HW: Dungeon Crawler

HW: Dungeon Crawler
Overview
Objectives
● Create and store values in a 2D dynamic array.
● Deallocate a 2D dynamic array.
● Resize a 2D dynamic array.
● Avoid memory leaks.
● Use pass by reference.
Introduction
You have just been hired by Foobar1
 Games as a game logic programmer. The company is
working on a retro dungeon crawler, which is a type of game where you control a character who
is navigating a fantasy dungeon environment.
You are in charge of implementing and testing part of the core game logic. The art and design
teams are still working on graphics and sound, so you are working on a text-based prototype for
developing and debugging your logic code.
In this assignment, you will implement the code that reads an in-game map (or “dungeon”)
from a file into a dynamic 2D array. You must also implement updating the map as the player
moves the character through the dungeon. The player’s goal is to pick up the treasure and go to
the level’s exit. Additionally, you will need to implement magic amulets that resize the dungeon
size as well as implement the logic for the monsters that chase the player.
1 Foobar
Getting Started
● Get the starter code (same as what you submit).
○ Dungeoncrawler.cpp
■ Contains the high level game control logic.
○ logic.h
■ Contains function prototypes for the game.
○ logic.cpp
■ Where you will implement the function definitions.
○ helper.h
■ Contains function prototypes for helper functions.
○ helper.cpp
■ Contains function definitions for helper functions.
● Allowed includes:
○ <iostream>
○ <fstream>
○ <string>
○ "logic.h"
○ "helper.h"
● Read over the starter code.
○ There is a struct in logic.h for the player with their position in the grid and a
count of their treasure.
○ There are tile status constants in logic.h that represent the tile type on the
map.
○ There are constants for the player’s status and keyboard inputs in logic.h.
● Read over the input file format for the program.
● Testing locally is very important for this assignment.
○ g++ -std=c++17 -Wall -Wextra -pedantic-errors -Weffc++ -
fsanitize=undefined,address *.cpp
○ ./a.out
● General procedure:
○ Pick a function to implement (start with functions that won’t need other functions
to work).
○ Read over the function specifications in logic.h.
○ Read over the function’s requirements in this document.
○ Write some test cases you expect your function to work with.
○ Write the function in logic.cpp.
○ Test your code.
○ If there are any failures, debug and re-evaluate your function.
● Refer to the appendix as needed.
Requirements
loadLevel()
1. Refer to the input file format.
2. Open logic.cpp and locate the loadLevel function. Make sure to read the block
comment describing the function.
3. Consider all the ways in which reading the dungeon map from the file could go wrong
and write code that detects when those things happen and responds correctly.
a. Correct behavior:
i. if the input file is invalid in any way, do not create the map but return
nullptr instead.
ii. For how to check validity, refer to the appendix and think back to checks
done on previous homeworks (this is intentionally left up to you to
discern).
1. One check is to ensure the total number of spaces does not
exceed INT32_MAX.
4. Consider what values are created or updated when the dungeon map file is valid and
write code that sets those values correctly.
a. Correct behavior:
i. maxRow is set to the number of rows in the dungeon level map
ii. maxCol is set to the number of columns in the dungeon level map
iii. player’s row and column attributes are set to the players starting location
in the dungeon level map
iv. The return value is a pointer to a dungeon level map in memory and the
contents of that map are the same as those in the input file (except the
player’s location which is marked using the player tile symbol).
getDirection()
1. Open logic.cpp and locate the getDirection function. Make sure to read the block
comment describing the function.
2. Consider what values are updated and write code that sets those values correctly.
a. Correct behavior:
i. nextRow and nextCol are set to the appropriate values depending on the
input direction
ii. Input other than MOVE_UP, MOVE_DOWN, MOVE_LEFT, or MOVE_RIGHT is
ignored (don’t move)
deleteMap()
1. Open logic.cpp and locate the deleteMap function. Make sure to read the block
comment describing the function.
