| fe4da5cc |
1 | * |
| 2 | * $Id$ |
| 3 | * |
| 4 | * $Log$ |
| 5 | * Revision 1.1.1.1 1995/10/24 10:20:54 cernlib |
| 6 | * Geant |
| 7 | * |
| 8 | * |
| 9 | #include "geant321/pilot.h" |
| 10 | *CMZ : 3.21/02 29/03/94 15.41.30 by S.Giani |
| 11 | *-- Author : |
| 12 | SUBROUTINE GNTRP (X, PAR, IACT, SNEXT, SNXT, SAFE) |
| 13 | C. |
| 14 | C. ****************************************************************** |
| 15 | C. * * |
| 16 | C. * COMPUTE DISTANCE UP TO INTERSECTION WITH 'TRAP' VOLUME, * |
| 17 | C. * FROM INSIDE POINT X(1-3) ALONG DIRECTION X(4-6) * |
| 18 | C. * * |
| 19 | C. * PAR (input) : volume parameters * |
| 20 | C. * IACT (input) : action flag * |
| 21 | C. * = 0 Compute SAFE only * |
| 22 | C. * = 1 Compute SAFE, and SNXT only if SNEXT .GT.new SAFE * |
| 23 | C. * = 2 Compute both SAFE and SNXT * |
| 24 | C. * = 3 Compute SNXT only * |
| 25 | C. * SNEXT (input) : see IACT = 1 * |
| 26 | C. * SNXT (output) : distance to volume boundary * |
| 27 | C. * SAFE (output) : shortest distance to any boundary * |
| 28 | C. * * |
| 29 | C. * ==>Called by : GNEXT, GTNEXT * |
| 30 | C. * Author A.McPherson ********* * |
| 31 | C. * * |
| 32 | C. ****************************************************************** |
| 33 | C. |
| 34 | #include "geant321/gconsp.inc" |
| 35 | DIMENSION X(6), PAR(11) |
| 36 | #if defined(CERNLIB_SINGLE) |
| 37 | DIMENSION XT(6), P(11) |
| 38 | #endif |
| 39 | #if !defined(CERNLIB_SINGLE) |
| 40 | DOUBLE PRECISION XT(6), P(11) |
| 41 | DOUBLE PRECISION A,B,C,DSN,TOP1,TOP2,BOT1,BOT2 |
| 42 | DOUBLE PRECISION DX1,DX2,X1,X2,X3,DCX1,DCX2,DX,DY |
| 43 | DOUBLE PRECISION SP1,SP2,DCX,DCY,TANG1,TANG2,A1,B1,A2,B2 |
| 44 | DOUBLE PRECISION XL1,XL2,XL3,XL4,CY,SY,SX,CX,C1,C2 |
| 45 | DOUBLE PRECISION TX,H0,DHDZ,CH |
| 46 | DOUBLE PRECISION CHTAN,SHTAN |
| 47 | DOUBLE PRECISION SN1,SN2,SN3,SN4,SN5,SN6,SN7,SN8,P15 |
| 48 | #endif |
| 49 | C. |
| 50 | C. -------------------------------------- |
| 51 | C. |
| 52 | SNXT = BIG |
| 53 | SAFE = 0.0 |
| 54 | DO 1 I=1,6 |
| 55 | 1 XT(I)=X(I) |
| 56 | DO 2 I=1,11 |
| 57 | 2 P(I)=PAR(I) |
| 58 | |
| 59 | P15=0.5/P(1) |
| 60 | DHDZ=(P(4)-P(8))*P15 |
| 61 | |
| 62 | IF (IACT .LT. 3) THEN |
| 63 | |
| 64 | |
| 65 | C ------------------------------------------------- |
| 66 | C | Compute safety-distance 'SAFE' (McPherson) | |
| 67 | C ------------------------------------------------- |
| 68 | |
| 69 | |
| 70 | C CALCULATE RECTANGLE ON FACE AT Z=-DZ. |
| 71 | |
| 72 | DX1=P(4)*P(7) |
| 73 | X1=-DX1-P(5) |
| 74 | X2=DX1-P(6) |
| 75 | IF(X2.GT.X1) X1=X2 |
