public boolean tryRotate() {
		
		boolean valid = true;
		incrementTYPE(true);
		int[][] key = screen[row][col].key();

		for (int i=0; i<3; i++) {
			int r = row+key[i][0];
			int c = col+key[i][1];
			if (r < 0 || r >= NUM_ROWS || c < 0 || c >= NUM_COLS || dead[r][c] == true)
				valid = false;
		}
		
		incrementTYPE(false);
		
		if (valid) 
			commitRotate();
		
		return valid;
	}