!  ***********************************************
!  ** (c) Interactive Software Services Ltd and **
!  **     Lahey Computer Systems Inc. 1997-2002 **
!  ** ----------------------------------------- **
!  ** This demonstration program source may be  **
!  ** modified for training and for product     **
!  ** familiarisation.                          **
!  ** ----------------------------------------- **
!  ** Purpose : Draw simple graphs              **
!  ***********************************************
!
!  Graphs demo for WINTERACTER Starter Kit
!
      PROGRAM GRAPH
!
      USE WINTERACTER
!
      IMPLICIT NONE
!
      INTEGER, PARAMETER :: IDR_MENU1 = 30001
      INTEGER, PARAMETER :: ID_LINE   = 40001
      INTEGER, PARAMETER :: ID_SCAT   = 40002
      INTEGER, PARAMETER :: ID_EXIT   = 40003
!
      INTEGER            :: IPICTURE,ITYPE
      TYPE(WIN_STYLE)    :: WINDOW
      TYPE(WIN_MESSAGE)  :: MESSAGE
!
      INTERFACE
        SUBROUTINE DrawGraph()
          IMPLICIT NONE
        END SUBROUTINE DrawGraph
        SUBROUTINE DrawScatterPlot()
          IMPLICIT NONE
        END SUBROUTINE DrawScatterPlot
      END INTERFACE
!
!  Initialise WiSK
!
      CALL WInitialise()
      IPICTURE = 1
!
!  Open root window and put initial data in it
!
      CALL WindowOpen(FLAGS =SysMenuOn + MinButton + MaxButton, &
                      MENUID=IDR_MENU1,                         &
                      TITLE ='WiSK Graph Plotting')
      CALL DrawGraph()
!
!  Loop forever until user terminates
!
      DO
        CALL WMessage(ITYPE, MESSAGE)
        SELECT CASE (ITYPE)
!
!  Menu item message
!
          CASE (MenuSelect)
            CALL WindowClear()
            SELECT CASE (MESSAGE%VALUE1)
              CASE (ID_LINE)             !  Draw line graph
                CALL DrawGraph()
                IPICTURE = 1
              CASE (ID_SCAT)             !  Draw scatter plot
                CALL DrawScatterPlot()
                IPICTURE = 2
              CASE (ID_EXIT)             !  Exit program
                EXIT
            END SELECT
!
!  Redisplay data if we get an expose or resize event
!
          CASE (Expose,Resize)
            IF (IPICTURE==1) THEN
                CALL DrawGraph()
            ELSE IF (IPICTURE==2) THEN
                CALL DrawScatterPlot()
            END IF
!
!  Close window
!
          CASE (CloseRequest)
            EXIT
        END SELECT
      END DO
!
      STOP
      END PROGRAM GRAPH
!
      SUBROUTINE DrawGraph()
!
!  Draw a simple line graph
!
      USE WINTERACTER
!
      IMPLICIT NONE
!
      REAL, DIMENSION(10)  :: X=(/ 5.0,15.0,25.0,30.0,35.0, &
                                  50.0,55.0,75.0,80.0,95.0/)
      REAL, DIMENSION(10)  :: Y=(/ 7.0,10.0,20.0,30.0,40.0, &
                                  50.0,60.0,70.0,80.0,90.0/)
      INTEGER  :: IX
!
      INTERFACE
        SUBROUTINE IAxes(X1,X2,XSTEP,Y1,Y2,YSTEP,TITLE)
          IMPLICIT NONE
          REAL , INTENT (IN) :: X1,X2,XSTEP,Y1,Y2,YSTEP
          CHARACTER (LEN=*), INTENT(IN) :: TITLE
        END SUBROUTINE IAxes
      END INTERFACE
!
!  Clear window
!
      CALL WindowClear()
!
!  Draw axes
!
      CALL IAxes(0.,100.,20.,0.,100.,20.,'Line Plot')
!
!  Draw graph lines
!
      CALL IGrLineType(SolidLine)
      CALL IGrColourN(191)
      CALL IGrMoveTo(0.0,0.0)
      DO IX = 1,10
        CALL IGrLineTo(X(IX),Y(IX))
      END DO
!
!  Change the line type to Dots
!
      CALL IGrLineType(Dotted)
      CALL IGrColourN(31)
      CALL IGrMoveTo(0.0,0.0)
      DO IX = 1,10
        CALL IGrLineTo(SQRT(X(IX)),Y(IX))
      END DO
!
!  Change the line type to Dashes
!
      CALL IGrLineType(Dashed)
      CALL IGrColourN(159)
      CALL IGrMoveTo(0.0,0.0)
      DO IX = 1,10
        CALL IGrLineTo(X(IX),SQRT(Y(IX)))
      END DO
      RETURN
      END SUBROUTINE DrawGraph
!
