G4PolyhedraSide Class Reference

#include <G4PolyhedraSide.hh>

Inheritance diagram for G4PolyhedraSide:

Classes
struct	sG4PolyhedraSideEdge
struct	sG4PolyhedraSideVec

Public Member Functions
	G4PolyhedraSide (const G4PolyhedraSideRZ *prevRZ, const G4PolyhedraSideRZ *tail, const G4PolyhedraSideRZ *head, const G4PolyhedraSideRZ *nextRZ, G4int numSide, G4double phiStart, G4double phiTotal, G4bool phiIsOpen, G4bool isAllBehind=false)
virtual	~G4PolyhedraSide ()
	G4PolyhedraSide (const G4PolyhedraSide &source)
G4PolyhedraSide &	operator= (const G4PolyhedraSide &source)
G4bool	Intersect (const G4ThreeVector &p, const G4ThreeVector &v, G4bool outgoing, G4double surfTolerance, G4double &distance, G4double &distFromSurface, G4ThreeVector &normal, G4bool &allBehind)
G4double	Distance (const G4ThreeVector &p, G4bool outgoing)
EInside	Inside (const G4ThreeVector &p, G4double tolerance, G4double *bestDistance)
G4ThreeVector	Normal (const G4ThreeVector &p, G4double *bestDistance)
G4double	Extent (const G4ThreeVector axis)
void	CalculateExtent (const EAxis axis, const G4VoxelLimits &voxelLimit, const G4AffineTransform &tranform, G4SolidExtentList &extentList)
G4VCSGface *	Clone ()
G4double	SurfaceTriangle (G4ThreeVector p1, G4ThreeVector p2, G4ThreeVector p3, G4ThreeVector *p4)
G4ThreeVector	GetPointOnPlane (G4ThreeVector p0, G4ThreeVector p1, G4ThreeVector p2, G4ThreeVector p3, G4double *Area)
G4double	SurfaceArea ()
G4ThreeVector	GetPointOnFace ()
	G4PolyhedraSide (__void__ &)
Public Member Functions inherited from G4VCSGface
	G4VCSGface ()
virtual	~G4VCSGface ()
virtual G4bool	Intersect (const G4ThreeVector &p, const G4ThreeVector &v, G4bool outgoing, G4double surfTolerance, G4double &distance, G4double &distFromSurface, G4ThreeVector &normal, G4bool &allBehind)=0
virtual G4double	Distance (const G4ThreeVector &p, G4bool outgoing)=0
virtual EInside	Inside (const G4ThreeVector &p, G4double tolerance, G4double *bestDistance)=0
virtual G4ThreeVector	Normal (const G4ThreeVector &p, G4double *bestDistance)=0
virtual G4double	Extent (const G4ThreeVector axis)=0
virtual void	CalculateExtent (const EAxis axis, const G4VoxelLimits &voxelLimit, const G4AffineTransform &tranform, G4SolidExtentList &extentList)=0
virtual G4VCSGface *	Clone ()=0
virtual G4double	SurfaceArea ()=0
virtual G4ThreeVector	GetPointOnFace ()=0

Protected Types
typedef struct G4PolyhedraSide::sG4PolyhedraSideEdge	G4PolyhedraSideEdge
typedef struct G4PolyhedraSide::sG4PolyhedraSideVec	G4PolyhedraSideVec

Protected Member Functions
G4bool	IntersectSidePlane (const G4ThreeVector &p, const G4ThreeVector &v, const G4PolyhedraSideVec &vec, G4double normSign, G4double surfTolerance, G4double &distance, G4double &distFromSurface)
G4int	LineHitsSegments (const G4ThreeVector &p, const G4ThreeVector &v, G4int *i1, G4int *i2)
G4int	ClosestPhiSegment (G4double phi)
G4int	PhiSegment (G4double phi)
G4double	GetPhi (const G4ThreeVector &p)
G4double	DistanceToOneSide (const G4ThreeVector &p, const G4PolyhedraSideVec &vec, G4double *normDist)
G4double	DistanceAway (const G4ThreeVector &p, const G4PolyhedraSideVec &vec, G4double *normDist)
void	CopyStuff (const G4PolyhedraSide &source)

Protected Attributes
G4int	numSide
G4double	r [2]
G4double	z [2]
G4double	startPhi
G4double	deltaPhi
G4double	endPhi
G4bool	phiIsOpen
G4bool	allBehind
G4IntersectingCone *	cone
G4PolyhedraSideVec *	vecs
G4PolyhedraSideEdge *	edges
G4double	lenRZ
G4double	lenPhi [2]
G4double	edgeNorm

Friends
struct	sG4PolyhedraSideVec

Detailed Description

Definition at line 68 of file G4PolyhedraSide.hh.

Member Typedef Documentation

G4PolyhedraSideEdge

typedef struct G4PolyhedraSide::sG4PolyhedraSideEdge G4PolyhedraSide::G4PolyhedraSideEdge

protected

G4PolyhedraSideVec

typedef struct G4PolyhedraSide::sG4PolyhedraSideVec G4PolyhedraSide::G4PolyhedraSideVec

protected

Constructor & Destructor Documentation

G4PolyhedraSide() [1/3]

G4PolyhedraSide::G4PolyhedraSide	(	const G4PolyhedraSideRZ *	prevRZ,
		const G4PolyhedraSideRZ *	tail,
		const G4PolyhedraSideRZ *	head,
		const G4PolyhedraSideRZ *	nextRZ,
		G4int	numSide,
		G4double	phiStart,
		G4double	phiTotal,
		G4bool	phiIsOpen,
		G4bool	isAllBehind = false
	)

Definition at line 56 of file G4PolyhedraSide.cc.

