1 Introduction

In this assignment, you will implement a game in which a player must escape from a dungeon of slugs.  Unlike assignment 1, in this assignment you will be using object-oriented programming and following the Apple Model-View-Controller (MVC) design pattern shown in lectures. In addition to creating code for modelling the game, you will be implementing a graphical user interface (GUI). An example of a final completed game is shown in Figure 1.

Figure 1: Example screenshot from a completed implementation.  Note that your display may look slightly different depending on your operating system.

2 Getting Started

Download a2. zip from Blackboard — this archive contains the necessary files to start this assign- ment. Once extracted, the a2. zip archive will provide the following files: a2. py  This is the only file you will submit and is where you write your code. Do not make changes to any other files.
support . py  Do not modify or submit this file, it contains pre-defined classes and constants to assist you in some parts of your assignment. In addition to these, you are encouraged to create your own constants and helper functions in a2. py where possible.
levels/ This folder contains a small collection of files used to initialize games of SlugDungeon.  In addition to these, you are encouraged to create your own files to help test your implementation where possible.

3 Gameplay

This section provides a brief overview of gameplay for Assignment 2.  Where interactions are not explicitly mentioned in this section, please see Section 4.

3.1 Overview and Terminology

SlugDungeon takes place on a 2D grid called a board, where each < row, col > position on the board is represented by a tile.  In the dungeon, there are also  entities, which move around the board and potentially attack other entities.

Each game consists of one player entity, and a number of slug entities.  Entities have a health and poison stat, and may optionally have an equipped  weapon.   An  entity  dies  when  their health is reduced to 0. At the end of each turn, if an entity is poisoned  (has a poison stat greater than 0) the entity takes damage equal to its poison amount before its poison stat is reduced by 1.  Each  turn, the player makes one move (either moving one square up, down, left, or right or remaining where they are). All entities attack every turn, but slugs can only move every second turn.

Weapons have an effect and a range (depending on their type).  Weapon’s effects can alter the health and poison stats of the entities at positions within their range.

3.2 Player Interaction

The game is played as a series of turns.  The user may instruct the player to move or stay where they are via keypresses (see Table 1 for the behaviours associated with each key). If the key pressed is not associated with a valid movement (e.g. it is not one of ’a’, ’s’, ’w’, ’d’, or ’space’, or it would move the player to a blocking tile or to another entity’s position) it is ignored and not counted as a turn. Otherwise, if the keypress does result in a valid move (or intentionally leaving the player in place), the following steps should occur:

1.  The player moves (or remains where it is) according to Table 1.

2.  If the player’s new position contains a weapon, the player picks up the weapon and discards any weapon it may have already been holding.

3. The player attacks from its new position.

4.  All slugs that die as a result of the player’s attack are removed from the game.  Each dead slug drops its weapon onto the tile it occupied when it died, replacing any weapon that already existed on that tile.

5.  The player’s poison is applied and then reduced.

6.  Each slug’s poison is applied and then reduced.

7.  If the slugs are able to move on this turn, all slugs should make their desired move.

8. All slugs attack from their (potentially new) position.

9.  If the player has won or lost the game, a messagebox is displayed informing the user of the outcome and asking whether the user would like to play again.  If the user chooses to play again, the game file should reload and the user should be able to play again.  If they select not to play again, the program should terminate gracefully.  Otherwise, the program should continue waiting for more keypresses to begin a new turn.

Table 1: Key press behaviours

3.3 Movement

Entities can only move one square at a time (directly up, down, left, or right).  Slugs are only allowed to move once for every second turn (where a turn is one player movement).  An entity can only move to a target position if they are allowed to move this turn, the target position does not contain a blocking tile or another entity, and the target position is one square away from the entity’s original position.

3.4 Attacking

Entities attempt to make an attack every turn after they have moved. When the player attacks, it applies its weapon’s effect to all slugs within its weapon’s range. When a slug attacks, it applies its weapon’s effect to the player if the player is within the slug’s weapon’s range.  If an entity is not holding a weapon its attack should have no effect.

3.5 Game End

The game ends when one of the following occurs:

•  The user wins the game because all slugs are dead and the player is on a goal tile.

•  The user loses the game because the player dies.

Figure 2: Basic class relationship diagram for the classes in assignment 2.

4.1.1 Weapon()

Weapon is an abstract class from which all instantiated types of weapon inherit. This class provides default weapon behaviour, which can be inherited or overridden by specific types of weapons.  All weapons should have a symbol, name, effect, and range.

• When a weapon is used to attack, it has an effect on its target, which may alter the targets health or poison stat. Weapon classes are not responsible for applying their effects to entities, but must provide details about their intended effects.   Within this class, a weapon’s effect is represented by a dictionary mapping strings to integers, where the string represents the type of effect and the integer represents the strength of the effect.  The valid effect types are "damage" (which reduces the target’s health), "healing" (which increases the target’s health), and "poison" (which increases the targets poison stat).

•  A weapon’s range is an integer representing how far the effects of the weapon reach in all 4 directions.  A range of 1 would mean that a weapon’s effects would reach entities located one position up, down, left, and right of the weapon.

