// @(#)root/geom:$Id: TGeoCone.cxx 24870 2008-07-17 16:30:58Z brun $
// Author: Andrei Gheata   31/01/02
// TGeoCone::Contains() and DistFromInside() implemented by Mihaela Gheata

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

//--------------------------------------------------------------------------
// TGeoCone - conical tube  class. It has 5 parameters :
//            dz - half length in z
//            Rmin1, Rmax1 - inside and outside radii at -dz
//            Rmin2, Rmax2 - inside and outside radii at +dz
//
//--------------------------------------------------------------------------
//Begin_Html
/*
<img src="gif/t_cone.gif">
*/
//End_Html
//
//Begin_Html
/*
<img src="gif/t_conedivR.gif">
*/
//End_Html
//
//Begin_Html
/*
<img src="gif/t_conedivPHI.gif">
*/
//End_Html
//Begin_Html
/*
<img src="gif/t_conedivZ.gif">
*/
//End_Html

//--------------------------------------------------------------------------
// TGeoConeSeg - a phi segment of a conical tube. Has 7 parameters :
//            - the same 5 as a cone;
//            - first phi limit (in degrees)
//            - second phi limit
//
//--------------------------------------------------------------------------
//
//Begin_Html
/*
<img src="gif/t_coneseg.gif">
*/
//End_Html
//
//Begin_Html
/*
<img src="gif/t_conesegdivstepZ.gif">
*/
//End_Html

#include "Riostream.h"

#include "TGeoManager.h"
#include "TGeoVolume.h"
#include "TVirtualGeoPainter.h"
#include "TGeoCone.h"
#include "TVirtualPad.h"
#include "TBuffer3D.h"
#include "TBuffer3DTypes.h"
#include "TMath.h"

ClassImp(TGeoCone)

//_____________________________________________________________________________
TGeoCone::TGeoCone()
{
// Default constructor
   SetShapeBit(TGeoShape::kGeoCone);
   fDz    = 0.0;
   fRmin1 = 0.0;
   fRmax1 = 0.0;
   fRmin2 = 0.0;
   fRmax2 = 0.0;
}

//_____________________________________________________________________________
TGeoCone::TGeoCone(Double_t dz, Double_t rmin1, Double_t rmax1,
                   Double_t rmin2, Double_t rmax2)
         :TGeoBBox(0, 0, 0)
{
// Default constructor specifying minimum and maximum radius
   SetShapeBit(TGeoShape::kGeoCone);
   SetConeDimensions(dz, rmin1, rmax1, rmin2, rmax2);
   if ((dz<0) || (rmin1<0) || (rmax1<0) || (rmin2<0) || (rmax2<0)) {
      SetShapeBit(kGeoRunTimeShape);
   }
   else ComputeBBox();
}

//_____________________________________________________________________________
TGeoCone::TGeoCone(const char *name, Double_t dz, Double_t rmin1, Double_t rmax1,
                   Double_t rmin2, Double_t rmax2)
         :TGeoBBox(name, 0, 0, 0)
{
// Default constructor specifying minimum and maximum radius
   SetShapeBit(TGeoShape::kGeoCone);
   SetConeDimensions(dz, rmin1, rmax1, rmin2, rmax2);
   if ((dz<0) || (rmin1<0) || (rmax1<0) || (rmin2<0) || (rmax2<0)) {
      SetShapeBit(kGeoRunTimeShape);
   }
   else ComputeBBox();
}

//_____________________________________________________________________________
TGeoCone::TGeoCone(Double_t *param)
         :TGeoBBox(0, 0, 0)
{
// Default constructor specifying minimum and maximum radius
// param[0] = dz
// param[1] = Rmin1
// param[2] = Rmax1
// param[3] = Rmin2
// param[4] = Rmax2
   SetShapeBit(TGeoShape::kGeoCone);
   SetDimensions(param);
   if ((fDz<0) || (fRmin1<0) || (fRmax1<0) || (fRmin2<0) || (fRmax2<0))
      SetShapeBit(kGeoRunTimeShape);
   else ComputeBBox();
}

//_____________________________________________________________________________
Double_t TGeoCone::Capacity() const
{
// Computes capacity of the shape in [length^3]
   return TGeoCone::Capacity(fDz, fRmin1, fRmax1, fRmin2, fRmax2);
}   

//_____________________________________________________________________________
Double_t TGeoCone::Capacity(Double_t dz, Double_t rmin1, Double_t rmax1, Double_t rmin2, Double_t rmax2)
{
// Computes capacity of the shape in [length^3]
   Double_t capacity = (2.*dz*TMath::Pi()/3.)*(rmax1*rmax1+rmax2*rmax2+rmax1*rmax2-
                                               rmin1*rmin1-rmin2*rmin2-rmin1*rmin2);
   return capacity;                                            
}   

//_____________________________________________________________________________
TGeoCone::~TGeoCone()
{
// destructor
}

//_____________________________________________________________________________
void TGeoCone::ComputeBBox()
{
// compute bounding box of the sphere
   TGeoBBox *box = (TGeoBBox*)this;
   box->SetBoxDimensions(TMath::Max(fRmax1, fRmax2), TMath::Max(fRmax1, fRmax2), fDz);
   memset(fOrigin, 0, 3*sizeof(Double_t));
}

//_____________________________________________________________________________
void TGeoCone::ComputeNormal(Double_t *point, Double_t *dir, Double_t *norm)
{
// Compute normal to closest surface from POINT.
   Double_t safr,safe,phi;
   memset(norm,0,3*sizeof(Double_t));
   phi = TMath::ATan2(point[1],point[0]);
   Double_t cphi = TMath::Cos(phi);
   Double_t sphi = TMath::Sin(phi);
   Double_t ro1 = 0.5*(fRmin1+fRmin2);
   Double_t tg1 = 0.5*(fRmin2-fRmin1)/fDz;
   Double_t cr1 = 1./TMath::Sqrt(1.+tg1*tg1);
   Double_t ro2 = 0.5*(fRmax1+fRmax2);
   Double_t tg2 = 0.5*(fRmax2-fRmax1)/fDz;
   Double_t cr2 = 1./TMath::Sqrt(1.+tg2*tg2);

   Double_t r=TMath::Sqrt(point[0]*point[0]+point[1]*point[1]);
   Double_t rin = tg1*point[2]+ro1;
   Double_t rout = tg2*point[2]+ro2;
   safe = TMath::Abs(fDz-TMath::Abs(point[2]));
   norm[2] = 1;

   safr = (ro1>0)?(TMath::Abs((r-rin)*cr1)):TGeoShape::Big();
   if (safr<safe) {
      safe = safr;
      norm[0] = cr1*cphi;
      norm[1] = cr1*sphi;
      norm[2] = -tg1*cr1;
   }
   safr = TMath::Abs((rout-r)*cr2);
   if (safr<safe) {
      norm[0] = cr2*cphi;
      norm[1] = cr2*sphi;
      norm[2] = -tg2*cr2;
   }
   if (norm[0]*dir[0]+norm[1]*dir[1]+norm[2]*dir[2]<0) {
      norm[0] = -norm[0];
      norm[1] = -norm[1];
      norm[2] = -norm[2];
   }
}

//_____________________________________________________________________________
void TGeoCone::ComputeNormalS(Double_t *point, Double_t *dir, Double_t *norm,
                              Double_t dz, Double_t rmin1, Double_t rmax1, Double_t rmin2, Double_t rmax2)
{
// Compute normal to closest surface from POINT.
   Double_t safe,phi;
   memset(norm,0,3*sizeof(Double_t));
   phi = TMath::ATan2(point[1],point[0]);
   Double_t cphi = TMath::Cos(phi);
   Double_t sphi = TMath::Sin(phi);
   Double_t ro1 = 0.5*(rmin1+rmin2);
   Double_t tg1 = 0.5*(rmin2-rmin1)/dz;
   Double_t cr1 = 1./TMath::Sqrt(1.+tg1*tg1);
   Double_t ro2 = 0.5*(rmax1+rmax2);
   Double_t tg2 = 0.5*(rmax2-rmax1)/dz;
   Double_t cr2 = 1./TMath::Sqrt(1.+tg2*tg2);

   Double_t r=TMath::Sqrt(point[0]*point[0]+point[1]*point[1]);
   Double_t rin = tg1*point[2]+ro1;
   Double_t rout = tg2*point[2]+ro2;
   safe = (ro1>0)?(TMath::Abs((r-rin)*cr1)):TGeoShape::Big();
   norm[0] = cr1*cphi;
   norm[1] = cr1*sphi;
   norm[2] = -tg1*cr1;
   if (TMath::Abs((rout-r)*cr2)<safe) {
      norm[0] = cr2*cphi;
      norm[1] = cr2*sphi;
      norm[2] = -tg2*cr2;
   }
   if (norm[0]*dir[0]+norm[1]*dir[1]+norm[2]*dir[2]<0) {
      norm[0] = -norm[0];
      norm[1] = -norm[1];
      norm[2] = -norm[2];
   }
}

//_____________________________________________________________________________
Bool_t TGeoCone::Contains(Double_t *point) const
{
// test if point is inside this cone
   if (TMath::Abs(point[2]) > fDz) return kFALSE;
   Double_t r2 = point[0]*point[0]+point[1]*point[1];
   Double_t rl = 0.5*(fRmin2*(point[2]+fDz)+fRmin1*(fDz-point[2]))/fDz;
   Double_t rh = 0.5*(fRmax2*(point[2]+fDz)+fRmax1*(fDz-point[2]))/fDz;
   if ((r2<rl*rl) || (r2>rh*rh)) return kFALSE;
   return kTRUE;
}

//_____________________________________________________________________________
Double_t TGeoCone::DistFromInsideS(Double_t *point, Double_t *dir, Double_t dz,
                              Double_t rmin1, Double_t rmax1, Double_t rmin2, Double_t rmax2)
{
// Compute distance from inside point to surface of the cone (static)
// Boundary safe algorithm.
   if (dz<=0) return TGeoShape::Big();
   // compute distance to surface
   // Do Z
   Double_t sz = TGeoShape::Big();
   if (dir[2]) {
      sz = (TMath::Sign(dz, dir[2])-point[2])/dir[2];
      if (sz<=0) return 0.0;
   }   
   Double_t rsq=point[0]*point[0]+point[1]*point[1];
   Double_t zinv = 1./dz;
   Double_t rin = 0.5*(rmin1+rmin2+(rmin2-rmin1)*point[2]*zinv);
   // Do Rmin
   Double_t sr = TGeoShape::Big();
   Double_t b,delta,zi;
   if (rin>0) {
      // Protection in case point is actually outside the cone
      if (rsq < rin*(rin+TGeoShape::Tolerance())) {
         Double_t ddotn = point[0]*dir[0]+point[1]*dir[1]+0.5*(rmin1-rmin2)*dir[2]*zinv*TMath::Sqrt(rsq);
         if (ddotn<=0) return 0.0;
      } else {         
         TGeoCone::DistToCone(point, dir, dz, rmin1, rmin2, b, delta);
         if (delta>0) {
            sr = -b-delta;
            if (sr>0) {
               zi = point[2]+sr*dir[2];
               if (TMath::Abs(zi)<=dz) return TMath::Min(sz,sr);
            }
            sr = -b+delta;   
            if (sr>0) {
               zi = point[2]+sr*dir[2];
               if (TMath::Abs(zi)<=dz) return TMath::Min(sz,sr);
            }
         }
      }
   }
   // Do Rmax
   Double_t rout = 0.5*(rmax1+rmax2+(rmax2-rmax1)*point[2]*zinv);
   if (rsq > rout*(rout-TGeoShape::Tolerance())) {
      Double_t ddotn = point[0]*dir[0]+point[1]*dir[1]+0.5*(rmax1-rmax2)*dir[2]*zinv*TMath::Sqrt(rsq);
      if (ddotn>=0) return 0.0;
      TGeoCone::DistToCone(point, dir, dz, rmax1, rmax2, b, delta);
      if (delta<0) return 0.0;
      sr = -b+delta;
      if (sr<0) return sz;
      if (TMath::Abs(-b-delta)>sr) return sz;
      zi = point[2]+sr*dir[2];
      if (TMath::Abs(zi)<=dz) return TMath::Min(sz,sr);
      return sz;
   }   
   TGeoCone::DistToCone(point, dir, dz, rmax1, rmax2, b, delta);
   if (delta>0) {
      sr = -b-delta;
      if (sr>0) {
         zi = point[2]+sr*dir[2];
         if (TMath::Abs(zi)<=dz) return TMath::Min(sz,sr);
      }
      sr = -b+delta;   
      if (sr>TGeoShape::Tolerance()) {
         zi = point[2]+sr*dir[2];
         if (TMath::Abs(zi)<=dz) return TMath::Min(sz,sr);
      }
   }
   return sz;   
}

