1 /* -*-c++-*-
2  *
3  * Copyright (C) 2006-2007 Mathias Froehlich
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation; either version 2 of the
8  * License, or (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
18  * MA 02110-1301, USA.
19  *
20  */
21 
22 #ifndef SG_DIRECTIONAL_LIGHT_BIN_HXX
23 #define SG_DIRECTIONAL_LIGHT_BIN_HXX
24 
25 class SGDirectionalLightBin {
26 public:
27   struct Light {
LightSGDirectionalLightBin::Light28     Light(const SGVec3f& p, const SGVec3f& n, const SGVec4f& c) :
29       position(p), normal(n), color(c)
30     { }
31     SGVec3f position;
32     SGVec3f normal;
33     SGVec4f color;
34   };
35   typedef std::vector<Light> LightList;
36 
insert(const Light & light)37   void insert(const Light& light)
38   { _lights.push_back(light); }
insert(const SGVec3f & p,const SGVec3f & n,const SGVec4f & c)39   void insert(const SGVec3f& p, const SGVec3f& n, const SGVec4f& c)
40   { insert(Light(p, n, c)); }
41 
getNumLights() const42   unsigned getNumLights() const
43   { return _lights.size(); }
getLight(unsigned i) const44   const Light& getLight(unsigned i) const
45   { return _lights[i]; }
46 
47   // helper for sorting lights back to front ...
48   struct DirectionLess {
DirectionLessSGDirectionalLightBin::DirectionLess49     DirectionLess(const SGVec3f& direction) :
50       _direction(direction)
51     { }
operator ()SGDirectionalLightBin::DirectionLess52     inline bool operator() (const Light& l, const Light& r) const
53     { return dot(_direction, l.position) < dot(_direction, r.position); }
54   private:
55     SGVec3f _direction;
56   };
57   typedef std::multiset<Light,DirectionLess> LightSet;
58 
getSortedLights(const SGVec3f & sortDirection) const59   LightList getSortedLights(const SGVec3f& sortDirection) const
60   {
61     LightSet lightSet = LightSet(DirectionLess(sortDirection));
62     for (unsigned i = 0; i < _lights.size(); ++i)
63       lightSet.insert(_lights[i]);
64 
65     LightList sortedLights;
66     sortedLights.reserve(_lights.size());
67     for (LightSet::const_iterator i = lightSet.begin(); i != lightSet.end(); ++i)
68       sortedLights.push_back(*i);
69 
70     return sortedLights;
71   }
72 
73 private:
74   LightList _lights;
75 };
76 
77 #endif
78