{
  kCarTolerance = G4GeometryTolerance::GetInstance()->GetSurfaceTolerance();
  fSurfaceArea=0.;
  fPhi.first = G4ThreeVector(0,0,0);
  fPhi.second= 0.0;
 
  //
  // Record values
  //
  r[0] = tail->r; z[0] = tail->z;
  r[1] = head->r; z[1] = head->z;
  
  G4double phiTotal;
  
  //
  // Set phi to our convention
  //
  startPhi = thePhiStart;
  while (startPhi < 0.0) startPhi += twopi;
  
  phiIsOpen = thePhiIsOpen;
  phiTotal = (phiIsOpen) ? thePhiTotal : twopi;
  
  allBehind = isAllBehind;
    
  //
  // Make our intersecting cone
  //
  cone = new G4IntersectingCone( r, z );
  
  //
  // Construct side plane vector set
  //
  numSide = theNumSide;
  deltaPhi = phiTotal/theNumSide;
  endPhi = startPhi+phiTotal;
  
  vecs = new G4PolyhedraSideVec[numSide];
  
  edges = new G4PolyhedraSideEdge[phiIsOpen ? numSide+1 : numSide];
  
  //
  // ...this is where we start
  //
  G4double phi = startPhi;
  G4ThreeVector a1( r[0]*std::cos(phi), r[0]*std::sin(phi), z[0] ),
          b1( r[1]*std::cos(phi), r[1]*std::sin(phi), z[1] ),
          c1( prevRZ->r*std::cos(phi), prevRZ->r*std::sin(phi), prevRZ->z ),
          d1( nextRZ->r*std::cos(phi), nextRZ->r*std::sin(phi), nextRZ->z ),
          a2, b2, c2, d2;
  G4PolyhedraSideEdge *edge = edges;
          
  G4PolyhedraSideVec *vec = vecs;
  do
  {
    //
    // ...this is where we are going
    //
    phi += deltaPhi;
    a2 = G4ThreeVector( r[0]*std::cos(phi), r[0]*std::sin(phi), z[0] );
    b2 = G4ThreeVector( r[1]*std::cos(phi), r[1]*std::sin(phi), z[1] );
    c2 = G4ThreeVector( prevRZ->r*std::cos(phi), prevRZ->r*std::sin(phi), prevRZ->z );
    d2 = G4ThreeVector( nextRZ->r*std::cos(phi), nextRZ->r*std::sin(phi), nextRZ->z );
    
    G4ThreeVector tt;  
    
    //
    // ...build some relevant vectors.
    //    the point is to sacrifice a little memory with precalcs 
    //    to gain speed
    //
    vec->center = 0.25*( a1 + a2 + b1 + b2 );
    
    tt = b2 + b1 - a2 - a1;
    vec->surfRZ = tt.unit();
    if (vec==vecs) lenRZ = 0.25*tt.mag();
    
    tt = b2 - b1 + a2 - a1;
    vec->surfPhi = tt.unit();
    if (vec==vecs)
    {
      lenPhi[0] = 0.25*tt.mag();
      tt = b2 - b1;
      lenPhi[1] = (0.5*tt.mag()-lenPhi[0])/lenRZ;
    }
    
    tt = vec->surfPhi.cross(vec->surfRZ);
    vec->normal = tt.unit();
    
    //
    // ...edge normals are the average of the normals of
    //    the two faces they connect.
    //
    // ...edge normals are necessary if we are to accurately
    //    decide if a point is "inside" a face. For non-convex
    //    shapes, it is absolutely necessary to know information
    //    on adjacent faces to accurate determine this.
    //
    // ...we don't need them for the phi edges, since that
    //    information is taken care of internally. The r/z edges,
    //    however, depend on the adjacent G4PolyhedraSide.
    //
    G4ThreeVector a12, adj;
    
    a12 = a2-a1;
 
    adj = 0.5*(c1+c2-a1-a2);
    adj = adj.cross(a12);  
    adj = adj.unit() + vec->normal;       
    vec->edgeNorm[0] = adj.unit();
    
    a12 = b1-b2;
    adj = 0.5*(d1+d2-b1-b2);
    adj = adj.cross(a12);  
    adj = adj.unit() + vec->normal;       
    vec->edgeNorm[1] = adj.unit();
    
    //
    // ...the corners are crucial. It is important that
    //    they are calculated consistently for adjacent
    //    G4PolyhedraSides, to avoid gaps caused by roundoff.
    //
    vec->edges[0] = edge;
    edge->corner[0] = a1;
    edge->corner[1] = b1;
    edge++;
    vec->edges[1] = edge;
 
    a1 = a2;
    b1 = b2;
    c1 = c2;
    d1 = d2;
  } while( ++vec < vecs+numSide );
  
  //
  // Clean up hanging edge
  //
  if (phiIsOpen)
  {
    edge->corner[0] = a2;
    edge->corner[1] = b2;
  }
  else
  {
    vecs[numSide-1].edges[1] = edges;
  }
  
  //
  // Go back and fill in remaining fields in edges
  //
  vec = vecs;
  G4PolyhedraSideVec *prev = vecs+numSide-1;
  do
  {
    edge = vec->edges[0];    // The edge between prev and vec
    
    //
    // Okay: edge normal is average of normals of adjacent faces
    //
    G4ThreeVector eNorm = vec->normal + prev->normal;
    edge->normal = eNorm.unit();  
    