//_____________________________________________________________________________
Double_t TGeoCone::DistFromInside(Double_t *point, Double_t *dir, Int_t iact, Double_t step, Double_t *safe) const
{
// Compute distance from inside point to surface of the cone
// Boundary safe algorithm.

   if (iact<3 && safe) {
      *safe = Safety(point, kTRUE);
      if (iact==0) return TGeoShape::Big();
      if ((iact==1) && (*safe>step)) return TGeoShape::Big();
   }
   // compute distance to surface
   return TGeoCone::DistFromInsideS(point, dir, fDz, fRmin1, fRmax1, fRmin2, fRmax2);
}

//_____________________________________________________________________________
Double_t TGeoCone::DistFromOutsideS(Double_t *point, Double_t *dir, Double_t dz,
                             Double_t rmin1, Double_t rmax1, Double_t rmin2, Double_t rmax2)
{
// Compute distance from outside point to surface of the tube
// Boundary safe algorithm.
   // compute distance to Z planes
   if (dz<=0) return TGeoShape::Big();
   Double_t snxt;
   Double_t xp, yp, zp;
   Bool_t inz = kTRUE;

   if (point[2]<=-dz) {
      if (dir[2]<=0) return TGeoShape::Big();
      snxt = (-dz-point[2])/dir[2];
      xp = point[0]+snxt*dir[0];
      yp = point[1]+snxt*dir[1];
      Double_t r2 = xp*xp+yp*yp;
      if ((r2>=rmin1*rmin1) && (r2<=rmax1*rmax1)) return snxt;
      inz = kFALSE;
   } else {
      if (point[2]>=dz) {
         if (dir[2]>=0) return TGeoShape::Big();
         snxt = (dz-point[2])/dir[2];
         xp = point[0]+snxt*dir[0];
         yp = point[1]+snxt*dir[1];
         Double_t r2 = xp*xp+yp*yp;
         if ((r2>=rmin2*rmin2) && (r2<=rmax2*rmax2)) return snxt;
         inz = kFALSE;
      }   
   }

   Double_t rsq = point[0]*point[0]+point[1]*point[1];
   Double_t dzinv = 1./dz;
   Double_t ro1=0.5*(rmin1+rmin2);
   Bool_t hasrmin = (ro1>0)?kTRUE:kFALSE;
   Double_t tg1 = 0.;
   Double_t rin = 0.;
   Bool_t inrmin = kTRUE;  // r>=rmin
   if (hasrmin) {
      tg1=0.5*(rmin2-rmin1)*dzinv;
      rin=ro1+tg1*point[2];
      if (rin>0 && rsq<rin*(rin-TGeoShape::Tolerance())) inrmin=kFALSE;
   }   
   Double_t ro2=0.5*(rmax1+rmax2);
   Double_t tg2=0.5*(rmax2-rmax1)*dzinv;
   Double_t rout=tg2*point[2]+ro2;
   Bool_t inrmax = kFALSE;
   if (rout>0 && rsq<rout*(rout+TGeoShape::Tolerance())) inrmax=kTRUE;
   Bool_t in = inz & inrmin & inrmax;
   Double_t b,delta;
   // If inside cone, we are most likely on a boundary within machine precision.
   if (in) {
      Double_t r=TMath::Sqrt(rsq);
      Double_t safz = dz-TMath::Abs(point[2]); // positive
      Double_t safrmin = (hasrmin)?(r-rin):TGeoShape::Big();
      Double_t safrmax = rout - r;
      if (safz<=safrmin && safz<=safrmax) {
         // on Z boundary
         if (point[2]*dir[2]<0) return 0.0;
         return TGeoShape::Big();
      }
      if (safrmax<safrmin) {
         // on rmax boundary
         Double_t ddotn = point[0]*dir[0]+point[1]*dir[1]-tg2*dir[2]*r;
         if (ddotn<=0) return 0.0;
         return TGeoShape::Big();
      }   
      // on rmin boundary
      Double_t ddotn = point[0]*dir[0]+point[1]*dir[1]-tg1*dir[2]*r;
      if (ddotn>=0) return 0.0;
      // we can cross (+) solution of rmin       
      TGeoCone::DistToCone(point, dir, dz, rmin1, rmin2, b, delta);

      if (delta<0) return 0.0;
      snxt = -b+delta;
      if (snxt<0) return TGeoShape::Big();
      if (TMath::Abs(-b-delta)>snxt) return TGeoShape::Big();
      zp = point[2]+snxt*dir[2];
      if (TMath::Abs(zp)<=dz) return snxt;
      return TGeoShape::Big();
   }
            
   // compute distance to inner cone
   snxt = TGeoShape::Big();
   if (!inrmin) {
      // ray can cross only inner cone
      TGeoCone::DistToCone(point, dir, dz, rmin1, rmin2, b, delta);
      if (delta<0) return TGeoShape::Big();
      snxt = -b+delta;
      if (snxt<=0) return TGeoShape::Big();
      zp = point[2]+snxt*dir[2];
      if (TMath::Abs(zp)<=dz) return snxt;
      snxt = -b-delta;
      if (snxt<=0) return TGeoShape::Big();
      zp = point[2]+snxt*dir[2];
      if (TMath::Abs(zp)<=dz) return snxt;      
      return TGeoShape::Big();
   } else {
      if (hasrmin) {
         TGeoCone::DistToCone(point, dir, dz, rmin1, rmin2, b, delta);
         if (delta>0) {
            Double_t din = -b+delta;
            if (din>0) {
               zp = point[2]+din*dir[2];
               if (TMath::Abs(zp)<=dz) snxt = din;
            }
         }
      }
   }   
   
   if (inrmax) return snxt;
   // we can cross only outer cone, both solutions possible
   // compute distance to outer cone
   TGeoCone::DistToCone(point, dir, dz, rmax1, rmax2, b, delta);
   if (delta<0) return snxt;
   Double_t dout = -b-delta;
   if (dout>0 && dout<snxt) {
      zp = point[2]+dout*dir[2];
      if (TMath::Abs(zp)<=dz) return dout;
   }
   dout = -b+delta;  
   if (dout<=0 || dout>snxt) return snxt;
   zp = point[2]+dout*dir[2];
   if (TMath::Abs(zp)<=dz) return dout;
   return snxt;
}

//_____________________________________________________________________________
Double_t TGeoCone::DistFromOutside(Double_t *point, Double_t *dir, Int_t iact, Double_t step, Double_t *safe) const
{
// compute distance from outside point to surface of the tube
   // compute safe radius
   if (iact<3 && safe) {
      *safe = Safety(point, kFALSE);
      if (iact==0) return TGeoShape::Big();
      if ((iact==1) && (*safe>step)) return TGeoShape::Big();
   }
// Check if the bounding box is crossed within the requested distance
   Double_t sdist = TGeoBBox::DistFromOutside(point,dir, fDX, fDY, fDZ, fOrigin, step);
   if (sdist>=step) return TGeoShape::Big();
   // compute distance to Z planes
   return TGeoCone::DistFromOutsideS(point, dir, fDz, fRmin1, fRmax1, fRmin2, fRmax2);
}

//_____________________________________________________________________________
void TGeoCone::DistToCone(Double_t *point, Double_t *dir, Double_t dz, Double_t r1, Double_t r2,
                              Double_t &b, Double_t &delta)
{
   // Static method to compute distance to a conical surface with :
   // - r1, z1 - radius and Z position of lower base
   // - r2, z2 - radius and Z position of upper base
   delta = -1.;
   if (dz<0) return;
   Double_t ro0 = 0.5*(r1+r2);
   Double_t tz  = 0.5*(r2-r1)/dz;
   Double_t rsq = point[0]*point[0] + point[1]*point[1];
   Double_t rc = ro0 + point[2]*tz;

   Double_t a = dir[0]*dir[0] + dir[1]*dir[1] - tz*tz*dir[2]*dir[2];
   b = point[0]*dir[0] + point[1]*dir[1] - tz*rc*dir[2];
   Double_t c = rsq - rc*rc;

   if (TMath::Abs(a)<TGeoShape::Tolerance()) {
      if (TMath::Abs(b)<TGeoShape::Tolerance()) return;
      b = 0.5*c/b;
      delta = 0.;
      return;
   }   
   a = 1./a;
   b *= a;
   c *= a;
   delta = b*b - c;
   if (delta>0) {
      delta = TMath::Sqrt(delta);
   } else {
      delta = -1.;
   }
}

//_____________________________________________________________________________
Int_t TGeoCone::DistancetoPrimitive(Int_t px, Int_t py)
{
// compute closest distance from point px,py to each corner
   Int_t n = gGeoManager->GetNsegments();
   const Int_t numPoints = 4*n;
   return ShapeDistancetoPrimitive(numPoints, px, py);
}

//_____________________________________________________________________________
TGeoVolume *TGeoCone::Divide(TGeoVolume *voldiv, const char *divname, Int_t iaxis, Int_t ndiv,
                             Double_t start, Double_t step)
{
//--- Divide this cone shape belonging to volume "voldiv" into ndiv volumes
// called divname, from start position with the given step. Returns pointer
// to created division cell volume in case of Z divisions. For Z division
// creates all volumes with different shapes and returns pointer to volume that
// was divided. In case a wrong division axis is supplied, returns pointer to
// volume that was divided.
   TGeoShape *shape;           //--- shape to be created
   TGeoVolume *vol;            //--- division volume to be created
   TGeoVolumeMulti *vmulti;    //--- generic divided volume
   TGeoPatternFinder *finder;  //--- finder to be attached
   TString opt = "";           //--- option to be attached
   Int_t id;
   Double_t end = start+ndiv*step;
   switch (iaxis) {
      case 1:  //---              R division
         Error("Divide","division of a cone on R not implemented");
         return 0;
      case 2:  // ---             Phi division
         finder = new TGeoPatternCylPhi(voldiv, ndiv, start, end);
         voldiv->SetFinder(finder);
         finder->SetDivIndex(voldiv->GetNdaughters());
         shape = new TGeoConeSeg(fDz, fRmin1, fRmax1, fRmin2, fRmax2, -step/2, step/2);
         vol = new TGeoVolume(divname, shape, voldiv->GetMedium());
         vmulti = gGeoManager->MakeVolumeMulti(divname, voldiv->GetMedium());
         vmulti->AddVolume(vol);
         opt = "Phi";
         for (id=0; id<ndiv; id++) {
            voldiv->AddNodeOffset(vol, id, start+id*step+step/2, opt.Data());
            ((TGeoNodeOffset*)voldiv->GetNodes()->At(voldiv->GetNdaughters()-1))->SetFinder(finder);
         }
         return vmulti;
      case 3: //---               Z division
         vmulti = gGeoManager->MakeVolumeMulti(divname, voldiv->GetMedium());
         finder = new TGeoPatternZ(voldiv, ndiv, start, end);
         voldiv->SetFinder(finder);
         finder->SetDivIndex(voldiv->GetNdaughters());
         for (id=0; id<ndiv; id++) {
            Double_t z1 = start+id*step;
            Double_t z2 = start+(id+1)*step;
            Double_t rmin1n = 0.5*(fRmin1*(fDz-z1)+fRmin2*(fDz+z1))/fDz;
            Double_t rmax1n = 0.5*(fRmax1*(fDz-z1)+fRmax2*(fDz+z1))/fDz;
            Double_t rmin2n = 0.5*(fRmin1*(fDz-z2)+fRmin2*(fDz+z2))/fDz;
            Double_t rmax2n = 0.5*(fRmax1*(fDz-z2)+fRmax2*(fDz+z2))/fDz;
            shape = new TGeoCone(0.5*step,rmin1n, rmax1n, rmin2n, rmax2n);
            vol = new TGeoVolume(divname, shape, voldiv->GetMedium());
            vmulti->AddVolume(vol);
            opt = "Z";
            voldiv->AddNodeOffset(vol, id, start+id*step+step/2, opt.Data());
            ((TGeoNodeOffset*)voldiv->GetNodes()->At(voldiv->GetNdaughters()-1))->SetFinder(finder);
         }
         return vmulti;
      default:
         Error("Divide", "Wrong axis type for division");
         return 0;
   }
}

//_____________________________________________________________________________
const char *TGeoCone::GetAxisName(Int_t iaxis) const
{
// Returns name of axis IAXIS.
   switch (iaxis) {
      case 1:
         return "R";
      case 2:
         return "PHI";
      case 3:
         return "Z";
      default:
         return "undefined";
   }
}

