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//
// G4TriangularFacet
//
// Class description:
//
//   The G4TriangularFacet class is used for the contruction of
//   G4TessellatedSolid.
//   It is defined by three fVertices, which shall be supplied in anti-clockwise
//   order looking from the outsider of the solid where it belongs.
//   Its constructor:
//   
//      G4TriangularFacet (const G4ThreeVector Pt0, const G4ThreeVector vt1,
//                         const G4ThreeVector vt2, G4FacetVertexType);
//
//   takes 4 parameters to define the three fVertices:
//      1) G4FacetvertexType = "ABSOLUTE": in this case Pt0, vt1 and vt2 are 
//         the 3 fVertices in anti-clockwise order looking from the outsider.
//      2) G4FacetvertexType = "RELATIVE": in this case the first vertex is Pt0,
//         the second vertex is Pt0+vt1 and the third vertex is Pt0+vt2, all  
//         in anti-clockwise order when looking from the outsider.

// 31 October 2004, P R Truscott, QinetiQ Ltd, UK - Created.
// 12 October 2012, M Gayer, CERN, - Reviewed optimized implementation.
// --------------------------------------------------------------------
#ifndef G4TRIANGULARFACET_HH
#define G4TRIANGULARFACET_HH 1

#include "G4VFacet.hh"
#include "G4Types.hh"
#include "G4ThreeVector.hh"

#include <vector>
#include <array>

class G4TriangularFacet : public G4VFacet
{
  public:  // with desctiption

    G4TriangularFacet ();
   ~G4TriangularFacet ();

    G4TriangularFacet (const G4ThreeVector& vt0, const G4ThreeVector& vt1,
                       const G4ThreeVector& vt2, G4FacetVertexType);
    G4TriangularFacet (const G4TriangularFacet& right);
    G4TriangularFacet (      G4TriangularFacet&& right);

    G4TriangularFacet& operator=(const G4TriangularFacet& right);    
    G4TriangularFacet& operator=(      G4TriangularFacet&& right);    

    G4VFacet* GetClone ();
    G4TriangularFacet* GetFlippedFacet ();

    G4ThreeVector Distance (const G4ThreeVector& p);
    G4double Distance (const G4ThreeVector& p, G4double minDist);
    G4double Distance (const G4ThreeVector& p, G4double minDist,
                       const G4bool outgoing);
    G4double Extent   (const G4ThreeVector axis);
    G4bool Intersect  (const G4ThreeVector& p, const G4ThreeVector& v,
                       const G4bool outgoing, G4double& distance,
                             G4double& distFromSurface, G4ThreeVector& normal);
    G4double GetArea () const;
    G4ThreeVector GetPointOnFace () const;

    G4ThreeVector GetSurfaceNormal () const;
    void SetSurfaceNormal (G4ThreeVector normal);

    G4GeometryType GetEntityType () const;

    inline G4bool IsDefined () const;
    inline G4int GetNumberOfVertices () const;
    inline G4ThreeVector GetVertex (G4int i) const;
    inline void SetVertex (G4int i, const G4ThreeVector& val);

    inline G4ThreeVector GetCircumcentre () const;
    inline G4double GetRadius () const;

    inline G4int AllocatedMemory();

    inline G4int GetVertexIndex (G4int i) const;
    inline void SetVertexIndex (G4int i, G4int j);
    inline void SetVertices(std::vector<G4ThreeVector>* v);

  private:

    void CopyFrom(const G4TriangularFacet& rhs);
    void MoveFrom(G4TriangularFacet& rhs);

    G4ThreeVector fSurfaceNormal;
    G4double fArea = 0.0;
    G4ThreeVector fCircumcentre;
    G4double fRadius = 0.0;
    std::array<G4int, 3> fIndices;
    std::vector<G4ThreeVector>* fVertices = nullptr;

    G4double fA, fB, fC;
    G4double fDet;
    G4double fSqrDist = 0.0;
    G4ThreeVector fE1, fE2;
    G4bool fIsDefined = false;
};

// --------------------------------------------------------------------
// Inlined Methods
// --------------------------------------------------------------------

inline G4bool G4TriangularFacet::IsDefined () const
{
  return fIsDefined;
}

inline G4int G4TriangularFacet::GetNumberOfVertices () const
{
  return 3;
}

inline G4ThreeVector G4TriangularFacet::GetVertex (G4int i) const
{      
  G4int indice = fIndices[i];
  return indice < 0 ? (*fVertices)[i] : (*fVertices)[indice];
}

inline void G4TriangularFacet::SetVertex (G4int i, const G4ThreeVector& val)
{
  (*fVertices)[i] = val;
}

inline G4ThreeVector G4TriangularFacet::GetCircumcentre () const
{
  return fCircumcentre;
}

inline G4double G4TriangularFacet::GetRadius () const
{
  return fRadius;
}

inline G4int G4TriangularFacet::AllocatedMemory()
{
  G4int size = sizeof(*this);
  size += GetNumberOfVertices() * sizeof(G4ThreeVector);
  return size;
}

inline G4int G4TriangularFacet::GetVertexIndex (G4int i) const
{
  if (i < 3) return fIndices[i];
  else       return 999999999;
}

inline void G4TriangularFacet::SetVertexIndex (G4int i, G4int j)
{
  fIndices[i] = j;
}

inline void G4TriangularFacet::SetVertices(std::vector<G4ThreeVector>* v)
{
  if (fIndices[0] < 0 && fVertices)
  {
    delete fVertices;
    fVertices = nullptr;
  }
  fVertices = v;
}

#endif