      SUBROUTINE DrawScatterPlot()
!
!  Draw a scatter plot
!
      USE WINTERACTER
!
      IMPLICIT NONE
!
      INTEGER, PARAMETER :: NPOINTS = 100
      INTEGER            :: IPOINT
      REAL               :: RAND,XPOS,YPOS,XMAX,YMAX
!
      INTERFACE
        SUBROUTINE IAxes(X1,X2,XSTEP,Y1,Y2,YSTEP,TITLE)
          IMPLICIT NONE
          REAL , INTENT (IN) :: X1,X2,XSTEP,Y1,Y2,YSTEP
          CHARACTER (LEN=*), INTENT(IN) :: TITLE
        END SUBROUTINE IAxes
      END INTERFACE
!
!  Clear window
!
      CALL WindowClear()
!
!  Draw axes
!
      XMAX = 100.0
      YMAX = 10.
      CALL IAxes(0.0,XMAX,20.,0.0,YMAX,1.0,'Scatter Plot')
!
      CALL WGrTextFont(FFCourier,WIDTH=.0066,HEIGHT=.02)
!
!  Draw a scatter plot
!
      DO IPOINT = 1,NPOINTS
!
!  Cluster of points towards top left
!
        CALL random_number(RAND)
        XPOS = RAND*XMAX*0.6
        CALL random_number(RAND)
        YPOS = YMAX*0.4 + RAND*YMAX*0.6
        CALL IGrColourN(160)
        CALL WGrTextString(XPOS,YPOS,'x')
!
!  Cluster of points towards lower right
!
        CALL random_number(RAND)
        XPOS = XMAX*0.4 + RAND*XMAX*0.6
        CALL random_number(RAND)
        YPOS = RAND*YMAX*0.6
        CALL IGrColourN(30)
        CALL WGrTextString(XPOS,YPOS,'o')
      END DO
      RETURN
      END SUBROUTINE DrawScatterPlot
!
      SUBROUTINE IAxes(X1,X2,XSTEP,Y1,Y2,YSTEP,TITLE)
!
!  Draw and annotate axes
!
      USE WINTERACTER
!
      IMPLICIT NONE
!
      REAL, INTENT (IN)  :: X1,X2,XSTEP,Y1,Y2,YSTEP
      CHARACTER (LEN=*), INTENT(IN) :: TITLE
!
      CHARACTER(LEN=4)   :: STRING
      REAL               :: XBORDER,YBORDER,XTICK,YTICK
!
!  Set up user defined co-ordinate system
!
      XBORDER = (X2 - X1)*0.1
      YBORDER = (Y2 - Y1)*0.1
      CALL IGrUnits(X1-XBORDER,Y1-YBORDER,X2+XBORDER,Y2+YBORDER)
!
!  Draw axis lines
!
      CALL IGrLineType(SolidLine)
      CALL IGrColourN(223)
      CALL IGrMoveTo(X1,Y2)
      CALL IGrLineTo(X1,Y1)
      CALL IGrLineTo(X2,Y1)
!
!  Select font (size is independent of user units)
!
      CALL WGrTextFont(FFHelvetica,WIDTH=0.017,HEIGHT=.048)
!
!  Draw some annotation on the X-axis
!
      CALL WGrTextOrientation(AlignCentre)
      XTICK = X1 + XSTEP
      DO WHILE (XTICK<X2)
       CALL IGrMoveTo(XTICK,Y1            )
       CALL IGrLineTo(XTICK,Y1-YBORDER*0.1)
       WRITE(STRING,'(F4.0)') XTICK
       CALL WGrTextString(XTICK,Y1-YBORDER*0.5,STRING)
       XTICK = XTICK + XSTEP
      END DO
!
!  Draw some annotation on the Y-axis
!
      CALL WGrTextOrientation(AlignRight)
      YTICK = Y1 + YSTEP
      DO WHILE (YTICK<Y2)
       CALL IGrMoveTo(X1            ,YTICK)
       CALL IGrLineTo(X1-XBORDER*0.1,YTICK)
       WRITE(STRING,'(F4.0)') YTICK
       CALL WGrTextString(X1-XBORDER*0.2,YTICK,STRING)
       YTICK = YTICK + YSTEP
      END DO
!
!  Draw a circle at axis intersection
!
      CALL IGrCircle(X1,Y1,(X2-X1)*0.01)
!
!  Now give graph a title centred at top of window
!
      CALL WGrTextOrientation(AlignCentre)
      CALL WGrTextFont(WIDTH=0.024,HEIGHT=.052)
      CALL IGrColourN(223)
      CALL WGrTextString(X1+(X2-X1)/2.0,Y2+YBORDER/2.0,TITLE)
      RETURN
      END SUBROUTINE IAxes