Topic: join lines

[domenicomaria]

@kasmo
because there are situations
where it's not the same thing
(and it's not easy to explain it)
and anyway it's more interesting
to write functions that are independent
from ACAD ...

[ribarm]

I had small mistake in chain.zip, so I reattached it again...

Sorry, but it happens from time to time...

[domenicomaria]

https://drive.google.com/file/d/1BTd9jFE7b4hb0iiaAKV5HW0qp8o0u-1e/view?usp=sharing

Thank you VovKa
Your code and mine do the same thing.
And they both work well.
Yours is blue. Mine is red.

Your code is as always very elegant
and I still have to study it.

ciao

[VovKa]

does not want to join these

Code: [Select]

(mapcar 'entmakex
'(((0 . "LINE") (10 6753.94 4368.45 0.0) (11 6768.27 4108.41 0.0))
  ((0 . "LINE") (10 6768.27 4108.41 0.0) (11 6469.86 3748.16 0.0))
  ((0 . "LINE") (10 6753.94 4368.45 0.0) (11 7467.73 4401.85 0.0))
  ((0 . "LINE") (10 7515.47 4172.82 0.0) (11 7467.73 4401.85 0.0))
  ((0 . "LINE") (10 7515.47 4172.82 0.0) (11 7396.11 3798.26 0.0))
  ((0 . "LINE") (10 7396.11 3798.26 0.0) (11 7157.39 3678.97 0.0))
  ((0 . "LINE") (10 7157.39 3678.97 0.0) (11 6768.27 4108.41 0.0))
)
)


[domenicomaria]

does not want to join these

Code: [Select]

(mapcar 'entmakex
'(((0 . "LINE") (10 6753.94 4368.45 0.0) (11 6768.27 4108.41 0.0))
  ((0 . "LINE") (10 6768.27 4108.41 0.0) (11 6469.86 3748.16 0.0))
  ((0 . "LINE") (10 6753.94 4368.45 0.0) (11 7467.73 4401.85 0.0))
  ((0 . "LINE") (10 7515.47 4172.82 0.0) (11 7467.73 4401.85 0.0))
  ((0 . "LINE") (10 7515.47 4172.82 0.0) (11 7396.11 3798.26 0.0))
  ((0 . "LINE") (10 7396.11 3798.26 0.0) (11 7157.39 3678.97 0.0))
  ((0 . "LINE") (10 7157.39 3678.97 0.0) (11 6768.27 4108.41 0.0))
)
)


Your code works perfectly !

My code fails !

Because the bad red segment !

I am not VovKa !

[domenicomaria]

I'm not worried about this type of error anyway ...

which I didn't think about ...

because I suppose that the segments touch each other
and define a shape (closed or open)
without strange or particular situations

[VovKa]

Your code works perfectly !

my code is by far not perfect
it produces different results depending on many random factors
i'd call it unpredictable

[domenicomaria]

@vovka
if we exclude the case where three or more segments have a common point, your code (but mine too) works perfectly...

[Lee Mac]

My LM:sortedchainselection from this program may be useful in this regard: given a selection set (which could easily be a list of segments instead), it will return a list of chained segments.

[domenicomaria]

@Lee Mac
as always your code exceeds expectations

Thank you

[ribarm]

@meja has founded topic that may be of interes...
https://www.theswamp.org/index.php?topic=55918.0

Note : After applying (c:joinlsp) on preselection, resulting entity is joined polyline/spline and it's always (entlast) "if connections were lines or arcs" - last entity (with splines/polylines with more vertices it's different - one of them in the chain inherited joinings - one of them from endings start/end)...

[xdcad]

Thank you VovKa ...

