GEANT321/cgpack/cgtset.F

   1 *
   2 * $Id$
   3 *
   4 * $Log$
   5 * Revision 1.1.1.1  1995/10/24 10:19:45  cernlib
   6 * Geant
   7 *
   8 *
   9 #include "geant321/pilot.h"
  10 *CMZ :  3.21/02 29/03/94  15.41.32  by  S.Giani
  11 *-- Author :
  12       SUBROUTINE CGTSET(N,T,IREP)
  13 ************************************************************************
  14 *                                                                      *
  15 *     Name: CGTSET                                                     *
  16 *     Author: E. Chernyaev                       Date:    31.07.88     *
  17 *                                                Revised:              *
  18 *                                                                      *
  19 *     Function: Set transformation to screen coordinates and           *
  20 *               find back transformation to world coordinates          *
  21 *                                                                      *
  22 *     References: none                                                 *
  23 *                                                                      *
  24 *     Input: N - transformation number                                 *
  25 *            T(4,3) - transformation matrix                            *
  26 *                                                                      *
  27 *     Output: IREP - reply ( 0 - O.K.                                  *
  28 *                           -1 - if illigal N,                         *
  29 *                           -2 - if DET(T)=0.)                         *
  30 *                                                                      *
  31 *     Errors: none                                                     *
  32 *                                                                      *
  33 ************************************************************************
  34 #include "geant321/cgctra.inc"
  35       REAL T(4,3)
  36 *-          P A R A M E T E R S   C H E C K
  37       IREP   = 0
  38       IF (N.LE.0 .OR. N.GT.NTMAX)       IREP = -1
  39       DET = T(1,1)*T(2,2)*T(3,3) - T(3,1)*T(2,2)*T(1,3) +
  40      +      T(3,1)*T(1,2)*T(2,3) - T(1,1)*T(3,2)*T(2,3) +
  41      +      T(2,1)*T(3,2)*T(1,3) - T(2,1)*T(1,2)*T(3,3)
  42 *      IF (ABS(DET) .LT. 1./DELWOR)      IREP = -2
  43       IF (IREP .LT. 0)                  GOTO 999
  44 *           S E T   T R A N S F O R M A T I O N   M A T R I X
  45       DO 200 I=1,4
  46         DO 100 J=1,3
  47           TSCRN(I,J,N) = T(I,J)
  48   100     CONTINUE
  49   200   CONTINUE
  50 *           F I N D   M A T R I X   F O R   B A C K   TRANSFORMATION
  51       TBACK(1,1,N) = (T(2,2)*T(3,3) - T(2,3)*T(3,2)) / DET
  52       TBACK(2,1,N) =-(T(2,1)*T(3,3) - T(2,3)*T(3,1)) / DET
  53       TBACK(3,1,N) = (T(2,1)*T(3,2) - T(2,2)*T(3,1)) / DET
  54       TBACK(4,1,N) =-(T(2,1)*T(3,2)*T(4,3) - T(4,1)*T(3,2)*T(2,3) +
  55      +                T(4,1)*T(2,2)*T(3,3) - T(2,1)*T(4,2)*T(3,3) +
  56      +                T(3,1)*T(4,2)*T(2,3) - T(3,1)*T(2,2)*T(4,3))/DET
  57       TBACK(1,2,N) =-(T(1,2)*T(3,3) - T(1,3)*T(3,2)) / DET
  58       TBACK(2,2,N) = (T(1,1)*T(3,3) - T(1,3)*T(3,1)) / DET
  59       TBACK(3,2,N) =-(T(1,1)*T(3,2) - T(1,2)*T(3,1)) / DET
  60       TBACK(4,2,N) = (T(1,1)*T(3,2)*T(4,3) - T(4,1)*T(3,2)*T(1,3) +
  61      +                T(4,1)*T(1,2)*T(3,3) - T(1,1)*T(4,2)*T(3,3) +
  62      +                T(3,1)*T(4,2)*T(1,3) - T(3,1)*T(1,2)*T(4,3))/DET
  63       TBACK(1,3,N) = (T(1,2)*T(2,3) - T(1,3)*T(2,2)) / DET
  64       TBACK(2,3,N) =-(T(1,1)*T(2,3) - T(1,3)*T(2,1)) / DET
  65       TBACK(3,3,N) = (T(1,1)*T(2,2) - T(1,2)*T(2,1)) / DET
  66       TBACK(4,3,N) =-(T(1,1)*T(2,2)*T(4,3) - T(4,1)*T(2,2)*T(1,3) +
  67      +                T(4,1)*T(1,2)*T(2,3) - T(1,1)*T(4,2)*T(2,3) +
  68      +                T(2,1)*T(4,2)*T(1,3) - T(2,1)*T(1,2)*T(4,3))/DET
  69 *
  70   999 RETURN
  71       END