4.     (+ (* (car p) (sin a)) (* (cadr p) (cos a)))
5.   )
6. )
7.  
8. (defun _m2p (a b) (mapcar '(lambda (a b) (/ (+ a b) 2.0)) a b))
9.  
10. (defun _pline_rotated_bb (e u / a b c d m o p r s a1 a2)
11.   (setq a (vlax-curve-getstartparam e)
12.         b (vlax-curve-getendparam e)
13.   )
14.   (while (<= a b)
15.     (setq p (vlax-curve-getpointatparam e a)
16.           r (_rot p (- u))
17.           a1 (if a1 (mapcar 'min a1 r) r)
18.           a2 (if a2 (mapcar 'max a2 r) r)
19.           s (vlax-curve-getsecondderiv e a)
20.           d (distance '(0.0 0.0) s)
21.     )
22.     (if
23.       (> d 0.0)
24.       (progn
25.         (setq o (polar
26.                   (setq m (vlax-curve-getpointatparam e (+ a 0.5)))
27.                   (angle m (_m2p p (vlax-curve-getpointatparam e (rem (1+ a) b))))
28.                   d
29.                 )
30.         )
31.         (foreach x '(0.0 0.5 1.0 1.5)
32.           (setq p (polar o (+ u (* x pi)) d))
33.           (if
34.             (and
35.               (setq c (vlax-curve-getparamatpoint e p))
36.               (< a c (1+ a))
37.             )
38.             (setq r (_rot p (- u))
39.                   a1 (mapcar 'min a1 r)
40.                   a2 (mapcar 'max a2 r)
41.             )
42.           )
43.         )
44.       )
45.     )
46.     (setq a (1+ a))
47.   )
48.   (list
49.     (_rot a1 u)
50.     (_rot (list (car a2) (cadr a1)) u)
51.     (_rot a2 u)
52.     (_rot (list (car a1) (cadr a2)) u)
53.   )
54. )
55.  
56. (defun c:test ( / *error* e u bb)
57. ;;;  (setq *error* (err))
58.   (if
59.     (and
60.       (setq e (ssget "_+.:S" '((0 . "*POLYLINE"))))
61.       (setq u (getangle "\nSpecify rotation angle: "))
62.       (setq bb (_pline_rotated_bb (ssname e 0) u))
63.     )
64.     (entmakex
65.       (append
66.        '(
67.           (0 . "LWPOLYLINE")
68.           (100 . "AcDbEntity")
69.           (100 . "AcDbPolyline")
70.           (90 . 4)
71.           (70 . 1)
72.         )
73.         (mapcar
74.          '(lambda (p)
75.             (cons 10 p)
76.           )
77.           bb
78.         )
79.       )
80.     )
81.   )
82. ;;;  (*error* nil)
83.   (princ)
84. )

[domenicomaria]

See replay #1 and #11... 

Marco, I apologize.
I didn't really notice the answer #11 ! 

Bravo.
Very interesting !

[domenicomaria]

@DEXUS

Here is an exact solution for polylines.
It is a mathematical solution, no entity is changed at all.

It works perfectly !

you are very good !

[domenicomaria]

See replay #1 and #11... 

. . . and your code works also with line, circle, arc, ellipse . . .
. . . while fails with spline, insert . . .

[dexus]

@DEXUS

Here is an exact solution for polylines.
It is a mathematical solution, no entity is changed at all.

It works perfectly !

you are very good !

I would love to take credit, but it should be @Stefan

[ribarm]

I think Stefan will fail if reference entity is INSERT...
I've included all that's possible in my BBox.lsp... It'll try even with nested inserts that overlap each other...

[domenicomaria]

@ Dexus and Stefan !

I would love to take credit, but it should be @Stefan

I'm always very distracted ! 

Stefan, YOU you are very good !

[domenicomaria]

I think Stefan will fail if reference entity is INSERT...
I've included all that's possible in my BBox.lsp... It'll try even with nested inserts that overlap each other...

The code of Stefan is only for polylines ...

[Stefan]

Thanks. My wife would disagree
But she knows nothing about lisp

[ribarm]

I've just tried my BBox.lsp and it fails with INSERTs too... I've fixed it only not to exit with error and I think that it explodes blocks if it runs on them, so be careful with *.lsp... But for curves it should work well and in 3d UCS... HTH., M.R.

[xdcad]

I think Stefan will fail if reference entity is INSERT...
I've included all that's possible in my BBox.lsp... It'll try even with nested inserts that overlap each other...

The code of Stefan is only for polylines ...

Code - Auto/Visual Lisp: [Select]

1. (defun c:tt ()
2.   (if (setq ss (xdrx-ssget "\nSelect Draw Boundingbox Objects<Quit>:"))
3.     (progn
4.       (while (setq e (xdrx-entsel
5.                        "\nPick a Direction Line<Quit>:"
6.                        '((0 . "*polyline,line"))
7.                      )
8.              )
9.         (setq xdir (xdrx-getpropertyvalue (car e) "firstderiv" (cadr e))
10.               box  (xdrx-entity-box ss xdir)
11.         )
12.         (xdrx-polyline-make (xdrx-points-ucs2wcs box) t)
13.         (xdrx-setpropertyvalue (entlast) "color" (xdrx-math-rand 1 220))
14.       )
15.     )
16.   )
17.   (princ)
18. )

[domenicomaria]

anyway, when there is a solid hatch, there are allways problems...
... but it doesn't depend from your great xdrx-entity-box function ...
which maybe should be called xdrx-ss-box