//_____________________________________________________________________________
Double_t TGeoCone::GetAxisRange(Int_t iaxis, Double_t &xlo, Double_t &xhi) const
{
// Get range of shape for a given axis.
   xlo = 0;
   xhi = 0;
   Double_t dx = 0;
   switch (iaxis) {
      case 2:
         xlo = 0.;
         xhi = 360.;
         return 360.;
      case 3:
         xlo = -fDz;
         xhi = fDz;
         dx = xhi-xlo;
         return dx;
   }
   return dx;
}

//_____________________________________________________________________________
void TGeoCone::GetBoundingCylinder(Double_t *param) const
{
//--- Fill vector param[4] with the bounding cylinder parameters. The order
// is the following : Rmin, Rmax, Phi1, Phi2, dZ
   param[0] = TMath::Min(fRmin1, fRmin2); // Rmin
   param[0] *= param[0];
   param[1] = TMath::Max(fRmax1, fRmax2); // Rmax
   param[1] *= param[1];
   param[2] = 0.;                         // Phi1
   param[3] = 360.;                       // Phi1
}

//_____________________________________________________________________________
TGeoShape *TGeoCone::GetMakeRuntimeShape(TGeoShape *mother, TGeoMatrix * /*mat*/) const
{
// in case shape has some negative parameters, these has to be computed
// in order to fit the mother
   if (!TestShapeBit(kGeoRunTimeShape)) return 0;
   if (!mother->TestShapeBit(kGeoCone)) {
      Error("GetMakeRuntimeShape", "invalid mother");
      return 0;
   }
   Double_t rmin1, rmax1, rmin2, rmax2, dz;
   rmin1 = fRmin1;
   rmax1 = fRmax1;
   rmin2 = fRmin2;
   rmax2 = fRmax2;
   dz = fDz;
   if (fDz<0) dz=((TGeoCone*)mother)->GetDz();
   if (fRmin1<0)
      rmin1 = ((TGeoCone*)mother)->GetRmin1();
   if (fRmax1<0)
      rmax1 = ((TGeoCone*)mother)->GetRmax1();
   if (fRmin2<0)
      rmin2 = ((TGeoCone*)mother)->GetRmin2();
   if (fRmax2<0)
      rmax2 = ((TGeoCone*)mother)->GetRmax2();

   return (new TGeoCone(GetName(), dz, rmin1, rmax1, rmin2, rmax2));
}

//_____________________________________________________________________________
Bool_t TGeoCone::GetPointsOnSegments(Int_t npoints, Double_t *array) const
{
// Fills array with n random points located on the line segments of the shape mesh.
// The output array must be provided with a length of minimum 3*npoints. Returns
// true if operation is implemented.
   if (npoints > (npoints/2)*2) {
      Error("GetPointsOnSegments","Npoints must be even number");
      return kFALSE;
   }   
   Bool_t hasrmin = (fRmin1>0 || fRmin2>0)?kTRUE:kFALSE;
   Int_t nc = 0;
   if (hasrmin)   nc = (Int_t)TMath::Sqrt(0.5*npoints);
   else           nc = (Int_t)TMath::Sqrt(1.*npoints);
   Double_t dphi = TMath::TwoPi()/nc;
   Double_t phi = 0;
   Int_t ntop = 0;
   if (hasrmin)   ntop = npoints/2 - nc*(nc-1);
   else           ntop = npoints - nc*(nc-1);
   Double_t dz = 2*fDz/(nc-1);
   Double_t z = 0;
   Int_t icrt = 0;
   Int_t nphi = nc;
   Double_t rmin = 0.;
   Double_t rmax = 0.;
   // loop z sections
   for (Int_t i=0; i<nc; i++) {
      if (i == (nc-1)) nphi = ntop;
      z = -fDz + i*dz;
      if (hasrmin) rmin = 0.5*(fRmin1+fRmin2) + 0.5*(fRmin2-fRmin1)*z/fDz;
      rmax = 0.5*(fRmax1+fRmax2) + 0.5*(fRmax2-fRmax1)*z/fDz; 
      // loop points on circle sections
      for (Int_t j=0; j<nphi; j++) {
         phi = j*dphi;
         if (hasrmin) {
            array[icrt++] = rmin * TMath::Cos(phi);
            array[icrt++] = rmin * TMath::Sin(phi);
            array[icrt++] = z;
         }
         array[icrt++] = rmax * TMath::Cos(phi);
         array[icrt++] = rmax * TMath::Sin(phi);
         array[icrt++] = z;
      }
   }
   return kTRUE;
}                    


//_____________________________________________________________________________
void TGeoCone::InspectShape() const
{
// print shape parameters
   printf("*** Shape %s TGeoCone ***\n", GetName());
   printf("    dz    =: %11.5f\n", fDz);
   printf("    Rmin1 = %11.5f\n", fRmin1);
   printf("    Rmax1 = %11.5f\n", fRmax1);
   printf("    Rmin2 = %11.5f\n", fRmin2);
   printf("    Rmax2 = %11.5f\n", fRmax2);
   printf(" Bounding box:\n");
   TGeoBBox::InspectShape();
}

//_____________________________________________________________________________
TBuffer3D *TGeoCone::MakeBuffer3D() const
{ 
   // Creates a TBuffer3D describing *this* shape.
   // Coordinates are in local reference frame.

   Int_t n = gGeoManager->GetNsegments();
   Int_t nbPnts = 4*n;
   Int_t nbSegs = 8*n;
   Int_t nbPols = 4*n; 
   TBuffer3D* buff = new TBuffer3D(TBuffer3DTypes::kGeneric,
                                   nbPnts, 3*nbPnts,
                                   nbSegs, 3*nbSegs,
                                   nbPols, 6*nbPols);

   if (buff)
   {
      SetPoints(buff->fPnts);   
      SetSegsAndPols(*buff);
   }
   return buff; 
}

//_____________________________________________________________________________
void TGeoCone::SetSegsAndPols(TBuffer3D &buffer) const
{
// Fill TBuffer3D structure for segments and polygons.
   Int_t i,j;
   Int_t n = gGeoManager->GetNsegments();
   Int_t c = GetBasicColor();

   for (i = 0; i < 4; i++) {
      for (j = 0; j < n; j++) {
         buffer.fSegs[(i*n+j)*3  ] = c;
         buffer.fSegs[(i*n+j)*3+1] = i*n+j;
         buffer.fSegs[(i*n+j)*3+2] = i*n+j+1;
      }
      buffer.fSegs[(i*n+j-1)*3+2] = i*n;
   }
   for (i = 4; i < 6; i++) {
      for (j = 0; j < n; j++) {
         buffer.fSegs[(i*n+j)*3  ] = c+1;
         buffer.fSegs[(i*n+j)*3+1] = (i-4)*n+j;
         buffer.fSegs[(i*n+j)*3+2] = (i-2)*n+j;
      }
   }
   for (i = 6; i < 8; i++) {
      for (j = 0; j < n; j++) {
         buffer.fSegs[(i*n+j)*3  ] = c;
         buffer.fSegs[(i*n+j)*3+1] = 2*(i-6)*n+j;
         buffer.fSegs[(i*n+j)*3+2] = (2*(i-6)+1)*n+j;
      }
   }

   Int_t indx = 0;
   i=0;
   for (j = 0; j < n; j++) {
      indx = 6*(i*n+j);
      buffer.fPols[indx  ] = c;
      buffer.fPols[indx+1] = 4;
      buffer.fPols[indx+5] = i*n+j;
      buffer.fPols[indx+4] = (4+i)*n+j;
      buffer.fPols[indx+3] = (2+i)*n+j;
      buffer.fPols[indx+2] = (4+i)*n+j+1;
   }
   buffer.fPols[indx+2] = (4+i)*n;
   i=1;
   for (j = 0; j < n; j++) {
      indx = 6*(i*n+j);
      buffer.fPols[indx  ] = c;
      buffer.fPols[indx+1] = 4;
      buffer.fPols[indx+2] = i*n+j;
      buffer.fPols[indx+3] = (4+i)*n+j;
      buffer.fPols[indx+4] = (2+i)*n+j;
      buffer.fPols[indx+5] = (4+i)*n+j+1;
   }
   buffer.fPols[indx+5] = (4+i)*n;
   i=2;
   for (j = 0; j < n; j++) {
      indx = 6*(i*n+j);
      buffer.fPols[indx  ] = c+i;
      buffer.fPols[indx+1] = 4;
      buffer.fPols[indx+2] = (i-2)*2*n+j;
      buffer.fPols[indx+3] = (4+i)*n+j;
      buffer.fPols[indx+4] = ((i-2)*2+1)*n+j;
      buffer.fPols[indx+5] = (4+i)*n+j+1;
   }
   buffer.fPols[indx+5] = (4+i)*n;
   i=3;
   for (j = 0; j < n; j++) {
      indx = 6*(i*n+j);
      buffer.fPols[indx  ] = c+i;
      buffer.fPols[indx+1] = 4;
      buffer.fPols[indx+5] = (i-2)*2*n+j;
      buffer.fPols[indx+4] = (4+i)*n+j;
      buffer.fPols[indx+3] = ((i-2)*2+1)*n+j;
      buffer.fPols[indx+2] = (4+i)*n+j+1;
   }
   buffer.fPols[indx+2] = (4+i)*n;
}

//_____________________________________________________________________________
Double_t TGeoCone::Safety(Double_t *point, Bool_t in) const
{
// computes the closest distance from given point to this shape, according
// to option. The matching point on the shape is stored in spoint.
   Double_t saf[3];
   Double_t ro1 = 0.5*(fRmin1+fRmin2);
   Double_t tg1 = 0.5*(fRmin2-fRmin1)/fDz;
   Double_t cr1 = 1./TMath::Sqrt(1.+tg1*tg1);
   Double_t ro2 = 0.5*(fRmax1+fRmax2);
   Double_t tg2 = 0.5*(fRmax2-fRmax1)/fDz;
   Double_t cr2 = 1./TMath::Sqrt(1.+tg2*tg2);

   Double_t r=TMath::Sqrt(point[0]*point[0]+point[1]*point[1]);
   Double_t rin = tg1*point[2]+ro1;
   Double_t rout = tg2*point[2]+ro2;
   saf[0] = fDz-TMath::Abs(point[2]);
   saf[1] = (ro1>0)?((r-rin)*cr1):TGeoShape::Big();
   saf[2] = (rout-r)*cr2;
   if (in) return saf[TMath::LocMin(3,saf)];
   for (Int_t i=0; i<3; i++) saf[i]=-saf[i];
   return saf[TMath::LocMax(3,saf)];
}

//_____________________________________________________________________________
Double_t TGeoCone::SafetyS(Double_t *point, Bool_t in, Double_t dz, Double_t rmin1, Double_t rmax1,
                           Double_t rmin2, Double_t rmax2, Int_t skipz)
{
// computes the closest distance from given point to this shape, according
// to option. The matching point on the shape is stored in spoint.
   Double_t saf[3];
   Double_t ro1 = 0.5*(rmin1+rmin2);
   Double_t tg1 = 0.5*(rmin2-rmin1)/dz;
   Double_t cr1 = 1./TMath::Sqrt(1.+tg1*tg1);
   Double_t ro2 = 0.5*(rmax1+rmax2);
   Double_t tg2 = 0.5*(rmax2-rmax1)/dz;
   Double_t cr2 = 1./TMath::Sqrt(1.+tg2*tg2);

   Double_t r=TMath::Sqrt(point[0]*point[0]+point[1]*point[1]);
   Double_t rin = tg1*point[2]+ro1;
   Double_t rout = tg2*point[2]+ro2;
   switch (skipz) {
      case 1: // skip lower Z plane
         saf[0] = dz - point[2];
         break;
      case 2: // skip upper Z plane
         saf[0] = dz + point[2];
         break;
      case 3: // skip both
         saf[0] = TGeoShape::Big();
         break;
      default:
         saf[0] = dz-TMath::Abs(point[2]);
   }
   saf[1] = (ro1>0)?((r-rin)*cr1):TGeoShape::Big();
   saf[2] = (rout-r)*cr2;
   if (in) return saf[TMath::LocMin(3,saf)];
   for (Int_t i=0; i<3; i++) saf[i]=-saf[i];
   return saf[TMath::LocMax(3,saf)];
}

//_____________________________________________________________________________
void TGeoCone::SavePrimitive(ostream &out, Option_t * /*option*/ /*= ""*/)
{
// Save a primitive as a C++ statement(s) on output stream "out".
   if (TObject::TestBit(kGeoSavePrimitive)) return;
   out << "   // Shape: " << GetName() << " type: " << ClassName() << endl;
   out << "   dz    = " << fDz << ";" << endl;
   out << "   rmin1 = " << fRmin1 << ";" << endl;
   out << "   rmax1 = " << fRmax1 << ";" << endl;
   out << "   rmin2 = " << fRmin2 << ";" << endl;
   out << "   rmax2 = " << fRmax2 << ";" << endl;
   out << "   TGeoShape *" << GetPointerName() << " = new TGeoCone(\"" << GetName() << "\", dz,rmin1,rmax1,rmin2,rmax2);" << endl;
   TObject::SetBit(TGeoShape::kGeoSavePrimitive);   
}
         
