[irtgeo.l] fix (use cond instead of when)

Author: Naoki-Hiraoka

irteus/irtgeo.l

@@ -471,25 +471,25 @@
            (mapcan #'(lambda (e)
                        (let ((p (geo::line-intersection3 (e . pvert) (e . nvert)
                                                          (car v) (cdr v))))
-                         (when (and (<= 0.0 (car p) 1.0)
-                                    (< 0.0 (cadr p) 1.0))
-                           (list e))
-                         (when (and (< 0.0 (car p) 1.0)
-                                    (or (= 0.0 (cadr p)) (= 1.0 (cadr p))))
-                           nil) ;; not implemented yet
-                         ;; duplicated vertices exist
-                         (when (and (or (= 0.0 (car p)) (= 1.0 (car p)))
-                                    (or (= 0.0 (cadr p)) (= 1.0 (cadr p)))
-                                    (not (or (memq (car v) (send e :vertices)) (memq (cdr v) (send e :vertices)))))
-                           (let* ((ev (if (= 0.0 (car p)) (e . pvert) (e . nvert)))
-                                  (ein (find-if #'(lambda (e) (eq ev (e . nvert))) (flatten (append (send-all hs :edges) (send f :edges)))))
-                                  (eout (find-if #'(lambda (e) (eq ev (e . pvert))) (flatten (append (send-all hs :edges) (send f :edges)))))
-                                  (v0 (eout . nvert))
-                                  (v1 (if (= 0.0 (cadr p)) (cdr v) (car v)))
-                                  (v2 (ein . pvert)))
-                             (when (< (mod (+ (vector-angle (v- v0 ev) (v- v1 ev) (send f :normal)) 2PI) 2PI)
-                                      (mod (+ (vector-angle (v- v0 ev) (v- v2 ev) (send f :normal)) 2PI) 2PI))
-                               (list e))))
+                         (cond ((and (<= 0.0 (car p) 1.0)
+                                     (< 0.0 (cadr p) 1.0))
+                                (list e))
+                               ((and (< 0.0 (car p) 1.0)
+                                     (or (= 0.0 (cadr p)) (= 1.0 (cadr p))))
+                                nil) ;; not implemented yet
+                               ;; vertex is shared by more than two edges. avoid intersecting.
+                               ((and (or (= 0.0 (car p)) (= 1.0 (car p)))
+                                     (or (= 0.0 (cadr p)) (= 1.0 (cadr p)))
+                                     (not (or (memq (car v) (send e :vertices)) (memq (cdr v) (send e :vertices)))))
+                                (let* ((ev (if (= 0.0 (car p)) (e . pvert) (e . nvert)))
+                                       (ein (find-if #'(lambda (e) (eq ev (e . nvert))) (flatten (append (send-all hs :edges) (send f :edges)))))
+                                       (eout (find-if #'(lambda (e) (eq ev (e . pvert))) (flatten (append (send-all hs :edges) (send f :edges)))))
+                                       (v0 (eout . nvert))
+                                       (v1 (if (= 0.0 (cadr p)) (cdr v) (car v)))
+                                       (v2 (ein . pvert)))
+                                  (when (< (mod (+ (vector-angle (v- v0 ev) (v- v1 ev) (send f :normal)) 2PI) 2PI)
+                                           (mod (+ (vector-angle (v- v0 ev) (v- v2 ev) (send f :normal)) 2PI) 2PI))
+                                    (list e)))))
                          ))
                    (flatten (append (send-all hs :edges) (send f :edges)))))
           (unless r