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diff --git a/src/libavoid/geometry.h b/src/libavoid/geometry.h
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+/*
+ * vim: ts=4 sw=4 et tw=0 wm=0
+ *
+ * libavoid - Fast, Incremental, Object-avoiding Line Router
+ * Copyright (C) 2004-2005  Michael Wybrow <mjwybrow@users.sourceforge.net>
+ *
+ * --------------------------------------------------------------------
+ * Much of the code in this module is based on code published with
+ * and/or described in "Computational Geometry in C" (Second Edition),
+ * Copyright (C) 1998  Joseph O'Rourke <orourke@cs.smith.edu>
+ * --------------------------------------------------------------------
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * 
+*/
+
+
+#ifndef _GEOMETRY_H
+#define _GEOMETRY_H
+
+#include "libavoid/geomtypes.h"
+
+namespace Avoid {
+
+
+extern double dist(const Point& a, const Point& b);
+extern bool segmentIntersect(const Point& a, const Point& b,
+        const Point& c, const Point& d);
+extern bool inPoly(const Polygn& poly, const Point& q);
+extern bool inValidRegion(const Point& a0, const Point& a1, const Point& a2,
+        const Point& b);
+
+
+// Direction from vector.
+// Looks at the position of point c from the directed segment ab and
+// returns the following:
+//      1   counterclockwise
+//      0   collinear
+//     -1   clockwise
+//
+// Based on the code of 'AreaSign'.
+//
+static inline int vecDir(const Point& a, const Point& b, const Point& c)
+{
+    double area2 = ((b.x - a.x) * (c.y - a.y)) -
+                   ((c.x - a.x) * (b.y - a.y));
+    
+    if (area2 < -0.001)
+    {
+        return -1;
+    }
+    else if (area2 > 0.001)
+    {
+        return 1;
+    }
+    return 0;
+}
+
+
+}
+
+
+#endif