    //
    // Vertex normal is average of norms of adjacent surfaces (all four)
    // However, vec->edgeNorm is unit vector in some direction
    // as the sum of normals of adjacent PolyhedraSide with vec.
    // The normalization used for this vector should be the same
    // for vec and prev.
    //
    eNorm = vec->edgeNorm[0] + prev->edgeNorm[0];
    edge->cornNorm[0] = eNorm.unit();
  
    eNorm = vec->edgeNorm[1] + prev->edgeNorm[1];
    edge->cornNorm[1] = eNorm.unit();
  } while( prev=vec, ++vec < vecs + numSide );
  
  if (phiIsOpen)
  {
    // G4double rFact = std::cos(0.5*deltaPhi);
    //
    // If phi is open, we need to patch up normals of the
    // first and last edges and their corresponding
    // vertices.
    //
    // We use vectors that are in the plane of the
    // face. This should be safe.
    //
    vec = vecs;
    
    G4ThreeVector normvec = vec->edges[0]->corner[0]
                          - vec->edges[0]->corner[1];
    normvec = normvec.cross(vec->normal);
    if (normvec.dot(vec->surfPhi) > 0) normvec = -normvec;
 
    vec->edges[0]->normal = normvec.unit();
    
    vec->edges[0]->cornNorm[0] = (vec->edges[0]->corner[0]
                                - vec->center).unit();
    vec->edges[0]->cornNorm[1] = (vec->edges[0]->corner[1]
                                - vec->center).unit();
    
    //
    // Repeat for ending phi
    //
    vec = vecs + numSide - 1;
    
    normvec = vec->edges[1]->corner[0] - vec->edges[1]->corner[1];
    normvec = normvec.cross(vec->normal);
    if (normvec.dot(vec->surfPhi) < 0) normvec = -normvec;
 
    vec->edges[1]->normal = normvec.unit();
    
    vec->edges[1]->cornNorm[0] = (vec->edges[1]->corner[0]
                                - vec->center).unit();
    vec->edges[1]->cornNorm[1] = (vec->edges[1]->corner[1]
                                - vec->center).unit();
  }
  
  //
  // edgeNorm is the factor one multiplies the distance along vector phi
  // on the surface of one of our sides in order to calculate the distance
  // from the edge. (see routine DistanceAway)
  //
  edgeNorm = 1.0/std::sqrt( 1.0 + lenPhi[1]*lenPhi[1] );
}

~G4PolyhedraSide()

G4PolyhedraSide::~G4PolyhedraSide ( )

virtual

Definition at line 310 of file G4PolyhedraSide.cc.

{
  delete cone;
  delete [] vecs;
  delete [] edges;
}

G4PolyhedraSide() [2/3]

G4PolyhedraSide::G4PolyhedraSide

(

const G4PolyhedraSide &

source

)

Definition at line 321 of file G4PolyhedraSide.cc.

  : G4VCSGface()
{
  CopyStuff( source );
}

G4PolyhedraSide() [3/3]

G4PolyhedraSide::G4PolyhedraSide

(

__void__ &

)

Definition at line 296 of file G4PolyhedraSide.cc.

  : numSide(0), startPhi(0.), deltaPhi(0.), endPhi(0.),
    phiIsOpen(false), allBehind(false), cone(0), vecs(0), edges(0),
    lenRZ(0.), edgeNorm(0.), kCarTolerance(0.), fSurfaceArea(0.)
{
  r[0] = r[1] = 0.;
  z[0] = z[1] = 0.;
  lenPhi[0] = lenPhi[1] = 0.;
}

Member Function Documentation

CalculateExtent()

void G4PolyhedraSide::CalculateExtent ( const EAxis  axis, const G4VoxelLimits &  voxelLimit, const G4AffineTransform &  tranform, G4SolidExtentList &  extentList  )

virtual

Implements G4VCSGface.

Definition at line 708 of file G4PolyhedraSide.cc.

{
  //
  // Loop over all sides
  //
  G4PolyhedraSideVec *vec = vecs;
  do
  {
    //
    // Fill our polygon with the four corners of
    // this side, after the specified transformation
    //
    G4ClippablePolygon polygon;
    
    polygon.AddVertexInOrder(transform.
                             TransformPoint(vec->edges[0]->corner[0]));
    polygon.AddVertexInOrder(transform.
                             TransformPoint(vec->edges[0]->corner[1]));
    polygon.AddVertexInOrder(transform.
                             TransformPoint(vec->edges[1]->corner[1]));
    polygon.AddVertexInOrder(transform.
                             TransformPoint(vec->edges[1]->corner[0]));
    
    //
    // Get extent
    //  
    if (polygon.PartialClip( voxelLimit, axis ))
    {
      //
      // Get dot product of normal along target axis
      //
      polygon.SetNormal( transform.TransformAxis(vec->normal) );
 
      extentList.AddSurface( polygon );
    }
  } while( ++vec < vecs+numSide );
  
  return;
}

Clone()

G4VCSGface * G4PolyhedraSide::Clone ( )

inlinevirtual

Implements G4VCSGface.

Definition at line 104 of file G4PolyhedraSide.hh.

{ return new G4PolyhedraSide( *this ); }

ClosestPhiSegment()

G4int G4PolyhedraSide::ClosestPhiSegment ( G4double  phi )

protected

Definition at line 920 of file G4PolyhedraSide.cc.

{
  G4int iPhi = PhiSegment( phi0 );
  if (iPhi >= 0) return iPhi;
  
  //
  // Boogers! The points falls inside the phi segment.
  // Look for the closest point: the start, or  end
  //
  G4double phi = phi0;
  
  while( phi < startPhi ) phi += twopi;
  G4double d1 = phi-endPhi;
 
  while( phi > startPhi ) phi -= twopi;
  G4double d2 = startPhi-phi;
  
  return (d2 < d1) ? 0 : numSide-1;
}

Referenced by Distance(), Inside(), and Normal().