//_____________________________________________________________________________
void TGeoCone::SetConeDimensions(Double_t dz, Double_t rmin1, Double_t rmax1,
                             Double_t rmin2, Double_t rmax2)
{
// Set cone dimensions.
   if (rmin1>=0) {
      if (rmax1>0) {
         if (rmin1<=rmax1) {
         // normal rmin/rmax
            fRmin1 = rmin1;
            fRmax1 = rmax1;
         } else {
            fRmin1 = rmax1;
            fRmax1 = rmin1;
            Warning("SetConeDimensions", "rmin1>rmax1 Switch rmin1<->rmax1");
            SetShapeBit(TGeoShape::kGeoBad);
         }
      } else {
         // run-time
         fRmin1 = rmin1;
         fRmax1 = rmax1;
      }
   } else {
      // run-time
      fRmin1 = rmin1;
      fRmax1 = rmax1;
   }
   if (rmin2>=0) {
      if (rmax2>0) {
         if (rmin2<=rmax2) {
         // normal rmin/rmax
            fRmin2 = rmin2;
            fRmax2 = rmax2;
         } else {
            fRmin2 = rmax2;
            fRmax2 = rmin2;
            Warning("SetConeDimensions", "rmin2>rmax2 Switch rmin2<->rmax2");
            SetShapeBit(TGeoShape::kGeoBad);
         }
      } else {
         // run-time
         fRmin2 = rmin2;
         fRmax2 = rmax2;
      }
   } else {
      // run-time
      fRmin2 = rmin2;
      fRmax2 = rmax2;
   }

   fDz   = dz;
}

//_____________________________________________________________________________
void TGeoCone::SetDimensions(Double_t *param)
{
// Set cone dimensions from an array.
   Double_t dz    = param[0];
   Double_t rmin1 = param[1];
   Double_t rmax1 = param[2];
   Double_t rmin2 = param[3];
   Double_t rmax2 = param[4];
   SetConeDimensions(dz, rmin1, rmax1, rmin2, rmax2);
}

//_____________________________________________________________________________
void TGeoCone::SetPoints(Double_t *points) const
{
// Create cone mesh points.
   Double_t dz, phi, dphi;
   Int_t j, n;

   n = gGeoManager->GetNsegments();
   dphi = 360./n;
   dz    = fDz;
   Int_t indx = 0;

   if (points) {
      for (j = 0; j < n; j++) {
         phi = j*dphi*TMath::DegToRad();
         points[indx++] = fRmin1 * TMath::Cos(phi);
         points[indx++] = fRmin1 * TMath::Sin(phi);
         points[indx++] = -dz;
      }
      
      for (j = 0; j < n; j++) {
         phi = j*dphi*TMath::DegToRad();
         points[indx++] = fRmax1 * TMath::Cos(phi);
         points[indx++] = fRmax1 * TMath::Sin(phi);
         points[indx++] = -dz;
      }

      for (j = 0; j < n; j++) {
         phi = j*dphi*TMath::DegToRad();
         points[indx++] = fRmin2 * TMath::Cos(phi);
         points[indx++] = fRmin2 * TMath::Sin(phi);
         points[indx++] = dz;
      }

      for (j = 0; j < n; j++) {
         phi = j*dphi*TMath::DegToRad();
         points[indx++] = fRmax2 * TMath::Cos(phi);
         points[indx++] = fRmax2 * TMath::Sin(phi);
         points[indx++] = dz;
      }
   }
}

//_____________________________________________________________________________
void TGeoCone::SetPoints(Float_t *points) const
{
// Create cone mesh points.
   Double_t dz, phi, dphi;
   Int_t j, n;

   n = gGeoManager->GetNsegments();
   dphi = 360./n;
   dz    = fDz;
   Int_t indx = 0;

   if (points) {
      for (j = 0; j < n; j++) {
         phi = j*dphi*TMath::DegToRad();
         points[indx++] = fRmin1 * TMath::Cos(phi);
         points[indx++] = fRmin1 * TMath::Sin(phi);
         points[indx++] = -dz;
      }
      
      for (j = 0; j < n; j++) {
         phi = j*dphi*TMath::DegToRad();
         points[indx++] = fRmax1 * TMath::Cos(phi);
         points[indx++] = fRmax1 * TMath::Sin(phi);
         points[indx++] = -dz;
      }

      for (j = 0; j < n; j++) {
         phi = j*dphi*TMath::DegToRad();
         points[indx++] = fRmin2 * TMath::Cos(phi);
         points[indx++] = fRmin2 * TMath::Sin(phi);
         points[indx++] = dz;
      }

      for (j = 0; j < n; j++) {
         phi = j*dphi*TMath::DegToRad();
         points[indx++] = fRmax2 * TMath::Cos(phi);
         points[indx++] = fRmax2 * TMath::Sin(phi);
         points[indx++] = dz;
      }
   }
}

//_____________________________________________________________________________
void TGeoCone::GetMeshNumbers(Int_t &nvert, Int_t &nsegs, Int_t &npols) const
{
// Returns numbers of vertices, segments and polygons composing the shape mesh.
   Int_t n = gGeoManager->GetNsegments();
   nvert = n*4;
   nsegs = n*8;
   npols = n*4;
}

//_____________________________________________________________________________
Int_t TGeoCone::GetNmeshVertices() const
{
// Return number of vertices of the mesh representation
   Int_t n = gGeoManager->GetNsegments();
   Int_t numPoints = n*4;
   return numPoints;
}

//_____________________________________________________________________________
void TGeoCone::Sizeof3D() const
{
///// fill size of this 3-D object
///    TVirtualGeoPainter *painter = gGeoManager->GetGeomPainter();
///    if (!painter) return;
///    Int_t n = gGeoManager->GetNsegments();
///    Int_t numPoints = n*4;
///    Int_t numSegs   = n*8;
///    Int_t numPolys  = n*4;
///    painter->AddSize3D(numPoints, numSegs, numPolys);
}

//_____________________________________________________________________________
const TBuffer3D & TGeoCone::GetBuffer3D(Int_t reqSections, Bool_t localFrame) const
{
// Fills a static 3D buffer and returns a reference.
   static TBuffer3D buffer(TBuffer3DTypes::kGeneric);

   TGeoBBox::FillBuffer3D(buffer, reqSections, localFrame);

   if (reqSections & TBuffer3D::kRawSizes) {
      Int_t n = gGeoManager->GetNsegments();
      Int_t nbPnts = 4*n;
      Int_t nbSegs = 8*n;
      Int_t nbPols = 4*n;
      if (buffer.SetRawSizes(nbPnts, 3*nbPnts, nbSegs, 3*nbSegs, nbPols, 6*nbPols)) {
         buffer.SetSectionsValid(TBuffer3D::kRawSizes);
      }
   }

   // TODO: Can we push this as common down to TGeoShape?
   if ((reqSections & TBuffer3D::kRaw) && buffer.SectionsValid(TBuffer3D::kRawSizes)) {
      SetPoints(buffer.fPnts);
      if (!buffer.fLocalFrame) {
         TransformPoints(buffer.fPnts, buffer.NbPnts());
      }

      SetSegsAndPols(buffer);
      buffer.SetSectionsValid(TBuffer3D::kRaw);
   }
      
   return buffer;
}

ClassImp(TGeoConeSeg)

//_____________________________________________________________________________
TGeoConeSeg::TGeoConeSeg()
{
// Default constructor
   SetShapeBit(TGeoShape::kGeoConeSeg);
   fPhi1 = fPhi2 = 0.0;
}

//_____________________________________________________________________________
TGeoConeSeg::TGeoConeSeg(Double_t dz, Double_t rmin1, Double_t rmax1,
                          Double_t rmin2, Double_t rmax2, Double_t phi1, Double_t phi2)
            :TGeoCone(dz, rmin1, rmax1, rmin2, rmax2)
{
// Default constructor specifying minimum and maximum radius
   SetShapeBit(TGeoShape::kGeoConeSeg);
   SetConsDimensions(dz, rmin1, rmax1, rmin2, rmax2, phi1, phi2);
   ComputeBBox();
}

//_____________________________________________________________________________
TGeoConeSeg::TGeoConeSeg(const char *name, Double_t dz, Double_t rmin1, Double_t rmax1,
                          Double_t rmin2, Double_t rmax2, Double_t phi1, Double_t phi2)
            :TGeoCone(name, dz, rmin1, rmax1, rmin2, rmax2)
{
// Default constructor specifying minimum and maximum radius
   SetShapeBit(TGeoShape::kGeoConeSeg);
   SetConsDimensions(dz, rmin1, rmax1, rmin2, rmax2, phi1, phi2);
   ComputeBBox();
}

//_____________________________________________________________________________
TGeoConeSeg::TGeoConeSeg(Double_t *param)
            :TGeoCone(0,0,0,0,0)
{
// Default constructor specifying minimum and maximum radius
// param[0] = dz
// param[1] = Rmin1
// param[2] = Rmax1
// param[3] = Rmin2
// param[4] = Rmax2
// param[5] = phi1
// param[6] = phi2
   SetShapeBit(TGeoShape::kGeoConeSeg);
   SetDimensions(param);
   ComputeBBox();
}

//_____________________________________________________________________________
TGeoConeSeg::~TGeoConeSeg()
{
// destructor
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::Capacity() const
{
// Computes capacity of the shape in [length^3]
   return TGeoConeSeg::Capacity(fDz, fRmin1, fRmax1, fRmin2, fRmax2, fPhi1, fPhi2);
}   

//_____________________________________________________________________________
Double_t TGeoConeSeg::Capacity(Double_t dz, Double_t rmin1, Double_t rmax1, Double_t rmin2, Double_t rmax2, Double_t phi1, Double_t phi2)
{
// Computes capacity of the shape in [length^3]
   Double_t capacity = (TMath::Abs(phi2-phi1)*TMath::DegToRad()*dz/3.)*
                       (rmax1*rmax1+rmax2*rmax2+rmax1*rmax2-
                        rmin1*rmin1-rmin2*rmin2-rmin1*rmin2);
   return capacity;                                            
}   

//_____________________________________________________________________________
void TGeoConeSeg::ComputeBBox()
{
// compute bounding box of the tube segment
   Double_t rmin, rmax;
   rmin = TMath::Min(fRmin1, fRmin2);
   rmax = TMath::Max(fRmax1, fRmax2);

   Double_t xc[4];
   Double_t yc[4];
   xc[0] = rmax*TMath::Cos(fPhi1*TMath::DegToRad());
   yc[0] = rmax*TMath::Sin(fPhi1*TMath::DegToRad());
   xc[1] = rmax*TMath::Cos(fPhi2*TMath::DegToRad());
   yc[1] = rmax*TMath::Sin(fPhi2*TMath::DegToRad());
   xc[2] = rmin*TMath::Cos(fPhi1*TMath::DegToRad());
   yc[2] = rmin*TMath::Sin(fPhi1*TMath::DegToRad());
   xc[3] = rmin*TMath::Cos(fPhi2*TMath::DegToRad());
   yc[3] = rmin*TMath::Sin(fPhi2*TMath::DegToRad());

   Double_t xmin = xc[TMath::LocMin(4, &xc[0])];
   Double_t xmax = xc[TMath::LocMax(4, &xc[0])];
   Double_t ymin = yc[TMath::LocMin(4, &yc[0])];
   Double_t ymax = yc[TMath::LocMax(4, &yc[0])];

   Double_t dp = fPhi2-fPhi1;
   Double_t ddp = -fPhi1;
   if (ddp<0) ddp+= 360;
   if (ddp<=dp) xmax = rmax;
   ddp = 90-fPhi1;
   if (ddp<0) ddp+= 360;
   if (ddp<=dp) ymax = rmax;
   ddp = 180-fPhi1;
   if (ddp<0) ddp+= 360;
   if (ddp<=dp) xmin = -rmax;
   ddp = 270-fPhi1;
   if (ddp<0) ddp+= 360;
   if (ddp<=dp) ymin = -rmax;
   fOrigin[0] = (xmax+xmin)/2;
   fOrigin[1] = (ymax+ymin)/2;
   fOrigin[2] = 0;
   fDX = (xmax-xmin)/2;
   fDY = (ymax-ymin)/2;
   fDZ = fDz;
}

