C SUBROUTINE VECTOR:
C
C 13 JAN 77 (007; PDH) ADD EDIT NUMBER TO PROGRAM NAME
C 20 MAY 76 (PDH) RE-TYPE FROM LISTING, AS RK CARTRIDGE GOT CLOBBERED
C 14 MAY 76 (PDH( TIDY UP STATEMENT NUMBERS AND EXTRA VARIABLES
C 13 MAY 76 (PDH) CONVERT FOR USE WITH THE VT15
C 5 DEC 72 - MOD FOR WATRAN COMPATIBLITY: M.K.HOLMBERG
C 2 SEP 71 EDITED AND DEBUGGED BY JIM STORM
C SOMETIME, 1969 - ORIGINALLY CODED BY J.A. FIELD FROM AN
C EARLIER PROGRAM (VECGEN, VECEDG), WHICH WAS
C THE CREATION OF J.A. FIELD AND STAN MIDDLESTADT.
C
C
C THIS SUBROUTINE WILL PLOT POINTS, STRAIGHT LINES,
C OR CURVES. IT PREVENTS LINES BEING DRAWN OUTSIDE
C THE SCREEN LIMITS, AND AS AN OPTION IT WILL TRIM
C LINES TO FIT WITHIN A GIVEN WINDOW.
C
C
C THE CALLING SEQUENCE IS:
C
C
C CALL VECTOR(MODE,ARRAY,BEGIN,END,IVECT,FIRST,LAST,INT,ISPACE,LTPEN)
C
C WHERE: ARRAY IS REAL
C LTPEN IS LOGICAL
C ALL OTHERS ARE INTEGER
C
C
C
C
C
C
C THE DISPLAY FILE IS GENERATED STARTING AT IVECT(FIRST)
C AND AFTER GENERATION, THE PROGRAM SETS 'LAST' SUCH
C THAT 'IVECT(LAST)' IS THE LAST ELEMENT IN THE DISPLAY
C FILE. 'INT' SPECIFIES THE DISPLAY INTENSITY (0-7),
C 'ISPACE' SPECIFIES POINT SPACING ON THE SCREEN (1,2,4,8)
C RASTER UNIT. IF 'LTPEN=.TRUE.' THEN LIGHT PEN INTERRUPTS
C ARE ENABLED.
C
C
C
C WHEN (MODE=1) OR (MODE=2), 'ARRAY' IS A (4 BY N)
C ARRAY SPECIFYING A SET AT LINES (X1,Y1, X2,Y2),
C AND ALL LINES BETWEEN 'ARRAY(1,BEGIN)' AND 'ARRAY(4,END)'
C WILL BE PLOTTED.
C FOR (MODE=2) ONLY THAT PART OF A LINE INSIDE A
C WINDOW IS PLOTTED.
C
C
C
C
C WHEN (MODE=3) OR (MODE=4) 'ARRAY' IS A (2 BY N)
C ARRAY SPECIFYING THE (X,Y) PAIRS OF A CURVE. THE
C CURVE BEGINS AT 'ARRAY(1,BEGIN)' AND ENDS AT
C ARRAY(2,END). FOR MODE=4, ONLY THAT PART OF THE
C CURVE INSIDE THE WINDOW IS PLOTTED.
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C WHEN (MODE=5) OR (MODE=6), 'ARRAY' IS A (2 BY N)
C ARRAY SPECIFYING (X,Y) POINTS TO BE PLOTTED.
C THE FIRST POINT IS AT 'ARRAY(1,FIRST),ARRAY(2,FIRST)
C AND THE LAST IS AT 'ARRAY(1,END),ARRAY(2,END).
C FOR MODE =6, ONLY THOSE POINTS INSIDE THE WINDOW
C ARE PLOTTED.
