Writing a Graphics Program

Like many programs, graphics programs work well when written in small units. Using discrete routines aids debugging by isolating the functional components of the program. The following example program and its associated subroutines show the steps involved in initializing, drawing, and closing a graphics program.

The SINE program draws a sine wave. Its procedures call many of the common graphics routines. The main program calls five subroutines that carry out the actual graphics commands (also located in the SINE.F90 file):

  ! SINE.F90 - Illustrates basic graphics commands.
  !
    USE DFLIB
    CALL graphicsmode( )
    CALL drawlines( )
    CALL sinewave( )
    CALL drawshapes( )
    END
     .
     .
     .

For information on the subroutines used in the SINE program, see:

• graphicsmode in section Activating a Graphics Mode
• drawlines in section Drawing Lines on the Screen
• sinewave in section Drawing a Sine Curve
• drawshapes in section Adding Shapes

The SINE program's output appears in the following figure. The SINE routines are in the Visual Fortran Sample TUTORIAL folder. The project is built as a Fortran Standard Graphics application.

Sine Program Output