CopyStuff()

void G4PolyhedraSide::CopyStuff ( const G4PolyhedraSide &  source )

protected

Definition at line 348 of file G4PolyhedraSide.cc.

{
  //
  // The simple stuff
  //
  numSide    = source.numSide;
  r[0]    = source.r[0];
  r[1]    = source.r[1];
  z[0]    = source.z[0];
  z[1]    = source.z[1];
  startPhi  = source.startPhi;
  deltaPhi  = source.deltaPhi;
  endPhi    = source.endPhi;
  phiIsOpen = source.phiIsOpen;
  allBehind = source.allBehind;
  
  lenRZ     = source.lenRZ;
  lenPhi[0] = source.lenPhi[0];
  lenPhi[1] = source.lenPhi[1];
  edgeNorm  = source.edgeNorm;
 
  kCarTolerance = source.kCarTolerance;
  fSurfaceArea = source.fSurfaceArea;
 
  cone = new G4IntersectingCone( *source.cone );
 
  //
  // Duplicate edges
  //
  G4int  numEdges = phiIsOpen ? numSide+1 : numSide;
  edges = new G4PolyhedraSideEdge[numEdges];
  
  G4PolyhedraSideEdge *edge = edges,
          *sourceEdge = source.edges;
  do
  {
    *edge = *sourceEdge;
  } while( ++sourceEdge, ++edge < edges + numEdges);
 
  //
  // Duplicate vecs
  //
  vecs = new G4PolyhedraSideVec[numSide];
  
  G4PolyhedraSideVec *vec = vecs,
         *sourceVec = source.vecs;
  do
  {
    *vec = *sourceVec;
    vec->edges[0] = edges + (sourceVec->edges[0] - source.edges);
    vec->edges[1] = edges + (sourceVec->edges[1] - source.edges);
  } while( ++sourceVec, ++vec < vecs + numSide );
}

Referenced by G4PolyhedraSide(), and operator=().

Distance()

G4double G4PolyhedraSide::Distance ( const G4ThreeVector &  p, G4bool  outgoing  )

virtual

Implements G4VCSGface.

Definition at line 563 of file G4PolyhedraSide.cc.

{
  G4double normSign = outgoing ? -1 : +1;
  
  //
  // Try the closest phi segment first
  //
  G4int iPhi = ClosestPhiSegment( GetPhi(p) );
  
  G4ThreeVector pdotc = p - vecs[iPhi].center;
  G4double normDist = pdotc.dot(vecs[iPhi].normal);
  
  if (normSign*normDist > -0.5*kCarTolerance)
  {
    return DistanceAway( p, vecs[iPhi], &normDist );
  }
 
  //
  // Now we have an interesting problem... do we try to find the
  // closest facing side??
  //
  // Considered carefully, the answer is no. We know that if we
  // are asking for the distance out, we are supposed to be inside,
  // and vice versa.
  //
  
  return kInfinity;
}

DistanceAway()

G4double G4PolyhedraSide::DistanceAway ( const G4ThreeVector &  p, const G4PolyhedraSideVec &  vec, G4double *  normDist  )

protected

Definition at line 1037 of file G4PolyhedraSide.cc.

{
  G4double distOut2;
  G4ThreeVector pct = p - vec.center;
  G4double distFaceNorm = *normDist;
  
  //
  // Okay, are we inside bounds?
  //
  G4double pcDotRZ  = pct.dot(vec.surfRZ);
  G4double pcDotPhi = pct.dot(vec.surfPhi);
  
  //
  // Go through all permutations.
  //                                                   Phi
  //               |              |                     ^
  //           B   |      H       |   E                 |
  //        ------[1]------------[3]-----               |
  //               |XXXXXXXXXXXXXX|                     +----> RZ
  //           C   |XXXXXXXXXXXXXX|   F
  //               |XXXXXXXXXXXXXX|
  //        ------[0]------------[2]----
  //           A   |      G       |   D
  //               |              |
  //
  // It's real messy, but at least it's quick
  //
  
