Building Levels

Formats

The following formats are supported by FXGL:

• .tmx, .json - Tiled Map Editor
• .txt - 2d grid of data, where each character (symbol) is mapped to an entity

Tiled Map Editor

A video tutorial is available on YouTube.

The editor can downloaded for free from here. Supported version: 1.1.2 (both .tmx and .json). Note: make sure to "embed tilesets" into maps. Given a .json file, say mario1.json from Tiled Map Editor, you can parse it as follows:

getGameWorld().setLevelFromMap("mario1.json");

// OR

getGameWorld().setLevelFromMap("mario1.tmx");

The objects from the file will be parsed using their type. The parser will expect an EntityFactory with @Spawns annotation for each of the object types. So, if you have an object with type Platform in your mario1.json, then the factory's

@Spawns("Platform")
public Entity newPlatform(SpawnData data) {
    return ...
}

will be called.

Text Format

The corresponding parser is TextLevelParser. There are two ways to set up level parsing. The recommended approach is to create an entity factory class. If you are developing a game called RocketPower, then RocketPowerFactory is the recommended name for that class.

public class RocketPowerFactory implements EntityFactory {

}

Generally, this is going to be the only class responsible for creating entities in your game. Now, imagine you have a level file called level1.txt, where you have a bunch of characters that represent level data. Say you use P for platforms. Let's create a method in the class above that will take care of platform creation.

@SpawnSymbol('P')
public Entity newPlatform(SpawnData data) {
    Entity platform = ...
    return platform;
}

First of all, the annotation SpawnSymbol signifies that this creation method will be called when P is encountered in the level data. The name of the method can be anything, however the required signature is as follows: public Entity ANY_METHOD_NAME(SpawnData data). The data object contains everything required to set up an entity before spawning it.

Finally, we just need to wire everything together.

@Override
public void initGame() {
    TextLevelParser parser = new TextLevelParser(new RocketPowerFactory());
    Level level = parser.parse("levels/level1.txt");
    getGameWorld().setLevel(level);
}

For each character found in the text level file the parser will ask our factory to create an entity. That's level parsing done! Sample code can be found here.

Spawning Entities Using Factories

Let's go back to our platform spawning method and add the Spawns annotation:

@Spawns("Platform")
@SpawnSymbol('P')
public Entity newPlatform(SpawnData data) {
    Entity platform = ...
    return platform;
}

Then, we can set the main factory to our game world as follows (in initGame()):

getGameWorld().addEntityFactory(new RocketPowerFactory());

Finally, we can spawn a new platform any time we want by calling:

getGameWorld().spawn("Platform", x, y);