OpenSceneGraph/include/osgUtil/HalfWayMapGenerator
2012-03-21 17:36:20 +00:00

54 lines
1.8 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#ifndef OSGUTIL_HALFWAYMAPGENERATOR_
#define OSGUTIL_HALFWAYMAPGENERATOR_
#include <osgUtil/Export>
#include <osgUtil/CubeMapGenerator>
namespace osgUtil
{
/** This cube map generator produces an Half-way vector map, useful for
* hardware-based specular lighting effects.
* It computes: C = normalize(R - L), where C is the resulting color,
* R is the reflection vector and L is the light direction.
*/
class OSGUTIL_EXPORT HalfWayMapGenerator: public CubeMapGenerator {
public:
HalfWayMapGenerator(const osg::Vec3 &light_direction, int texture_size = 64);
HalfWayMapGenerator(const HalfWayMapGenerator &copy, const osg::CopyOp &copyop);
protected:
virtual ~HalfWayMapGenerator() {}
HalfWayMapGenerator &operator=(const HalfWayMapGenerator &) { return *this; }
inline virtual osg::Vec4 compute_color(const osg::Vec3 &R) const;
private:
osg::Vec3 ldir_;
};
// INLINE METHODS
inline osg::Vec4 HalfWayMapGenerator::compute_color(const osg::Vec3 &R) const
{
const osg::Vec3 V = (R / R.length()) - ldir_;
return vector_to_color(V / V.length());
}
}
#endif