procedure TForm1.FormPaint(Sender: TObject);
const pi = 3.1415926;
var
y0:real;
x,y,i,j:integer;
begin
//Canvas.Pen.Color := RGB(150,200,180);
for i:=20 to 100 do
begin
Canvas.Pixels[100,5*i-80] := clBlue;
Canvas.Pixels[5*i,200] := clBlue;
end;
for j:=0 to 360 do
begin
y0 := 50*sin(2*pi*j/360);
y := 200-round(y0);
x := 100+j;
Canvas.Pixels[x,y] := clRed;
if(x mod 3) <> 0 then
begin
Canvas.MoveTo(x,200);
Canvas.LineTo(x,y);
end;
y := 200+round(y0);
Canvas.Pixels[x,y] := clRed;
end;
end;