| 76 | X2=-DX1+P(5) |
| 77 | X3=DX1+P(6) |
| 78 | IF(X3.LT.X2) X2=X3 |
| 79 | DCX1=(X1+X2)*0.5 |
| 80 | DX1=(X2-X1)*0.5 |
| 81 | C |
| 82 | C CALCULATE RECTANGLE ON FACE AT Z=DZ. |
| 83 | C |
| 84 | DX2=P(8)*P(11) |
| 85 | X1=-DX2-P(9) |
| 86 | X2=DX2-P(10) |
| 87 | IF(X2.GT.X1) X1=X2 |
| 88 | X2=-DX2+P(9) |
| 89 | X3=DX2+P(10) |
| 90 | IF(X3.LT.X2) X2=X3 |
| 91 | DCX2=(X1+X2)*0.5 |
| 92 | DX2=(X2-X1)*0.5 |
| 93 | |
| 94 | C |
| 95 | TX=P(2)+(DCX2-DCX1)*P15 |
| 96 | C |
| 97 | C CALCULATE LOCAL RECTANGLE. |
| 98 | C |
| 99 | SP1=(P(1)-XT(3))*P15 |
| 100 | SP2=(P(1)+XT(3))*P15 |
| 101 | C |
| 102 | DY=P(4)*SP1+P(8)*SP2 |
| 103 | DX=DX1*SP1+DX2*SP2 |
| 104 | DCX=(DCX1+DCX2)*0.5+TX*XT(3) |
| 105 | DCY=P(3)*XT(3) |
| 106 | C |
| 107 | C CHECK POINT IS INSIDE RECTANGLE. |
| 108 | C |
| 109 | IF(ABS(XT(1)-DCX).GT.DX) GO TO 10 |
| 110 | C |
| 111 | C CALCULATE ANGLE OF YZ PLANES. |
| 112 | C |
| 113 | TANG1=TX+(DX1-DX2)*P15 |
| 114 | TANG2=TX-(DX1-DX2)*P15 |
| 115 | C |
| 116 | C CALCULATE SAFETY FROM YZ PLANES. |
| 117 | C |
| 118 | SAF1=(XT(1)-DCX+DX)/SQRT(1.0+TANG1*TANG1) |
| 119 | SAF2=(DX-XT(1)+DCX)/SQRT(1.0+TANG2*TANG2) |
| 120 | C |
| 121 | C CALCULATE ANGLE OF XZ PLANES. |
| 122 | C |
| 123 | TANG1=P(3)+DHDZ |
| 124 | TANG2=P(3)-DHDZ |
| 125 | C |
| 126 | C CALCULATE SAFETY FROM XZ PLANES. |
| 127 | C |
| 128 | SAF3=(XT(2)-DCY+DY)/SQRT(1.0+TANG1*TANG1) |
| 129 | SAF4=(DY-XT(2)+DCY)/SQRT(1.0+TANG2*TANG2) |
| 130 | C |
| 131 | C CALCULATE SAFETY FROM XY PLANES. |
| 132 | C |
| 133 | SAF5=P(1)-ABS(XT(3)) |
| 134 | C |
| 135 | C OVERALL SAFETY. |
| 136 | C |
| 137 | SAFE = MIN(SAF1,SAF2,SAF3,SAF4,SAF5) |
| 138 | |
| 139 | |
| 140 | IF (IACT .EQ. 0) GO TO 999 |
| 141 | IF (IACT .EQ. 1) THEN |
| 142 | IF (SNEXT .LT. SAFE) GO TO 999 |
| 143 | ENDIF |
| 144 | ENDIF |
| 145 | |
| 146 | |
| 147 | 10 CONTINUE |
| 148 | |
| 149 | C ------------------------------------------------ |
| 150 | C | Compute vector-distance 'SNXT' (McPherson) | |
| 151 | C ------------------------------------------------ |
| 152 | |
| 153 | |
| 154 | |
| 155 | C FIRST FIND S TO Z LIMITS. |
| 156 | |
| 157 | SN1=BIG |
| 158 | SN2=BIG |
| 159 | SN3=BIG |
| 160 | SN4=BIG |
| 161 | C |
| 162 | IF(XT(6).EQ.0.0) GOTO 15 |
| 163 | SN1=(P(1)-XT(3))/XT(6) |
| 164 | SN2=-(P(1)+XT(3))/XT(6) |
| 165 | IF(SN1.GE.0.) GOTO 15 |
| 166 | SNX=SN1 |
| 167 | SN1=SN2 |
| 168 | SN2=SNX |
| 169 | 15 CONTINUE |
| 170 | C |
| 171 | C NOW Y LIMITS. |
| 172 | C |
| 173 | H0=(P(4)+P(8))*0.5 |
| 174 | C |
| 175 | TOP1=H0-DHDZ*XT(3) |
| 176 | TOP2=XT(2)-XT(3)*P(3) |
