// from the following website
// https://root.cern.ch/doc/master/classTGeoCtub.html

void targetbox1()
{
   TCanvas *c = new TCanvas("c", "c",0,0,600,600);
   new TGeoManager("ctub", "poza3");
   TGeoMaterial *mat = new TGeoMaterial("Al", 26.98,13,2.7);
   TGeoMedium *med = new TGeoMedium("MED",1,mat);
   TGeoVolume *top = gGeoManager->MakeBox("TOP",med,100,100,100);
   gGeoManager->SetTopVolume(top);

   Double_t angle1 = 190;
   Double_t angle2 = 170;
  
//   Double_t angle1 =   0;
//   Double_t angle2 = 360;
  
   Double_t theta = 160.*TMath::Pi()/180.;
   Double_t phi   = 30.*TMath::Pi()/180.;

   Double_t nlow[3];
   nlow[0] = TMath::Sin(theta)*TMath::Cos(phi);
   nlow[1] = TMath::Sin(theta)*TMath::Sin(phi);
   nlow[2] = TMath::Cos(theta);

   cout << "1 - lx: " << nlow[0] << " ly: " << nlow[1] << " lz: " << nlow[2] << endl;

   nlow[0] =  0;
   nlow[1] =  0;
   nlow[2] = -1;

   cout << "2 - lx: " << nlow[0] << " ly: " << nlow[1] << " lz: " << nlow[2] << endl;
   
   
   //   theta = 20.*TMath::Pi()/180.;
   //   phi   = 60.*TMath::Pi()/180.;
   theta =  25.*TMath::Pi()/180.;
   phi   = 180.*TMath::Pi()/180.;

   Double_t nhi[3];
   nhi[0] = TMath::Sin(theta)*TMath::Cos(phi);
   nhi[1] = TMath::Sin(theta)*TMath::Sin(phi);
   nhi[2] = TMath::Cos(theta);

   cout << "3 - hx: " <<  nhi[0] << " hy: " <<  nhi[1] << " hz: " <<  nhi[2] << endl;
   
// TGeoVolume *ctub = gGeoManager->MakeCtub("CTUB", med, 25, 27, 30, 200, 160, nlow[0], nlow[1], nlow[2], nhi[0], nhi[1], nhi[2]);


//   // Durchmesser   35.56 cm
//   // Wanddicke      0.3 cm
//
//   // 0.4 + 53.31 + cos(25.*acos(-1.)/180.) * 0.6 = 54.25 cm
//
//   53.31 cm - tan(25.*acos(-1.)/180.) * 17.78 cm = 45.019050 cm

//   // check
//   60.98 - 45.2 - cos(25.*acos(-1.)/180.) * 0.6 = 15.236215
//   60.98 cm - 45.2 cm - cos(25.*acos(-1.)/180.) * 0.6 cm = 15.24 cm
//
//   15.24 + 38.0 - 7.7 - 0.4 = 45.14    
//   15.24 cm + 38.0 cm - 7.7 cm - 0.4 cm = 45.14 cm    
//
//   // Laenge       45.1 cm
//
//   // offset to left side
//   38.0 - 7.7 - 0.4 = 29.9 
//
//   // Offset       29.9 cm
   
   Double_t rmax   = 35.56/2.;
   Double_t rmin   = rmax - 0.3;
   Double_t length = 45.1;
   Double_t offset = 29.9;
   
   TGeoVolume *ctub = gGeoManager->MakeCtub("CTUB", med, rmin, rmax, length/2., angle1, angle2,
					    nlow[0], nlow[1], nlow[2], nhi[0], nhi[1], nhi[2]);
   ctub->SetLineWidth(2);
   TGeoTranslation* tctub = new TGeoTranslation("tctub", 0, 0, -offset+length/2.);
   top->AddNode(ctub, 1, tctub);

 
   //   from z= -29.9 to z= 15.2 cm

   Double_t rmin1   = 15.9 /2.;
   Double_t thick1  =  0.4;

   // upstream cover
   TGeoVolume *cups = gGeoManager->MakeCtub("CUPS", med, rmin1, rmax, thick1/2., angle1, angle2, 0, 0,-1, 0, 0, 1);
   cups->SetLineWidth(2);
   TGeoTranslation* tups = new TGeoTranslation("tups", 0, 0, -offset-thick1/2.);
   top->AddNode(cups, 1, tups);

   
   // Hoehe                   35.56 cm
   // Breite   19.62 cm * 2 = 39.24 cm
   // Dicke                    0.60 mm

   Double_t rmin2   =  5.0 /2.;
   Double_t thick2  =  0.6;

   // downstream cover 1 
//   TGeoVolume *dwst = gGeoManager->MakeEltu("DWST", med, 39.24/2., 35.56/2., thick2/2.);
//   dwst->SetLineWidth(2);
//   TGeoRotation* dwrot = new TGeoRotation();
//   dwrot->RotateY(-25.);
//   TGeoCombiTrans* tdwst = new TGeoCombiTrans("tdwst", 0, 0, -offset +length +thick2/2., dwrot);
//   TGeoTranslation* tdwst = new TGeoTranslation("tdwst", 0, 0, -offset +length +thick2/2.);
//   top->AddNode(dwst, 1, tdwst);

   
   // downstream cover 2
   TGeoVolume *cdown = gGeoManager->MakeCtub("CDOWN", med, rmin2, rmax, thick2/2., angle1, angle2,
					    -nhi[0],-nhi[1],-nhi[2], nhi[0], nhi[1], nhi[2]);
   cdown->SetLineWidth(2);
   TGeoTranslation* tdown = new TGeoTranslation("tdown", 0, 0, -offset +length +thick2/2.);
   top->AddNode(cdown, 1, tdown);


   // tan(25 deg) * 5.4 cm = 2.518 cm
   // tan(25.*acos(-1.)/180.) * 5.4 = 2.5180614
   // 47.12 - tan(25.*acos(-1.)/180.)*5.4 - 0.6 = 44.0 cm 
   // Laenge       44.0 cm
   // Durchmesser   5.4 cm
   // Wanddicke     0.2 cm

   Double_t rmax3   =  5.4 /2.;
   Double_t rmin3   =  rmax3-0.2;
   Double_t length3 = 44.0;


   // downstream pipe 
   TGeoVolume *cpip = gGeoManager->MakeCtub("CPIP", med, rmin2, rmax3, length3/2., angle1, angle2,
					    -nhi[0],-nhi[1],-nhi[2],-nlow[0],-nlow[1],-nlow[2]);
   cpip->SetLineWidth(2);
   TGeoTranslation* tpip = new TGeoTranslation("tpip", 0, 0, -offset +length +thick2 +length3/2.);
   top->AddNode(cpip, 1, tpip);


   gGeoManager->CloseGeometry();
   gGeoManager->SetNsegments(80);
   gGeoManager->CheckOverlaps(0.001);

   top->Draw();
   TView *view = gPad->GetView();
   view->ShowAxis();
}