int on_pos = lrint(lufs_to_pos(level_lu, height()));
QRect off_rect(0, 0, width(), on_pos);
QRect on_rect(0, on_pos, width(), height() - on_pos);
int on_pos = lrint(lufs_to_pos(level_lu, height()));
QRect off_rect(0, 0, width(), on_pos);
QRect on_rect(0, on_pos, width(), height() - on_pos);