//_____________________________________________________________________________
void TGeoConeSeg::ComputeNormal(Double_t *point, Double_t *dir, Double_t *norm)
{
// Compute normal to closest surface from POINT.
   Double_t saf[3];
   Double_t ro1 = 0.5*(fRmin1+fRmin2);
   Double_t tg1 = 0.5*(fRmin2-fRmin1)/fDz;
   Double_t cr1 = 1./TMath::Sqrt(1.+tg1*tg1);
   Double_t ro2 = 0.5*(fRmax1+fRmax2);
   Double_t tg2 = 0.5*(fRmax2-fRmax1)/fDz;
   Double_t cr2 = 1./TMath::Sqrt(1.+tg2*tg2);

   Double_t c1 = TMath::Cos(fPhi1*TMath::DegToRad());
   Double_t s1 = TMath::Sin(fPhi1*TMath::DegToRad());
   Double_t c2 = TMath::Cos(fPhi2*TMath::DegToRad());
   Double_t s2 = TMath::Sin(fPhi2*TMath::DegToRad());

   Double_t r=TMath::Sqrt(point[0]*point[0]+point[1]*point[1]);
   Double_t rin = tg1*point[2]+ro1;
   Double_t rout = tg2*point[2]+ro2;
   saf[0] = TMath::Abs(fDz-TMath::Abs(point[2]));
   saf[1] = (ro1>0)?(TMath::Abs((r-rin)*cr1)):TGeoShape::Big();
   saf[2] = TMath::Abs((rout-r)*cr2);
   Int_t i = TMath::LocMin(3,saf);
   if (((fPhi2-fPhi1)<360.) && TGeoShape::IsCloseToPhi(saf[i], point,c1,s1,c2,s2)) {
      TGeoShape::NormalPhi(point,dir,norm,c1,s1,c2,s2);
      return;
   }
   if (i==0) {
      norm[0] = norm[1] = 0.;
      norm[2] = TMath::Sign(1.,dir[2]);
      return;
   }

   Double_t phi = TMath::ATan2(point[1],point[0]);
   Double_t cphi = TMath::Cos(phi);
   Double_t sphi = TMath::Sin(phi);

   if (i==1) {
      norm[0] = cr1*cphi;
      norm[1] = cr1*sphi;
      norm[2] = -tg1*cr1;
   } else {
      norm[0] = cr2*cphi;
      norm[1] = cr2*sphi;
      norm[2] = -tg2*cr2;
   }

   if (norm[0]*dir[0]+norm[1]*dir[1]+norm[2]*dir[2]<0) {
      norm[0] = -norm[0];
      norm[1] = -norm[1];
      norm[2] = -norm[2];
   }
}

//_____________________________________________________________________________
void TGeoConeSeg::ComputeNormalS(Double_t *point, Double_t *dir, Double_t *norm,
                                 Double_t dz, Double_t rmin1, Double_t rmax1, Double_t rmin2, Double_t rmax2,
                                 Double_t c1, Double_t s1, Double_t c2, Double_t s2)
{
// Compute normal to closest surface from POINT.
   Double_t saf[2];
   Double_t ro1 = 0.5*(rmin1+rmin2);
   Double_t tg1 = 0.5*(rmin2-rmin1)/dz;
   Double_t cr1 = 1./TMath::Sqrt(1.+tg1*tg1);
   Double_t ro2 = 0.5*(rmax1+rmax2);
   Double_t tg2 = 0.5*(rmax2-rmax1)/dz;
   Double_t cr2 = 1./TMath::Sqrt(1.+tg2*tg2);

   Double_t r=TMath::Sqrt(point[0]*point[0]+point[1]*point[1]);
   Double_t rin = tg1*point[2]+ro1;
   Double_t rout = tg2*point[2]+ro2;
   saf[0] = (ro1>0)?(TMath::Abs((r-rin)*cr1)):TGeoShape::Big();
   saf[1] = TMath::Abs((rout-r)*cr2);
   Int_t i = TMath::LocMin(2,saf);
   if (TGeoShape::IsCloseToPhi(saf[i], point,c1,s1,c2,s2)) {
      TGeoShape::NormalPhi(point,dir,norm,c1,s1,c2,s2);
      return;
   }

   Double_t phi = TMath::ATan2(point[1],point[0]);
   Double_t cphi = TMath::Cos(phi);
   Double_t sphi = TMath::Sin(phi);

   if (i==0) {
      norm[0] = cr1*cphi;
      norm[1] = cr1*sphi;
      norm[2] = -tg1*cr1;
   } else {
      norm[0] = cr2*cphi;
      norm[1] = cr2*sphi;
      norm[2] = -tg2*cr2;
   }

   if (norm[0]*dir[0]+norm[1]*dir[1]+norm[2]*dir[2]<0) {
      norm[0] = -norm[0];
      norm[1] = -norm[1];
      norm[2] = -norm[2];
   }
}

//_____________________________________________________________________________
Bool_t TGeoConeSeg::Contains(Double_t *point) const
{
// test if point is inside this sphere
   if (!TGeoCone::Contains(point)) return kFALSE;
   Double_t dphi = fPhi2 - fPhi1;
   if (dphi >= 360.) return kTRUE;
   Double_t phi = TMath::ATan2(point[1], point[0]) * TMath::RadToDeg();
   if (phi < 0 ) phi+=360.;
   Double_t ddp = phi-fPhi1;
   if (ddp < 0) ddp+=360.;
//   if (ddp > 360) ddp-=360;
   if (ddp > dphi) return kFALSE;
   return kTRUE;
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::DistToCons(Double_t *point, Double_t *dir, Double_t r1, Double_t z1, Double_t r2, Double_t z2, Double_t phi1, Double_t phi2)
{
   // Static method to compute distance to a conical surface with :
   // - r1, z1 - radius and Z position of lower base
   // - r2, z2 - radius and Z position of upper base
   // - phi1, phi2 - phi limits
   Double_t dz = z2-z1;
   if (dz<=0) {
      return TGeoShape::Big();
   }

   Double_t dphi = phi2 - phi1;
   Bool_t hasphi = kTRUE;
   if (dphi >= 360.) hasphi=kFALSE;
   if (dphi < 0) dphi+=360.;
//   printf("phi1=%f phi2=%f dphi=%f\n", phi1, phi2, dphi);

   Double_t ro0 = 0.5*(r1+r2);
   Double_t fz  = (r2-r1)/dz;
   Double_t r0sq = point[0]*point[0] + point[1]*point[1];
   Double_t rc = ro0 + fz*(point[2]-0.5*(z1+z2));

   Double_t a = dir[0]*dir[0] + dir[1]*dir[1] - fz*fz*dir[2]*dir[2];
   Double_t b = point[0]*dir[0] + point[1]*dir[1] - fz*rc*dir[2];
   Double_t c = r0sq - rc*rc;

   if (a==0) return TGeoShape::Big();
   a = 1./a;
   b *= a;
   c *= a;
   Double_t delta = b*b - c;
   if (delta<0) return TGeoShape::Big();
   delta = TMath::Sqrt(delta);

   Double_t snxt = -b-delta;
   Double_t ptnew[3];
   Double_t ddp, phi;
   if (snxt>0) {
      // check Z range
      ptnew[2] = point[2] + snxt*dir[2];
      if (((ptnew[2]-z1)*(ptnew[2]-z2)) < 0) {
      // check phi range
         if (!hasphi) return snxt;
         ptnew[0] = point[0] + snxt*dir[0];
         ptnew[1] = point[1] + snxt*dir[1];
         phi = TMath::ATan2(ptnew[1], ptnew[0]) * TMath::RadToDeg();
         if (phi < 0 ) phi+=360.;
         ddp = phi-phi1;
         if (ddp < 0) ddp+=360.;
//	 printf("snxt1=%f phi=%f ddp=%f\n", snxt, phi, ddp);
         if (ddp<=dphi) return snxt;
      }
   }
   snxt = -b+delta;
   if (snxt>0) {
      // check Z range
      ptnew[2] = point[2] + snxt*dir[2];
      if (((ptnew[2]-z1)*(ptnew[2]-z2)) < 0) {
      // check phi range
         if (!hasphi) return snxt;
         ptnew[0] = point[0] + snxt*dir[0];
         ptnew[1] = point[1] + snxt*dir[1];
         phi = TMath::ATan2(ptnew[1], ptnew[0]) * TMath::RadToDeg();
         if (phi < 0 ) phi+=360.;
         ddp = phi-phi1;
         if (ddp < 0) ddp+=360.;
//	 printf("snxt2=%f phi=%f ddp=%f\n", snxt, phi, ddp);
         if (ddp<=dphi) return snxt;
      }
   }
   return TGeoShape::Big();
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::DistFromInsideS(Double_t *point, Double_t *dir, Double_t dz, 
                       Double_t rmin1, Double_t rmax1, Double_t rmin2, Double_t rmax2, 
                       Double_t c1, Double_t s1, Double_t c2, Double_t s2, Double_t cm, Double_t sm, Double_t cdfi)
{
// compute distance from inside point to surface of the tube segment
   if (dz<=0) return TGeoShape::Big();
   // Do Z
   Double_t scone = TGeoCone::DistFromInsideS(point,dir,dz,rmin1,rmax1,rmin2,rmax2);
   if (scone<=0) return 0.0;
   Double_t sfmin = TGeoShape::Big();
   Double_t rsq = point[0]*point[0]+point[1]*point[1];
   Double_t r = TMath::Sqrt(rsq);
   Double_t cpsi=point[0]*cm+point[1]*sm;
   if (cpsi>r*cdfi+TGeoShape::Tolerance())  {
      sfmin = TGeoShape::DistToPhiMin(point, dir, s1, c1, s2, c2, sm, cm);
      return TMath::Min(scone,sfmin);
   }
   // Point on the phi boundary or outside   
   // which one: phi1 or phi2
   Double_t ddotn, xi, yi;
   if (TMath::Abs(point[1]-s1*r) < TMath::Abs(point[1]-s2*r)) {
      ddotn = s1*dir[0]-c1*dir[1];
      if (ddotn>=0) return 0.0;
      ddotn = -s2*dir[0]+c2*dir[1];
      if (ddotn<=0) return scone;
      sfmin = s2*point[0]-c2*point[1];
      if (sfmin<=0) return scone;
      sfmin /= ddotn;
      if (sfmin >= scone) return scone;
      xi = point[0]+sfmin*dir[0];
      yi = point[1]+sfmin*dir[1];
      if (yi*cm-xi*sm<0) return scone;
      return sfmin;
   }
   ddotn = -s2*dir[0]+c2*dir[1];
   if (ddotn>=0) return 0.0;
   ddotn = s1*dir[0]-c1*dir[1];
   if (ddotn<=0) return scone;
   sfmin = -s1*point[0]+c1*point[1];
   if (sfmin<=0) return scone;
   sfmin /= ddotn;
   if (sfmin >= scone) return scone;
   xi = point[0]+sfmin*dir[0];
   yi = point[1]+sfmin*dir[1];
   if (yi*cm-xi*sm>0) return scone;
   return sfmin;
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::DistFromInside(Double_t *point, Double_t *dir, Int_t iact, Double_t step, Double_t *safe) const
{
// compute distance from inside point to surface of the tube segment
   if (iact<3 && safe) {
      *safe = TGeoConeSeg::SafetyS(point, kTRUE, fDz,fRmin1,fRmax1,fRmin2,fRmax2,fPhi1,fPhi2);
      if (iact==0) return TGeoShape::Big();
      if ((iact==1) && (*safe>step)) return TGeoShape::Big();
   }
   if ((fPhi2-fPhi1)>=360.) return TGeoCone::DistFromInsideS(point,dir,fDz,fRmin1,fRmax1,fRmin2,fRmax2);
   Double_t phi1 = fPhi1*TMath::DegToRad();
   Double_t phi2 = fPhi2*TMath::DegToRad();
   Double_t c1 = TMath::Cos(phi1);
   Double_t c2 = TMath::Cos(phi2);
   Double_t s1 = TMath::Sin(phi1);
   Double_t s2 = TMath::Sin(phi2);
   Double_t phim = 0.5*(phi1+phi2);
   Double_t cm = TMath::Cos(phim);
   Double_t sm = TMath::Sin(phim);
   Double_t dfi = 0.5*(phi2-phi1);
   Double_t cdfi = TMath::Cos(dfi);

