关于LWPOLYLINE的几个函数

marting

判断是否是矩形

[JavaScript] 纯文本查看 复制代码

(defun rectangle-p ( ent / p1 p2 p3 p4 )
    (and (setq enx (entget ent))
         (= "LWPOLYLINE" (cdr (assoc 0 enx)))
         (= 4 (cdr (assoc 90 enx)))
         (= 1 (logand 1 (cdr (assoc 70 enx)))) 
         (nobulge-p enx)
         (mapcar 'set '(p1 p2 p3 p4) (lwvertices enx))
         (equal (distance p1 p2) (distance p3 p4) 1e-8)
         (equal (distance p2 p3) (distance p1 p4) 1e-8)
         (equal (distance p1 p3) (distance p2 p4) 1e-8)
    )
)

判断多段线不包括弧线段

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(defun nobulge-p ( enx / bul )
    (or (not (setq bul (assoc 42 enx)))
        (and (equal 0.0 (cdr bul) 1e-8)
             (nobulge-p (cdr (member bul enx)))
        )
    )
)

获得LWPOLYLINE的顶点表

[JavaScript] 纯文本查看 复制代码

(defun lwvertices ( enx / vtx )
    (if (setq vtx (assoc 10 enx))
        (cons (cdr vtx) (lwvertices (cdr (member vtx enx))))
    )
)

fan_zh

这个判断有问题的，试试自交四边形