{Circle.inc by Kari Lammassaari . Based on pseudocode of
                                  PC Game Programmers Encyclopedia = pcgpe.exe
                                  at teeri.oulu.fi }

Procedure Circle(CenterX,CenterY,Radius:Integer;Page,Color,LogOp:Byte);
  Var d,x,y :Integer;
  Begin
     d := 3 - (2 * Radius);
     x := 0;
     y :=Radius;
     Repeat
       If d < 0 Then d := d+(4 * x)+6
        Else
          Begin
             d:=d + 4 * (x-y)+10;
             y :=y-1;
          End;

       Pset(CenterX+x,CenterY+y,Page,Color,LogOp);
       Pset(CenterX+x,CenterY-y,Page,Color,LogOp);
       Pset(CenterX-x,CenterY+y,Page,Color,LogOp);
       Pset(CenterX-x,CenterY-y,Page,Color,LogOp);
       Pset(CenterX+y,CenterY+x,Page,Color,LogOp);
       Pset(CenterX+y,CenterY-x,Page,Color,LogOp);
       Pset(CenterX-y,CenterY+x,Page,Color,LogOp);
       Pset(CenterX-y,CenterY-x,Page,Color,LogOp);
       x := x+1;
     Until x >= y;
  End;