protected boolean move(double xa, double ya) {
		List<BB> bbs = level.getClipBBs(this);
		if (physicsSlide || (xa==0||ya==0)) {
			boolean moved = false;
			if (!removed)
				moved |= partMove(bbs, xa, 0);
			if (!removed)
				moved |= partMove(bbs, 0, ya);
			return moved;
		} else {
			boolean moved = true;
			if (!removed)
				moved &= partMove(bbs, xa, 0);
			if (!removed)
				moved &= partMove(bbs, 0, ya);
			return moved;
		}
	}