2. Consider what values are updated and write code that sets those values correctly.
a. Correct behavior:
i. Deallocate the 2D array pointed at by the pointer map, and make sure not
to leak memory! (Hint: what should the parameter maxRow be used for?)
ii. Update map to be nullptr
iii. Update maxRow to be 0
resizeMap()
1. Open logic.cpp and locate the resizeMap function. Make sure to read the block
comment describing the function.
2. Consider what values are created or updated and write code that sets those values
correctly
a. Correct behavior:
i. An enlarged version of the dungeon map is created
1. A new 2D array, with (2 * maxRow) rows and (2 * maxCol)
columns, is dynamically allocated.
2. The content of the array map is copied into the subarray A exactly
(including the adventurer). The content of the array map is copied
into each of the subarrays B, C, and D, except for the adventurer,
which should be replaced by TILE_OPEN.
a. Visually, we can divide this 2D array into four
maxRow×maxCol subarrays:
ii. The original map is deallocated
iii. maxRow is doubled
iv. maxCol is doubled.
v. A pointer to the enlarged map is returned
vi. A nullptr if the map is null or one of the dimensions is invalid.
A B
C D
doPlayerMove()
1. Refer to Appendix C: Gameplay
2. Open logic.cpp and locate the doPlayerMove function. Make sure to read the block
comment describing the function. You will be returning a status from logic.h that
gives the result of the attempted move.
3. Consider all possible and meaningfully different map/game states and write code that
implements the correct behavior for those states.
a. Correct behavior:
i. Update player.row and player.col based on the value of nextRow
and nextColumn.
1. If the next position places the adventurer outside the bounds of
the array or on an impassable tile (a pillar or a monster), set the
status to STATUS_STAY and update nextRow and nextCol to be
the adventurer’s current position (i.e., the adventurer did not
move). Remember to check that nextRow and nextCol are
within bounds before using them to check a tile’s value (short
circuit evaluation might be useful, see zyBook).
2. If the next position is on a treasure tile, set the appropriate status
and increment the adventurer’s treasure by one.
3. If the next position is on an amulet tile, set the appropriate status.
4. If the next position is on a door (to the next level), set the
appropriate status.
5. If the next position is on an exit (to the whole dungeon) and the
adventurer has at least one piece of treasure, set the appropriate
status. If the adventurer has no treasure, treat the door as you
would a pillar.
ii. Update the map by updating the adventurer’s position to the next
position, setting the new position to TILE_PLAYER and the adventurer’s
old position to TILE_OPEN.
iii. Return the appropriate status flag.
doMonsterAttack()
1. Open logic.cpp and locate the doMonsterAttack function. Make sure to read the
block comment describing the function.
2. Consider all possible and meaningfully different map/game states and write code that
implements the correct behavior for those states.
a. Correct behavior:
i. All monsters with a vertical or horizontal line of sight to the player move 1
tile closer to the player
1. Starting from the tile above the adventurer’s location and working
upward, check each individual tile to see if there is a monster on
the tile.
2. If there is a monster on a tile, move the monster one tile closer to
the adventurer.
3. Continue to check until you have reached the top of the map or
reach a pillar (monsters can’t see through pillars)
4. Repeat the same logic with down, left, and right (in that order).
Make sure all monsters that are supposed to move do so before
you go to the next step.
ii. Return true if a monster reaches the player, false otherwise.
1. The adventurer is killed if a monster moves onto their tile (check if
the player position now contains a monster), return true
(adventurer killed, game over) if so, otherwise return false (the
monsters did not attack the adventurer, yet…).
createMap()
1. Open logic.cpp and locate the createMap function. Make sure to read the block
comment describing the function.
2. Consider all possible input values and write code to implement the correct behavior for
the function.
a. Correct behavior:
i. If the input values are invalid, do not create a new map but instead return
the null pointer.
ii. Otherwise, dynamically allocate a 2D char array with maxRow rows and
maxCol columns. Initialize each array element to TILE_OPEN.
iii. Return a pointer to the new map in memory.
