xdrx-geom-searchoutline <e1..ss1..e2..s2> [mode] [nil or t] [nil or t])
Parameter Description:
1. e1..s1..: Any combination of entities and selection sets
2. mode: -1,0,1,2
-1 (default) uses the API system variable BoundaryType value （xdrx-setvar "boundarytype" <0,1,2>)
0: Scattered native curves, LINE, ARC...
1: POLYLINE border
2: SPLINE boundary
3. The first T or NIL or None: T returns the point list
4. The second T or NIL or None: delete the original selection set and entities, leaving only the boundaries
=========================
What's important is that：
1. It supports unequal proportions of tiles
2. For ellipses, the ellipses transformed from circles of unequal proportions are not fitted with straight lines, but with "double
arcs" that are tangent at the end.
3. In the future, SPLINE will also support double arc fitting, making it smoother
4. Its sister functions are: xdrx-geom-searchregions, one is to search the outer contour, and the other is to search the inner closed region
(xdrx-begin)
(xdrx
-setvar "boundaryType" 1);//2:生成边界用SPLINE，1：POLYLINE "\nPick the block that generates the outline<Exit>:"
'((0 . "insert"))
)
)
(if (setq outline
(xdrx
-geom
-searchoutline e
)) (xdrx-setpropertyvalue outline "color" 1)
(xdrx
-entity
-redraw outlines
1) )
)
)
(xdrx-end)
)
