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// $Id: G4PolyhedraSide.hh,v 1.5 2002/10/28 11:47:51 gcosmo Exp $
// GEANT4 tag $Name: geant4-05-00 $
//
// 
// --------------------------------------------------------------------
// GEANT 4 class header file
//
//
// G4PolyhedraSide
//
// Class description:
//
//   Class implementing a face that represents one segmented side
//   of a polyhedra:
//
//   G4PolyhedraSide( const G4PolyhedraSideRZ *prevRZ,
//                    const G4PolyhedraSideRZ *tail,
//                    const G4PolyhedraSideRZ *head,
//                    const G4PolyhedraSideRZ *nextRZ,
//                          G4int    numSide,
//                          G4double phiStart, G4double phiTotal, 
//                          G4bool phiIsOpen,  G4bool isAllBehind=false )
//
//   Values for r1,z1 and r2,z2 should be specified in clockwise
//   order in (r,z).

// Author: 
//   David C. Williams (davidw@scipp.ucsc.edu)
// --------------------------------------------------------------------

#ifndef G4PolyhedraSide_hh
#define G4PolyhedraSide_hh

#include "G4VCSGface.hh"

class G4IntersectingCone;

typedef struct
{
  G4double r, z;  // start of vector
} G4PolyhedraSideRZ;

class G4PolyhedraSide : public G4VCSGface
{

  public:

  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() { return new G4PolyhedraSide( *this ); }
  
  protected:

  //
  // A couple internal data structures
  //
  struct sG4PolyhedraSideVec;    // Secret recipe for allowing
  friend struct sG4PolyhedraSideVec;  // protected nested structures

  typedef struct sG4PolyhedraSideEdge
  {
    G4ThreeVector  normal;       // Unit normal to this edge
    G4ThreeVector  corner[2];    // The two corners of this phi edge
    G4ThreeVector  cornNorm[2];  // The normals of these corners
  } G4PolyhedraSideEdge;
  
  typedef struct sG4PolyhedraSideVec
  {
    G4ThreeVector  normal,   // Normal (point out of the shape)
                   center,   // Point in center of side
                   surfPhi,  // Unit vector on surface pointing along phi
                   surfRZ;   // Unit vector on surface pointing along R/Z
    G4PolyhedraSideEdge *edges[2];  // The phi boundary edges to this side 
                                    //     [0]=low phi [1]=high phi
    G4ThreeVector  edgeNorm[2];     // RZ edge normals [i] at {r[i],z[i]}
  } G4PolyhedraSideVec;

  G4int   numSide;      // Number sides
  G4double r[2], z[2];  // r, z parameters, in specified order
  G4double startPhi,    // Start phi (0 to 2pi), if phiIsOpen
           deltaPhi,    // Delta phi (0 to 2pi), if phiIsOpen
           endPhi;      // End phi (>startPhi), if phiIsOpen
  G4bool   phiIsOpen;   // True if there is a phi slice
  G4bool   allBehind;   // True if the entire solid is "behind" this face
  
  G4IntersectingCone  *cone;  // Our intersecting cone
  
  G4PolyhedraSideVec  *vecs;    // Vector set for each facet of our face
  G4PolyhedraSideEdge *edges;   // The edges belong to vecs
  G4double    lenRZ,      // RZ length of each side
              lenPhi[2];  // Phi dimensions of each side
  G4double    edgeNorm;   // Normal in RZ/Phi space to each side
  
  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 DistanceToOneSide( const G4ThreeVector &p,
                              const G4PolyhedraSideVec &vec,
                                    G4double *normDist );

  G4double DistanceAway( const G4ThreeVector &p,
                         const G4PolyhedraSideVec &vec,
                               G4double *normDist );
             
  void CopyStuff( const G4PolyhedraSide &source );
};

#endif