Using Intel® Visual Fortran to Create and Build Windows*-Based Applications

ID 757211
Date 7/23/2021
Document Table of Contents
Give Feedback

Adding Shapes

After drawing the sine curve, Writing a Graphics Program Overview calls drawshapesto put two rectangles and two ellipses on the screen. The fill flag alternates between $GBORDER and $GFILLINTERIOR:

 ! DRAWSHAPES - Draws two boxes and two ellipses.
  SUBROUTINE drawshapes( )
     EXTERNAL    newx, newy
     INTEGER(2)  dummy, newx, newy
  !  Create a masking (fill) pattern.
     INTEGER(1) diagmask(8), horzmask(8)
     DATA diagmask / #93, #C9, #64, #B2, #59, #2C, #96, #4B /
     DATA horzmask / #FF, #00, #7F, #FE, #00, #00, #00, #CC /
  !  Draw the rectangles.
     CALL SETFILLMASK( diagmask )
     dummy = RECTANGLE( $GBORDER,newx(INT2(50)),newy(INT2(-325)), &
     & newx(INT2(200)),newy(INT2(-425)))
     dummy = RECTANGLE( $GFILLINTERIOR,newx(INT2(550)), &
     & newy(INT2(-325)),newx(INT2(700)),newy(INT2(-425)))
  !  Draw the ellipses.
     CALL SETFILLMASK( horzmask )
     dummy = ELLIPSE( $GBORDER,newx(INT2(50)),newy(INT2(325)), &
     & newx(INT2(200)),newy(INT2(425)))
     dummy = ELLIPSE( $GFILLINTERIOR,newx(INT2(550)), &
     & znewy(INT2(325)),newx(INT2(700)),newy(INT2(425)))

The call to SETLINESTYLE resets the line pattern to a solid line. Omitting this routine causes the first rectangle to appear with a dashed border, because the drawlines subroutine called earlier changed the line style to a dashed line.

ELLIPSE draws an ellipse using parameters similar to those for RECTANGLE. It, too, requires a fill flag and two corners of a bounding rectangle. The following figure shows how an ellipse uses a bounding rectangle:

Bounding Rectangle

The $GFILLINTERIOR constant fills the shape with the current fill pattern. To create a pattern, pass the address of an 8-byte array to SETFILLMASK. In drawshapes, the diagmaskarray is initialized with the pattern shown in the following table:

Fill Patterns

Bit pattern                  Value in diagmask
Bit No. 7 6 5 4 3 2 1 0
      x o o x o o x x       diagmask(1) = #93
      x x o o x o o x       diagmask(2) = #C9
      o x x o o x o o       diagmask(3) = #64
      x o x x o o x o       diagmask(4) = #B2
      o x o x x o o x       diagmask(5) = #59
      o o x o x x o o       diagmask(6) = #2C
      x o o x o x x o       diagmask(7) = #96
      o x o o x o x x       diagmask(8) = #4B