void rasterCircle(int x0, int y0, int radius)
{
	int f = 1 - radius;
	int ddF_x = 0;
	int ddF_y = -2 * radius;
	int x = 0;
	int y = radius;

	pixelColor(display,x0,y0+radius,0xff0000ff);
	pixelColor(display,x0,y0-radius,0xff0000ff);
	pixelColor(display,x0+radius,y0,0xff0000ff);
	pixelColor(display,x0-radius,y0,0xff0000ff);

	while(x < y)
	{
		if(f >= 0)
		{
			y--;
			ddF_y += 2;
			f += ddF_y;
		}
		x++;
		ddF_x += 2;
		f += ddF_x + 1;


		pixelColor(display,x0+x,y0+y,0x00ff00ff);
		pixelColor(display,x0-x,y0+y,0x0000ffff);
		pixelColor(display,x0+x,y0-y,0xffff00ff);
		pixelColor(display,x0-x,y0-y,0x00ffffff);
		pixelColor(display,x0+y,y0+x,0xff00ffff);
		pixelColor(display,x0-y,y0+x,0xffffffff);
		pixelColor(display,x0+y,y0-x,0x808080ff);
		pixelColor(display,x0-y,y0-x,0xff8080ff);
	}
}