C
C
C
C
C
C
C WINDOW:
C
C TO SPECIFY A WINDOW REQUIRES THE STATEMENT:
C
C COMMON/FRAME/A,B,C,D
C
C IN THE MAIN PROGRAM. THE WINDOW KEEPS-
C A.LE.X.LE.B
C C.LE.Y.LE.D
C
C NOTE: THESE LIMITS ARE INDEPENDENT OF 'XMAX' ETC.,
C THAT SPECIFY THE SCREEN SIZE. THERE IS NO NEED
C FOR THE WINDOW TO BE COMPLETELY ON THE SCREEN.
C
C
C
C
C
C
C
C
SUBROUTINE VECTOR (MODE,PICT,FIRST,LAST,IVECT,II,JJ,INT,ISPACE,
*LTPEN)
LOGICAL LTPEN,SWITCH
INTEGER FIRST,OLDX,OLDY
DIMENSION PICT(2,5000),IVECT(5000)
COMMON /LIMITS/ XMIN,XMAX,YMIN,YMAX
COMMON /FRAME/ A,B,C,D
COMMON /LINEND/ XBEGIN,YBEGIN,XFINAL,YFINAL
10 L = 1
SWITCH = .FALSE.
IF (MODE .LT. 1) STOP 12345
IF (MODE .GT. 6) STOP 12345
GO TO (101,102,103,104,105,106),MODE
101 SWITCH = .TRUE.
102 IFIRST = FIRST*2 - 1
ILAST = LAST*2
INCRE = 2
GO TO 21
105 SWITCH = .TRUE.
106 L = 0
ILAST = LAST
GO TO 20
103 SWITCH = .TRUE.
104 ILAST = LAST - 1
20 IFIRST = FIRST
INCRE = 1
21 OLDX = -1
J = II + 1
C
C PARAMETER 1: INTENSITY ENABLE BIT, SCALE 0 (202020 -> 66576);
C THEN SET USER SPECIFIED INTENSITY LEVEL.
C
INTX = INT
IF (INT .LT. 0) INTX = 7
IF (INT .GT. 7) INTX = 7
IVECT(J) = 66576 + INTX*128
J = J+1
C
C PARAMETER 2: BLINK OFF (FOR INITIAL IMPLEMENTATION, EDGE
C INTERRUPTS DISABLED, ROTATE HORIZONTAL, LIGHT
C PEN ENABLE BIT, OFFSET OFF (211252 -> 70314);
C THEN SET LIGHT PEN ON OR OFF, AS SPECIFIED.
C
IVECT(J) = 70314
IF (LTPEN) IVECT(J) = 70318
J = J+1
C
C PARAMETER 3: (ONLY PRESENT IF LIGHT PEN ON) LIGHT PEN INTERRUPT
C ENABLE (220044 -> 73764).
C
IF (.NOT. LTPEN) GO TO 30
IVECT(J) = 73764
J = J+1
30 XLOW = AMIN1 (XMIN,XMAX)
XHIGH = AMAX1 (XMIN,XMAX)
YLOW = AMIN1 (YMIN,YMAX)
YHIGH = AMAX1 (YMIN,YMAX)
IF (SWITCH) GO TO 31
XLOW = AMAX1 (XLOW, AMIN1(AMIN1(A,B),XHIGH))
XHIGH = AMIN1 (XHIGH,AMAX1(AMAX1(A,B), XLOW))
YLOW = AMAX1 (YLOW, AMIN1(AMIN1(C,D),YHIGH))
YHIGH = AMIN1 (YHIGH,AMAX1(AMAX1(C,D), YLOW))
31 IF (XLOW.EQ.XHIGH .OR. YLOW.EQ.YHIGH) GO TO 91
XDIFF = 1023./(XMAX-XMIN)
YDIFF = 1023./(YMAX-YMIN)
C
C NOW THAT WE HAVE THE INITIALIZATION OUT OF THE WAY, WE CAN
C PROCEED TO MARCH THROUGH THE 'PICT' ARRAY, GENERATING THE
C SPECIFIED VECTORS OR POINTS.
