Table of contents

  1. Map Class Overview
    1. Map Resources Setup
    2. Map Class Methods
    3. Map Subclasses

Map Class Overview

Map Resources Setup

The Map class does A LOT of setup upon instantiation for resources such as the camera, NPCs, map tile structure, etc. Since the Map class handles and coordinates so many different areas of the game logic, getting the setup step perfect is key for a successful level. Most of the game logic in the Map class is for the initial setup.

The Map class is abstract, meaning it cannot be instantiated without a subclass. The constructor for the Map class has two parameters defined:

  • mapFileName – the map file name that defines the tile layout and map dimensions, which are text files located in the MapFiles folder of this project
  • tileset – which tiles this map uses – this along with the map file will determine which map tile graphics are loaded in which locations

From there, the map does several setup steps to get all of its resources in order and ready to go for the game:

  1. Read in map file (read more about the map file here)
  2. Create map tiles and place them in the appropriate locations (process detailed here)
  3. Setup enhanced map tiles (read more about enhanced map tiles here)
  4. Setup NPCs (read more about NPCs here)
  5. Setup triggers (read more about Triggers here)
  6. Setup camera which handles which area of the map are shown on the screen at any given time (read more about the camera here)

Map Class Methods

The Map class has a lot of methods, but most of them are very simple, and many of them are just getters. Nearly all of these methods will be covered in the other setup pages linked above, as most are directly involved with the setup step. The methods loadNPCs, loadEnhancedMapTiles, loadTriggers, and loadScripts are all intended to be overridden by a subclass of the Map class.

The update method is very small, as the Camera class does most of the work updating the map, however there are two very important methods it does call itself: adjustMovementX and adjustMovementY. These two methods are covered in the Player class documentation here, and are critical to allowing the map to properly “scroll” as the player moves.

The draw method tells the Camera class to draw what area of the map should be shown on the screen.

Map Subclasses

Game maps are defined by subclassing the Map class. These are found in the Maps package. Currently, TestMap is the only map in the game that plays out a level. There is also TitleScreenMap which just acts as the background to the title screen.

Each Map subclass must satisfy the super class and specify the map file name and tileset. It is also a good idea to set the playerStartLocation in the map subclass’s constructor.

TestMap defines a map file of test_map.txt, and the CommonTileset class as its tileset choice (more on tilesets here),

public TestMap() {
    super("test_map.txt", new CommonTileset());
    this.playerStartPosition = getMapTile(17, 20).getLocation();
}

It also sets the playerStartLocation variable to a specific location, which is what tells the game where to start the player at in the map when it’s first loaded.

Each map subclass can also override the loadNPCs, loadEnhancedMapTiles, loadTriggers, and loadScripts methods in order to define NPCs, enhanced map tiles, triggers and scripts for a map.

For example, in TestMap, the loadNPCs override method looks like this:

@Override
public ArrayList<NPC> loadNPCs() {
    ArrayList<NPC> npcs = new ArrayList<>();

    Walrus walrus = new Walrus(1, getMapTile(4, 28).getLocation().subtractY(40));
    walrus.setInteractScript(new WalrusScript());
    npcs.add(walrus);

    Dinosaur dinosaur = new Dinosaur(2, getMapTile(13, 4).getLocation());
    dinosaur.setExistenceFlag("hasTalkedToDinosaur");
    dinosaur.setInteractScript(new DinoScript());
    npcs.add(dinosaur);

    Bug bug = new Bug(3, getMapTile(7, 12).getLocation().subtractX(20));
    bug.setInteractScript(new BugScript());
    npcs.add(bug);

    return npcs;
}

This adds three NPCs to the map – the walrus (Walrus class), the dinosaur (Dinosaur class), and the bug (Bug class). The getMapTile Map method is used to make it easier to place the NPC on a specific tile index in the map by getting the tile at that index’s location. The other setters, like setExistenceFlag and setInteractScript are map entity attributes that can be used to make the NPCs behave a specific way, and are covered in more detail in both the scripts and NPCs pages.