[LISP程序]：一个可以求多义线（复线）旋向的程序

KERRYWM

(DEFUN GE_WHATPOLY (OBJ / NVERTS CNT TMP X1 Y1);;;
  (SETQ PT_LIST(VLA-GET-COORDINATES OBJ))
  (SETQ CNT 0)
  (SETQ NVERTS(/ (+(VLAX-SAFEARRAY-GET-U-BOUND (VLAX-VARIANT-VALUE PT_LIST ) 1)1) 2))
  (SETQ AREA 0.0)
  (WHILE (< CNT (1- NVERTS))
    (SETQ Y1(VLAX-SAFEARRAY-GET-ELEMENT (VLAX-VARIANT-VALUE PT_LIST ) (+(* CNT 2)1)))
    (SETQ X1(VLAX-SAFEARRAY-GET-ELEMENT (VLAX-VARIANT-VALUE PT_LIST ) (* (+ CNT 1) 2)))
    (SETQ AREA(+ AREA (* Y1 X1)))
    (SETQ CNT(1+ CNT))
    )
  (SETQ Y1(VLAX-SAFEARRAY-GET-ELEMENT (VLAX-VARIANT-VALUE PT_LIST ) (+(* CNT 2)1)))
  (SETQ X1(VLAX-SAFEARRAY-GET-ELEMENT (VLAX-VARIANT-VALUE PT_LIST ) 0))
  (SETQ AREA(+ AREA(* Y1 X1)))
  (SETQ CNT 0)
  (SETQ TMP 0.0)
  (WHILE (< CNT (1- NVERTS))
    (SETQ Y1(VLAX-SAFEARRAY-GET-ELEMENT (VLAX-VARIANT-VALUE PT_LIST ) (+(* (+ CNT 1) 2)1)))
    (SETQ X1(VLAX-SAFEARRAY-GET-ELEMENT (VLAX-VARIANT-VALUE PT_LIST ) (* CNT 2)))
    (SETQ TMP(+ TMP (* Y1 X1)))
    (SETQ CNT(+ CNT 1))
    )
  (SETQ Y1(VLAX-SAFEARRAY-GET-ELEMENT (VLAX-VARIANT-VALUE PT_LIST )1))
  (SETQ X1(VLAX-SAFEARRAY-GET-ELEMENT (VLAX-VARIANT-VALUE PT_LIST)(* CNT 2)))
  (SETQ TMP(+ TMP (* Y1 X1)))
  (SETQ AREA(- AREA TMP))
  (COND
    ((< AREA 0.0) (SETQ AREA -1))
    ((> AREA 0.0) (SETQ AREA 1))
    (T (SETQ AREA 0))
    )
  AREA
  )
不好意思，程序没有注解，你就仔细看看吧，有什么问题，可以共同交流。