end caps on extrudes working!

git-svn-id: svn://anubis/fart/trunk@279 7f9b0f55-74a9-4bce-be96-3c2cd072584d

util/Polygon.cc

@@ -5,7 +5,41 @@
 
 #define FP_EQUAL(x,y) (fabs((x)-(y)) < 1E-6)
 
-bool Polygon::containsPoint(const Vector & v)
+/*
+ * from http://local.wasp.uwa.edu.au/~pbourke/geometry/insidepoly/
+ * Return the angle between two vectors on a plane
+ * The angle is from vector 1 to vector 2, positive anticlockwise
+ * The result is between -pi -> pi
+*/
+double angle2D(double x1, double y1, double x2, double y2)
+{
+    double dtheta, theta1, theta2;
+
+    theta1 = atan2(y1,x1);
+    theta2 = atan2(y2,x2);
+    dtheta = theta2 - theta1;
+    while (dtheta > M_PI)
+        dtheta -= 2.0 * M_PI;
+    while (dtheta < -M_PI)
+        dtheta += 2.0 * M_PI;
+
+    return dtheta;
+}
+
+bool Polygon::containsPoint2D(const Vector & v) const
+{
+    double angle_sum = 0.0;
+    for (int i = 0, sz = size(); i < sz; i++)
+    {
+        Vector v1 = *(*this)[i] - v;
+        Vector v2 = *(*this)[(i+1) % sz] - v;
+        double angle = angle2D(v1[0], v1[1], v2[0], v2[1]);
+        angle_sum += angle;
+    }
+    return FP_EQUAL(angle_sum, 2.0 * M_PI);
+}
+
+bool Polygon::containsPointConvex(const Vector & v) const
 {
     double angle_sum = 0.0;
     for (int i = 0, sz = size(); i < sz; i++)

util/Polygon.h

@@ -20,7 +20,8 @@ class Polygon : public std::vector< refptr<Vector> >
             push_back(v);
             return *this;
         }
-        bool containsPoint(const Vector & v);
+        bool containsPoint2D(const Vector & v) const;
+        bool containsPointConvex(const Vector & v) const;
 };
 
 #endif