  if (pcDotRZ < -lenRZ)
  {
    G4double lenPhiZ = lenPhi[0] - lenRZ*lenPhi[1];
    G4double distOutZ = pcDotRZ+lenRZ;
    //
    // Below in RZ
    //
    if (pcDotPhi < -lenPhiZ)
    {
      //
      // ...and below in phi. Find distance to point (A)
      //
      G4double distOutPhi = pcDotPhi+lenPhiZ;
      distOut2 = distOutPhi*distOutPhi + distOutZ*distOutZ;
      G4ThreeVector pa = p - vec.edges[0]->corner[0];
      *normDist = pa.dot(vec.edges[0]->cornNorm[0]);
    }
    else if (pcDotPhi > lenPhiZ)
    {
      //
      // ...and above in phi. Find distance to point (B)
      //
      G4double distOutPhi = pcDotPhi-lenPhiZ;
      distOut2 = distOutPhi*distOutPhi + distOutZ*distOutZ;
      G4ThreeVector pb = p - vec.edges[1]->corner[0];
      *normDist = pb.dot(vec.edges[1]->cornNorm[0]);
    }
    else
    {
      //
      // ...and inside in phi. Find distance to line (C)
      //
      G4ThreeVector pa = p - vec.edges[0]->corner[0];
      distOut2 = distOutZ*distOutZ;
      *normDist = pa.dot(vec.edgeNorm[0]);
    }
  }
  else if (pcDotRZ > lenRZ)
  {
    G4double lenPhiZ = lenPhi[0] + lenRZ*lenPhi[1];
    G4double distOutZ = pcDotRZ-lenRZ;
    //
    // Above in RZ
    //
    if (pcDotPhi < -lenPhiZ)
    {
      //
      // ...and below in phi. Find distance to point (D)
      //
      G4double distOutPhi = pcDotPhi+lenPhiZ;
      distOut2 = distOutPhi*distOutPhi + distOutZ*distOutZ;
      G4ThreeVector pd = p - vec.edges[0]->corner[1];
      *normDist = pd.dot(vec.edges[0]->cornNorm[1]);
    }
    else if (pcDotPhi > lenPhiZ)
    {
      //
      // ...and above in phi. Find distance to point (E)
      //
      G4double distOutPhi = pcDotPhi-lenPhiZ;
      distOut2 = distOutPhi*distOutPhi + distOutZ*distOutZ;
      G4ThreeVector pe = p - vec.edges[1]->corner[1];
      *normDist = pe.dot(vec.edges[1]->cornNorm[1]);
    }
    else
    {
      //
      // ...and inside in phi. Find distance to line (F)
      //
      distOut2 = distOutZ*distOutZ;
      G4ThreeVector pd = p - vec.edges[0]->corner[1];
      *normDist = pd.dot(vec.edgeNorm[1]);
    }
  }
  else
  {
    G4double lenPhiZ = lenPhi[0] + pcDotRZ*lenPhi[1];
    //
    // We are inside RZ bounds
    // 
    if (pcDotPhi < -lenPhiZ)
    {
      //
      // ...and below in phi. Find distance to line (G)
      //
      G4double distOut = edgeNorm*(pcDotPhi+lenPhiZ);
      distOut2 = distOut*distOut;
      G4ThreeVector pd = p - vec.edges[0]->corner[1];
      *normDist = pd.dot(vec.edges[0]->normal);
    }
    else if (pcDotPhi > lenPhiZ)
    {
      //
      // ...and above in phi. Find distance to line (H)
      //
      G4double distOut = edgeNorm*(pcDotPhi-lenPhiZ);
      distOut2 = distOut*distOut;
      G4ThreeVector pe = p - vec.edges[1]->corner[1];
      *normDist = pe.dot(vec.edges[1]->normal);
    }
    else
    {
      //
      // Inside bounds! No penalty.
      //
      return std::fabs(distFaceNorm);
    }
  }
  return std::sqrt( distFaceNorm*distFaceNorm + distOut2 );
}

Referenced by Distance(), and DistanceToOneSide().

DistanceToOneSide()

G4double G4PolyhedraSide::DistanceToOneSide ( const G4ThreeVector &  p, const G4PolyhedraSideVec &  vec, G4double *  normDist  )

protected

Definition at line 1013 of file G4PolyhedraSide.cc.

{
  G4ThreeVector pct = p - vec.center;
  
  //
  // Get normal distance
  //
  *normDist = vec.normal.dot(pct);
 
  //
  // Add edge penalty
  //
  return DistanceAway( p, vec, normDist );
}

Referenced by Inside(), and Normal().

Extent()

G4double G4PolyhedraSide::Extent ( const G4ThreeVector  axis )

virtual

Implements G4VCSGface.

Definition at line 648 of file G4PolyhedraSide.cc.

{
  if (axis.perp2() < DBL_MIN)
  {
    //
    // Special case
    //
    return axis.z() < 0 ? -cone->ZLo() : cone->ZHi();
  }
 
  G4int iPhi, i1, i2;
  G4double best;
  G4ThreeVector *list[4];
  
  //
  // Which phi segment, if any, does the axis belong to
  //
  iPhi = PhiSegment( GetPhi(axis) );
  
  if (iPhi < 0)
  {
    //
    // No phi segment? Check front edge of first side and
    // last edge of second side
    //
    i1 = 0; i2 = numSide-1;
  }
  else
  {
    //
    // Check all corners of matching phi side
    //
    i1 = iPhi; i2 = iPhi;
  }
  
  list[0] = vecs[i1].edges[0]->corner;
  list[1] = vecs[i1].edges[0]->corner+1;
  list[2] = vecs[i2].edges[1]->corner;
  list[3] = vecs[i2].edges[1]->corner+1;
        
  //
  // Who's biggest?
  //
  best = -kInfinity;
  G4ThreeVector **vec = list;
  do
  {
    G4double answer = (*vec)->dot(axis);
    if (answer > best) best = answer;
  } while( ++vec < list+4 );
  
  return best;
}

GetPhi()

G4double G4PolyhedraSide::GetPhi ( const G4ThreeVector &  p )

protected

Definition at line 986 of file G4PolyhedraSide.cc.

{
  G4double val=0.;
 
  if (fPhi.first != p)
  {
    val = p.phi();
    fPhi.first = p;
    fPhi.second = val;
  }
  else
  {
    val = fPhi.second;
  }
  return val;
}

Referenced by Distance(), Extent(), Inside(), and Normal().

GetPointOnFace()

G4ThreeVector G4PolyhedraSide::GetPointOnFace ( )

virtual

Implements G4VCSGface.

Definition at line 1263 of file G4PolyhedraSide.cc.

