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1 | * |
| 2 | * $Id$ |
| 3 | * |
| 4 | * $Log$ |
| 5 | * Revision 1.1.1.1 1995/10/24 10:19:41 cernlib |
| 6 | * Geant |
| 7 | * |
| 8 | * |
| 9 | #include "geant321/pilot.h" |
| 10 | *CMZ : 3.21/02 29/03/94 15.41.31 by S.Giani |
| 11 | *-- Author : |
| 12 | SUBROUTINE CGBFIT(FACE,ABCD,NT) |
| 13 | ************************************************************************ |
| 14 | * * |
| 15 | * Name: CGBFIT * |
| 16 | * Author: E. Chernyaev Date: 15.03.89 * |
| 17 | * Revised: S.Giani 1992 * |
| 18 | * * |
| 19 | * Function: Find all intersection points of face with plane * |
| 20 | * * |
| 21 | * References: none * |
| 22 | * * |
| 23 | * Input: FACE(*) - face * |
| 24 | * ABCD(4) - plane * |
| 25 | * * |
| 26 | * Output: NT - number of intersections * |
| 27 | * * |
| 28 | * * |
| 29 | ************************************************************************ |
| 30 | #include "geant321/cggpar.inc" |
| 31 | #include "geant321/cgcedg.inc" |
| 32 | #include "geant321/cgdelt.inc" |
| 33 | REAL FACE(*),ABCD(4) |
| 34 | #if !defined(CERNLIB_SINGLE) |
| 35 | DOUBLE PRECISION A,B,C,D |
| 36 | #endif |
| 37 | INTEGER KCG(6) |
| 38 | DATA KCG/KCGX1,KCGY1,KCGZ1,KCGX2,KCGY2,KCGZ2/ |
| 39 | *- |
| 40 | ERROR = EEWOR |
| 41 | A = ABCD(1) |
| 42 | B = ABCD(2) |
| 43 | C = ABCD(3) |
| 44 | D = ABCD(4) |
| 45 | * D1=0 |
| 46 | * D2=0 |
| 47 | XDELT = FACE(KCGBB)*C - B*FACE(KCGCC) |
| 48 | YDELT = FACE(KCGCC)*A - C*FACE(KCGAA) |
| 49 | ZDELT = FACE(KCGAA)*B - A*FACE(KCGBB) |
| 50 | K = 1 |
| 51 | IF (ABS(YDELT) .GT. ABS(XDELT)) K = 2 |
| 52 | IF (ABS(ZDELT) .GT. ABS(DELTA(K))) K = 3 |
| 53 | IF(ABS(DELTA(K)).LT.ERROR)RETURN |
| 54 | DD = 1./ABS(DELTA(K)) |
| 55 | DELTA(1) = DELTA(1) * DD |
| 56 | DELTA(2) = DELTA(2) * DD |
| 57 | DELTA(3) = DELTA(3) * DD |
| 58 | KCG1 = KCG(K) |
| 59 | KCG2 = KCG(K+3) |
| 60 | * F I N D I N T E R S E C T I O N S P O I N T S |
| 61 | J = LCGFAC - LCGEDG |
| 62 | NT = 0 |
| 63 | NEDGE = FACE(KCGNE) |
| 64 | DO 600 NE=1,NEDGE |
| 65 | J = J + LCGEDG |
| 66 | D1 = A*FACE(J+KCGX1) + B*FACE(J+KCGY1) + C*FACE(J+KCGZ1) + D |
| 67 | D2 = A*FACE(J+KCGX2) + B*FACE(J+KCGY2) + C*FACE(J+KCGZ2) + D |
| 68 | IF (ABS(D1) .LE. ERROR) D1 = 0. |
| 69 | IF (ABS(D2) .LE. ERROR) D2 = 0. |
| 70 | IF (D1*D2 .GT. 0.) GOTO 600 |
| 71 | NT = NT + 1 |
| 72 | IF (D1.EQ.0. .AND. D2.EQ.0.) GOTO 500 |
| 73 | IF (D1.LT.0. .OR. D2.GT.0.) TTT(2,NT) =-1. |
| 74 | IF (D1.GT.0. .OR. D2.LT.0.) TTT(2,NT) =+1. |
| 75 | * D 1 O R D 2 I S N O T Z E R O |
| 76 | IF (NT .NE. 1) GOTO 400 |
| 77 | XA = (D2*FACE(J+KCGX1)-D1*FACE(J+KCGX2)) / (D2 - D1) |
| 78 | YA = (D2*FACE(J+KCGY1)-D1*FACE(J+KCGY2)) / (D2 - D1) |
| 79 | ZA = (D2*FACE(J+KCGZ1)-D1*FACE(J+KCGZ2)) / (D2 - D1) |
| 80 | TTT(1,1) = 0. |
| 81 | GOTO 600 |
| 82 | 400 X = (D2*FACE(J+KCG1)-D1*FACE(J+KCG2)) / (D2 - D1) |
| 83 | TTT(1,NT) = (X - AA(K)) / DELTA(K) |
| 84 | GOTO 600 |
| 85 | * D 1 A N D D 2 B O T H A R E Z E R O |
| 86 | 500 IF (NT .NE. 1) GOTO 510 |
| 87 | XA = FACE(J+KCGX1) |
| 88 | YA = FACE(J+KCGY1) |
| 89 | ZA = FACE(J+KCGZ1) |
| 90 | TTT(1,1) = 0. |
| 91 | TTT(2,1) = 0. |
| 92 | GOTO 520 |
| 93 | 510 X = FACE(J+KCG1) |
| 94 | TTT(1,NT) = (X - AA(K)) / DELTA(K) |
| 95 | TTT(2,NT) = 0. |
| 96 | 520 NT = NT + 1 |
| 97 | X = FACE(J+KCG2) |
| 98 | TTT(1,NT) = (X - AA(K)) / DELTA(K) |
| 99 | TTT(2,NT) = 2. |
| 100 | IF (TTT(1,NT) .GT. TTT(1,NT-1)) GOTO 600 |
| 101 | TTT(2,NT-1)= 2. |
| 102 | TTT(2,NT) = 0. |
| 103 | 600 CONTINUE |
| 104 | RETURN |
| 105 | END |
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