Circles — Draws circles

Here is an example program for drawing circles or ellipses, filled or unfilled:

    PROC draw:
          LOCAL d%
          DO
                dINIT "Draw a circle or an ellipse?"
                dBUTTONS "Circle",%c OR $200,"Ellipse",%e OR $200,"Cancel",-27
                d%=DIALOG
                IF d%=%c
                      circle:
                ELSEIF d%=%e
                      ellipse:
                ENDIF
          UNTIL d%=0
    ENDP
    
    PROC circle:
          LOCAL x&,y&,r&,f%
          dINIT "Drawing parameters"
          x&=320 :dLONG x&,"Centre x position",0,639
          y&=120 :dLONG y&,"Centre y position",0,249
          r&=20 :dLONG r&,"Radius",1,320
          f%=0 :dCHECKBOX f%,"Filled"
          dBUTTONS "Draw",%d,"Cancel",-27
          IF DIALOG
                gAT x&,y&
                gCIRCLE r&,f%
                GET
                gCLS
          ENDIF
    ENDP
    
    PROC ellipse:
          LOCAL x&,y&,hr&,vr&,f%
          dINIT "Drawing parameters"
          x&=320 :dLONG x&,"Centre x position",0,639
          y&=120 :dLONG y&,"Centre y position",0,249
          hr&=20 :dLONG hr&,"Horizontal Radius",1,320
          vr&=20 :dLONG vr&,"Vertical Radius",1,320
          f%=0 :dCHECKBOX f%,"Filled"
          dBUTTONS "Draw",%d,"Cancel",-27
          IF DIALOG
                gAT x&,y&
                gELLIPSE hr&,vr&,f%
                GET
                gCLS
          ENDIF
    ENDP