//////////////////////////////////////////////////////////////////////////////////////////
/// \class RAT::SNONCDAnchor
///
/// \brief Geometry Class describing the NCD anchor subregions.
///
/// \author Aksel Hallin aksel.hallin@ualberta.ca
///
/// Revision History: \n
/// 2014-06-30  Aksel Hallin
///
///\detail This class implements NCD anchors as subregions of the SNOAV class.
///
/////////////////////////////////////////////////////////////////////////////////////////

#ifndef RAT__SNONCDAnchor__
#define RAT__SNONCDAnchor__

#include <RAT/SphericalSubregion.hh>

namespace RAT{
class SNONCDAnchor :public SphericalSubregion{
public:
    /// Constructor.  The NCD anchor is defined by a position, and is modelled as a right circular cylindrical region
    ///               bounded by concentric spherical faces.  This is a slight approximation for the inner face, but the
    ///               curvature is less than the machining accuracy.
    /// @param[in] rmin  The distance from the center of the AV to the "top" of the NCD anchor.
    /// @param[in] rmax  The distance from the center of the AV to the glue joint between NCD anchor and AV (the AV radius)
    /// @param[in] radius The radius of the NCD anchor (considering it to be a cylinder)
    /// @param[in] position The coordinates of the center of the NCD face at the radius rmax.
    SNONCDAnchor(G4double rmin, G4double rmax, G4double radius, const G4ThreeVector &position);
    /// Implements G4VSolid (SphericalSubregion) method
    G4double DistanceToIn(const G4ThreeVector &p, const G4ThreeVector &n, const G4double dInner[2], const G4double dOuter[2])const;
    /// Implements G4VSolid (SphericalSubregion) method
    G4double DistanceToIn(const G4ThreeVector &p)const;
    /// Implements G4VSolid (SphericalSubregion) method
    G4double DistanceToOut(const G4ThreeVector &p, const G4ThreeVector &n, const G4double dInner[2], const G4double dOuter[2])const;
    /// Implements G4VSolid (SphericalSubregion) method
    G4double DistanceToOut(const G4ThreeVector &p)const;
    /// Implements G4VSolid (SphericalSubregion) method
    EInside Inside(const G4ThreeVector &p)const;
    /// Calculates the 4 vectors corresponding to the corners of the region from which a particle can intersect the NCD anchor,
    /// without passing out of the volume between the concentric spheres at rmin and rmax.
    /// @param[out] corners[4] The vectors corresponding to the extent of the region.
    G4bool OverlapsRegion(const G4ThreeVector corners[4])const ;
    /// Calculates the perpendicular distance between the axis of the NCD anchor cylinder and the point p
    /// @param[in] p  The point for which to calculate the distance.
    G4double Radius(const G4ThreeVector &p)const{ G4ThreeVector skew = (p - fPosition); skew = skew - (skew*fDirection)*fDirection; return skew.mag(); }
    /// Implements G4VSolid (SphericalSubregion) method
    G4ThreeVector SurfaceNormal(const G4ThreeVector &p, G4bool &IsValid)const;
private:
    const G4ThreeVector fPosition;  ///<  The coordinates of the NCD anchor, corresponding to the center of the glued on face.
    G4ThreeVector fDirection;  ///< The direction of the NCD axis
    G4double fRmin; ///< The distance between the center of the AV and the top of the NCD anchor
    G4double fRmax;  ///< The distance between the center of the AV and the glued face of the ncd anchor
    G4double fRadius;  ///<  The cylindrical radius of the NCD anchor.
    G4double fThreshold;
};
} //::RAT
#endif