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geant4/source/geometry/solids/BREPS/include/G4Parabola.icc
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2016-06-08 15:09:25 +02:00

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inline void G4Parabola::Init(const G4Axis2Placement3D& position0,
G4double focalDist0) {
position= position0;
focalDist= focalDist0;
// focus
F= position.GetLocation()+focalDist*position.GetPX();
// line
L0= position.GetLocation()-focalDist*position.GetPX();
//l= position.GetPY();
}
inline double G4Parabola::GetFocalDist() const {
return focalDist;
}
//////////////////////////////////////////////////////////////////////////////
inline G4double G4Parabola::GetPMax() {
return -1;
}
inline G4Point3D G4Parabola::GetPoint(G4double param) {
return position.GetLocation()
+ focalDist* (param*param*position.GetPX() + 2*param*position.GetPY());
}
inline G4double G4Parabola::GetPPoint(const G4Point3D& pt) {
G4Point3D ptLocal= position.GetToPlacementCoordinates()*pt;
return ptLocal.y()/(2*focalDist);
}
//////////////////////////////////////////////////////////////////////////////
#include "G4CurveRayIntersection.hh"
/*
inline void G4Parabola::IntersectRay2D(const G4Ray& ray,
G4CurveRayIntersection& is)
{
is.Init(*this, ray);
const G4Point3D& S= ray.GetStart();
const G4Vector3D& d= ray.GetDir();
const G4Vector3D& l= position.GetPY();
// a == 1
G4Vector3D SMinusF= S-F;
G4double bHalf= SMinusF*d - (d.x()*l.y()-d.y()*l.x());
G4double c= SMinusF.mag2() + ( (S.x()-L0.x())*l.y() - (S.y()-L0.y())*l.x() );
G4double discr= bHalf*bHalf-c;
if (discr >= 0) {
// 2 intersections (maybe 1, but this case is rare)
G4double sqrtdiscr= sqrt(discr);
// find the smallest positive i
G4double i= -bHalf-sqrtdiscr;
if (i<kCarTolerance) {
i= -bHalf+sqrtdiscr;
if (i<kCarTolerance) {
return;
}
}
G4CurveRayIntersection isTmp(*this, ray);
isTmp.ResetDistance(i);
is.Update(isTmp);
}
}
*/
inline G4int G4Parabola::IntersectRay2D(const G4Ray& ray)
{
// NOT VERIFIED
const G4Point3D& S= ray.GetStart();
const G4Vector3D& d= ray.GetDir();
const G4Vector3D& l= position.GetPY();
// a == 1
G4Vector3D SMinusF= S-F;
G4double bHalf= SMinusF*d - (d.x()*l.y()-d.y()*l.x());
G4double c= SMinusF.mag2() + ( (S.x()-L0.x())*l.y() - (S.y()-L0.y())*l.x() );
G4int nbinter = 0;
G4double discr= bHalf*bHalf-c;
if (discr >= 0)
{
// 2 intersections (maybe 1, but this case is rare)
G4double sqrtdiscr= sqrt(discr);
G4double i= -bHalf-sqrtdiscr;
if (i>kCarTolerance)
nbinter++;
i= -bHalf+sqrtdiscr;
if (i>kCarTolerance)
nbinter++;
}
return nbinter++;
}