INTERFACE TO SUBROUTINE J06ZHK [C] (FONTNM,FONTSZ,LCOL,NCOL)
      CHARACTER*(*) FONTNM
      REAL*4 FONTSZ [REFERENCE]
      LOGICAL LCOL [REFERENCE]
      INTEGER*4 NCOL [REFERENCE]
      END
      INTERFACE TO SUBROUTINE J06ZHL [C] (STR,X,Y,ROT)
      CHARACTER*(*) STR
      REAL*4 X [REFERENCE]
      REAL*4 Y [REFERENCE]
      REAL*4 ROT [REFERENCE]
      END
      SUBROUTINE J06ZHM(STR)
C     NAG GRAPHICS LIBRARY, MARK 4 RELEASE. NAG COPYRIGHT 1994.
C
C     NAG Graphical Interface - Inventor - double to single precision
C     ---------------------------------------------------------------
C
C     The characters are output using the Hershey routine, as Inventor
C     text is difficult with character size.
C     No proportional spacing option is included in this routine.
C
C     .. Scalar Arguments ..
      CHARACTER*(*)     STR
C     .. Scalars in Common ..
      DOUBLE PRECISION  CHSCAL, COSA, DGTORD, DX, DX1, DXO, DY, DY1,
     *                  DYO, RDTODG, RH, RW, SINA, UX, UY, XNFAC,
     *                  XNFAC1, XPOS, YNFAC, YNFAC1, YPOS, ZGCHT, ZGCPR,
     *                  ZGCPT, ZGCPX, ZGCPY, ZGCSPX, ZGCSPY, ZGCWD,
     *                  ZGCX, ZGCY, ZGMSZ, ZGTPX, ZGTPY, ZGXD, ZGXHIH,
     *                  ZGXLOW, ZGXMAX, ZGXMIN, ZGYD, ZGYHIH, ZGYLOW,
     *                  ZGYMAX, ZGYMIN
      INTEGER           NGCOL, NGFONT, NGFSTL, NGIHAT, NGIPEN, NGLSTL,
     *                  NGMARG, NLEN
      LOGICAL           ATFLAG, LCHDEF, LCOLOR, LMKDEF, LMSZAF, POLAR,
     *                  ZGXDIR, ZGYDIR
C     .. Arrays in Common ..
      DOUBLE PRECISION  COLB(2,17), COLG(2,17), COLR(2,17)
      CHARACTER*26      FNTLST(15)
C     .. Local Scalars ..
      DOUBLE PRECISION  SWIDTH, UX1, UY1, W1T, W2T, W3T, W4T, X, Y
      REAL              FONTSZ, ROT1
      INTEGER           FONTLN, I, MARGIN
      LOGICAL           PLCOOR, PROPOR
      CHARACTER*2       CHR
      CHARACTER*26      FONTNM
C     .. External Subroutines ..
      EXTERNAL          J06YBF, J06ZHK, J06ZHL, J06ZHP, J06ZHQ
C     .. External Functions ..
      DOUBLE PRECISION  J06YAW, J06YAX
      INTEGER           J06ZUF
      EXTERNAL          J06YAW, J06YAX, J06ZUF
C     .. Intrinsic Functions ..
      INTRINSIC         ATAN2, REAL
C     .. Common blocks ..
      COMMON            /AJ06WB/ZGXLOW, ZGXHIH, ZGYLOW, ZGYHIH
      COMMON            /AJ06XA/ZGXMIN, ZGXMAX, ZGYMIN, ZGYMAX, NGMARG
      COMMON            /AJ06YH/ATFLAG
      COMMON            /BJ06YA/NGCOL, NGLSTL, NGFONT, NGFSTL, NGIHAT
      COMMON            /BJ06ZH/NLEN
      COMMON            /CJ06XA/ZGMSZ, ZGCWD, ZGCHT, ZGCSPX, ZGCSPY,
     *                  ZGCPX, ZGCPY, NGIPEN
      COMMON            /DJ06ZH/XPOS, YPOS, DXO, DYO, UX, UY
      COMMON            /EJ06ZH/DX, DY, ZGCX, ZGCY, XNFAC, YNFAC, DX1,
     *                  DY1, SINA, COSA, XNFAC1, YNFAC1
      COMMON            /FJ06XA/ZGTPX, ZGTPY, LCHDEF, LMKDEF, LMSZAF
      COMMON            /FJ06ZH/RW, RH
      COMMON            /HJ06XA/ZGCPR, ZGCPT, POLAR
      COMMON            /KJ06XA/DGTORD, RDTODG
      COMMON            /KJ06ZH/CHSCAL
      COMMON            /XJ06XA/ZGXD, ZGYD, ZGXDIR, ZGYDIR
      COMMON            /YJ06XA/COLR, COLG, COLB, LCOLOR
      COMMON            /ZJ06ZA/FNTLST
C     .. Save statement ..