   // compute distance to surface
   return TGeoConeSeg::DistFromInsideS(point,dir,fDz,fRmin1,fRmax1,fRmin2,fRmax2,c1,s1,c2,s2,cm,sm,cdfi);
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::DistFromOutsideS(Double_t *point, Double_t *dir, Double_t dz, 
                       Double_t rmin1, Double_t rmax1, Double_t rmin2, Double_t rmax2, 
                       Double_t c1, Double_t s1, Double_t c2, Double_t s2, Double_t cm, Double_t sm, Double_t cdfi)
{
// compute distance from outside point to surface of arbitrary tube
   if (dz<=0) return TGeoShape::Big();
   Double_t r2, cpsi;
   // check Z planes
   Double_t xi, yi, zi;
   Double_t b,delta;
   zi = dz - TMath::Abs(point[2]);
   Double_t rin,rout;
   Double_t s = TGeoShape::Big();
   Double_t snxt=TGeoShape::Big();
   Bool_t in = kFALSE;
   Bool_t inz = (zi<0)?kFALSE:kTRUE;
   if (!inz) {
      if (point[2]*dir[2]>=0) return TGeoShape::Big();
      s = -zi/TMath::Abs(dir[2]);
      xi = point[0]+s*dir[0];
      yi = point[1]+s*dir[1];
      r2=xi*xi+yi*yi;
      if (dir[2]>0) {
         rin = rmin1;
         rout = rmax1;
      } else {
         rin = rmin2;
         rout = rmax2;
      }      
      if ((rin*rin<=r2) && (r2<=rout*rout)) {
         cpsi=xi*cm+yi*sm;
         if (cpsi>=(cdfi*TMath::Sqrt(r2))) return s;
      }
   }
   Double_t zinv = 1./dz;
   Double_t rsq = point[0]*point[0]+point[1]*point[1];   
   Double_t r = TMath::Sqrt(rsq);
   Double_t ro1=0.5*(rmin1+rmin2);
   Bool_t hasrmin = (ro1>0)?kTRUE:kFALSE;
   Double_t tg1 = 0.0;
   Bool_t inrmin = kFALSE;
   rin = 0.0;
   if (hasrmin) {
      tg1=0.5*(rmin2-rmin1)*zinv;
      rin = ro1+tg1*point[2];
      if (rsq > rin*(rin-TGeoShape::Tolerance())) inrmin=kTRUE;
   } else {
      inrmin = kTRUE;
   }     
   Double_t ro2=0.5*(rmax1+rmax2);
   Double_t tg2=0.5*(rmax2-rmax1)*zinv;
   rout = ro2+tg2*point[2];
   Bool_t inrmax = kFALSE;
   if (rsq < rout*(rout+TGeoShape::Tolerance())) inrmax = kTRUE;
   Bool_t inphi = kFALSE;
   cpsi=point[0]*cm+point[1]*sm;
   if (cpsi>r*cdfi-TGeoShape::Tolerance())  inphi = kTRUE;
   in = inz & inrmin & inrmax & inphi;
   // If inside, we are most likely on a boundary within machine precision.
   if (in) { 
      Double_t safphi = (cpsi-r*cdfi)*TMath::Sqrt(1.-cdfi*cdfi);
      Double_t safrmin = (hasrmin)?TMath::Abs(r-rin):(TGeoShape::Big());
      Double_t safrmax = TMath::Abs(r-rout);
      // check if on Z boundaries
      if (zi<safrmax && zi<safrmin && zi<safphi) {
         if (point[2]*dir[2]<0) return 0.0;
         return TGeoShape::Big();
      }   
      // check if on Rmax boundary
      if (safrmax<safrmin && safrmax<safphi) {
         Double_t ddotn = point[0]*dir[0]+point[1]*dir[1]-tg2*dir[2]*r;      
         if (ddotn<=0) return 0.0;
         return TGeoShape::Big();
      }
      // check if on phi boundary
      if (safphi<safrmin) {
      // We may cross again a phi of rmin boundary
      // check first if we are on phi1 or phi2
         Double_t un;
         if (TMath::Abs(point[1]-s1*r) < TMath::Abs(point[1]-s2*r)) {
            un = dir[0]*s1-dir[1]*c1;
            if (un < 0) return 0.0;
            if (cdfi>=0) return TGeoShape::Big();
            un = -dir[0]*s2+dir[1]*c2;
            if (un<0) {
               s = -point[0]*s2+point[1]*c2;
               if (s>0) {
                  s /= (-un);
                  zi = point[2]+s*dir[2];
                  if (TMath::Abs(zi)<=dz) {
                     xi = point[0]+s*dir[0];
                     yi = point[1]+s*dir[1];
                     if ((yi*cm-xi*sm)>0) {
                        r2=xi*xi+yi*yi;
                        rin = ro1+tg1*zi;
                        rout = ro2+tg2*zi;
                        if ((rin*rin<=r2) && (rout*rout>=r2)) return s;
                     }
                  }
               }
            }   
         } else {
            un = -dir[0]*s2+dir[1]*c2;
            if (un < 0) return 0.0;
            if (cdfi>=0) return TGeoShape::Big();
            un = dir[0]*s1-dir[1]*c1;
            if (un<0) {
               s = point[0]*s1-point[1]*c1;
               if (s>0) {
                  s /= (-un);
                  zi = point[2]+s*dir[2];
                  if (TMath::Abs(zi)<=dz) {
                     xi = point[0]+s*dir[0];
                     yi = point[1]+s*dir[1];
                     if ((yi*cm-xi*sm)<0) {
                        r2=xi*xi+yi*yi;
                        rin = ro1+tg1*zi;
                        rout = ro2+tg2*zi;
                        if ((rin*rin<=r2) && (rout*rout>=r2)) return s;
                     }
                  }
               }
            }
         }      
         // We may also cross rmin, second solution coming from outside
         Double_t ddotn = point[0]*dir[0]+point[1]*dir[1]-tg1*dir[2]*r;
         if (ddotn>=0) return TGeoShape::Big();
         if (cdfi>=0) return TGeoShape::Big();              
         TGeoCone::DistToCone(point, dir, dz, rmin1, rmin2, b, delta); 
         if (delta<0) return TGeoShape::Big();
         snxt = -b-delta;
         if (snxt<0) return TGeoShape::Big();
         snxt = -b+delta;
         zi = point[2]+snxt*dir[2];           
         if (TMath::Abs(zi)>dz) return TGeoShape::Big();
         xi = point[0]+snxt*dir[0];
         yi = point[1]+snxt*dir[1];
         r2=xi*xi+yi*yi;
         cpsi=xi*cm+yi*sm;
         if (cpsi>=(cdfi*TMath::Sqrt(r2))) return snxt;
         return TGeoShape::Big();
      }
      // We are on rmin boundary: we may cross again rmin or a phi facette   
      Double_t ddotn = point[0]*dir[0]+point[1]*dir[1]-tg1*dir[2]*r;
      if (ddotn>=0) return 0.0;
      TGeoCone::DistToCone(point, dir, dz, rmin1, rmin2, b, delta);
      if (delta<0) return 0.0;
      snxt = -b+delta;
      if (snxt<0) return TGeoShape::Big();
      if (TMath::Abs(-b-delta)>snxt) return TGeoShape::Big();
      zi = point[2]+snxt*dir[2];
      if (TMath::Abs(zi)>dz) return TGeoShape::Big();
      // OK, we cross rmin at snxt - check if within phi range
      xi = point[0]+snxt*dir[0];
      yi = point[1]+snxt*dir[1];
      r2=xi*xi+yi*yi;
      cpsi=xi*cm+yi*sm;
      if (cpsi>=(cdfi*TMath::Sqrt(r2))) return snxt;
      // we cross rmin in the phi gap - we may cross a phi facette
      if (cdfi>=0) return TGeoShape::Big();
      Double_t un=-dir[0]*s1+dir[1]*c1;
      if (un > 0) {
         s=point[0]*s1-point[1]*c1;
         if (s>=0) {
            s /= un;
            zi=point[2]+s*dir[2];
            if (TMath::Abs(zi)<=dz) {
               xi=point[0]+s*dir[0];
               yi=point[1]+s*dir[1];
               if ((yi*cm-xi*sm)<=0) {
                  r2=xi*xi+yi*yi;
                  rin = ro1+tg1*zi;
                  rout = ro2+tg2*zi;
                  if ((rin*rin<=r2) && (rout*rout>=r2)) return s;
               }   
            }
         }
      }         
      un=dir[0]*s2-dir[1]*c2;
      if (un > 0) {
         s=(point[1]*c2-point[0]*s2)/un;
         if (s>=0) {
            zi=point[2]+s*dir[2];
            if (TMath::Abs(zi)<=dz) {
               xi=point[0]+s*dir[0];
               yi=point[1]+s*dir[1];
               if ((yi*cm-xi*sm)>=0) {
                  r2=xi*xi+yi*yi;
                  rin = ro1+tg1*zi;
                  rout = ro2+tg2*zi;
                  if ((rin*rin<=r2) && (rout*rout>=r2)) return s;
               }
            }
         }
      }            
      return TGeoShape::Big();
   }   

   // The point is really outside
   Double_t sr1 = TGeoShape::Big();
   if (!inrmax) {
      // check crossing with outer cone
      TGeoCone::DistToCone(point, dir, dz, rmax1, rmax2, b, delta);
      if (delta>=0) {
         s = -b-delta;
         if (s>0) {
            zi=point[2]+s*dir[2];
            if (TMath::Abs(zi)<=dz) {
               xi=point[0]+s*dir[0];
               yi=point[1]+s*dir[1];
               r2=xi*xi+yi*yi;
               cpsi=xi*cm+yi*sm;
               if (cpsi>=(cdfi*TMath::Sqrt(r2))) return s; // rmax crossing
            }
         }
         s = -b+delta;
         if (s>0) {
            zi=point[2]+s*dir[2];
            if (TMath::Abs(zi)<=dz) {
               xi=point[0]+s*dir[0];
               yi=point[1]+s*dir[1];
               r2=xi*xi+yi*yi;
               cpsi=xi*cm+yi*sm;
               if (cpsi>=(cdfi*TMath::Sqrt(r2))) sr1=s;
            }
         }
      }
   }
   // check crossing with inner cone
   Double_t sr2 = TGeoShape::Big();
   TGeoCone::DistToCone(point, dir, dz, rmin1, rmin2, b, delta);      
   if (delta>=0) {      
      s = -b-delta;
      if (s>0) {
         zi=point[2]+s*dir[2];
         if (TMath::Abs(zi)<=dz) {
            xi=point[0]+s*dir[0];
            yi=point[1]+s*dir[1];
            r2=xi*xi+yi*yi;
            cpsi=xi*cm+yi*sm;
            if (cpsi>=(cdfi*TMath::Sqrt(r2))) sr2=s;
         }
      }
      if (sr2>1E10) {
         s = -b+delta;
         if (s>0) {
         zi=point[2]+s*dir[2];
            if (TMath::Abs(zi)<=dz) {
               xi=point[0]+s*dir[0];
               yi=point[1]+s*dir[1];
               r2=xi*xi+yi*yi;
               cpsi=xi*cm+yi*sm;
               if (cpsi>=(cdfi*TMath::Sqrt(r2))) sr2=s;
            }
         }
      }
   }
   snxt = TMath::Min(sr1,sr2);   
   // Check phi crossing   
   s = TGeoShape::DistToPhiMin(point,dir,s1,c1,s2,c2,sm,cm,kFALSE);      
   if (s>snxt) return snxt;
   zi=point[2]+s*dir[2];
   if (TMath::Abs(zi)>dz) return snxt;
   xi=point[0]+s*dir[0];
   yi=point[1]+s*dir[1];
   r2=xi*xi+yi*yi;
   rout = ro2+tg2*zi;
   if (r2>rout*rout) return snxt;
   rin = ro1+tg1*zi;
   if (r2>=rin*rin) return s; // phi crossing
   return snxt;
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::DistFromOutside(Double_t *point, Double_t *dir, Int_t iact, Double_t step, Double_t *safe) const
{
// compute distance from outside point to surface of the tube
   // compute safe radius
   if (iact<3 && safe) {
      *safe = Safety(point, kFALSE);
      if (iact==0) return TGeoShape::Big();
      if ((iact==1) && (*safe>step)) return TGeoShape::Big();
   }
// Check if the bounding box is crossed within the requested distance
   Double_t sdist = TGeoBBox::DistFromOutside(point,dir, fDX, fDY, fDZ, fOrigin, step);
   if (sdist>=step) return TGeoShape::Big();
   if ((fPhi2-fPhi1)>=360.) return TGeoCone::DistFromOutsideS(point,dir,fDz,fRmin1,fRmax1,fRmin2,fRmax2);
   Double_t phi1 = fPhi1*TMath::DegToRad();
   Double_t phi2 = fPhi2*TMath::DegToRad();
   Double_t c1 = TMath::Cos(phi1);
   Double_t c2 = TMath::Cos(phi2);
   Double_t s1 = TMath::Sin(phi1);
   Double_t s2 = TMath::Sin(phi2);
   Double_t phim = 0.5*(phi1+phi2);
   Double_t cm = TMath::Cos(phim);
   Double_t sm = TMath::Sin(phim);
   Double_t dfi = 0.5*(phi2-phi1);
   Double_t cdfi = TMath::Cos(dfi);
   return TGeoConeSeg::DistFromOutsideS(point,dir,fDz,fRmin1,fRmax1,fRmin2,fRmax2,c1,s1,c2,s2,cm,sm,cdfi);
}

