/************************************************************************** * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * * * * Author: The ALICE Off-line Project. * * Contributors are mentioned in the code where appropriate. * * * * Permission to use, copy, modify and distribute this software and its * * documentation strictly for non-commercial purposes is hereby granted * * without fee, provided that the above copyright notice appears in all * * copies and that both the copyright notice and this permission notice * * appear in the supporting documentation. The authors make no claims * * about the suitability of this software for any purpose. It is * * provided "as is" without express or implied warranty. * **************************************************************************/ /* $Log$ Revision 1.4 2000/11/30 07:12:49 alibrary Introducing new Rndm and QA classes Revision 1.3 2000/10/26 14:15:54 morsch - Base class now - Change from theta, phi to general coordinates Coor1, Coor2 - PropagateCylinder: bug in calculation of distance to limiting radius corrected. Revision 1.2 2000/07/13 16:19:09 fca Mainly coding conventions + some small bug fixes Revision 1.1 2000/07/12 08:56:25 fca Coding convention correction and warning removal Revision 1.16 2000/05/26 08:35:03 fca Move the check on z after z has been retrieved Revision 1.15 2000/05/16 13:10:40 fca New method IsNewTrack and fix for a problem in Father-Daughter relations Revision 1.14 2000/04/27 10:38:21 fca Correct termination of Lego Run and introduce Lego getter in AliRun Revision 1.13 2000/04/26 10:17:31 fca Changes in Lego for G4 compatibility Revision 1.12 2000/04/07 11:12:33 fca G4 compatibility changes Revision 1.11 2000/03/22 13:42:26 fca SetGenerator does not replace an existing generator, ResetGenerator does Revision 1.10 2000/02/23 16:25:22 fca AliVMC and AliGeant3 classes introduced ReadEuclid moved from AliRun to AliModule Revision 1.9 1999/12/03 10:54:01 fca Fix lego summary Revision 1.8 1999/10/01 09:54:33 fca Correct logics for Lego StepManager Revision 1.7 1999/09/29 09:24:29 fca Introduction of the Copyright and cvs Log */ #include "AliLegoGenerator.h" #include "AliRun.h" ClassImp(AliLegoGenerator) //___________________________________________ AliLegoGenerator::AliLegoGenerator() { // // Default Constructor // SetName("Lego"); fCoor1Bin = fCoor2Bin = -1; fCurCoor1 = fCurCoor2 = 0; } AliLegoGenerator::AliLegoGenerator(Int_t nc1, Float_t c1min, Float_t c1max, Int_t nc2, Float_t c2min, Float_t c2max, Float_t rmin, Float_t rmax, Float_t zmax) : AliGenerator(0), fRadMin(rmin), fRadMax(rmax), fZMax(zmax), fNCoor1(nc1), fNCoor2(nc2), fCoor1Bin(nc1), fCoor2Bin(-1), fCurCoor1(0), fCurCoor2(0) { // // Standard generator for Lego rays // SetCoor1Range(nc1, c1min, c1max); SetCoor2Range(nc2, c2min, c2max); SetName("Lego"); } //___________________________________________ void AliLegoGenerator::Generate() { // Create a geantino with kinematics corresponding to the current bins // Here: Coor1 = theta // Coor2 = phi. // // Rootinos are 0 const Int_t kMpart = 0; Float_t orig[3], pmom[3]; Float_t t, cost, sint, cosp, sinp; if (fCoor1Bin==-1) fCoor1Bin=fNCoor1; // Prepare for next step if(fCoor1Bin>=fNCoor1-1) if(fCoor2Bin>=fNCoor2-1) { Warning("Generate","End of Lego Generation"); return; } else { fCoor2Bin++; printf("Generating rays in phi bin:%d\n",fCoor2Bin); fCoor1Bin=0; } else fCoor1Bin++; fCurCoor1 = (fCoor1Min+(fCoor1Bin+0.5)*(fCoor1Max-fCoor1Min)/fNCoor1); fCurCoor2 = (fCoor2Min+(fCoor2Bin+0.5)*(fCoor2Max-fCoor2Min)/fNCoor2); cost = TMath::Cos(fCurCoor1 * TMath::Pi()/180.); sint = TMath::Sin(fCurCoor1 * TMath::Pi()/180.); cosp = TMath::Cos(fCurCoor2 * TMath::Pi()/180.); sinp = TMath::Sin(fCurCoor2 * TMath::Pi()/180.); pmom[0] = cosp*sint; pmom[1] = sinp*sint; pmom[2] = cost; // --- Where to start orig[0] = orig[1] = orig[2] = 0; Float_t dalicz = 3000; if (fRadMin > 0) { t = PropagateCylinder(orig,pmom,fRadMin,dalicz); orig[0] = pmom[0]*t; orig[1] = pmom[1]*t; orig[2] = pmom[2]*t; if (TMath::Abs(orig[2]) > fZMax) return; } Float_t polar[3]={0.,0.,0.}; Int_t ntr; gAlice->SetTrack(1, -1, kMpart, pmom, orig, polar, 0, kPPrimary, ntr); } //___________________________________________ Float_t AliLegoGenerator::PropagateCylinder(Float_t *x, Float_t *v, Float_t r, Float_t z) { // Propagate to cylinder from inside Double_t hnorm, sz, t, t1, t2, t3, sr; Double_t d[3]; const Float_t kSmall = 1e-8; const Float_t kSmall2 = kSmall*kSmall; // ---> Find intesection with Z planes d[0] = v[0]; d[1] = v[1]; d[2] = v[2]; hnorm = TMath::Sqrt(1/(d[0]*d[0]+d[1]*d[1]+d[2]*d[2])); d[0] *= hnorm; d[1] *= hnorm; d[2] *= hnorm; if (d[2] > kSmall) sz = (z-x[2])/d[2]; else if (d[2] < -kSmall) sz = -(z+x[2])/d[2]; else sz = 1.e10; // ---> Direction parallel to X-Y, no intersection // ---> Intersection with cylinders // Intersection point (x,y,z) // (x,y,z) is on track : x=X(1)+t*D(1) // y=X(2)+t*D(2) // z=X(3)+t*D(3) // (x,y,z) is on cylinder : x**2 + y**2 = R**2 // // (D(1)**2+D(2)**2)*t**2 // +2.*(X(1)*D(1)+X(2)*D(2))*t // +X(1)**2+X(2)**2-R**2=0 // ---> Solve second degree equation t1 = d[0]*d[0] + d[1]*d[1]; if (t1 <= kSmall2) { t = sz; // ---> Track parallel to the z-axis, take distance to planes } else { t2 = x[0]*d[0] + x[1]*d[1]; t3 = x[0]*x[0] + x[1]*x[1]; // ---> It should be positive, but there may be numerical problems sr = (-t2 +TMath::Sqrt(TMath::Max(t2*t2-(t3-r*r)*t1,0.)))/t1; // ---> Find minimum distance between planes and cylinder t = TMath::Min(sz,sr); } return t; }