Add functionality for generated maps

[TheRamenChef]

LITIEngine currently has very little support for maps generated at runtime. I would like to have this functionality for the game I’m working on.

[steffen-wilke]

In general, I think this is a good idea. @TheRamenChef could you describe your requirements in more detail? What are the required engine extensions in you eyes?

[TheRamenChef]

Basically, I want to be able to make procedurally-generated levels for better replay value.

[TheRamenChef]

Any updates on this feature?

[steffen-wilke]

In general, I think most of the API in the de.gurkenlabs.litiengine.tilemap and de.gurkenlabs.litiengine.tilemap.xml namespaces should already allow for generating maps from code. We've done this in a few games we made in the past.

However, I still think there might be some missing or non-public APIs that we didn't come across yet. I'll investigate this and check for any missing pieces.

[steffen-wilke]

I just wrote a quick test that checks for the available methods of the XML implementation compared to what is available on the interfaces (public API).

de.gurkenlabs.litiengine.environment.tilemap.xml.CustomProperty ✔
de.gurkenlabs.litiengine.environment.tilemap.xml.CustomPropertyProvider ✔
de.gurkenlabs.litiengine.environment.tilemap.xml.Frame ✔
de.gurkenlabs.litiengine.environment.tilemap.xml.package-info ✔
de.gurkenlabs.litiengine.environment.tilemap.xml.PolyShape ✔
de.gurkenlabs.litiengine.environment.tilemap.xml.Terrain ✔
de.gurkenlabs.litiengine.environment.tilemap.xml.TileAnimation ✔
de.gurkenlabs.litiengine.environment.tilemap.xml.TileOffset ✔
de.gurkenlabs.litiengine.environment.tilemap.xml.TilesetEntry ✔

de.gurkenlabs.litiengine.environment.tilemap.xml.Blueprint

• build missing
• keepIds missing
• getItems missing
• getBounds missing
• setPolyline missing

de.gurkenlabs.litiengine.environment.tilemap.xml.GroupLayer

• setRenderType missing
• setOpacity missing

de.gurkenlabs.litiengine.environment.tilemap.xml.ImageLayer

• setRenderType missing
• setOpacity missing

de.gurkenlabs.litiengine.environment.tilemap.xml.Layer

• setRenderType missing
• setOpacity missing

de.gurkenlabs.litiengine.environment.tilemap.xml.MPublic APImage

• getHeight missing
• getWidth missing

de.gurkenlabs.litiengine.environment.tilemap.xml.MapObject

• getBounds missing
• setPolyline missing

de.gurkenlabs.litiengine.environment.tilemap.xml.MapObjectLayer

• setRenderType missing
• setOpacity missing

de.gurkenlabs.litiengine.environment.tilemap.xml.Text

• getFontName missing
• getPixelSize missing
• isBold missing
• useKerning missing
• isItalic missing
• isStrikeout missing
• isUnderlined missing

de.gurkenlabs.litiengine.environment.tilemap.xml.Tile

• setTileCoordinate missing

de.gurkenlabs.litiengine.environment.tilemap.xml.TileChunk

• getValue missing
• getHeight missing
• getX missing
• getWidth missing
• getY missing

de.gurkenlabs.litiengine.environment.tilemap.xml.TileData$Compression

• isValid missing

de.gurkenlabs.litiengine.environment.tilemap.xml.TileData$Encoding

• isValid missing

de.gurkenlabs.litiengine.environment.tilemap.xml.TileData

• encode missing
• getValue missing
• setValue missing
• getEncoding missing
• setEncoding missing
• setCompression missing
• getCompression missing
• getTiles missing

de.gurkenlabs.litiengine.environment.tilemap.xml.TileLayer

• setRenderType missing
• setOpacity missing

de.gurkenlabs.litiengine.environment.tilemap.xml.Tileset

• load missing
• finish missing
• saveSource missing
• isExternal missing
• updateTileTerrain missing

de.gurkenlabs.litiengine.environment.tilemap.xml.TmxMap

• setHeight missing
• setWidth missing
• finish missing
• setPath missing
• setVersion missing
• setTileWidth missing
• setStaggerIndex missing
• setOrientation missing
• setStaggerAxis missing
• setHexSideLength missing
• setTiledVersion missing
• setTileHeight missing
• setRenderOrder missing
• getExternalTilesets missing

As a first step, we should iterate over these missing methods and check which ones should be included in the public interface. Then we can define further API that simplifies map generation, e.g. a helper class that simplifies the generation (also see #329 and This forum post)

[ghost]

Not to be greedy, but can you point a link to these past games?
Litiengine doesn't seem to be automagically reading & using collision boxes from tmx files.
It would be helpful to see how you get that to work

[steffen-wilke]

Not to be greedy, but can you point a link to these past games?

