#define plot(x, y) put_pixel_clip(img, x, y, r, g, b)

void raster_circle(
        image img,
        unsigned int x0,
        unsigned int y0,
        unsigned int radius,
        color_component r,
        color_component g,
        color_component b )
{
    int f = 1 - radius;
    int ddF_x = 0;
    int ddF_y = -2 * radius;
    int x = 0;
    int y = radius;

    plot(x0, y0 + radius);
    plot(x0, y0 - radius);
    plot(x0 + radius, y0);
    plot(x0 - radius, y0);

    while(x < y)
    {
        if(f >= 0)
        {
            y--;
            ddF_y += 2;
            f += ddF_y;
        }
        x++;
        ddF_x += 2;
        f += ddF_x + 1;
        plot(x0 + x, y0 + y);
        plot(x0 - x, y0 + y);
        plot(x0 + x, y0 - y);
        plot(x0 - x, y0 - y);
        plot(x0 + y, y0 + x);
        plot(x0 - y, y0 + x);
        plot(x0 + y, y0 - x);
        plot(x0 - y, y0 - x);
    }
}
#undef plot