{
  // Define the variables
  //
  std::vector<G4double>areas;
  std::vector<G4ThreeVector>points;
  G4double area=0;
  G4double result1;
  G4ThreeVector point1;
  G4ThreeVector v1,v2,v3,v4; 
  G4PolyhedraSideVec *vec = vecs;
 
  // Do a loop on all SideEdge
  //
  do
  {
    // Define 4points for a Plane or Triangle
    //
    v1=vec->edges[0]->corner[0];
    v2=vec->edges[0]->corner[1];
    v3=vec->edges[1]->corner[1];
    v4=vec->edges[1]->corner[0];
    point1=GetPointOnPlane(v1,v2,v3,v4,&result1);
    points.push_back(point1);
    areas.push_back(result1);
    area+=result1;
  } while( ++vec < vecs+numSide );
 
  // Choose randomly one of the surfaces and point on it
  //
  G4double chose = area*G4UniformRand();
  G4double Achose1,Achose2;
  Achose1=0;Achose2=0.; 
  G4int i=0;
  do 
  {
    Achose2+=areas[i];
    if(chose>=Achose1 && chose<Achose2)
    {
      point1=points[i] ; break;     
    }
    i++; Achose1=Achose2;
  } while( i<numSide );
 
  return point1;
}

GetPointOnPlane()

G4ThreeVector G4PolyhedraSide::GetPointOnPlane	(	G4ThreeVector	p0,
		G4ThreeVector	p1,
		G4ThreeVector	p2,
		G4ThreeVector	p3,
		G4double *	Area
	)

Definition at line 1206 of file G4PolyhedraSide.cc.

{
  G4double chose,aOne,aTwo;
  G4ThreeVector point1,point2;
  aOne = SurfaceTriangle(p0,p1,p2,&point1);
  aTwo = SurfaceTriangle(p2,p3,p0,&point2);
  *Area= aOne+aTwo;
 
  chose = G4UniformRand()*(aOne+aTwo);
  if( (chose>=0.) && (chose < aOne) )
  {
   return (point1);    
  }
  return (point2);
}

Referenced by GetPointOnFace(), and SurfaceArea().

Inside()

EInside G4PolyhedraSide::Inside ( const G4ThreeVector &  p, G4double  tolerance, G4double *  bestDistance  )

virtual

Implements G4VCSGface.

Definition at line 596 of file G4PolyhedraSide.cc.

{
  //
  // Which phi segment is closest to this point?
  //
  G4int iPhi = ClosestPhiSegment( GetPhi(p) );
  
  G4double norm;
  
  //
  // Get distance to this segment
  //
  *bestDistance = DistanceToOneSide( p, vecs[iPhi], &norm );
  
  //
  // Use distance along normal to decide return value
  //
  if ( (std::fabs(norm) < tolerance) && (*bestDistance < 2.0*tolerance) )
    return kSurface;
  else if (norm < 0)
    return kInside;
  else  
    return kOutside;
}

Intersect()

G4bool G4PolyhedraSide::Intersect ( const G4ThreeVector &  p, const G4ThreeVector &  v, G4bool  outgoing, G4double  surfTolerance, G4double &  distance, G4double &  distFromSurface, G4ThreeVector &  normal, G4bool &  allBehind  )

virtual

Implements G4VCSGface.

Definition at line 444 of file G4PolyhedraSide.cc.

{
  G4double normSign = outgoing ? +1 : -1;
  
  //
  // ------------------TO BE IMPLEMENTED---------------------
  // Testing the intersection of individual phi faces is
  // pretty straight forward. The simple thing therefore is to
  // form a loop and check them all in sequence.
  //
  // But, I worry about one day someone making
  // a polygon with a thousands sides. A linear search
  // would not be ideal in such a case.
  //
  // So, it would be nice to be able to quickly decide
  // which face would be intersected. One can make a very
  // good guess by using the intersection with a cone.
  // However, this is only reliable in 99% of the cases.
  //
  // My solution: make a decent guess as to the one or
  // two potential faces might get intersected, and then
  // test them. If we have the wrong face, use the test
  // to make a better guess.
  //
  // Since we might have two guesses, form a queue of
  // potential intersecting faces. Keep an array of 
  // already tested faces to avoid doing one more than
  // once.
  //
  // Result: at worst, an iterative search. On average,
  // a little more than two tests would be required.
  //
  G4ThreeVector q = p + v;
  
  G4int face = 0;
  G4PolyhedraSideVec *vec = vecs;
  do
  {
    //
    // Correct normal?
    //
    G4double dotProd = normSign*v.dot(vec->normal);
    if (dotProd <= 0) continue;
  
    //
    // Is this face in front of the point along the trajectory?
    //
    G4ThreeVector delta = p - vec->center;
    distFromSurface = -normSign*delta.dot(vec->normal);
    
    if (distFromSurface < -surfTolerance) continue;
    
    //
    //                            phi
    //      c -------- d           ^
    //      |          |           |
    //      a -------- b           +---> r/z
    //
    //
    // Do we remain on this particular segment?
    //
    G4ThreeVector qc = q - vec->edges[1]->corner[0];
    G4ThreeVector qd = q - vec->edges[1]->corner[1];
    
    if (normSign*qc.cross(qd).dot(v) < 0) continue;
    
    G4ThreeVector qa = q - vec->edges[0]->corner[0];
    G4ThreeVector qb = q - vec->edges[0]->corner[1];
    
    if (normSign*qa.cross(qb).dot(v) > 0) continue;
    
    //
    // We found the one and only segment we might be intersecting.
    // Do we remain within r/z bounds?
    //
    
    if (r[0] > 1/kInfinity && normSign*qa.cross(qc).dot(v) < 0) return false;
    if (r[1] > 1/kInfinity && normSign*qb.cross(qd).dot(v) > 0) return false;
    
    //
    // We allow the face to be slightly behind the trajectory
    // (surface tolerance) only if the point p is within
    // the vicinity of the face
    //
    if (distFromSurface < 0)
    {
      G4ThreeVector ps = p - vec->center; 
      
      G4double rz = ps.dot(vec->surfRZ);
      if (std::fabs(rz) > lenRZ+surfTolerance) return false; 
 
      G4double pp = ps.dot(vec->surfPhi);
      if (std::fabs(pp) > lenPhi[0] + lenPhi[1]*rz + surfTolerance) return false;
    }
      
 
    //
    // Intersection found. Return answer.
    //
    distance = distFromSurface/dotProd;
    normal = vec->normal;
    isAllBehind = allBehind;
    return true;
  } while( ++vec, ++face < numSide );
 
  //
  // Oh well. Better luck next time.
  //
  return false;
}

IntersectSidePlane()

G4bool G4PolyhedraSide::IntersectSidePlane ( const G4ThreeVector &  p, const G4ThreeVector &  v, const G4PolyhedraSideVec &  vec, G4double  normSign, G4double  surfTolerance, G4double &  distance, G4double &  distFromSurface  )

protected

Definition at line 779 of file G4PolyhedraSide.cc.

