The line end points are snapped to polylines, but there is no vertex and no break.
I’m afraid this code is not what will solve the Problem. Because it is the wrong approach, from the polylines. But we want to know if every line is attached to a polyline on at least one Endpoint.
So maybe collecting all the lines in a ss and than foreach checking the Endpoints. But with what? We can’ t do it with equal because there is no point to compare, it is somewhere on the polyline.
So ether we let zoom in again on the points and try with ssget point and filter set to Polyline (to me the easiest but not the most reliable way).
Or you make a ssget with a little window and filter set to Polyline on each checked Endpoint.
Than you can check with the found Polyline or polylines if the drawing is tense if there is a intersection point between the vertex’s and the line we are checking. Doing so with the inters function or
(setq ar
(vlax-invoke-method
(vlax-ename->vla-object ent1)
'IntersectWith
(vlax-ename->vla-object ent2)
acExtendNone
)
)
This code I found somewhere else but I only used it once and so did not test a lot.
But the question remains: why doing all this, you said the lines where drawn with snap to the polylines.