OpenSceneGraph/include/osg/Plane

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/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 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.
*/
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#ifndef OSG_PLANE
#define OSG_PLANE 1
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#include <osg/Export>
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#include <osg/Vec3>
#include <osg/Vec4>
#include <osg/Matrix>
#include <osg/BoundingSphere>
#include <osg/BoundingBox>
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#include <vector>
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namespace osg {
/** A plane class. It can be used to represent an infinite plane.*/
class SG_EXPORT Plane
{
public:
inline Plane():_fv(0.0f,0.0f,0.0f,0.0f) { _lowerBBCorner = 0; _upperBBCorner = 0; }
inline Plane(const Plane& pl):_fv(pl._fv) { calculateUpperLowerBBCorners(); }
inline Plane(float a,float b,float c,float d):_fv(a,b,c,d) { calculateUpperLowerBBCorners(); }
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inline Plane(const Vec4& vec):_fv(vec) { calculateUpperLowerBBCorners(); }
inline Plane(const Vec3& norm,float d):_fv(norm[0],norm[1],norm[2],d) { calculateUpperLowerBBCorners(); }
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inline Plane(const Vec3& v1, const Vec3& v2, const Vec3& v3) { set(v1,v2,v3); calculateUpperLowerBBCorners(); }
inline Plane& operator = (const Plane& pl)
{
if (&pl==this) return *this;
_fv = pl._fv;
_lowerBBCorner = pl._lowerBBCorner;
_upperBBCorner = pl._upperBBCorner;
return *this;
}
inline void set(const Plane& pl) { _fv = pl._fv; calculateUpperLowerBBCorners(); }
inline void set(float a,float b,float c,float d) { _fv.set(a,b,c,d); calculateUpperLowerBBCorners(); }
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inline void set(const Vec4& vec) { _fv = vec; calculateUpperLowerBBCorners(); }
inline void set(const Vec3& norm,float d) { _fv.set(norm[0],norm[1],norm[2],d); calculateUpperLowerBBCorners(); }
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inline void set(const Vec3& v1, const Vec3& v2, const Vec3& v3)
{
osg::Vec3 norm = (v2-v1)^(v3-v2);
float length = norm.length();
if (length>1e-6) norm/= length;
else norm.set(0.0f,0.0f,0.0f);
_fv.set(norm[0],norm[1],norm[2],-(v1*norm));
calculateUpperLowerBBCorners();
}
inline void set(const Vec3& norm, const Vec3& point)
{
float d = -norm[0]*point[0] - norm[1]*point[1] - norm[2]*point[2];
_fv.set(norm[0],norm[1],norm[2],d);
calculateUpperLowerBBCorners();
}
/** flip/reverse the orientation of the plane.*/
inline void flip()
{
_fv = -_fv;
calculateUpperLowerBBCorners();
}
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inline void makeUnitLength()
{
float length = sqrtf(_fv[0]*_fv[0] + _fv[1]*_fv[1]+ _fv[2]*_fv[2]);
_fv /= length;
}
/** calculate the upper and lower bounding box corners to be used
* in the intersect(BoundingBox&) method for speeding calculations.*/
inline void calculateUpperLowerBBCorners()
{
_upperBBCorner = (_fv.x()>=0.0f?1:0) |
(_fv.y()>=0.0f?2:0) |
(_fv.z()>=0.0f?4:0);
_lowerBBCorner = (~_upperBBCorner)&7;
}
inline bool valid() const { return _fv.valid(); }
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inline bool operator == (const Plane& plane) const { return _fv==plane._fv; }
inline bool operator != (const Plane& plane) const { return _fv!=plane._fv; }
inline bool operator < (const Plane& plane) const { return _fv<plane._fv; }
inline float* ptr() { return _fv.ptr(); }
inline const float* ptr() const { return _fv.ptr(); }
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inline Vec4& asVec4() { return _fv; }
inline const Vec4& asVec4() const { return _fv; }
inline float& operator [] (unsigned int i) { return _fv[i]; }
inline float operator [] (unsigned int i) const { return _fv[i]; }
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inline osg::Vec3 getNormal() const { return osg::Vec3(_fv[0],_fv[1],_fv[2]); }
/** calculate the distance between a point and the plane.*/
inline float distance(const osg::Vec3& v) const
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{
return _fv[0]*v.x()+
_fv[1]*v.y()+
_fv[2]*v.z()+
_fv[3];
}
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/** intersection test between plane and vertex list
return 1 if the bs is completely above plane,
return 0 if the bs intersects the plane,
return -1 if the bs is completely below the plane.*/
inline int intersect(const std::vector<Vec3>& vertices) const
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{
if (vertices.empty()) return -1;
int noAbove = 0;
int noBelow = 0;
int noOn = 0;
for(std::vector<Vec3>::const_iterator itr=vertices.begin();
itr != vertices.end();
++itr)
{
float d = distance(*itr);
if (d>0.0f) ++noAbove;
else if (d<0.0f) ++noBelow;
else ++noOn;
}
if (noAbove>0)
{
if (noBelow>0) return 0;
else return 1;
}
return -1; // treat points on line as outside...
}
/** intersection test between plane and bounding sphere.
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return 1 if the bs is completely above plane,
return 0 if the bs intersects the plane,
return -1 if the bs is completely below the plane.*/
inline int intersect(const BoundingSphere& bs) const
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{
float d = distance(bs.center());
if (d>bs.radius()) return 1;
else if (d<-bs.radius()) return -1;
else return 0;
}
/** intersection test between plane and bounding sphere.
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return 1 if the bs is completely above plane,
return 0 if the bs intersects the plane,
return -1 if the bs is completely below the plane.*/
inline int intersect(const BoundingBox& bb) const
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{
// if lowest point above plane than all above.
if (distance(bb.corner(_lowerBBCorner))>0.0f) return 1;
// if highest point is below plane then all below.
if (distance(bb.corner(_upperBBCorner))<0.0f) return -1;
// d_lower<=0.0f && d_upper>=0.0f
// therefore must be crossing plane.
return 0;
}
/** Transform the plane by matrix. Note, this operation carries out
* the calculation of the inverse of the matrix since a plane
* must be multiplied by the inverse transposed to transform it. This
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* make this operation expensive. If the inverse has been already
* calculated elsewhere then use transformProvidingInverse() instead.
* See http://www.worldserver.com/turk/computergraphics/NormalTransformations.pdf*/
inline void transform(const osg::Matrix& matrix)
{
osg::Matrix inverse;
inverse.invert(matrix);
transformProvidingInverse(inverse);
}
/** Transform the plane by providing a pre inverted matrix.
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* see transform for details. */
inline void transformProvidingInverse(const osg::Matrix& matrix)
{
// note pre multiplications, which effectively transposes matrix.
_fv = matrix * _fv;
makeUnitLength();
calculateUpperLowerBBCorners();
}
friend inline std::ostream& operator << (std::ostream& output, const Plane& pl);
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protected:
Vec4 _fv;
// variables cached to optimize calcs against bounding boxes.
unsigned int _upperBBCorner;
unsigned int _lowerBBCorner;
};
inline std::ostream& operator << (std::ostream& output, const Plane& pl)
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{
output << pl._fv[0] << " "
<< pl._fv[1] << " "
<< pl._fv[2] << " "
<< pl._fv[3];
return output; // to enable cascading
}
} // end of namespace
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#endif