added AABB class, calculating AABB in Extrude objects, added Extrude intersect() optimization to throw out rays not hitting the AABB

git-svn-id: svn://anubis/fart/trunk@306 7f9b0f55-74a9-4bce-be96-3c2cd072584d

util/AABB.h

@@ -0,0 +1,21 @@
+
+#ifndef AABB_H
+#define AABB_H
+
+class AABB
+{
+    public:
+        Vector min;
+        Vector max;
+
+        AABB()
+        {
+        }
+
+        AABB(const Vector & min, const Vector & max)
+            : min(min), max(max)
+        {
+        }
+};
+
+#endif /* AABB_H */