... in the meantime I solved it too

and it also works with various segment groups

I will study your code, because what you do is always interesting !

if you want to do some tests, use the attached dwg

thanks

bye

==========

Regarding 3dpolyline JOIN, ideas:
1. Project to XY (Z->0)
2. JOIN
3. Modify the Z coordinate to the original corresponding 3D point and regenerate the 3D polyline

==========

Code - Auto/Visual Lisp: [Select]

1. (defun c:tt ()
2. ;|
3. Project the selection set curve to the XY plane, Z=0
4. |;
5.   (defun _Project->XY (ss)
6.     (setq plane (xdge::constructor "kPlane" '(0 0 0) '(0 0 1.0)))
7.      ;Coordinate origin 0,0, normal vector (0 0 1.0) AcGe kPlane
8.     (mapcar '(lambda (x)
9.                (setq g (xdge::constructor x))
10.      ; Generate AcGe curve from AcDb curve
11.                (setq g1 (xdge::getpropertyvalue g "orthoproject" plane))
12.      ;Geometric curves are orthogonally projected onto the plane plane
13.                (setq e1 (xdge::entity:make g1))
14.      ;Generate entity after projection
15.                (if (xdrx_object_isa x "AcDb2dPolyline")
16.                  (xdrx_polyline_convertto e1)
17.                ) ;_ end of if
18.      ;If it is 2d Polyline, convert it to lwpolyline
19.                (xdrx_entity_matchprop x e1)
20.      ;The entity attributes match the original curve, color, layer, linetype....
21.                (xdrx_object_swapid e1 x)
22.      ;Entity ObjectId exchange to ensure that the newly generated curve entity name remains unchanged
23.                (xdrx_entity_delete e1)
24.      ;Delete the original curve
25.                (xdge::free g)
26.      ;Geometric curve entities release memory
27.              ) ;_ end of lambda
28.             (xdrx_pickset->ents ss)
29.      ;Select set to entity table
30.     ) ;_ end of mapcar
31.     (xdge::free plane)
32.      ;Geometry plane object releases memory
33.   ) ;_ end of defun
34. ;|
35.    Two-dimensional points query the original three-dimensional point table to obtain the coordinate Z value.
36.    Make a new table ((x y) z)
37. |;
38.   (defun _query (pt pts)
39.     (last (assoc (list (car pt) (cadr pt)) pts))
40.   ) ;_ end of defun
41.   (if (and (xdrx_initssget "\nSelect Curve<Exit>:")
42.            (setq ss (xdrx_ssget '((0 . "*line,arc,ellipse,circle"))))
43.       ) ;_ end of and
44.     (progn
45.      ;|
46.         Save the 3dpolyline vertex table for later querying the Z value corresponding to the two-dimensional point
47.         ( ((x1 y1) z1)((x2 y2) z2) ... ((xn yn) zn) )
48.      |;
49.       (setq pts  (xdrx-getpropertyvalue ss "vertices")
50.                                         ;Select set curve vertex table
51.             pts  (xd::list:flat-point pts)
52.                                         ;One level bracket point table
53.             pts1 (mapcar '(lambda (x)
54.                             (list (list (car x) (cadr x)) (caddr x))
55.                           ) ;_ end of lambda
56.                          pts
57.                  ) ;_ end of mapcar
58.       ) ;_ end of setq
59.       (_Project->XY ss)
60.       ;;3dpolyline -> lwpolyline
61.       (xdrx-curve-join ss)
62.       ;; LWPOLYLINE JOIN
63.       (setq nPnts nil)
64.       (foreach n verts
65.         (setq z (_query n pts1))
66.         (setq pt    (list (car n) (cadr n) z)
67.               nPnts (cons pt nPnts)
68.         ) ;_ end of setq
69.         (setq i (1+ i))
70.       ) ;_ end of foreach
71.       (setq nPnts (reverse nPnts))
72.       (setq pl3d (xdrx-3dpolyline-make nPnts ))
73.       ;;Generate new 3dpolyline
74.     ) ;_ end of progn
75.   ) ;_ end of if
76.   (princ)
77. )
78.  

=============

The above LISP code uses the XDRX-API, which can be downloaded from https://github.com/xdcad/XDrx-API and is updated at any time.

The XDRX API encapsulates AcDb, AcEd, AcGe, AcBr... C++ library, using C++ methods to develop LISP programs.Thousands of Lisp functions are available.