//_____________________________________________________________________________
Int_t TGeoConeSeg::DistancetoPrimitive(Int_t px, Int_t py)
{
// compute closest distance from point px,py to each corner
   Int_t n = gGeoManager->GetNsegments()+1;
   const Int_t numPoints = 4*n;
   return ShapeDistancetoPrimitive(numPoints, px, py);
}

//_____________________________________________________________________________
TGeoVolume *TGeoConeSeg::Divide(TGeoVolume *voldiv, const char *divname, Int_t iaxis, Int_t ndiv,
                             Double_t start, Double_t step)
{
//--- Divide this cone segment shape belonging to volume "voldiv" into ndiv volumes
// called divname, from start position with the given step. Returns pointer
// to created division cell volume in case of Z divisions. For Z division
// creates all volumes with different shapes and returns pointer to volume that
// was divided. In case a wrong division axis is supplied, returns pointer to
// volume that was divided.
   TGeoShape *shape;           //--- shape to be created
   TGeoVolume *vol;            //--- division volume to be created
   TGeoVolumeMulti *vmulti;    //--- generic divided volume
   TGeoPatternFinder *finder;  //--- finder to be attached
   TString opt = "";           //--- option to be attached
   Double_t dphi;
   Int_t id;
   Double_t end = start+ndiv*step;
   switch (iaxis) {
      case 1:  //---               R division
         Error("Divide","division of a cone segment on R not implemented");
         return 0;
      case 2:  //---               Phi division
         dphi = fPhi2-fPhi1;
         if (dphi<0) dphi+=360.;
         finder = new TGeoPatternCylPhi(voldiv, ndiv, start, end);
         voldiv->SetFinder(finder);
         finder->SetDivIndex(voldiv->GetNdaughters());
         shape = new TGeoConeSeg(fDz, fRmin1, fRmax1, fRmin2, fRmax2, -step/2, step/2);
         vol = new TGeoVolume(divname, shape, voldiv->GetMedium());
         vmulti = gGeoManager->MakeVolumeMulti(divname, voldiv->GetMedium());
         vmulti->AddVolume(vol);
         opt = "Phi";
         for (id=0; id<ndiv; id++) {
            voldiv->AddNodeOffset(vol, id, start+id*step+step/2, opt.Data());
            ((TGeoNodeOffset*)voldiv->GetNodes()->At(voldiv->GetNdaughters()-1))->SetFinder(finder);
         }
         return vmulti;
      case 3: //---                 Z division
         finder = new TGeoPatternZ(voldiv, ndiv, start, end);
         vmulti = gGeoManager->MakeVolumeMulti(divname, voldiv->GetMedium());
         voldiv->SetFinder(finder);
         finder->SetDivIndex(voldiv->GetNdaughters());
         for (id=0; id<ndiv; id++) {
            Double_t z1 = start+id*step;
            Double_t z2 = start+(id+1)*step;
            Double_t rmin1n = 0.5*(fRmin1*(fDz-z1)+fRmin2*(fDz+z1))/fDz;
            Double_t rmax1n = 0.5*(fRmax1*(fDz-z1)+fRmax2*(fDz+z1))/fDz;
            Double_t rmin2n = 0.5*(fRmin1*(fDz-z2)+fRmin2*(fDz+z2))/fDz;
            Double_t rmax2n = 0.5*(fRmax1*(fDz-z2)+fRmax2*(fDz+z2))/fDz;
            shape = new TGeoConeSeg(step/2, rmin1n, rmax1n, rmin2n, rmax2n, fPhi1, fPhi2);
            vol = new TGeoVolume(divname, shape, voldiv->GetMedium());
            vmulti->AddVolume(vol);
            opt = "Z";
            voldiv->AddNodeOffset(vol, id, start+id*step+step/2, opt.Data());
            ((TGeoNodeOffset*)voldiv->GetNodes()->At(voldiv->GetNdaughters()-1))->SetFinder(finder);
         }
         return vmulti;
      default:
         Error("Divide", "Wrong axis type for division");
         return 0;
   }
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::GetAxisRange(Int_t iaxis, Double_t &xlo, Double_t &xhi) const
{
// Get range of shape for a given axis.
   xlo = 0;
   xhi = 0;
   Double_t dx = 0;
   switch (iaxis) {
      case 2:
         xlo = fPhi1;
         xhi = fPhi2;
         dx = xhi-xlo;
         return dx;
      case 3:
         xlo = -fDz;
         xhi = fDz;
         dx = xhi-xlo;
         return dx;
   }
   return dx;
}

//_____________________________________________________________________________
void TGeoConeSeg::GetBoundingCylinder(Double_t *param) const
{
//--- Fill vector param[4] with the bounding cylinder parameters. The order
// is the following : Rmin, Rmax, Phi1, Phi2
   param[0] = TMath::Min(fRmin1, fRmin2); // Rmin
   param[0] *= param[0];
   param[1] = TMath::Max(fRmax1, fRmax2); // Rmax
   param[1] *= param[1];
   param[2] = (fPhi1<0)?(fPhi1+360.):fPhi1; // Phi1
   param[3] = fPhi2;                        // Phi2
   while (param[3]<param[2]) param[3]+=360.;
}

//_____________________________________________________________________________
TGeoShape *TGeoConeSeg::GetMakeRuntimeShape(TGeoShape *mother, TGeoMatrix * /*mat*/) const
{
// in case shape has some negative parameters, these has to be computed
// in order to fit the mother
   if (!TestShapeBit(kGeoRunTimeShape)) return 0;
   if (!mother->TestShapeBit(kGeoConeSeg)) {
      Error("GetMakeRuntimeShape", "invalid mother");
      return 0;
   }
   Double_t rmin1, rmax1, rmin2, rmax2, dz;
   rmin1 = fRmin1;
   rmax1 = fRmax1;
   rmin2 = fRmin2;
   rmax2 = fRmax2;
   dz = fDz;
   if (fDz<0) dz=((TGeoCone*)mother)->GetDz();
   if (fRmin1<0)
      rmin1 = ((TGeoCone*)mother)->GetRmin1();
   if ((fRmax1<0) || (fRmax1<fRmin1))
      rmax1 = ((TGeoCone*)mother)->GetRmax1();
   if (fRmin2<0)
      rmin2 = ((TGeoCone*)mother)->GetRmin2();
   if ((fRmax2<0) || (fRmax2<fRmin2))
      rmax2 = ((TGeoCone*)mother)->GetRmax2();

   return (new TGeoConeSeg(GetName(), dz, rmin1, rmax1, rmin2, rmax2, fPhi1, fPhi2));
}

//_____________________________________________________________________________
void TGeoConeSeg::InspectShape() const
{
// print shape parameters
   printf("*** Shape %s: TGeoConeSeg ***\n", GetName());
   printf("    dz    = %11.5f\n", fDz);
   printf("    Rmin1 = %11.5f\n", fRmin1);
   printf("    Rmax1 = %11.5f\n", fRmax1);
   printf("    Rmin2 = %11.5f\n", fRmin2);
   printf("    Rmax2 = %11.5f\n", fRmax2);
   printf("    phi1  = %11.5f\n", fPhi1);
   printf("    phi2  = %11.5f\n", fPhi2);
   printf(" Bounding box:\n");
   TGeoBBox::InspectShape();
}

 //_____________________________________________________________________________
TBuffer3D *TGeoConeSeg::MakeBuffer3D() const
{  
   // Creates a TBuffer3D describing *this* shape.
   // Coordinates are in local reference frame.

   Int_t n = gGeoManager->GetNsegments()+1;
   Int_t nbPnts = 4*n;
   Int_t nbSegs = 2*nbPnts;
   Int_t nbPols = nbPnts-2; 
   TBuffer3D* buff = new TBuffer3D(TBuffer3DTypes::kGeneric,
                                   nbPnts, 3*nbPnts, 
                                   nbSegs, 3*nbSegs,
                                   nbPols, 6*nbPols);

   if (buff)
   {
      SetPoints(buff->fPnts);
      SetSegsAndPols(*buff);
   }

   return buff;
}

//_____________________________________________________________________________
void TGeoConeSeg::SetSegsAndPols(TBuffer3D &buffer) const
{
// Fill TBuffer3D structure for segments and polygons.
   Int_t i, j;
   Int_t n = gGeoManager->GetNsegments()+1;
   Int_t c = GetBasicColor();

   memset(buffer.fSegs, 0, buffer.NbSegs()*3*sizeof(Int_t));
   for (i = 0; i < 4; i++) {
      for (j = 1; j < n; j++) {
         buffer.fSegs[(i*n+j-1)*3  ] = c;
         buffer.fSegs[(i*n+j-1)*3+1] = i*n+j-1;
         buffer.fSegs[(i*n+j-1)*3+2] = i*n+j;
      }
   }
   for (i = 4; i < 6; i++) {
      for (j = 0; j < n; j++) {
         buffer.fSegs[(i*n+j)*3  ] = c+1;
         buffer.fSegs[(i*n+j)*3+1] = (i-4)*n+j;
         buffer.fSegs[(i*n+j)*3+2] = (i-2)*n+j;
      }
   }
   for (i = 6; i < 8; i++) {
      for (j = 0; j < n; j++) {
         buffer.fSegs[(i*n+j)*3  ] = c;
         buffer.fSegs[(i*n+j)*3+1] = 2*(i-6)*n+j;
         buffer.fSegs[(i*n+j)*3+2] = (2*(i-6)+1)*n+j;
      }
   }

   Int_t indx = 0;
   memset(buffer.fPols, 0, buffer.NbPols()*6*sizeof(Int_t));
   i = 0;
   for (j = 0; j < n-1; j++) {
      buffer.fPols[indx++] = c;
      buffer.fPols[indx++] = 4;
      buffer.fPols[indx++] = (4+i)*n+j+1;
      buffer.fPols[indx++] = (2+i)*n+j;
      buffer.fPols[indx++] = (4+i)*n+j;
      buffer.fPols[indx++] = i*n+j;
   }
   i = 1;
   for (j = 0; j < n-1; j++) {
      buffer.fPols[indx++] = c;
      buffer.fPols[indx++] = 4;
      buffer.fPols[indx++] = i*n+j;
      buffer.fPols[indx++] = (4+i)*n+j;
      buffer.fPols[indx++] = (2+i)*n+j;
      buffer.fPols[indx++] = (4+i)*n+j+1;
   }
   i = 2;
   for (j = 0; j < n-1; j++) {
      buffer.fPols[indx++] = c+i;
      buffer.fPols[indx++] = 4;
      buffer.fPols[indx++] = (i-2)*2*n+j;
      buffer.fPols[indx++] = (4+i)*n+j;
      buffer.fPols[indx++] = ((i-2)*2+1)*n+j;
      buffer.fPols[indx++] = (4+i)*n+j+1;
   }
   i = 3;
   for (j = 0; j < n-1; j++) {
      buffer.fPols[indx++] = c+i;
      buffer.fPols[indx++] = 4;
      buffer.fPols[indx++] = (4+i)*n+j+1;
      buffer.fPols[indx++] = ((i-2)*2+1)*n+j;
      buffer.fPols[indx++] = (4+i)*n+j;
      buffer.fPols[indx++] = (i-2)*2*n+j;
   }
   buffer.fPols[indx++] = c+2;
   buffer.fPols[indx++] = 4;
   buffer.fPols[indx++] = 6*n;
   buffer.fPols[indx++] = 4*n;
   buffer.fPols[indx++] = 7*n;
   buffer.fPols[indx++] = 5*n;
   buffer.fPols[indx++] = c+2;
   buffer.fPols[indx++] = 4;
   buffer.fPols[indx++] = 6*n-1;
   buffer.fPols[indx++] = 8*n-1;
   buffer.fPols[indx++] = 5*n-1;
   buffer.fPols[indx++] = 7*n-1;
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::Safety(Double_t *point, Bool_t in) const
{
// computes the closest distance from given point to this shape, according
// to option. The matching point on the shape is stored in spoint.

