Corrected stack pointer to optical photons.
[u/mrichter/AliRoot.git] / TFluka / magfld.cxx
CommitLineData
8fd1d27e 1#include "TVirtualMCApplication.h"
4ba5ffc7 2#include "Fdblprc.h" //(DBLPRC) fluka common
3//
4// #include "TCallf77.h"
5
6#ifndef WIN32
7#define magfld magfld_
8#define type_of_call
9#else
10#define magfld MAGFLD
11#define type_of_call _stdcall
12#endif
13
14extern "C" void type_of_call magfld(double& x, double& y, double& z,
15 double& btx, double& bty, double& btz, double& b,
a7bb59a2 16 int& /*nreg*/,int& idisc)
4ba5ffc7 17{
18
19/*
20*----------------------------------------------------------------------*
21* *
22* *
23* Input variables: *
24* x,y,z = current position *
25* nreg = current region *
26* Output variables: *
27* btx,bty,btz = cosines of the magn. field vector *
28* B = magnetic field intensity (Tesla) *
29* idisc = set to 1 if the particle has to be discarded *
30* *
31*----------------------------------------------------------------------*
32*/
4ba5ffc7 33
34 idisc = 0;
35
8fd1d27e 36 Double_t bc[3];
37 Double_t xc[3];
4ba5ffc7 38
b36901ee 39 xc[0] = x;
40 xc[1] = y;
4ba5ffc7 41 xc[2] = z;
42
43
44
8fd1d27e 45 (TVirtualMCApplication::Instance())->Field(xc, bc);
4ba5ffc7 46
47 b = sqrt(bc[0] * bc[0] + bc[1] * bc[1] + bc[2] * bc[2]);
48 if (b) {
a8e80ce5 49 btx = bc[0]/b;
50 bty = bc[1]/b;
4ba5ffc7 51 Double_t btt = btx * btx + bty * bty;
52 if (btt >= (Double_t) 1.) {
53 btx /= TMath::Sqrt(btt);
54 bty /= TMath::Sqrt(btt);
55 b /= TMath::Sqrt(btt);
56 btz = (Double_t) 0.;
57 } else {
a8e80ce5 58 btz = TMath::Sign(TMath::Sqrt((Double_t) 1. - btt), bc[2]);
4ba5ffc7 59 }
60 } else {
61 btx = 0.;
62 bty = 0.;
63 btz = 1.;
64 }
65
66 // from kG to T
67 b /= (Double_t) 10.;
4ba5ffc7 68}