212 lines
7.4 KiB
Plaintext
212 lines
7.4 KiB
Plaintext
//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
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//Distributed under the terms of the GNU Library General Public License (LGPL)
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//as published by the Free Software Foundation.
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#ifndef OSG_PLANE
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#define OSG_PLANE 1
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#include <osg/Export>
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#include <osg/Vec3>
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#include <osg/Vec4>
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#include <osg/Matrix>
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#include <osg/BoundingSphere>
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#include <osg/BoundingBox>
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#include <vector>
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namespace osg {
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/** A plane class. It can be used to represent an infinite plane.*/
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class SG_EXPORT Plane
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{
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public:
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inline Plane():_fv(0.0f,0.0f,0.0f,0.0f) { _lowerBBCorner = 0; _upperBBCorner = 0; }
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inline Plane(const Plane& pl):_fv(pl._fv) { calculateUpperLowerBBCorners(); }
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inline Plane(const float a,const float b,const float c,const float d):_fv(a,b,c,d) { calculateUpperLowerBBCorners(); }
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inline Plane(const Vec4& vec):_fv(vec) { calculateUpperLowerBBCorners(); }
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inline Plane(const Vec3& norm,const 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(); }
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inline Plane& operator = (const Plane& pl)
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{
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if (&pl==this) return *this;
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_fv = pl._fv;
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_lowerBBCorner = pl._lowerBBCorner;
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_upperBBCorner = pl._upperBBCorner;
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return *this;
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}
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inline void set(const Plane& pl) { _fv = pl._fv; calculateUpperLowerBBCorners(); }
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inline void set(const float a,const float b,const float c,const float d) { _fv.set(a,b,c,d); calculateUpperLowerBBCorners(); }
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inline void set(const Vec4& vec) { _fv = vec; calculateUpperLowerBBCorners(); }
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inline void set(const Vec3& norm,const 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)
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{
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osg::Vec3 norm = (v2-v1)^(v3-v2);
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float length = norm.length();
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if (length>1e-6) norm/= length;
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else norm.set(0.0f,0.0f,0.0f);
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_fv.set(norm[0],norm[1],norm[2],-(v1*norm));
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calculateUpperLowerBBCorners();
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}
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/** flip/reverse the orientation of the plane.*/
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inline void flip()
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{
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_fv = -_fv;
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calculateUpperLowerBBCorners();
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}
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inline void makeUnitLength()
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{
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float length = sqrtf(_fv[0]*_fv[0] + _fv[1]*_fv[1]+ _fv[2]*_fv[2]);
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_fv /= length;
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}
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/** calculate the upper and lower bounding box corners to be used
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* in the intersect(BoundingBox&) method for speeding calculations.*/
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inline void calculateUpperLowerBBCorners()
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{
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_upperBBCorner = (_fv.x()>=0.0f?1:0) |
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(_fv.y()>=0.0f?2:0) |
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(_fv.z()>=0.0f?4:0);
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_lowerBBCorner = (~_upperBBCorner)&7;
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}
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inline const bool valid() const { return _fv[0]==0.0f && _fv[1]==0.0f && _fv[2]==0.0f; }
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inline Vec4& asVec4() { return _fv; }
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inline const Vec4& asVec4() const { return _fv; }
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inline float& operator [] (const int i) { return _fv[i]; }
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inline float operator [] (const int i) const { return _fv[i]; }
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inline osg::Vec3 getNormal() { return osg::Vec3(_fv[0],_fv[1],_fv[2]); }
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/** calculate the distance between a point and the plane.*/
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inline const float distance(const osg::Vec3& v) const
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{
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return _fv[0]*v.x()+
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_fv[1]*v.y()+
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_fv[2]*v.z()+
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_fv[3];
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}
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/** intersection test between plane and vertex list
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return 1 if the bs is completely above plane,
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return 0 if the bs intersects the plane,
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return -1 if the bs is completely below the plane.*/
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inline const int intersect(const std::vector<Vec3>& vertices) const
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{
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if (vertices.empty()) return -1;
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int noAbove = 0;
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int noBelow = 0;
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int noOn = 0;
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for(std::vector<Vec3>::const_iterator itr=vertices.begin();
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itr != vertices.end();
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++itr)
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{
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float d = distance(*itr);
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if (d>0.0f) ++noAbove;
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else if (d<0.0f) ++noBelow;
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else ++noOn;
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}
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if (noAbove>0)
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{
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if (noBelow>0) return 0;
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else return 1;
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}
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return -1; // treat points on line as outside...
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}
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/** intersection test between plane and bounding sphere.
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return 1 if the bs is completely above plane,
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return 0 if the bs intersects the plane,
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return -1 if the bs is completely below the plane.*/
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inline const int intersect(const BoundingSphere& bs) const
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{
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float d = distance(bs.center());
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if (d>bs.radius()) return 1;
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else if (d<-bs.radius()) return -1;
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else return 0;
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}
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/** intersection test between plane and bounding sphere.
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return 1 if the bs is completely above plane,
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return 0 if the bs intersects the plane,
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return -1 if the bs is completely below the plane.*/
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inline const int intersect(const BoundingBox& bb) const
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{
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// if lowest point above plane than all above.
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if (distance(bb.corner(_lowerBBCorner))>0.0f) return 1;
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// if highest point is below plane then all below.
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if (distance(bb.corner(_upperBBCorner))<0.0f) return -1;
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// d_lower<=0.0f && d_upper>=0.0f
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// therefore must be crossing plane.
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return 0;
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}
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/** Transform the plane by matrix. Note, this operations carries out
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* the calculation of the inverse of the matrix since to transforms
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* planes must be multiplied my the inverse transposed. This
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* make this operation expensive. If the inverse has been already
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* calculated elsewhere then use transformProvidingInverse() instead.
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* See http://www.worldserver.com/turk/computergraphics/NormalTransformations.pdf*/
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inline void transform(const osg::Matrix& matrix)
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{
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osg::Matrix inverse;
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inverse.invert(matrix);
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transformProvidingInverse(inverse);
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}
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/** Transform the plane by provide a pre inverted matrix.
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* see transform for details. */
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inline void transformProvidingInverse(const osg::Matrix& matrix)
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{
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// note pre multiplications, which effectively transposes matrix.
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_fv = matrix * _fv;
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makeUnitLength();
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calculateUpperLowerBBCorners();
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}
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friend inline std::ostream& operator << (std::ostream& output, const Plane& pl);
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protected:
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Vec4 _fv;
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// variables cached to optimize calcs against bounding boxes.
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unsigned int _upperBBCorner;
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unsigned int _lowerBBCorner;
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};
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inline std::ostream& operator << (std::ostream& output, const Plane& pl)
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{
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output << pl._fv[0] << " "
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<< pl._fv[1] << " "
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<< pl._fv[2] << " "
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<< pl._fv[3];
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return output; // to enable cascading
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}
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} // end of namespace
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#endif
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