      SAVE              /AJ06YH/, /AJ06WB/, /AJ06XA/, /BJ06YA/,
     *                  /BJ06ZH/, /CJ06XA/, /DJ06ZH/, /EJ06ZH/,
     *                  /FJ06XA/, /FJ06ZH/, /HJ06XA/, /KJ06XA/,
     *                  /KJ06ZH/, /XJ06XA/, /YJ06XA/, /ZJ06ZA/
C     .. Executable Statements ..
C
C     If angled text flag is set calculate angles
C     Plot the string horizontally if angled text flag is not set
C
      IF (ATFLAG) THEN
C
C           Calculate and set apparent text angle (in radians)
C           1. linear coordinates : (ZGTPX,ZGTPY) indicates direction
C           2.  polar coordinates : ZGTPY denotes the angle in degrees
C                                ZGTPX is not used
C           The apparent text angle is used for plotting of characters
C
C           Apply scaling factors to the basic character spacing
C           Calculate apparent character up direction
C
         IF ( .NOT. POLAR) THEN
            UX1 = ZGTPX*(ZGYMAX-ZGYMIN)
            UY1 = ZGTPY*(ZGXMAX-ZGXMIN)
            ROT1 = REAL(ATAN2(UY1,UX1))
C
            DXO = DXO*ZGXD*ZGYD
            DYO = DYO*ZGXD*ZGYD
            DX1 = DX1*XNFAC
            DY1 = DY1*YNFAC
         ELSE
            ROT1 = REAL(ZGTPY*DGTORD)
C
            DXO = DXO*ZGXD
            DYO = DYO*ZGXD
            DX1 = DX1*XNFAC
            DY1 = DY1*XNFAC
         END IF
      ELSE
         ROT1 = 0.0
C
         DXO = DXO*ZGXD
         DYO = DYO*ZGXD
         DX1 = DX1*XNFAC
         DY1 = DY1*YNFAC
      END IF
C
C     Character spacing after transformation
C
      DX = DX1*COSA - DY1*SINA
      DY = DX1*SINA + DY1*COSA
C
C     Text font
C
      FONTNM = FNTLST(NGFONT)
      FONTLN = J06ZUF(FONTNM)
      FONTSZ = REAL(RH*YNFAC*CHSCAL)
      CALL J06ZHK(FONTNM(1:FONTLN)//CHAR(0),FONTSZ,LCOLOR,NGCOL)
C
C     Text is drawn in linear ndc coordinates
C     store original values and calculate new cursor position
C
      CALL J06ZHQ(W1T,W2T,W3T,W4T,MARGIN,PLCOOR,X,Y)
C
C     Draw one character at a time
C
      DO 20 I = 1, NLEN
         IF (ZGCPX.GE.ZGXLOW .AND. ZGCPX.LE.ZGXHIH .AND.
     *       ZGCPY.GE.ZGYLOW .AND. ZGCPY.LE.ZGYHIH) THEN
            CHR(1:1) = STR(I:I)
            CHR(2:2) = CHAR(0)
            CALL J06ZHL(CHR,REAL(J06YAX(ZGCPX)),REAL(J06YAW(ZGCPY)),
     *                  ROT1)
         END IF
         CALL J06YBF(DX*ZGXD,DY*ZGYD)
   20 CONTINUE
C
C     Reset data region and ensure that current position is updated
C
      PROPOR = .FALSE.
      CALL J06ZHP(W1T,W2T,W3T,W4T,MARGIN,PLCOOR,PROPOR,SWIDTH,NLEN)
C
      RETURN
C
      END