ture(main_img[i], pos);
    if ((o_offset[i].x <= pos.x) && (o_offset[i].y <= pos.y) && (pos.x < (o_offset[i].x + o_size[i].x)) && (pos.y < (o_offset[i].y + o_size[i].y))) {
        vec4 ovr = texture(overlay_img[i], pos - o_offset[i]);
        res = ovr * ovr.a + res * (1.0f - ovr.a);
        res.a = 1.0f;
        imageStore(output_img[i], pos, res);
    }
    imageStore(output_img[i], pos, res);
}