Appendix
A: Testing Your Code
Sample Dungeons
Included in the starter code from Canvas is a folder of sample dungeon levels. You will find the
4 tutorial levels, 2 levels for the “easy” dungeon, and 3 levels for the “hard” dungeon.
See Appendix B for more information about playing the game. As an example, to play the hard
dungeon, you would enter “levels/hard 3” at the beginning prompt. You may want to test
with the tutorial or easy dungeon. The hard dungeon is not for the faint of heart! Can you
escape it?2
Of course, feel free to create your own levels! Review Appendix A for information about the level
file structure.
Debug Printouts
Because we want to only print out the map with each action, you will need to remove the INFO
statements or other debugging output from your code before submitting for the full program test
cases. The full program cases do not include any debugging output, so Gradescope will not allow
them to pass if INFO or “cout” statements are present in the final code.
Test Cases
In addition to the extensive unit tests that you considered (i.e. inputs and expected results),
Gradescope also has unit tests associated with each function. There are also full system tests
which check the integration of your code into the existing gameplay loop (in
dungeoncrawler.cpp).
However, you should remember that you are responsible for correctly implementing the game
logic and testing your code, so some test cases may not have thorough coverage of every
possible edge case. Try to think of edge cases and test them out yourself while developing!
Note that video games can be particularly challenging to find all bugs through test-driven
development. Games rely extensively on user interaction, so it is possible for a nearly-infinite
combination of edge cases to exist. The gaming industry has helped popularize play-testing jobs
and beta software releases as one means of identifying bugs during development.
2 2 It is possible to escape it in 65 steps with 1 treasure, or 88 steps with 4 treasures. Can you do better?
More Ideas
After you have finished and earned a score on Gradescope with which you are satisfied, here are
some other game mechanics you can think about implementing. You won’t get extra credit for
these, but if you have some free time you might find them both enjoyable and good practice.
● Monsters with different behaviors, for example up/down or left/right every turn,
diagonally, two or more squares per turn, etc.
○ Note: Most of what we have done so far in this course has been procedural, but as
you learn more about object-oriented approaches, think about how we could do
more complicated monster behaviors. You could keep a list of monster objects,
each with their own location, actions, etc. that you update each turn.
● Doors that require different amounts of treasure to unlock, or let you go back to a
previous level.
● Nonlinear dungeons, where levels have multiple doors to different levels.
● Levels that shrink each turn, like a trash compactor.
● More items with different properties, for example a shield to protect you against
monsters, a sword to let you attack monsters, a potion that lets you move faster or freeze
monsters, bombs that blow up pillars, etc.
● The ability to restart a level if the adventurer is killed.
● Update the map on the console without reprinting it.
Even though this is a very rudimentary game, we hope you can imagine how this assignment
relates to modern computer games. With some graphics, music and sound effects, and a little
polish, you’ve built the basics of a turn-based dungeon crawler!
B: Input Map Text File
This assignment will involve reading a text file that contains information of the dungeon map's
internal representation. This text file consists of three parts:
● Line 1: Map Dimensions. This line contains two values for representing the map's number
of rows and number of columns, respectively. (Neither can be bigger than 999,999)
● Line 2: Player Starting Location. This line contains two values for representing the
player's starting row and column, respectively.
● Lines 3+: These lines contain the individual tile information of the dungeon map as char
values.
○ The first number in Line 3 represents the map tile at (0, 0), where the first value
is the row position and the second value is the column position.
○ Refer to the tile status constants in logic.h for more details.
The following is an example text file for a 5×3 tile representation of a dungeon map.
5 3
3 0
M + -
- + -
- + !
- - -
@ - $
● Line 1; The map has 5 rows and 3 columns.
● Line 2: The player will start at map location (3, 0), where 3 is the row position and 0 is
the column position. Remember that indexing starts from 0, so the top left corner will be
map location (0, 0).
● Lines 3-7: The map's internal representation for each map tile.
○ Note #1: Whitespace for lines 3 and after are purely for aesthetic purposes, so
you must not assume that line breaks represent the actual map dimensions or
that there will be spaces in between the char values.
