private void addHidden(int startIndex) {
		// Find out what kind of pieces can move in this delta
		int pieceType = ATTACK_ARRAY[move_to - startIndex + 128];

		// If rook is one of types, call addSlider with the right delta and rook
		// as piece type
		// same if bishop is one of the types
		switch (pieceType) {
		case ATTACK_KQR:
		case ATTACK_QR:
			addSlider(startIndex, DELTA_ARRAY[startIndex - move_to + 128],
					W_ROOK);
			break;
		case ATTACK_KQBwP:
		case ATTACK_KQBbP:
		case ATTACK_QB:
			addSlider(startIndex, DELTA_ARRAY[startIndex - move_to + 128],
					W_BISHOP);
			break;
		}

	}