G4EnclosingCylinder Class Reference

G4EnclosingCylinder is a utility class defining an envelope for quickly deciding if a point is clearly outside a polyhedra or polycone or deciding if a trajectory is clearly going to miss those shapes. More...

#include <G4EnclosingCylinder.hh>

Public Member Functions
	G4EnclosingCylinder (const G4ReduciblePolygon *rz, G4bool phiIsOpen, G4double startPhi, G4double totalPhi)
	~G4EnclosingCylinder ()=default
G4bool	MustBeOutside (const G4ThreeVector &p) const
G4bool	ShouldMiss (const G4ThreeVector &p, const G4ThreeVector &v) const
	G4EnclosingCylinder (__void__ &)

Detailed Description

G4EnclosingCylinder is a utility class defining an envelope for quickly deciding if a point is clearly outside a polyhedra or polycone or deciding if a trajectory is clearly going to miss those shapes.

Definition at line 51 of file G4EnclosingCylinder.hh.

Constructor & Destructor Documentation

G4EnclosingCylinder() [1/2]

G4EnclosingCylinder::G4EnclosingCylinder	(	const G4ReduciblePolygon *	rz,
		G4bool	phiIsOpen,
		G4double	startPhi,
		G4double	totalPhi )

Constructs the envelope, given its parameters.

Parameters

[in]	rz	Pointer to the polygon structure.
[in]	phiIsOpen	Boolean flag to indicate if it is a section in Phi.
[in]	startPhi	Starting Phi angle.
[in]	totalPhi	Total Phi angle of the section.

Definition at line 39 of file G4EnclosingCylinder.cc.

  : startPhi(theStartPhi), totalPhi(theTotalPhi),
    concave(theTotalPhi > pi)
{
  //
  // Obtain largest r and smallest and largest z
  //
  radius = rz->Amax();
  zHi = rz->Bmax();
  zLo = rz->Bmin();
 
  G4double kCarTolerance = G4GeometryTolerance::GetInstance()
                           ->GetSurfaceTolerance();
  //
  // Save phi info
  //
  phiIsOpen = thePhiIsOpen;
  if ( phiIsOpen )
  {    
    rx1 = std::cos(startPhi);
    ry1 = std::sin(startPhi);
    dx1 = +ry1*10*kCarTolerance;
    dy1 = -rx1*10*kCarTolerance;
    
    rx2 = std::cos(startPhi+totalPhi);
    ry2 = std::sin(startPhi+totalPhi);
    dx2 = -ry2*10*kCarTolerance;
    dy2 = +rx2*10*kCarTolerance;
  }
  
  //
  // Add safety
  //
  radius += 10*kCarTolerance;
  zLo    -= 10*kCarTolerance;
  zHi    += 10*kCarTolerance;
}

~G4EnclosingCylinder()

G4EnclosingCylinder::~G4EnclosingCylinder ( )

default

Default Destructor.

G4EnclosingCylinder() [2/2]

G4EnclosingCylinder::G4EnclosingCylinder

(

__void__ &

)

Fake default constructor for usage restricted to direct object persistency for clients requiring preallocation of memory for persistifiable objects.

Definition at line 83 of file G4EnclosingCylinder.cc.

: radius(0.), zLo(0.), zHi(0.), phiIsOpen(false), startPhi(0.), totalPhi(0.),
  concave(false)
{
}

Member Function Documentation

MustBeOutside()

G4bool G4EnclosingCylinder::MustBeOutside

(

const G4ThreeVector &

p

)

const

Decides very rapidly if the point 'p' is outside the cylinder.

Returns

If not certain to be outside, return false.

Definition at line 95 of file G4EnclosingCylinder.cc.

{
  if (p.perp() > radius) { return true; }
  if (p.z() < zLo) { return true; }
  if (p.z() > zHi) { return true; }
 
  if (phiIsOpen)
  {
    if (concave)
    {
      if ( ((p.x()-dx1)*ry1 - (p.y()-dy1)*rx1) < 0) { return false; }
      if ( ((p.x()-dx2)*ry2 - (p.y()-dy2)*rx2) > 0) { return false; }
    }
    else
    {
      if ( ((p.x()-dx1)*ry1 - (p.y()-dy1)*rx1) > 0) { return true; }
      if ( ((p.x()-dx2)*ry2 - (p.y()-dy2)*rx2) < 0) { return true; }
    }
  }
  
  return false;
}

Referenced by ShouldMiss().

ShouldMiss()

G4bool G4EnclosingCylinder::ShouldMiss	(	const G4ThreeVector &	p,
		const G4ThreeVector &	v ) const

Decides very rapidly if the trajectory is going to miss the cylinder.

Returns

If not certain to miss, return false.

Definition at line 124 of file G4EnclosingCylinder.cc.

{
  if (!MustBeOutside(p)) { return false; }
  
  G4double cross = p.x()*v.y() - p.y()*v.x();
  if (cross > radius) { return true; }
  
  if (p.perp() > radius)
  {
    G4double dot = p.x()*v.x() + p.y()*v.y();
    if (dot > 0) { return true; }
  }
 
  return false;
}

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

• G4EnclosingCylinder.hh
• G4EnclosingCylinder.cc