//
// G4PolyhedraSide
//
// Declaration of a face that represents one segmented side of a polyhedra
//
// ----------------------------------------------------------
// This code implementation is the intellectual property of
// the GEANT4 collaboration.
//
// By copying, distributing or modifying the Program (or any work
// based on the Program) you indicate your acceptance of this statement,
// and all its terms.
//
#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,
			 const G4int    numSide,
			 const G4double phiStart, const G4double phiTotal, 
			 const G4bool phiIsOpen, const G4bool isAllBehind=false );
	virtual ~G4PolyhedraSide();
	
	G4PolyhedraSide( const G4PolyhedraSide &source );
	G4PolyhedraSide *operator=( const G4PolyhedraSide &source );
	
	G4bool Intersect( const G4ThreeVector &p, const G4ThreeVector &v,	
			  const G4bool outgoing, const G4double surfTolerance,
			  G4double &distance, G4double &distFromSurface,
			  G4ThreeVector &normal, G4bool &allBehind );

        G4double Distance( const G4ThreeVector &p, const G4bool outgoing );
	
	EInside Inside( const G4ThreeVector &p, const 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,
				   const G4double normSign, 
				   const G4double surfTolerance,
				   G4double &distance, G4double &distFromSurface );

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

	G4int ClosestPhiSegment( const G4double phi );
	
	G4int PhiSegment( const 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