{
  //
  // Correct normal? Here we have straight sides, and can safely ignore
  // intersections where the dot product with the normal is zero.
  //
  G4double dotProd = normSign*v.dot(vec.normal);
  
  if (dotProd <= 0) return false;
  
  //
  // Calculate distance to surface. If the side is too far
  // behind the point, we must reject it.
  //
  G4ThreeVector delta = p - vec.center;
  distFromSurface = -normSign*delta.dot(vec.normal);
    
  if (distFromSurface < -surfTolerance) return false;
 
  //
  // Calculate precise distance to intersection with the side
  // (along the trajectory, not normal to the surface)
  //
  distance = distFromSurface/dotProd;
  
  //
  // Do we fall off the r/z extent of the segment?
  //
  // Calculate this very, very carefully! Why?
  //         1. If a RZ end is at R=0, you can't miss!
  //         2. If you just fall off in RZ, the answer must
  //            be consistent with adjacent G4PolyhedraSide faces.
  // (2) implies that only variables used by other G4PolyhedraSide
  // faces may be used, which includes only: p, v, and the edge corners.
  // It also means that one side is a ">" or "<", which the other
  // must be ">=" or "<=". Fortunately, this isn't a new problem.
  // The solution below I borrowed from Joseph O'Rourke,
  // "Computational Geometry in C (Second Edition)"
  // See: http://cs.smith.edu/~orourke/
  //
  G4ThreeVector ic = p + distance*v - vec.center;
  G4double atRZ = vec.surfRZ.dot(ic);
  
  if (atRZ < 0)
  {
    if (r[0]==0) return true;    // Can't miss!
    
    if (atRZ < -lenRZ*1.2) return false;  // Forget it! Missed by a mile.
    
    G4ThreeVector q = p + v;    
    G4ThreeVector qa = q - vec.edges[0]->corner[0],
                  qb = q - vec.edges[1]->corner[0];
    G4ThreeVector qacb = qa.cross(qb);
    if (normSign*qacb.dot(v) < 0) return false;
    
    if (distFromSurface < 0)
    {
      if (atRZ < -lenRZ-surfTolerance) return false;
    }
  }
  else if (atRZ > 0)
  {
    if (r[1]==0) return true;    // Can't miss!
    
    if (atRZ > lenRZ*1.2) return false;  // Missed by a mile
    
    G4ThreeVector q = p + v;    
    G4ThreeVector qa = q - vec.edges[0]->corner[1],
                  qb = q - vec.edges[1]->corner[1];
    G4ThreeVector qacb = qa.cross(qb);
    if (normSign*qacb.dot(v) >= 0) return false;
    
    if (distFromSurface < 0)
    {
      if (atRZ > lenRZ+surfTolerance) return false;
    }
  }
 
  return true;
}

LineHitsSegments()

G4int G4PolyhedraSide::LineHitsSegments ( const G4ThreeVector &  p, const G4ThreeVector &  v, G4int *  i1, G4int *  i2  )

protected

Definition at line 874 of file G4PolyhedraSide.cc.

{
  G4double s1, s2;
  //
  // First, decide if and where the line intersects the cone
  //
  G4int n = cone->LineHitsCone( p, v, &s1, &s2 );
  
  if (n==0) return 0;
  
  //
  // Try first intersection.
  //
  *i1 = PhiSegment( std::atan2( p.y() + s1*v.y(), p.x() + s1*v.x() ) );
  if (n==1)
  {
    return (*i1 < 0) ? 0 : 1;
  }
  
  //
  // Try second intersection
  //
  *i2 = PhiSegment( std::atan2( p.y() + s2*v.y(), p.x() + s2*v.x() ) );
  if (*i1 == *i2) return 0;
  
  if (*i1 < 0)
  {
    if (*i2 < 0) return 0;
    *i1 = *i2;
    return 1;
  }
 
  if (*i2 < 0) return 1;
  
  return 2;
}

Normal()

G4ThreeVector G4PolyhedraSide::Normal ( const G4ThreeVector &  p, G4double *  bestDistance  )

virtual

Implements G4VCSGface.

Definition at line 627 of file G4PolyhedraSide.cc.

{
  //
  // Which phi segment is closest to this point?
  //
  G4int iPhi = ClosestPhiSegment( GetPhi(p) );
 
  //
  // Get distance to this segment
  //
  G4double norm;
  *bestDistance = DistanceToOneSide( p, vecs[iPhi], &norm );
 
  return vecs[iPhi].normal;
}

operator=()

G4PolyhedraSide & G4PolyhedraSide::operator=

(

const G4PolyhedraSide &

source

)

Definition at line 331 of file G4PolyhedraSide.cc.

{
  if (this == &source) return *this;
  
  delete cone;
  delete [] vecs;
  delete [] edges;
  
  CopyStuff( source );
 
  return *this;
}

PhiSegment()

G4int G4PolyhedraSide::PhiSegment ( G4double  phi )

protected

Definition at line 948 of file G4PolyhedraSide.cc.

