C J3SINT    SOURCE    CHAT      05/01/13    00:47:23     5004           
      SUBROUTINE J3SINT(XY1,XY2,XY3,XY4,XTOL,XLAM,XGAM,XY)
C----------------------------------------------------
C     SEGMENT INTERSECTION
C
C     ESCLAVE DE J3COTO
C
C     PP 6/97
C     Pierre Pegon/JRC Ispra
C----------------------------------------------------
C
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8(A-H,O-Z)
-INC CCREEL
      DIMENSION XY1(2),XY2(2),XY3(2),XY4(2),XY(2)
C
      XLAM=XGRAND
      XGAM=XGRAND
C
      DET=(XY2(1)-XY1(1))*(XY3(2)-XY4(2))
     >   -(XY2(2)-XY1(2))*(XY3(1)-XY4(1))
C
C     LES SEGMENTS SONT PARALLELS
C
      IF(ABS(DET).LT.XTOL)RETURN
C
C     LES SEGMENTS SE COUPENT
C
      XLAM=((XY3(1)-XY1(1))*(XY3(2)-XY4(2))
     >     -(XY3(2)-XY1(2))*(XY3(1)-XY4(1)))/DET
      XGAM=((XY2(1)-XY1(1))*(XY3(2)-XY1(2))
     >     -(XY2(2)-XY1(2))*(XY3(1)-XY1(1)))/DET
C
      DO IE1=1,2
        XY(IE1)=XLAM*XY2(IE1)+(1-XLAM)*XY1(IE1)
      ENDDO
C
      RETURN
      END