G4IntersectingCone Class Reference

#include <G4IntersectingCone.hh>

Public Member Functions
	G4IntersectingCone (const G4double r[2], const G4double z[2])
virtual	~G4IntersectingCone ()
G4int	LineHitsCone (const G4ThreeVector &p, const G4ThreeVector &v, G4double *s1, G4double *s2)
G4bool	HitOn (const G4double r, const G4double z)
G4double	RLo () const
G4double	RHi () const
G4double	ZLo () const
G4double	ZHi () const
	G4IntersectingCone (__void__ &)
Protected Member Functions
G4int	LineHitsCone1 (const G4ThreeVector &p, const G4ThreeVector &v, G4double *s1, G4double *s2)
G4int	LineHitsCone2 (const G4ThreeVector &p, const G4ThreeVector &v, G4double *s1, G4double *s2)
Protected Attributes
G4double	zLo
G4double	zHi
G4double	rLo
G4double	rHi
G4bool	type1
G4double	A
G4double	B

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Detailed Description

Definition at line 51 of file G4IntersectingCone.hh.

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Constructor & Destructor Documentation

G4IntersectingCone::G4IntersectingCone	(	const G4double	r[2],
		const G4double	z[2]
	)

Definition at line 46 of file G4IntersectingCone.cc.

References A, B, G4GeometryTolerance::GetInstance(), G4GeometryTolerance::GetSurfaceTolerance(), rHi, rLo, type1, zHi, and zLo.

{ 
  static const G4double halfCarTolerance
    = 0.5 * G4GeometryTolerance::GetInstance()->GetSurfaceTolerance();

  //
  // What type of cone are we?
  //
  type1 = (std::fabs(z[1]-z[0]) > std::fabs(r[1]-r[0]));
  
  if (type1)
  {
    B = (r[1]-r[0])/(z[1]-z[0]);      // tube like
    A = 0.5*( r[1]+r[0] - B*(z[1]+z[0]) );
  }
  else
  {
    B = (z[1]-z[0])/(r[1]-r[0]);      // disk like
    A = 0.5*( z[1]+z[0] - B*(r[1]+r[0]) );
  }
  //
  // Calculate extent
  //
  if (r[0] < r[1])
  {
    rLo = r[0]-halfCarTolerance; rHi = r[1]+halfCarTolerance;
  }
  else
  {
    rLo = r[1]-halfCarTolerance; rHi = r[0]+halfCarTolerance;
  }
  
  if (z[0] < z[1])
  {
    zLo = z[0]-halfCarTolerance; zHi = z[1]+halfCarTolerance;
  }
  else
  {
    zLo = z[1]-halfCarTolerance; zHi = z[0]+halfCarTolerance;
  }
}

G4IntersectingCone::~G4IntersectingCone

(

)

[virtual]

Definition at line 103 of file G4IntersectingCone.cc.

{
}

G4IntersectingCone::G4IntersectingCone

(

__void__ &

)

Definition at line 94 of file G4IntersectingCone.cc.

  : zLo(0.), zHi(0.), rLo(0.), rHi(0.), type1(false), A(0.), B(0.)
{
}

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Member Function Documentation

G4bool G4IntersectingCone::HitOn	(	const G4double	r,
		const G4double	z
	)

Definition at line 114 of file G4IntersectingCone.cc.

References rHi, type1, and zHi.

Referenced by G4PolyconeSide::PointOnCone().

{
  //
  // Be careful! The inequalities cannot be "<=" and ">=" here without
  // punching a tiny hole in our shape!
  //
  if (type1)
  {
    if (z < zLo || z > zHi) return false;
  }
  else
  {
    if (r < rLo || r > rHi) return false;
  }

  return true;
}

G4int G4IntersectingCone::LineHitsCone	(	const G4ThreeVector &	p,
		const G4ThreeVector &	v,
		G4double *	s1,
		G4double *	s2
	)

Definition at line 140 of file G4IntersectingCone.cc.

References LineHitsCone1(), LineHitsCone2(), and type1.

Referenced by G4PolyconeSide::Intersect(), and G4PolyhedraSide::LineHitsSegments().

{
  if (type1)
  {
    return LineHitsCone1( p, v, s1, s2 );
  }
  else
  {
    return LineHitsCone2( p, v, s1, s2 );
  }
}

G4int G4IntersectingCone::LineHitsCone1	(	const G4ThreeVector &	p,
		const G4ThreeVector &	v,
		G4double *	s1,
		G4double *	s2
	)			[protected]

Definition at line 214 of file G4IntersectingCone.cc.

References A, B, and sqr().

Referenced by LineHitsCone().

{
  G4double x0 = p.x(), y0 = p.y(), z0 = p.z();
  G4double tx = v.x(), ty = v.y(), tz = v.z();

  G4double a = tx*tx + ty*ty - sqr(B*tz);
  G4double b = 2*( x0*tx + y0*ty - (A*B + B*B*z0)*tz);
  G4double c = x0*x0 + y0*y0 - sqr(A + B*z0);
  