{
  //
  // How far are we from phiStart? Come up with a positive answer
  // that is less than 2*PI
  //
  G4double phi = phi0 - startPhi;
  while( phi < 0      ) phi += twopi;
  while( phi > twopi ) phi -= twopi;
 
  //
  // Divide
  //
  G4int answer = (G4int)(phi/deltaPhi);
  
  if (answer >= numSide)
  {
    if (phiIsOpen)
    {
      return -1;  // Looks like we missed
    }
    else
    {
      answer = numSide-1;  // Probably just roundoff
    }
  }
  
  return answer;
}

Referenced by ClosestPhiSegment(), Extent(), and LineHitsSegments().

SurfaceArea()

G4double G4PolyhedraSide::SurfaceArea ( )

virtual

Implements G4VCSGface.

Definition at line 1228 of file G4PolyhedraSide.cc.

{
  if( fSurfaceArea==0. )
  { 
    // Define the variables
    //
    G4double area,areas;
    G4ThreeVector point1;
    G4ThreeVector v1,v2,v3,v4; 
    G4PolyhedraSideVec *vec = vecs;
    areas=0.;
 
    // Do a loop on all SideEdge
    //
    do
    {
      // Define 4points for a Plane or Triangle
      //
      v1=vec->edges[0]->corner[0];
      v2=vec->edges[0]->corner[1];
      v3=vec->edges[1]->corner[1];
      v4=vec->edges[1]->corner[0];
      point1=GetPointOnPlane(v1,v2,v3,v4,&area);
      areas+=area;
    } while( ++vec < vecs + numSide);
 
    fSurfaceArea=areas;
  }
  return fSurfaceArea;
}

SurfaceTriangle()

G4double G4PolyhedraSide::SurfaceTriangle	(	G4ThreeVector	p1,
		G4ThreeVector	p2,
		G4ThreeVector	p3,
		G4ThreeVector *	p4
	)

Definition at line 1183 of file G4PolyhedraSide.cc.

{
  G4ThreeVector v, w;
  
  v = p3 - p1;
  w = p1 - p2;
  G4double lambda1 = G4UniformRand();
  G4double lambda2 = lambda1*G4UniformRand();
 
  *p4=p2 + lambda1*w + lambda2*v;
  return 0.5*(v.cross(w)).mag();
}

Referenced by GetPointOnPlane().

Friends And Related Function Documentation

sG4PolyhedraSideVec

friend struct sG4PolyhedraSideVec

friend

Definition at line 133 of file G4PolyhedraSide.hh.

Member Data Documentation

allBehind

G4bool G4PolyhedraSide::allBehind

protected

Definition at line 188 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), G4PolyhedraSide(), and Intersect().

cone

G4IntersectingCone* G4PolyhedraSide::cone

protected

Definition at line 190 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), Extent(), G4PolyhedraSide(), LineHitsSegments(), operator=(), and ~G4PolyhedraSide().

deltaPhi

G4double G4PolyhedraSide::deltaPhi

protected

Definition at line 185 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), G4PolyhedraSide(), and PhiSegment().

edgeNorm

G4double G4PolyhedraSide::edgeNorm

protected

Definition at line 196 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), DistanceAway(), and G4PolyhedraSide().

edges

G4PolyhedraSideEdge* G4PolyhedraSide::edges

protected

Definition at line 193 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), G4PolyhedraSide(), operator=(), and ~G4PolyhedraSide().

endPhi

G4double G4PolyhedraSide::endPhi

protected

Definition at line 186 of file G4PolyhedraSide.hh.

Referenced by ClosestPhiSegment(), CopyStuff(), and G4PolyhedraSide().

lenPhi

G4double G4PolyhedraSide::lenPhi[2]

protected

Definition at line 195 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), DistanceAway(), G4PolyhedraSide(), and Intersect().

lenRZ

G4double G4PolyhedraSide::lenRZ

protected

Definition at line 194 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), DistanceAway(), G4PolyhedraSide(), Intersect(), and IntersectSidePlane().

numSide

G4int G4PolyhedraSide::numSide

protected

Definition at line 182 of file G4PolyhedraSide.hh.

Referenced by CalculateExtent(), ClosestPhiSegment(), CopyStuff(), Extent(), G4PolyhedraSide(), GetPointOnFace(), Intersect(), PhiSegment(), and SurfaceArea().

phiIsOpen

G4bool G4PolyhedraSide::phiIsOpen

protected

Definition at line 187 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), G4PolyhedraSide(), and PhiSegment().

r

G4double G4PolyhedraSide::r[2]

protected

Definition at line 183 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), G4PolyhedraSide(), Intersect(), and IntersectSidePlane().

startPhi

G4double G4PolyhedraSide::startPhi

protected

Definition at line 184 of file G4PolyhedraSide.hh.

Referenced by ClosestPhiSegment(), CopyStuff(), G4PolyhedraSide(), and PhiSegment().

vecs

G4PolyhedraSideVec* G4PolyhedraSide::vecs

protected

Definition at line 192 of file G4PolyhedraSide.hh.

Referenced by CalculateExtent(), CopyStuff(), Distance(), Extent(), G4PolyhedraSide(), GetPointOnFace(), Inside(), Intersect(), Normal(), operator=(), SurfaceArea(), and ~G4PolyhedraSide().

z

G4double G4PolyhedraSide::z[2]

protected

Definition at line 183 of file G4PolyhedraSide.hh.

Referenced by CopyStuff(), and G4PolyhedraSide().

---

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

• G4PolyhedraSide.hh
• G4PolyhedraSide.cc