○ Note #2: In previous assignments you used column-major order when working
with 2D arrays and PPM files, which is the norm in the graphics community. In
this assignment you will be using row-major ordering when working with your 2D
arrays, as this is how a C++ program will typically order a multidimensional array.
○ Note #3: Each level of a dungeon has its own map stored in a different file, each
named according to the dungeon name followed by the level number. For
example, if the dungeon is named “tutorial” and has four levels, the files will
be “tutorial1.txt”, “tutorial2.txt”, “tutorial3.txt”, and
“tutorial4.txt”.
○ Note #4: Only the final level will have an exit (an ! symbol); all the other levels
have doors (a ? symbol) to the next level.
■ It is possible for a “final level” to have both an exit and a door (for
example, a “secret” level).
C: Gameplay
These are sketches and descriptions from the design team of the expected gameplay that you
must implement and test.
Loading a Game
Each game starts with a printout of the instructions, followed by a prompt for the dungeon name
and the number of levels in the dungeon. Here our dungeon is called tutorial and it has 4
levels (user input in dark red):
---------------------------------------------------------
Good day, adventurer!
Your goal is to get the treasure and escape the dungeon!
--- SYMBOLS ---
o : That is you, the adventurer!
$ : These are treasures. Lots of money!
@ : These magical amulets resize the level.
M : These are monsters; avoid them!
+, -, | : These are unpassable obstacles.
? : A door to another level.
! : A door to escape the dungeon.
--- CONTROLS ---
w, a, s, d : Keys for moving up, left, down, and right.
e : Key for staying still for a turn.
q : Key for abandoning your quest.
---------------------------------------------------------
Please enter the dungeon name and number of rooms: tutorial 4↵
Navigating the Dungeon
Our dungeon crawler uses the WASD3
 method of controlling the in-game adventurer: w and s
move the adventurer up one row and down one row respectively, while a and d move the
adventurer left one column and right one column respectively. Entering e will cause the
adventurer to stay still for a turn.
Tiles with unpassable obstacles (a pillar) cannot be moved onto, and are represented by the +
symbol. The door to the next level is represented by the ? symbol, while the door out of the
dungeon (and thus the game) is represented by the ! symbol.
3 WASD keys
Level 1
+---------+
| o ? |
| + |
| |
+---------+
Enter command (w,a,s,d: move, e: stay still, q: quit): s↵
+---------+
| o ? |
| + |
| |
+---------+
You didn't move. Are you lost?
Enter command (w,a,s,d: move, e: stay still, q: quit): d↵
+---------+
| o |
| + |
| |
+---------+
You have moved to row 0 and column 1
You go through the doorway into the unknown beyond...
Treasure
Dungeons are dangerous places, so why would you put up with all that risk for no reward? Tiles
with treasure on them are represented by the $ symbol. Pick up a piece of treasure by moving
the adventurer to that tile.
Upon exiting, the game will tell you how much treasure was picked up by the adventurer across
all levels. But make sure you don’t leave empty-handed, since the door out of the dungeon
(represented by the ! symbol) won’t open if you don’t have at least one piece of treasure!
Level 2
+---------------+
| ? |
| o $ |
| |
+---------------+
Enter command (w,a,s,d: move, e: stay still, q: quit): d↵
+---------------+
| ? |
| o |
| |
+---------------+
You have moved to row 1 and column 1
Well done, adventurer! You found some treasure.
You now have 1 treasure.
Enter command (w,a,s,d: move, e: stay still, q: quit): w↵
+---------------+
| ? o |
| |
| |
+---------------+
You have moved to row 0 and column 1
Enter command (w,a,s,d: move, e: stay still, q: quit): w↵
+---------------+
| ? o |
| |
| |
+---------------+
You didn't move. Are you lost?
Enter command (w,a,s,d: move, e: stay still, q: quit): a↵
+---------------+
| o |
| |
| |
+---------------+
You have moved to row 0 and column 0
You go through the doorway into the unknown beyond...