  G4double radical = b*b - 4*a*c;
 
  if (radical < -1E-6*std::fabs(b))  { return 0; }    // No solution
  
  if (radical < 1E-6*std::fabs(b))
  {
    //
    // The radical is roughly zero: check for special, very rare, cases
    //
    if (std::fabs(a) > 1/kInfinity)
      {
      if(B==0.) { return 0; }
      if ( std::fabs(x0*ty - y0*tx) < std::fabs(1E-6/B) )
      {
         *s1 = -0.5*b/a;
         return 1;
      }
      return 0;
    }
  }
  else
  {
    radical = std::sqrt(radical);
  }
  
  if (a > 1/kInfinity)
  {
    G4double sa, sb, q = -0.5*( b + (b < 0 ? -radical : +radical) );
    sa = q/a;
    sb = c/q;
    if (sa < sb) { *s1 = sa; *s2 = sb; } else { *s1 = sb; *s2 = sa; }
    if (A + B*(z0+(*s1)*tz) < 0)  { return 0; }
    return 2;
  }
  else if (a < -1/kInfinity)
  {
    G4double sa, sb, q = -0.5*( b + (b < 0 ? -radical : +radical) );
    sa = q/a;
    sb = c/q;
    *s1 = (B*tz > 0)^(sa > sb) ? sb : sa;
    return 1;
  }
  else if (std::fabs(b) < 1/kInfinity)
  {
    return 0;
  }
  else
  {
    *s1 = -c/b;
    if (A + B*(z0+(*s1)*tz) < 0)  { return 0; }
    return 1;
  }
}

G4int G4IntersectingCone::LineHitsCone2	(	const G4ThreeVector &	p,
		const G4ThreeVector &	v,
		G4double *	s1,
		G4double *	s2
	)			[protected]

Definition at line 304 of file G4IntersectingCone.cc.

References A, B, and sqr().

Referenced by LineHitsCone().

{
  G4double x0 = p.x(), y0 = p.y(), z0 = p.z();
  G4double tx = v.x(), ty = v.y(), tz = v.z();
  
  
  // Special case which might not be so rare: B = 0 (precisely)
  //
  if (B==0)
  {
    if (std::fabs(tz) < 1/kInfinity)  { return 0; }
    
    *s1 = (A-z0)/tz;
    return 1;
  }

  G4double B2 = B*B;

  G4double a = tz*tz - B2*(tx*tx + ty*ty);
  G4double b = 2*( (z0-A)*tz - B2*(x0*tx + y0*ty) );
  G4double c = sqr(z0-A) - B2*( x0*x0 + y0*y0 );
  
  G4double radical = b*b - 4*a*c;
 
  if (radical < -1E-6*std::fabs(b)) { return 0; }   // No solution
  
  if (radical < 1E-6*std::fabs(b))
  {
    //
    // The radical is roughly zero: check for special, very rare, cases
    //
    if (std::fabs(a) > 1/kInfinity)
    {
      if ( std::fabs(x0*ty - y0*tx) < std::fabs(1E-6/B) )
      {
        *s1 = -0.5*b/a;
        return 1;
      }
      return 0;
    }
  }
  else
  {
    radical = std::sqrt(radical);
  }
  
  if (a < -1/kInfinity)
  {
    G4double sa, sb, q = -0.5*( b + (b < 0 ? -radical : +radical) );
    sa = q/a;
    sb = c/q;
    if (sa < sb) { *s1 = sa; *s2 = sb; } else { *s1 = sb; *s2 = sa; }
    if ((z0 + (*s1)*tz  - A)/B < 0)  { return 0; }
    return 2;
  }
  else if (a > 1/kInfinity)
  {
    G4double sa, sb, q = -0.5*( b + (b < 0 ? -radical : +radical) );
    sa = q/a;
    sb = c/q;
    *s1 = (tz*B > 0)^(sa > sb) ? sb : sa;
    return 1;
  }
  else if (std::fabs(b) < 1/kInfinity)
  {
    return 0;
  }
  else
  {
    *s1 = -c/b;
    if ((z0 + (*s1)*tz  - A)/B < 0)  { return 0; }
    return 1;
  }
}

G4double G4IntersectingCone::RHi

(

)

const [inline]

Definition at line 64 of file G4IntersectingCone.hh.

References rHi.

{ return rHi; }

G4double G4IntersectingCone::RLo

(

)

const [inline]

Definition at line 63 of file G4IntersectingCone.hh.

References rLo.

{ return rLo; }

G4double G4IntersectingCone::ZHi

(

)

const [inline]

Definition at line 66 of file G4IntersectingCone.hh.

References zHi.

Referenced by G4PolyhedraSide::Extent(), and G4PolyconeSide::Extent().

{ return zHi; }

G4double G4IntersectingCone::ZLo

(

)

const [inline]

Definition at line 65 of file G4IntersectingCone.hh.

References zLo.

Referenced by G4PolyhedraSide::Extent(), and G4PolyconeSide::Extent().

{ return zLo; }

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Field Documentation

G4double G4IntersectingCone::A [protected]

Definition at line 83 of file G4IntersectingCone.hh.

Referenced by G4IntersectingCone(), LineHitsCone1(), and LineHitsCone2().

G4double G4IntersectingCone::B [protected]

Definition at line 83 of file G4IntersectingCone.hh.

Referenced by G4IntersectingCone(), LineHitsCone1(), and LineHitsCone2().

G4double G4IntersectingCone::rHi [protected]

Definition at line 78 of file G4IntersectingCone.hh.

Referenced by G4IntersectingCone(), HitOn(), and RHi().

G4double G4IntersectingCone::rLo [protected]

Definition at line 78 of file G4IntersectingCone.hh.

Referenced by G4IntersectingCone(), and RLo().

G4bool G4IntersectingCone::type1 [protected]

Definition at line 81 of file G4IntersectingCone.hh.

Referenced by G4IntersectingCone(), HitOn(), and LineHitsCone().

G4double G4IntersectingCone::zHi [protected]

Definition at line 78 of file G4IntersectingCone.hh.

Referenced by G4IntersectingCone(), HitOn(), and ZHi().

G4double G4IntersectingCone::zLo [protected]

Definition at line 78 of file G4IntersectingCone.hh.

Referenced by G4IntersectingCone(), and ZLo().

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The documentation for this class was generated from the following files:

• G4IntersectingCone.hh
• G4IntersectingCone.cc

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