SUBROUTINE GUNMOV
C
C	THIS SUBROUTINE CONTROLS THE POSITIONING OF THE PLAYER'S GUN.
C	THIS IS DONE BY MOVING THE GUN IN THE DIRECTION SPECIFIED IN
C	THE VARIABLE 'DIRCOD', WHICH IS SET BY THE UNSOLICITED CHARACTER
C	INPUT AST ROUTINE, INPAST.
C
      IMPLICIT INTEGER(A - Z)
      PARAMETER MAXCNT = 24
C SCREEN BOUNDARIES
      PARAMETER LMAR = 2, RMAR = 30, TMAR = 2, BMAR = 23, GMAR = 18
C DIRECTIONALS
      PARAMETER HALT = 0, UP = 1, DOWN = 2, LEFT = 4, RIGHT = 8
      PARAMETER UPL = 10, UPR = 9, DOWNL = 12, DOWNR = 11
C DISPLAYABLE CHARACTERS
	PARAMETER GUNCHR="166, CBODY="140, MSHCHR="146, BULCHR="170
	PARAMETER SPICHR="173, FLECHR="175, SCOCHR="142, PSNCHR="052
	PARAMETER CLHEAD="074, CRHEAD="076, CDHEAD="126
	PARAMETER SHFIN="17, SHFOUT="16, SPACE="40
C QIO FUNCTION CODES
	PARAMETER IOATA="1410, IOWVB="11000, SFSMC="2440
C
      INTEGER*4SCORE, FRESCO, TIMER, SEED, FLETIM, SPITIM, SCOTIM, CNTTI
     *M
      DIMENSION PRL(6), CX(MAXCNT, 12), CY(MAXCNT, 12)
      DIMENSION CLEN(MAXCNT), CDIR(MAXCNT), CRISE(MAXCNT), CBOT(MAXCNT)
      BYTE CNTBRD(BMAR, RMAR), MSHBRD(BMAR, RMAR), PSNBRD(BMAR, RMAR)
      COMMON/DIRCOM/DIRCOD, FIRCOD
      COMMON/CNTCOM/PRL, SCORE, TIMER, SEED, CX, CY, CLEN, CDIR, CRISE, 
     *CBOT, GUNX, GUNY, FRESCO, CNTBRD, MSHBRD, PSNBRD, BULACT, BULX, BU
     *LY, FLETIM, FLEACT, FLEX, FLEY, SPITIM, SPIACT, SPIX, SPIY, SPILR,
     * SCOTIM, SCOACT, SCOX, SCOY, SCODIR, GUNCNT, CNTTIM, BOARD, CNTWAV
C
C	VT100 DISPLAY CONTROL PARAMETER DEFINITIONS
C
CCURSOR POSITION REPORT
CCURSOR UP
CCURSOR DOWN
CCURSOR FORWARD
CCURSOR BACK
CDOUBLE WIDTH LINE
      PARAMETER CUP = 1, CUU = 2, CUD = 3, CUF = 4, CUB = 5, DECDWL = 6,
     * DECDHL = 7, DECRC = 8, DECSC = 9, DECSWL = 10, ED = 11, EL = 12, 
     *SGR = 13, NEL = 14, SCS = 15, SM = 16, RM = 17, ANSI = 18, CPP=19
      IF (.NOT.(DIRCOD .GT. HALT)) GOTO 2000
CMOTION REQUESTED
CSAVE OLD GUN COORDINATES
        NEWX = GUNX
        NEWY = GUNY
        IF (.NOT.(DIRCOD .EQ. UP)) GOTO 2020
CUPDATE GUNSIGHT X,Y COORDINATES
          NEWX = GUNX - 1
          GOTO 2030
2020    CONTINUE
        IF (.NOT.(DIRCOD .EQ. DOWN)) GOTO 2040
          NEWX = GUNX + 1
          GOTO 2030
2040    CONTINUE
        IF (.NOT.(DIRCOD .EQ. LEFT)) GOTO 2060
          NEWY = GUNY - 1
          GOTO 2030
2060    CONTINUE
        IF (.NOT.(DIRCOD .EQ. RIGHT)) GOTO 2080
          NEWY = GUNY + 1
          GOTO 2030
2080    CONTINUE
        IF (.NOT.(DIRCOD .EQ. UPL)) GOTO 2100
          NEWX = GUNX - 1
          NEWY = GUNY - 1
          GOTO 2030
2100    CONTINUE
        IF (.NOT.(DIRCOD .EQ. UPR)) GOTO 2120
          NEWX = GUNX - 1
          NEWY = GUNY + 1
          GOTO 2030
2120    CONTINUE
        IF (.NOT.(DIRCOD .EQ. DOWNL)) GOTO 2140
          NEWX = GUNX + 1
          NEWY = GUNY - 1
          GOTO 2030
2140    CONTINUE
        IF (.NOT.(DIRCOD .EQ. DOWNR)) GOTO 2160
          NEWX = GUNX + 1
          NEWY = GUNY + 1
C
C	  IF NEW POSITION IS OUTSIDE OF LEGAL LIMITS, CORRECT IT.
C
2160    CONTINUE
2030    CONTINUE
        IF (.NOT.(NEWX .LT. GMAR)) GOTO 2180
CTOO FAR TO TOP OF SCREEN
          NEWX = GMAR
          GOTO 2190
2180    CONTINUE
        IF (.NOT.(NEWX .GT. BMAR)) GOTO 2200
CTOO FAR TO BOTTOM OF SCREEN
          NEWX = BMAR
2200    CONTINUE
2190    CONTINUE
        IF (.NOT.(NEWY .LT. LMAR)) GOTO 2220
CTOO FAR TO LEFT OF SCREEN
          NEWY = LMAR
          GOTO 2230
2220    CONTINUE
        IF (.NOT.(NEWY .GT. RMAR)) GOTO 2240
CTOO FAR TO RIGHT OF SCREEN
          NEWY = RMAR
2240    CONTINUE
2230    CONTINUE
        IF (.NOT.(MSHBRD(NEWX, NEWY) .EQ. 0)) GOTO 2260
CCLEAR MOTION INDICATOR
          DIRCOD = HALT
CBLANK OUT CURRENT DISPLAY OF GUNSIGHT
          CALL UVT100(CPP, GUNX, GUNY, SPACE)
          GUNX = NEWX
          GUNY = NEWY
CDISPLAY GUN AT NEW LOCATION
          CALL UVT100(CPP, GUNX, GUNY, GUNCHR)
CCHECK FOR COLLISION WITH GUN
          CALL COLIDE
2260    CONTINUE
2000  CONTINUE
      RETURN
      END