SDL_DEMO.CBL

      ******************************************************************
      * Author:
      * Date:
      * Purpose:
      * Tectonics: cobc
      ******************************************************************
       IDENTIFICATION DIVISION.
       PROGRAM-ID. MAIN-METHOD.
       DATA DIVISION.
       FILE SECTION.
       WORKING-STORAGE SECTION.
        77 SDL-WINDOW USAGE POINTER.
        77 SDL-RENDERER USAGE POINTER.
        77 WIDTH PIC 9(3) VALUE 640.
        77 HEIGHT PIC 9(3) VALUE 480.
        77 X1 PIC 9(3).
        77 X2 PIC 9(3).
        77 Y1 PIC 9(3).
        77 Y2 PIC 9(3).
        77 COLOR_R PIC 9(3).
        77 COLOR_G PIC 9(3).
        77 COLOR_B PIC 9(3).
        01 E.
         05 E_TYPE USAGE BINARY-INT UNSIGNED.
         05 USAGE BINARY-CHAR OCCURS 60 TIMES.
        77 E_RETURN PIC 9(1).
        77 WINDOWTITLE PIC X(20) VALUE Z"SDL COBOL DEMO".
       PROCEDURE DIVISION.
       MAIN-PROCEDURE.

           CALL "SDL_Init" USING
           BY VALUE 62001
           END-CALL.

           CALL "SDL_CreateWindow" USING
           BY CONTENT WINDOWTITLE
           BY VALUE WIDTH
           BY VALUE HEIGHT
           BY VALUE WIDTH
           BY VALUE HEIGHT
           BY VALUE 2
           RETURNING SDL-WINDOW
           END-CALL.

           CALL "SDL_CreateRenderer" USING
            BY VALUE SDL-WINDOW
            BY VALUE -1
            BY VALUE 1
            RETURNING SDL-RENDERER
           END-CALL.

           CALL "SDL_SetRenderDrawColor" USING
            BY VALUE SDL-RENDERER
            BY VALUE 255
            BY VALUE 255
            BY VALUE 255
            BY VALUE 255
           END-CALL.


           CALL "SDL_RenderClear" USING BY VALUE SDL-RENDERER END-CALL.
           PERFORM DRAW-LINE 9999 TIMES.
           GOBACK.
       DRAW-LINE.
             COMPUTE COLOR_R=FUNCTION RANDOM()*256.
             COMPUTE COLOR_G=FUNCTION RANDOM()*256.
             COMPUTE COLOR_B=FUNCTION RANDOM()*256.
             CALL "SDL_SetRenderDrawColor" USING
               BY VALUE SDL-RENDERER
               BY VALUE COLOR_R
               BY VALUE COLOR_G
               BY VALUE COLOR_B
               BY VALUE 255
             END-CALL.
             DISPLAY "Color = (" WITH NO ADVANCING.
             DISPLAY COLOR_R WITH NO ADVANCING.
             DISPLAY ", " WITH NO ADVANCING.
             DISPLAY COLOR_G WITH NO ADVANCING.
             DISPLAY ", " WITH NO ADVANCING.
             DISPLAY COLOR_B WITH NO ADVANCING.
             DISPLAY ")".
             COMPUTE X1=FUNCTION RANDOM()*WIDTH.
             COMPUTE X2=FUNCTION RANDOM()*WIDTH.
             COMPUTE Y1=FUNCTION RANDOM()*HEIGHT.
             COMPUTE Y2=FUNCTION RANDOM()*HEIGHT.

             DISPLAY "Line = (" WITH NO ADVANCING.
             DISPLAY X1 WITH NO ADVANCING.
             DISPLAY ", " WITH NO ADVANCING.
             DISPLAY Y1 WITH NO ADVANCING.
             DISPLAY ", " WITH NO ADVANCING.
             DISPLAY X2 WITH NO ADVANCING.
             DISPLAY ", " WITH NO ADVANCING.
             DISPLAY Y2 WITH NO ADVANCING.
             DISPLAY ")".
             CALL "SDL_RenderDrawLine" USING
               BY VALUE SDL-RENDERER
               BY VALUE X1
               BY VALUE Y1
               BY VALUE X2
               BY VALUE Y2
             END-CALL.
             CALL "SDL_RenderPresent"
                USING BY VALUE SDL-RENDERER
             END-CALL.
             CALL "SDL_Delay" USING BY VALUE 1 END-CALL.
            PERFORM CHECK_QUIT.
       CHECK_QUIT.
            CALL "SDL_PollEvent"
             USING BY REFERENCE E
             RETURNING E_RETURN
            END-CALL.

            PERFORM UNTIL E_RETURN EQUALS 0
             IF E_TYPE=256 THEN
              DISPLAY "EXIT"
              STOP RUN
             END-IF
             CALL "SDL_PollEvent"
              USING BY REFERENCE E
              RETURNING E_RETURN
             END-CALL
            END-PERFORM.


       END PROGRAM MAIN-METHOD.