| 177 | BOT1=XT(5)-XT(6)*P(3) |
| 178 | BOT2=DHDZ*XT(6) |
| 179 | C |
| 180 | IF(BOT1+BOT2.NE.0.0) SN3=(TOP1-TOP2)/(BOT1+BOT2) |
| 181 | IF(BOT2-BOT1.NE.0.0) SN4=(TOP1+TOP2)/(BOT2-BOT1) |
| 182 | C |
| 183 | C NOW X LIMTS. |
| 184 | C |
| 185 | XL1=(P(5)+P(6)+P(9)+P(10))*0.25 |
| 186 | XL2=(P(5)-P(6)+P(9)-P(10))*0.25 |
| 187 | XL3=(P(5)+P(6)-P(9)-P(10))*0.25 |
| 188 | XL4=(P(5)-P(6)-P(9)+P(10))*0.25 |
| 189 | C |
| 190 | CY=XT(2)-XT(3)*P(3) |
| 191 | SY=XT(5)-XT(6)*P(3) |
| 192 | CH=H0-DHDZ*XT(3) |
| 193 | C |
| 194 | A1=XL4*XT(6)*SY+XL3*XT(6)*XT(6)*DHDZ |
| 195 | B1=XL4*(XT(6)*CY+XT(3)*SY)-XL3*XT(6)*(CH-XT(3)*DHDZ)-XL2*P(1)*SY- |
| 196 | +XL1*XT(6)*DHDZ*P(1) |
| 197 | C1=XL4*CY*XT(3)-XL3*XT(3)*CH-XL2*CY*P(1)+XL1*CH*P(1) |
| 198 | C |
| 199 | CHTAN=(P(7)*P(4)+P(11)*P(8))*0.5 |
| 200 | SHTAN=-(P(7)*P(4)-P(11)*P(8))*P15 |
| 201 | CHTAN=CHTAN+SHTAN*XT(3) |
| 202 | SHTAN=SHTAN*XT(6) |
| 203 | CX=XT(1)-XT(3)*P(2) |
| 204 | SX=XT(4)-XT(6)*P(2) |
| 205 | C |
| 206 | A2=-P(1)*(DHDZ*XT(6)*SX+SY*SHTAN) |
| 207 | B2=P(1)*(CH*SX-DHDZ*XT(6)*CX-CY*SHTAN-SY*CHTAN) |
| 208 | C2=P(1)*(CH*CX-CY*CHTAN) |
| 209 | C |
| 210 | ISN56=0 |
| 211 | A=A1+A2 |
| 212 | B=B1+B2 |
| 213 | C=C1+C2 |
| 214 | IF(B*B-A*C*4.0.LT.0.0) GO TO 20 |
| 215 | IF(ABS(A).LT.1.0E-7) GO TO 19 |
| 216 | DSN=SQRT(B*B-A*C*4.0) |
| 217 | SN5=(-B+DSN)*0.5/A |
| 218 | SN6=(-B-DSN)*0.5/A |
| 219 | ISN56=1 |
| 220 | GO TO 20 |
| 221 | 19 CONTINUE |
| 222 | IF(ABS(B).LT.1.0E-5) GO TO 20 |
| 223 | ISN56=1 |
| 224 | SN5=-C/B |
| 225 | SN6=-C/B |
| 226 | 20 CONTINUE |
| 227 | C |
| 228 | ISN78=0 |
| 229 | A=A1-A2 |
| 230 | B=B1-B2 |
| 231 | C=C1-C2 |
| 232 | IF(B*B-A*C*4.0.LT.0.0) GO TO 30 |
| 233 | DSN=SQRT(B*B-A*C*4.0) |
| 234 | IF(ABS(A).LT.1.0E-7) GO TO 25 |
| 235 | SN7=(-B+DSN)*0.5/A |
| 236 | SN8=(-B-DSN)*0.5/A |
| 237 | ISN78=1 |
| 238 | GO TO 30 |
| 239 | 25 CONTINUE |
| 240 | IF(ABS(B).LT.1.0E-5) GO TO 30 |
| 241 | ISN78=1 |
| 242 | SN7=-C/B |
| 243 | SN8=-C/B |
| 244 | 30 CONTINUE |
| 245 | C |
| 246 | IF(SN2.GT.0.0.AND.SN2.LT.SN1) SN1=SN2 |
| 247 | IF(SN3.GT.0.0.AND.SN3.LT.SN1) SN1=SN3 |
| 248 | IF(SN4.GT.0.0.AND.SN4.LT.SN1) SN1=SN4 |
| 249 | IF(ISN56.EQ.0) GO TO 40 |
| 250 | IF(SN5.GT.0.0.AND.SN5.LT.SN1) SN1=SN5 |
| 251 | IF(SN6.GT.0.0.AND.SN6.LT.SN1) SN1=SN6 |
| 252 | 40 CONTINUE |
| 253 | IF(ISN78.EQ.0) GO TO 50 |
| 254 | IF(SN7.GT.0.0.AND.SN7.LT.SN1) SN1=SN7 |
| 255 | IF(SN8.GT.0.0.AND.SN8.LT.SN1) SN1=SN8 |
| 256 | 50 CONTINUE |
| 257 | C |
| 258 | SNXT=SN1 |
| 259 | C |
| 260 | 999 CONTINUE |
| 261 | END |
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