Monsters
So, what makes dungeons so dangerous anyway? The monsters kept in them to guard the
treasure of course! Monsters are represented by the symbol M, and will chase any adventurer in
their line of sight (i.e., if the adventurer is a rook’s4
 move from them). Thankfully, they are slow
and move only one tile per turn, and cannot see over unpassable obstacles, allowing the
adventurer to hide behind them.
The adventurer is quick enough that he can get through a door before a monster attacks on the
next turn, but won’t be able to pick up an item and then withstand an attack. Monster attacks are
lethal, and being killed by the monster will cause you to lose the game. The adventurer is not
strong enough to attack a monster, so the only strategy is to run away. Monsters are powerful,
4 Rook
and will destroy any (passable) obstacle in their path - including treasure, amulets, and even
doors!5
 Make sure that the monsters don’t destroy the only way out...
Level 3
+---------+
| M $ |
| $ $ |
| |
| o |
| |
| ? |
+---------+
Enter command (w,a,s,d: move, e: stay still, q: quit): s↵
+---------+
| $ |
| M $ |
| |
| |
| o |
| ? |
+---------+
You have moved to row 4 and column 0
Enter command (w,a,s,d: move, e: stay still, q: quit): s↵
+---------+
| $ |
| $ |
| M |
| |
| |
| o ? |
+---------+
You have moved to row 5 and column 0
Enter command (w,a,s,d: move, e: stay still, q: quit): d↵
+---------+
| $ |
| $ |
| M |
| |
| |
| o |
+---------+
You have moved to row 5 and column 1
You go through the doorway into the unknown beyond...
5 Note: This is actually a simplification so that testing and development will be easier.
Magic Amulets
The dungeon also holds many ancient and mysterious artifacts, such as magic amulets. Magic
amulets are represented by the @ symbol. Picking up an amulet will cause the level to double in
size, with three additional copies of the level (without additional adventurers, but with additional
monsters and items) appearing below, to the right, and diagonally below and right of the level.
Unfortunately, the amulet is destroyed in the process and isn’t copied as well.
Be careful, magic can be dangerous to use - make sure you don’t accidentally have a monster
appear right next to you! But in wise hands, magic can help you escape from otherwise
impossible levels...
Level 4
+---------+
| o |
| + + |
| @ + ! |
+---------+
Enter command (w,a,s,d: move, e: stay still, q: quit): s↵
+---------+
| |
| o + + |
| @ + ! |
+---------+
You have moved to row 1 and column 0
Enter command (w,a,s,d: move, e: stay still, q: quit): s↵
+------------------+
| |
| + + + + |
| o + ! + ! |
| |
| + + + + |
| + ! + ! |
+------------------+
You have moved to row 2 and column 0
The magic amulet sparkles and crumbles into dust.
The ground begins to rumble. Are the walls moving?
Enter command (w,a,s,d: move, e: stay still, q: quit): s↵
+------------------+
| |
| + + + + |
| + ! + ! |
| o |
| + + + + |
| + ! + ! |
+------------------+
You have moved to row 3 and column 0
Enter command (w,a,s,d: move, e: stay still, q: quit): d↵
+------------------+
| |
| + + + + |
| + ! + ! |
| o |
| + + + + |
| + ! + ! |
+------------------+
You have moved to row 3 and column 1
Enter command (w,a,s,d: move, e: stay still, q: quit): d↵
+------------------+
| |
| + + + + |
| + ! + ! |
| o |
| + + + + |
| + ! + ! |
+------------------+
You have moved to row 3 and column 2
Enter command (w,a,s,d: move, e: stay still, q: quit): w↵
+------------------+
| |
| + + + + |
| + o + ! |
| |
| + + + + |
| + ! + ! |
+------------------+
You have moved to row 2 and column 2
Congratulations, adventurer! You have escaped the dungeon!
You escaped with 1 treasure and in 16 total moves.
Quitting the Game
You can quit the game at any time by entering the symbol q. Just be careful, as there is no way
to save your progress.