   Double_t saf[3];
   Double_t ro1 = 0.5*(fRmin1+fRmin2);
   Double_t tg1 = 0.5*(fRmin2-fRmin1)/fDz;
   Double_t cr1 = 1./TMath::Sqrt(1.+tg1*tg1);
   Double_t ro2 = 0.5*(fRmax1+fRmax2);
   Double_t tg2 = 0.5*(fRmax2-fRmax1)/fDz;
   Double_t cr2 = 1./TMath::Sqrt(1.+tg2*tg2);

   Double_t r=TMath::Sqrt(point[0]*point[0]+point[1]*point[1]);
   Double_t rin = tg1*point[2]+ro1;
   Double_t rout = tg2*point[2]+ro2;
   Double_t safe = TGeoShape::Big();
   if (in) {
      saf[0] = fDz-TMath::Abs(point[2]);
      saf[1] = (r-rin)*cr1;
      saf[2] = (rout-r)*cr2;
      safe = saf[TMath::LocMin(3,saf)];
   } else {
      saf[0] = TMath::Abs(point[2])-fDz; // positive if inside
      saf[1] = (rin-r)*cr1;
      saf[2] = (r-rout)*cr2;
      safe = saf[TMath::LocMax(3,saf)];
   }
   if ((fPhi2-fPhi1)>=360.) return safe;
   Double_t safphi = TGeoShape::SafetyPhi(point, in, fPhi1, fPhi2);

   if (in) return TMath::Min(safe, safphi);
   return TMath::Max(safe, safphi);
}

//_____________________________________________________________________________
Double_t TGeoConeSeg::SafetyS(Double_t *point, Bool_t in, Double_t dz, Double_t rmin1, Double_t rmax1,
                              Double_t rmin2, Double_t rmax2, Double_t phi1, Double_t phi2, Int_t skipz)
{
// Static method to compute the closest distance from given point to this shape.
   Double_t saf[3];
   Double_t ro1 = 0.5*(rmin1+rmin2);
   Double_t tg1 = 0.5*(rmin2-rmin1)/dz;
   Double_t cr1 = 1./TMath::Sqrt(1.+tg1*tg1);
   Double_t ro2 = 0.5*(rmax1+rmax2);
   Double_t tg2 = 0.5*(rmax2-rmax1)/dz;
   Double_t cr2 = 1./TMath::Sqrt(1.+tg2*tg2);

   Double_t r=TMath::Sqrt(point[0]*point[0]+point[1]*point[1]);
   Double_t rin = tg1*point[2]+ro1;
   Double_t rout = tg2*point[2]+ro2;

   Double_t safe = TGeoShape::Big();
   switch (skipz) {
      case 1: // skip lower Z plane
         saf[0] = dz - point[2];
         break;
      case 2: // skip upper Z plane
         saf[0] = dz + point[2];
         break;
      case 3: // skip both
         saf[0] = TGeoShape::Big();
      default:
         saf[0] = dz-TMath::Abs(point[2]);
   }
   saf[1] = (r-rin)*cr1;
   saf[2] = (rout-r)*cr2;
   Double_t safphi = TGeoShape::SafetyPhi(point,in,phi1,phi2);
   if (in) {
      safe = saf[TMath::LocMin(3,saf)];
      return TMath::Min(safe,safphi);
   }
   for (Int_t i=0; i<3; i++) saf[i]=-saf[i];
   safe = saf[TMath::LocMax(3,saf)];
   return TMath::Max(safe,safphi);
}

//_____________________________________________________________________________
void TGeoConeSeg::SavePrimitive(ostream &out, Option_t * /*option*/ /*= ""*/)
{
// Save a primitive as a C++ statement(s) on output stream "out".
   if (TObject::TestBit(kGeoSavePrimitive)) return;
   out << "   // Shape: " << GetName() << " type: " << ClassName() << endl;
   out << "   dz    = " << fDz << ";" << endl;
   out << "   rmin1 = " << fRmin1 << ";" << endl;
   out << "   rmax1 = " << fRmax1 << ";" << endl;
   out << "   rmin2 = " << fRmin2 << ";" << endl;
   out << "   rmax2 = " << fRmax2 << ";" << endl;
   out << "   phi1  = " << fPhi1 << ";" << endl;
   out << "   phi2  = " << fPhi2 << ";" << endl;
   out << "   TGeoShape *" << GetPointerName() << " = new TGeoConeSeg(\"" << GetName() << "\", dz,rmin1,rmax1,rmin2,rmax2,phi1,phi2);" << endl;
   TObject::SetBit(TGeoShape::kGeoSavePrimitive);  
}

//_____________________________________________________________________________
void TGeoConeSeg::SetConsDimensions(Double_t dz, Double_t rmin1, Double_t rmax1,
                   Double_t rmin2, Double_t rmax2, Double_t phi1, Double_t phi2)
{
// Set dimensions of the cone segment.
   fDz   = dz;
   fRmin1 = rmin1;
   fRmax1 = rmax1;
   fRmin2 = rmin2;
   fRmax2 = rmax2;
   fPhi1 = phi1;
   if (fPhi1<0) fPhi1+=360.;
   fPhi2 = phi2;
   while (fPhi2<fPhi1) fPhi2+=360.;
}

//_____________________________________________________________________________
void TGeoConeSeg::SetDimensions(Double_t *param)
{
// Set dimensions of the cone segment from an array.
   Double_t dz    = param[0];
   Double_t rmin1 = param[1];
   Double_t rmax1 = param[2];
   Double_t rmin2 = param[3];
   Double_t rmax2 = param[4];
   Double_t phi1  = param[5];
   Double_t phi2  = param[6];
   SetConsDimensions(dz, rmin1, rmax1,rmin2, rmax2, phi1, phi2);
}

//_____________________________________________________________________________
void TGeoConeSeg::SetPoints(Double_t *points) const
{
// Create cone segment mesh points.
   Int_t j, n;
   Float_t dphi,phi,phi1, phi2,dz;

   n = gGeoManager->GetNsegments()+1;
   dz    = fDz;
   phi1 = fPhi1;
   phi2 = fPhi2;

   dphi = (phi2-phi1)/(n-1);

   Int_t indx = 0;

   if (points) {
      for (j = 0; j < n; j++) {
         phi = (fPhi1+j*dphi)*TMath::DegToRad();
         points[indx++] = fRmin1 * TMath::Cos(phi);
         points[indx++] = fRmin1 * TMath::Sin(phi);
         points[indx++] = -dz;
      }
      for (j = 0; j < n; j++) {
         phi = (fPhi1+j*dphi)*TMath::DegToRad();
         points[indx++] = fRmax1 * TMath::Cos(phi);
         points[indx++] = fRmax1 * TMath::Sin(phi);
         points[indx++] = -dz;
      }
      for (j = 0; j < n; j++) {
         phi = (fPhi1+j*dphi)*TMath::DegToRad();
         points[indx++] = fRmin2 * TMath::Cos(phi);
         points[indx++] = fRmin2 * TMath::Sin(phi);
         points[indx++] = dz;
      }
      for (j = 0; j < n; j++) {
         phi = (fPhi1+j*dphi)*TMath::DegToRad();
         points[indx++] = fRmax2 * TMath::Cos(phi);
         points[indx++] = fRmax2 * TMath::Sin(phi);
         points[indx++] = dz;
      }
   }
}

//_____________________________________________________________________________
void TGeoConeSeg::SetPoints(Float_t *points) const
{
// Create cone segment mesh points.
   Int_t j, n;
   Float_t dphi,phi,phi1, phi2,dz;

   n = gGeoManager->GetNsegments()+1;
   dz    = fDz;
   phi1 = fPhi1;
   phi2 = fPhi2;

   dphi = (phi2-phi1)/(n-1);

   Int_t indx = 0;

   if (points) {
      for (j = 0; j < n; j++) {
         phi = (fPhi1+j*dphi)*TMath::DegToRad();
         points[indx++] = fRmin1 * TMath::Cos(phi);
         points[indx++] = fRmin1 * TMath::Sin(phi);
         points[indx++] = -dz;
      }
      for (j = 0; j < n; j++) {
         phi = (fPhi1+j*dphi)*TMath::DegToRad();
         points[indx++] = fRmax1 * TMath::Cos(phi);
         points[indx++] = fRmax1 * TMath::Sin(phi);
         points[indx++] = -dz;
      }
      for (j = 0; j < n; j++) {
         phi = (fPhi1+j*dphi)*TMath::DegToRad();
         points[indx++] = fRmin2 * TMath::Cos(phi);
         points[indx++] = fRmin2 * TMath::Sin(phi);
         points[indx++] = dz;
      }
      for (j = 0; j < n; j++) {
         phi = (fPhi1+j*dphi)*TMath::DegToRad();
         points[indx++] = fRmax2 * TMath::Cos(phi);
         points[indx++] = fRmax2 * TMath::Sin(phi);
         points[indx++] = dz;
      }
   }
}

//_____________________________________________________________________________
void TGeoConeSeg::GetMeshNumbers(Int_t &nvert, Int_t &nsegs, Int_t &npols) const
{
// Returns numbers of vertices, segments and polygons composing the shape mesh.
   Int_t n = gGeoManager->GetNsegments()+1;
   nvert = n*4;
   nsegs = n*8;
   npols = n*4-2;
}

//_____________________________________________________________________________
Int_t TGeoConeSeg::GetNmeshVertices() const
{
// Return number of vertices of the mesh representation
   Int_t n = gGeoManager->GetNsegments()+1;
   Int_t numPoints = n*4;
   return numPoints;
}

//_____________________________________________________________________________
void TGeoConeSeg::Sizeof3D() const
{
///// fill size of this 3-D object
///    TVirtualGeoPainter *painter = gGeoManager->GetGeomPainter();
///    if (!painter) return;
///
///    Int_t n = gGeoManager->GetNsegments()+1;
///
///    Int_t numPoints = n*4;
///    Int_t numSegs   = n*8;
///    Int_t numPolys  = n*4-2;
///    painter->AddSize3D(numPoints, numSegs, numPolys);
}

//_____________________________________________________________________________
const TBuffer3D & TGeoConeSeg::GetBuffer3D(Int_t reqSections, Bool_t localFrame) const
{
// Fills a static 3D buffer and returns a reference.
   static TBuffer3D buffer(TBuffer3DTypes::kGeneric);

   TGeoBBox::FillBuffer3D(buffer, reqSections, localFrame);

   if (reqSections & TBuffer3D::kRawSizes) {
      Int_t n = gGeoManager->GetNsegments()+1;
      Int_t nbPnts = 4*n;
      Int_t nbSegs = 2*nbPnts;
      Int_t nbPols = nbPnts-2;
      if (buffer.SetRawSizes(nbPnts, 3*nbPnts, nbSegs, 3*nbSegs, nbPols, 6*nbPols)) {
         buffer.SetSectionsValid(TBuffer3D::kRawSizes);
      }
   }
   if ((reqSections & TBuffer3D::kRaw) && buffer.SectionsValid(TBuffer3D::kRawSizes)) {
      SetPoints(buffer.fPnts);
      if (!buffer.fLocalFrame) {
         TransformPoints(buffer.fPnts, buffer.NbPnts());
      }

      SetSegsAndPols(buffer);
      buffer.SetSectionsValid(TBuffer3D::kRaw);
   }
      
   return buffer;
}

//_____________________________________________________________________________
Bool_t TGeoConeSeg::GetPointsOnSegments(Int_t npoints, Double_t *array) const
{
// Fills array with n random points located on the line segments of the shape mesh.
// The output array must be provided with a length of minimum 3*npoints. Returns
// true if operation is implemented.
   if (npoints > (npoints/2)*2) {
      Error("GetPointsOnSegments","Npoints must be even number");
      return kFALSE;
   }   
   Int_t nc = (Int_t)TMath::Sqrt(0.5*npoints);
   Double_t dphi = (fPhi2-fPhi1)*TMath::DegToRad()/(nc-1);
   Double_t phi = 0;
   Double_t phi1 = fPhi1 * TMath::DegToRad();
   Int_t ntop = npoints/2 - nc*(nc-1);
   Double_t dz = 2*fDz/(nc-1);
   Double_t z = 0;
   Double_t rmin = 0.;
   Double_t rmax = 0.;
   Int_t icrt = 0;
   Int_t nphi = nc;
   // loop z sections
   for (Int_t i=0; i<nc; i++) {
      if (i == (nc-1)) {
         nphi = ntop;
         dphi = (fPhi2-fPhi1)*TMath::DegToRad()/(nphi-1);
      }   
      z = -fDz + i*dz;
      rmin = 0.5*(fRmin1+fRmin2) + 0.5*(fRmin2-fRmin1)*z/fDz;
      rmax = 0.5*(fRmax1+fRmax2) + 0.5*(fRmax2-fRmax1)*z/fDz; 
      // loop points on circle sections
      for (Int_t j=0; j<nphi; j++) {
         phi = phi1 + j*dphi;
         array[icrt++] = rmin * TMath::Cos(phi);
         array[icrt++] = rmin * TMath::Sin(phi);
         array[icrt++] = z;
         array[icrt++] = rmax * TMath::Cos(phi);
         array[icrt++] = rmax * TMath::Sin(phi);
         array[icrt++] = z;
      }
   }
   return kTRUE;
}