void drawCircle(int xc, int yc, int x, int y)
{
    al_put_pixel(xc+x, yc+y, al_map_rgb(0,0,0));
    al_put_pixel(xc-x, yc+y, al_map_rgb(0,0,0));
    al_put_pixel(xc+x, yc-y, al_map_rgb(0,0,0));
    al_put_pixel(xc-x, yc-y, al_map_rgb(0,0,0));
    al_put_pixel(xc+y, yc+x, al_map_rgb(0,0,0));
    al_put_pixel(xc-y, yc+x, al_map_rgb(0,0,0));
    al_put_pixel(xc+y, yc-x, al_map_rgb(0,0,0));
    al_put_pixel(xc-y, yc-x, al_map_rgb(0,0,0));
}

void circleBres(int xc, int yc, int r)
{
    int x = 0, y = r;
    int d = 3 - 2 * r;
    drawCircle(xc, yc, x, y);
    while (y >= x)
    {
        x++;

        if (d > 0)
        {
            y--;
            d = d + 4 * (x - y) + 10;
        }
        else
            d = d + 4 * x + 6;
        drawCircle(xc, yc, x, y);
    }
}