C
DO 90 I = IFIRST,ILAST,INCRE
C
C GET END POINTS OF LINE
C
XBEGIN = PICT(1,I)
YBEGIN = PICT(2,I)
K = I+L
XFINAL = PICT(1,K)
YFINAL = PICT(2,K)
C
C TRIM LINE SO THAT IT WILL FIT ON THE SCREEN
C
SWITCH = ABS(XFINAL-XBEGIN) .GT. ABS(YFINAL-YBEGIN)
IF (SWITCH) GO TO 45
40 IF (XBEGIN.GT.XFINAL) CALL SWAP
IF (XBEGIN.GT.XHIGH.OR.XFINAL.LT.XLOW) GO TO 90
IF (XBEGIN.LT.XLOW) CALL TRIM(XBEGIN,YBEGIN,XLOW, XFINAL,YFINAL)
IF (XFINAL.GT.XHIGH)CALL TRIM(XFINAL,YFINAL,XHIGH,XBEGIN,YBEGIN)
IF (SWITCH) GO TO 50
45 IF (YBEGIN.GT.YFINAL) CALL SWAP
IF (YBEGIN.GT.YHIGH.OR.YFINAL.LT.YLOW) GO TO 90
IF (YBEGIN.LT.YLOW) CALL TRIM(YBEGIN,XBEGIN,YLOW, YFINAL,XFINAL)
IF (YFINAL.GT.YHIGH)CALL TRIM(YFINAL,XFINAL,YHIGH,YBEGIN,XBEGIN)
IF (SWITCH) GO TO 40
C
C CONVERT END POINTS TO SCREEN COORDINATES
C
50 IXX1 = (XBEGIN - XMIN)*XDIFF + 0.5
IYY1 = (YBEGIN - YMIN)*YDIFF + 0.5
IXX2 = (XFINAL - XMIN)*XDIFF + 0.5
IYY2 = (YFINAL - YMIN)*YDIFF + 0.5
C
C CHECK IF BEAM REPOSITIONING IS REQUIRED
C
IF (IXX1 .NE. OLDX) GO TO 51
IF (IYY1 .EQ. OLDY) GO TO 55
51 IF (IXX2 .NE. OLDX) GO TO 52
IF (IYY2 .NE. OLDY) GO TO 52
IXX2 = IXX1
IYY2 = IYY1
IXX1 = OLDX
IYY1 = OLDY
GO TO 55
C
C BEAM POSITIONING IS REQUIRED.
C SET THE NEW X-COORDINATE (144000+X -> 51200+X),
C AND THE NEW Y-COORDINATE (160000+Y -> 57344+Y).
C
52 IVECT(J) = 51200 + IXX1
J = J+1
IVECT(J) = 57344 + IYY1
J = J+1
C
C REMEMBER WHERE THE END OF LINE NOW IS
C
55 OLDX = IXX2
OLDY = IYY2
C
C GENERATE THE REQUIRED VECTOR. INITIALLY WE WILL USE ONLY
C ARBITRARY LONG VECTORS, WITH LIGHT PEN ENABLED:
C IXWORD = 130000+DX -> 45056+DX
C IYWORD = 100000+DY -> 32768+DY
C
IXWORD = 45056
IYWORD = 32768
C
C BUILD THE X-WORD OF THE VECTOR, WITH APPROPRIATE SIGN
C (4000 -> 2048) AND MAGNITUDE.
C
60 IXINC = IXX2 - IXX1
IF (IXINC) 61,70,70
61 IXWORD = IXWORD + 2048
IXINC = -IXINC
C
C AND BUILD THE Y-WORD, WITH APPROPRIATE SIGN AND MAGNITUDE.
C
70 IYINC = IYY2 - IYY1
IF (IYINC) 71,80,80
71 IYWORD = IYWORD + 2048
IYINC = -IYINC
C
C NOW CHECK TO SEE IF WE HAVE A LINE OR A POINT
C
80 IF (IXINC + IYINC) 81,90,81
81 IVECT(J) = IXWORD + IXINC
J = J+1
IVECT(J) = IYWORD + IYINC
J = J+1
90 CONTINUE
91 JJ = J+1
RETURN
END