Abstract weapons have no effects and a range of 0. The init method does not take any arguments beyond self. Weapon must implement the following methods:

• get name(self)  ->  str

Returns the name of this weapon.

• get symbol(self)  ->  str

Returns the symbol of this weapon.

• get effect(self)  ->  dict[str,  int]

Returns a dictionary representing the weapon’s effects.

• get targets(self, position:  Position)  ->  list[Position]

Returns a list of all positions within range for this weapon, given that the weapon is currently at position. Note that this method does not need to check whether the target positions exist within a dungeon.

• str (self)  ->  str

Returns the name of this weapon.

• repr (self)  ->  str

Returns a string which could be copied and pasted into a REPL to construct a new instance identical to self.

Examples:

>>>  weapon  = Weapon() >>>  weapon. get_name() 'AbstractWeapon'

>>> weapon. get_symbol() 'W'

>>> weapon. get_effect() {}

>>> weapon. get_targets((1,  1))

[]

>>>  str(weapon)   'AbstractWeapon'

>>>  weapon Weapon()

4.1.2 PoisonDart(Weapon)

PoisonDart inherits from Weapon.  A poison dart has a range of 2 and applies 2 poison to its targets.

Examples:

>>> poison_dart  =  PoisonDart() >>> poison_dart. get_name()

'PoisonDart'

>>> poison_dart. get_symbol() 'D'

>>> poison_dart. get_effect() {'poison':  2}

>>> poison_dart. get_targets((1,  1))

[(1,  2),  (1,  0),  (2,  1),  (0,  1),  (1,  3),  (1,  -1),  (3,  1),  (-1,  1)] >>> poison_dart. get_targets((8,  8))

[(8,  9),  (8,  7),  (9,  8),  (7,  8),  (8,  10),  (8,  6),  (10,  8),  (6,  8)] >>>  str(poison_dart)

'PoisonDart'

>>> poison_dart PoisonDart()

4.1.3 PoisonSword(Weapon)

PoisonSword inherits from Weapon.  A poison sword has a range of 1 and both damages its targets by 2 and increases their poison stat by 1.

Examples:

>>> poison_sword  =  PoisonSword() >>> poison_sword. get_name()

'PoisonSword'

>>> poison_sword. get_symbol() 'S'

>>> poison_sword. get_effect() {'damage':  2,  'poison':   1}

>>> poison_sword. get_targets((1,  1)) [(1,  2),  (1,  0),  (2,  1),  (0,  1)]

>>> poison_sword. get_targets((0,  0)) [(0,  1),  (0,  -1),  (1,  0),  (-1,  0)]

>>>  str(poison_sword)

'PoisonSword'

>>> poison_sword PoisonSword()

4.1.4 HealingRock(Weapon)

HealingRock inherits from Weapon. A healing rock has a range of 2 and increases its targets health by 2.

Examples:

>>> healing_rock  =  HealingRock() >>> healing_rock. get_name()

'HealingRock'

>>> healing_rock. get_symbol() 'H'

>>> healing_rock. get_effect() {'healing':  2}

>>> healing_rock. get_targets((1,  1))

[(1,  2),  (1,  0),  (2,  1),  (0,  1),  (1,  3),  (1,  -1),  (3,  1),  (-1,  1)] >>>  str(healing_rock)

'HealingRock'

>>> healing_rock HealingRock()

4.1.5 Tile()

Tile is a class representing individual tiles (positions) in the dungeon.  A tile may or may not be blocking and may or may not have a weapon sitting on it.  Entities cannot move onto blocking tiles, but weapon effects can pass through blocking tiles.
Each tile has a symbol which represents what type of tile it is. Tile must implement the following methods:

• init (self,  symbol:  str,  is blocking:  bool)  ->  None

Constructs a new tile instance with the given symbol and is_blocking status.  Newly instan- tiated tiles do not have a weapon on them.

•  is blocking(self)  -> bool

Returns True if this tile is blocking and False otherwise.

• get weapon(self)  ->  Optional[Weapon]

Returns the weapon that’s on this tile, or None if there is no weapon on this tile.

•  set weapon(self,  weapon:  Weapon)  ->  None

Sets the weapon on this tile to weapon, replacing any weapon that may already be there.

• remove weapon(self)  ->  None

Removes the tiles’s current weapon.

• str (self)  ->  str

Returns the symbol associated with this tile.

• repr (self)  ->  str

Returns a string which could be copied and pasted into a REPL to construct an instance of Tile with the same symbol and is_blocking status as self.

Examples:

>>>  tile  =  Tile("#",  True) >>>  tile. is_blocking()

True

>>>  tile. get_weapon()

>>> healing_rock  =  HealingRock()   >>>  tile. set_weapon(healing_rock)

>>>  tile. get_weapon() HealingRock()

>>>  tile. get_weapon() . get_effect() {'healing':  2}

>>>  tile. remove_weapon() >>>  tile. get_weapon()

>>>  str(tile)

'#'

>>>  tile

Tile('#',  True)

>>>  tile  =  Tile("hello",  False) >>>  tile

Tile('hello',  False)

>>>  tile. is_blocking() False