SUBROUTINE CLIPT(BUFIN,OUTBF)
      DIMENSION  BUFIN(1),OUTBF(1)
      COMMON /TKTRNX/ TMINVX,TMINVY,TMAXVX,TMAXVY,TREALX,TREALY,
     1 TIMAGX,TIMAGY,TRCOSF,TRSINF,TRSCAL,TRFACX,TRFACY,
     2 TRPAR1,TRPAR2,TRPAR3,TRPAR4,TRPAR5,TRPAR6,KMOFLG(8),KPAD2,
     3 KBAUDR,KGNFLG,KGRAFL,KHOMEY,KKMODE,KHORSZ,KVERSZ,KTBLSZ,
     4 KSIZEF,KLMRGN,KRMRGN,KFACTR,KTERM,KLINE,KZAXIS,KBEAMX,KBEAMY,
     5 KMOVEF,KPCHAR(5),KDASHT,KMINSX,KMINSY,KMAXSX,KMAXSY,KEYCON,
     6 KINLFT,KOTLFT,KUNIT
      GSTAX=BUFIN(1)
      GSTAY=BUFIN(2)
      GENDX=BUFIN(3)
      GENDY=BUFIN(4)
      IF(GSTAX.GE.TMINVX)GO TO 10
      IF(GENDX.GE.TMINVX)GO TO 20
      GO TO 110
10    IF(GSTAX.LE.TMAXVX)GO TO 20
      IF(GENDX.LE.TMAXVX)GO TO 20
      GO TO 110
20    IF(GSTAY.GE.TMINVY)GO TO 21
      IF(GENDY.GE.TMINVY)GO TO 30
      GO TO 110
21    IF(GSTAY.LE.TMAXVY)GO TO 30
      IF(GENDY.LE.TMAXVY)GO TO 30
      GO TO 110
30    IF(GSTAX.NE.GENDX)GO TO 31
      DSTAX=GSTAX
      DENDX=GSTAX
      CALL PARCLT(GSTAY,GENDY,TMINVY,TMAXVY,DSTAY,DENDY)
      GO TO 120
31    IF(GSTAY.NE.GENDY)GO TO 40
      DSTAY=GSTAY
      DENDY=GSTAY
      CALL PARCLT(GSTAX,GENDX,TMINVX,TMAXVX,DSTAX,DENDX)
      GO TO 120
40    A=GENDX-GSTAX
      B=GENDY-GSTAY
      IF(GSTAX.LT.TMINVX)GO TO 41
      IF(GSTAX.LE.TMAXVX)GO TO 43
      Q=TMAXVX
      GO TO 42
43    IF(GSTAY.GT.TMAXVY)GO TO 140
      IF(GSTAY.LT.TMINVY)GO TO 44
      DSTAX=GSTAX
      DSTAY=GSTAY
      GO TO 150
41    Q=TMINVX
42    DSTAY=GSTAY+((Q-GSTAX)*B/A)
      IF(DSTAY.GT.TMAXVY)GO TO 140
      IF(DSTAY.LT.TMINVY)GO TO 44
      DSTAX=Q
      GO TO 150
44    R=TMINVY
      GO TO 45
140   R=TMAXVY
45    DSTAX=GSTAX+((R-GSTAY)*A/B)
      IF(DSTAX.GT.TMAXVX)GO TO 110
      IF(DSTAX.LT.TMINVX)GO TO 110
      DSTAY=R
150   IF(GENDX.LT.TMINVX)GO TO 50
      IF(GENDX.GT.TMAXVX)GO TO 51
      IF(GENDY.GT.TMAXVY)GO TO 160
      IF(GENDY.LT.TMINVY)GO TO 52
      DENDX=GENDX
      DENDY=GENDY
      GO TO 120
51    Q=TMAXVX
      GO TO 53
50    Q=TMINVX
53    DENDY=GSTAY+((Q-GSTAX)*B/A)
      IF(DENDY.GT.TMAXVY)GO TO 160
      IF(DENDY.LT.TMINVY)GO TO 52
      DENDX=Q
      GO TO 120
52    R=TMINVY
      GO TO 60
160   R=TMAXVY
60    DENDX=GSTAX+((R-GSTAY)*A/B)
      DENDY=R
120   OUTBF(1)=DSTAX
      OUTBF(2)=DSTAY
      OUTBF(3)=DENDX
      OUTBF(4)=DENDY
      KGNFLG=0
      GO TO 70
C * SET FLAG IF LINE OUTSIDE WINDOW
110   KGNFLG=1
70    RETURN
      END