1 // Copyright (C) 2008 - 2009  Mathias Froehlich - Mathias.Froehlich@web.de
2 //
3 // This library is free software; you can redistribute it and/or
4 // modify it under the terms of the GNU Library General Public
5 // License as published by the Free Software Foundation; either
6 // version 2 of the License, or (at your option) any later version.
7 //
8 // This library is distributed in the hope that it will be useful,
9 // but WITHOUT ANY WARRANTY; without even the implied warranty of
10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11 // Library General Public License for more details.
12 //
13 // You should have received a copy of the GNU General Public License
14 // along with this program; if not, write to the Free Software
15 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
16 //
17 
18 #ifndef BVHNode_hxx
19 #define BVHNode_hxx
20 
21 #include <vector>
22 #include <simgear/math/SGGeometry.hxx>
23 #include <simgear/structure/SGReferenced.hxx>
24 
25 namespace simgear {
26 
27 class BVHGroup;
28 class BVHVisitor;
29 class BVHPageNode;
30 
31 // Base for the tree nodes
32 class BVHNode : public SGReferenced {
33 public:
34     BVHNode();
35     virtual ~BVHNode();
36 
37     // visitors ...
38     virtual void accept(BVHVisitor& visitor) = 0;
39 
getBoundingSphere() const40     const SGSphered& getBoundingSphere() const
41     {
42         if (_dirtyBoundingSphere) {
43             _boundingSphere = computeBoundingSphere();
44             _dirtyBoundingSphere = false;
45         }
46         return _boundingSphere;
47     }
48     virtual SGSphered computeBoundingSphere() const = 0;
49 
50     /// A unique id for some kind of BVHNodes.
51     /// Currently only motions transforms.
52     typedef unsigned Id;
53 
54     // Factory to get a new id
55     static Id getNewId();
56 
57 protected:
58     friend class BVHGroup;
59     friend class BVHPageNode;
60     void addParent(BVHNode* parent);
61     void removeParent(BVHNode* parent);
62 
63     void invalidateParentBound();
64     virtual void invalidateBound();
65 
66 private:
67     mutable bool _dirtyBoundingSphere;
68     mutable SGSphered _boundingSphere;
69 
70     typedef std::vector<BVHNode*> ParentList;
71     ParentList _parents;
72 };
73 
74 }
75 
76 #endif
77