openscenegraph
AnisotropicLighting
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1/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
2 *
3 * This library is open source and may be redistributed and/or modified under
4 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
5 * (at your option) any later version. The full license is in LICENSE file
6 * included with this distribution, and on the openscenegraph.org website.
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
11 * OpenSceneGraph Public License for more details.
12*/
13//osgFX - Copyright (C) 2003 Marco Jez
14
15#ifndef OSGFX_ANISOTROPICLIGHTING_
16#define OSGFX_ANISOTROPICLIGHTING_
17
18#include <osgFX/Export>
19#include <osgFX/Effect>
20
21#include <osg/ref_ptr>
22#include <osg/Texture2D>
23
24namespace osgFX
25{
26
27 /**
28 This single-pass effect implements a sort of anisotropic
29 lighting that replaces the standard OpenGL lighting model.
30 The final color of vertices is not computed directly, it is
31 the result of a texture lookup on a user-supplied lighting
32 image map. A vertex program is used to compute the s and t
33 texture coordinates as follows: s = (N dot H) ; t = (N dot L)
34 where N is the vertex normal, L is the light-to-vertex vector,
35 H is the half-way vector. This is a good example of how you
36 can use the State::getInitialViewMatrix() method to retrieve
37 the view matrix and perform view-dependant effects without
38 fakes of any kind.
39 This effect requires the ARB_vertex_program extension.
40 */
41 class OSGFX_EXPORT AnisotropicLighting: public Effect {
42 public:
43 AnisotropicLighting();
44 AnisotropicLighting(const AnisotropicLighting& copy, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY);
45
46 META_Effect(osgFX, AnisotropicLighting,
47
48 "Anisotropic Lighting",
49
50 "This single-pass effect implements a sort of anisotropic "
51 "lighting that replaces the standard OpenGL lighting model.\n"
52 "The final color of vertices is not computed directly, it is "
53 "the result of a texture lookup on a user-supplied lighting "
54 "image map. A vertex program is used to compute the s and t "
55 "texture coordinates as follows: s = (N dot H) ; t = (N dot L) "
56 "where N is the vertex normal, L is the light-to-vertex vector, "
57 "H is the half-way vector. This is a good example of how you "
58 "can use the State::getInitialViewMatrix() method to retrieve "
59 "the view matrix and perform view-dependant effects without "
60 "fakes of any kind.\n"
61 "This effect requires the ARB_vertex_program extension.",
62
63 "Marco Jez");
64
65
66 /** get the lighting map */
67 inline osg::Image* getLightingMap();
68
69 /** get the const lighting map */
70 inline const osg::Image* getLightingMap() const;
71
72 /** set the lighting map */
73 inline void setLightingMap(osg::Image* image);
74
75 /** get the OpenGL light number */
76 inline int getLightNumber() const;
77
78 /** set the OpenGL light number that will be used in lighting computations */
79 inline void setLightNumber(int n);
80
81 protected:
82 virtual ~AnisotropicLighting() {}
83 AnisotropicLighting& operator=(const AnisotropicLighting&) { return *this; }
84
85 bool define_techniques();
86
87 private:
88 int _lightnum;
89 osg::ref_ptr<osg::Texture2D> _texture;
90 };
91
92 // INLINE METHODS
93
94 inline osg::Image* AnisotropicLighting::getLightingMap()
95 {
96 return _texture->getImage();
97 }
98
99 inline const osg::Image* AnisotropicLighting::getLightingMap() const
100 {
101 return _texture->getImage();
102 }
103
104 inline void AnisotropicLighting::setLightingMap(osg::Image* image)
105 {
106 _texture->setImage(image);
107 }
108
109 inline int AnisotropicLighting::getLightNumber() const
110 {
111 return _lightnum;
112 }
113
114 inline void AnisotropicLighting::setLightNumber(int n)
115 {
116 _lightnum = n;
117 dirtyTechniques();
118 }
119
120}
121
122#endif