SUBROUTINE CARC(XC,YC,RADIUS,START,END) C C NAME: CARC C C LANGUAGE: FORTRAN C C OPERATING SYSTEM: UNIVERSAL C C ORDER NUMBER: 5428-SE C C PART NUMBER: 000-026366 NOVEMBER 1985 C C PRODUCT: UNIVERSAL VERSAPLOT COLOR RANDOM 2.0 C C VERSATEC, INC., SANTA CLARA, CALIFORNIA 95051 C A XEROX COMPANY C C Copyright (C) 1985 by Xerox Corporation. All rights reserved. C C "NOTICE. THIS PROGRAM IS THE EXCLUSIVE PROPERTY OF VERSATEC, C INC. AND IS ISSUED IN STRICT CONFIDENCE UNDER A PREARRANGED C LICENSE AGREEMENT AND IS NOT TO BE DISCLOSED IN ANY MANNER TO C PERSONS OUTSIDE THE LICENSED ORGANIZATION AND SHALL NOT BE C REPRODUCED OR DISSEMINATED, IN WHOLE OR PART, TO ANYONE OUTSIDE C THE LICENSED ORGANIZATION WITHOUT THE PRIOR WRITTEN APPROVAL OF C VERSATEC, INC. UNLESS OTHERWISE PROVIDED FOR BY SUCH LICENSE C AGREEMENT. THIS WORK IS PROTECTED AS AN UNPUBLISHED WORK UNDER C THE COPYRIGHT ACT OF 1976." C C CARC PLOTS A CIRCULAR ARC WITH CENTER AT (XC,YC) AND A RADIUS C OF RADIUS. THE ARC BETWEEN THE ANGLES START AND END. THE ARC C IS PLOTTED BETWEEN THE ANGLES START AND END IN A COUNTER- C CLOCKWISE DIRECTION. C C ENTRY: CALL CARC(X,Y,RADIUS,START,END) C X,Y - COORDINATES OF CENTER OF CIRCULAR ARC C RADIUS - DISTANCE FROM CENTER TO ARC SEGMENT C START,END - ANGLES OF START AND END POINTS OF ARC C IN DEGREES. C C EXIT: RETURNS WITH THE CURRENT POSITION AT CENTER OF ARC C C CALLS: C COS, SIN, MAX1, PLOT C C CALLED BY: USER C C COMMON USED: C /DVCOM/ C I RADN - DEGREES TO RADIAN ANGLE CONVERSION FACTOR C C /MSGCOM/ C R RELARG()- ARRAY FOR PASSING REAL OUTPUT ARGUMENTS C C LOCAL VARIABLES USED: C C ANGINC = ANGULAR INCREMENT FOR EACH POINT ON THE ARC. C COSINC = COSINE OF THE ANGULAR INCREMENT. C IA = LOOP COUNTER, WHOSE RANGE IS 1 TO NPTS. C NPTS = NUMBER OF POINTS FOR THE ARC. C SININC = SINE OF THE ANGULAR INCREMENT. C STRTRN = STARTING ANGLE (START), IN RADIANS. C X0 = X-COORDINATE OF THE LAST POSITION ON THE ARC. C X1 = X-COORDINATE OF THE PRESENT POSITION ON THE ARC. C Y0 = Y-COORDINATE OF THE LAST POSITION ON THE ARC. C Y1 = Y-COORDINATE OF THE PRESENT POSITION ON THE ARC. C C C LOGICAL ROT90,PMOVE,IPDEF,DASHPN,XMAJOR,VSFLAG INTEGER PWIDTH,XNIPS,YNIPS,PENPAT,VSMAX,PFONT C... COMMON /DVCOM/ PHASE I COMMON VARIABLES C COMMON /DVCOM/ * ANC, DASHPN, FACT, HTC, ICUT, ICWTV, ICXPTS, * IEOJ, ILWM, ILWP, IOPEN, ISORT, ITFLAG, IX1, * IX2, IY1, IY2, JFONT, JPEN, KPAT, KWIDTH, * LASTX, LASTY, MAXPAT, MSB, MSKALL, NCH, NCLIP, * NIBSX, NLPAT, NPLOT, PFONT, PMOVE, PXMIN, PXMAX, * PYMIN, PYMAX, RADN, ROT90, SXC, SYC, TSINA, * TCOSA, XDEN, XFAC, XNIPS, XOFF, YDEN, YFAC, * YOFF, YNIPS, VSFLAG, VSMAX, XMAJOR, * IPAT(16,256), IEOP(4), IHBUF(2), IPDEF(64), * NPAT(255), PENPAT(4,64), PWIDTH(64), * RORG(2), VCP(2), VP(4), WIN(4), WTV(4), WX(4), WY(4), * IAUTXT(15) C C C C... COMMON /MSGCOM/ - MESSAGE OUTPUT VARIABLES C COMMON /MSGCOM/ INTARG(8), RELARG(12) C C-D DEBUG MESSAGE C RELARG(1)=XC C RELARG(2)=YC C RELARG(3)=RADIUS C RELARG(4)=START C RELARG(5)=END C CALL MSGLG1(3) C-D C C C C RETURN TO CALLING PROGRAM IF THE RADIUS IS ZERO. C IF (RADIUS .LE. 0.0) GO TO 9999 C C SET THE DEFAULT NUMBER OF POINTS PER ARC TO 60. C NPTS = 60 C CALCULATE THE ANGULAR INCREMENT ( IN RADIANS ). C XTEMP = END - START 50 IF (XTEMP .GT. 360.0) XTEMP = XTEMP - 360.0 IF (XTEMP .LT. 0.0) XTEMP = XTEMP + 360.0 IF (XTEMP .GE. 0.0 .AND. XTEMP .LE. 360.0) GO TO 55 GO TO 50 C C XTEMP IS NOW BETWEEN 0.0 AND 360.0 FOR ARCS TO BE DRAWN C IN A COUNTER CLOCKWISE DIRECTION OR IN A POSITIVE ANGLE MOVEMENT. C NOW SEE HOW MANY POINTS ARE ON THE ARC. C IF LESS THAN 60*2 FOR SEGMENTS 2 NIBS LONG, THEN SET THE C NUMBER OF POINTS FOR DRAWING 2 NIB VECTORS AND MAKE SURE C THERE IS AT LEAST ONE SEGMENT. C 55 CTEMP = 6.28319 * RADIUS * (XTEMP/360.0) * (XDEN/2.0) IF (CTEMP .LT. 60.0) NPTS = MAX1 (CTEMP,1.0) ANGINC = (XTEMP*RADN) / FLOAT (NPTS) C C CALCULATE THE SINE AND COSINE OF THE ANGULAR INCREMENT. C SININC = SIN( ANGINC ) COSINC = COS( ANGINC ) C C CONVERT THE STARTING ANGLE TO RADIANS FROM DEGREES. C STRTRN = AMOD (START,360.0) * RADN C C DETERMINE THE INITIAL POINT ON THE ARC AND MOVE THERE. C X0 = XC + RADIUS * COS( STRTRN ) Y0 = YC + RADIUS * SIN( STRTRN ) CALL PLOT ( X0, Y0, 3 ) C C CALCULATE EACH POINT ON THE CURVE AND DRAW A LINE TO EACH POINT. C DO 100 IA=1,NPTS C C CALCULATE THE NEW X AND Y COORDINATES ON THE ARC. C X1 = XC + ( X0 - XC ) * COSINC - ( Y0 - YC ) * SININC Y1 = YC + ( X0 - XC ) * SININC + ( Y0 - YC ) * COSINC C C DRAW TO THE NEW POINT ON THE CIRCULAR ARC. C CALL PLOT ( X1, Y1, 2 ) C C REPLACE THE OLD X,Y COORDINATES WITH THE NEW X,Y. C X0 = X1 Y0 = Y1 100 CONTINUE C C MOVE BACK TO CENTER OF ARC C CALL PLOT (XC,YC,3) C 9999 CONTINUE RETURN END