include/Geant4/G4PolyPhiFace.icc

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0025 //
0026 // Implementation of inline methods of G4PolyPhiFace
0027 // --------------------------------------------------------------------
0028
0029 inline
0030 G4VCSGface* G4PolyPhiFace::Clone()
0031 {
0032   return new G4PolyPhiFace(*this);
0033 }
0034
0035 // ExactZOrder
0036 //
0037 // Decide precisely whether a trajectory passes to the left, right, or exactly
0038 // passes through the z position of a vertex point in our face.
0039 //
0040 // Result is only determined within an arbitrary (positive) factor.
0041 //      > 0 to the right
0042 //      < 0 to the left
0043 //      = 0 exactly on top of
0044 // In 99.9999% of the cases, a trivial calculation is used. In difficult
0045 // cases, a precise, compliant calculation is relied on.
0046 //
0047 inline
0048 G4double G4PolyPhiFace::ExactZOrder( G4double z,
0049                                      G4double qx, G4double qy, G4double qz,
0050                                const G4ThreeVector& v,
0051                                      G4double normSign,
0052                                const G4PolyPhiFaceVertex* vert ) const
0053 {
0054   G4double answer = vert->z - z;
0055   if (std::fabs(answer) < kCarTolerance)
0056   {
0057     G4ThreeVector qa( qx - vert->x + radial.x(),
0058                       qy - vert->y + radial.y(), qz - vert->z ),
0059                       qb( qx - vert->x, qy - vert->y, qz - vert->z );
0060     G4ThreeVector qacb = qa.cross(qb);
0061
0062     answer = normSign*qacb.dot(v)*(normal.y()*radial.x()-normal.x()*radial.y());
0063   }
0064
0065   return answer;
0066 }