Sorry, these were internal projects. But I'm currently working on extending Gurk Nukem with a mechanism to generate maps at runtime as an example project.

In general: collision boxes are just MapObjects with the type MapObjectType.COLLISIONBOX.
Our utiliti editor is basically the best publically available example for adding map objects to a map.
Basically, what you need is a IMapObjectLayer and then you can add as many objects of different types as you desire:

Adding a mapobject to a layer

litiengine/utiliti/src/de/gurkenlabs/utiliti/components/MapComponent.java

Lines 378 to 389 in 3455fa6

	public void add(IMapObject mapObject, IMapObjectLayer layer) {
	if (layer == null || mapObject == null) {
	return;
	}
	layer.addMapObject(mapObject);
	Game.world().environment().loadFromMap(mapObject.getId());
	Game.window().getRenderComponent().requestFocus();
	this.setFocus(mapObject, false);
	this.setEditMode(EDITMODE_EDIT);
	}

Creating a new MapObjectLayer

litiengine/utiliti/src/de/gurkenlabs/utiliti/components/MapComponent.java

Lines 709 to 716 in 3455fa6

	if (map.getMapObjectLayers().isEmpty()) {
	// make sure there's a map object layer on the map because we need one
	// to add any kind of entities
	MapObjectLayer layer = new MapObjectLayer();
	layer.setName(DEFAULT_MAPOBJECTLAYER_NAME);
	map.addLayer(layer);
	}

Creating a new MapObject

litiengine/utiliti/src/de/gurkenlabs/utiliti/components/MapComponent.java

Lines 866 to 904 in 3455fa6

	private IMapObject createNewMapObject(MapObjectType type) {
	final Rectangle2D newObjectArea = this.getMouseSelectArea(true);
	IMapObject mo = new MapObject();
	mo.setType(type.toString());
	mo.setX((float) newObjectArea.getX());
	mo.setY((float) newObjectArea.getY());
	// ensure a minimum size for the new object
	float width = (float) newObjectArea.getWidth();
	float height = (float) newObjectArea.getHeight();
	mo.setWidth(width == 0 ? 16 : width);
	mo.setHeight(height == 0 ? 16 : height);
	mo.setId(Game.world().environment().getNextMapId());
	mo.setName("");
	switch (type) {
	case PROP:
	mo.setValue(MapObjectProperty.COLLISIONBOX_WIDTH, (newObjectArea.getWidth() * 0.4));
	mo.setValue(MapObjectProperty.COLLISIONBOX_HEIGHT, (newObjectArea.getHeight() * 0.4));
	mo.setValue(MapObjectProperty.COLLISION, true);
	mo.setValue(MapObjectProperty.COMBAT_INDESTRUCTIBLE, false);
	mo.setValue(MapObjectProperty.PROP_ADDSHADOW, true);
	break;
	case LIGHTSOURCE:
	mo.setValue(MapObjectProperty.LIGHT_COLOR, Color.WHITE);
	mo.setValue(MapObjectProperty.LIGHT_SHAPE, "ellipse");
	mo.setValue(MapObjectProperty.LIGHT_ACTIVE, true);
	break;
	case COLLISIONBOX:
	mo.setValue(MapObjectProperty.COLLISION_TYPE, Collision.STATIC);
	break;
	case SPAWNPOINT:
	default:
	break;
	}
	this.add(mo);
	return mo;
	}

If you'd rather use the engines Entity implementation to create your MapObject you could have a look at the MapObjectSerializer.

[ghost]

Genius, that will work in theory. I'll check it out

[steffen-wilke]

96be92d introduces a new API to support generating maps: Resources.maps().generate(...)

Usage

IMap generatedMap;
try (MapGenerator generator = Resources.maps().generate(MapOrientations.ORTHOGONAL, "mymap", 100, 100, 16, 16, Resources.tilesets().get("tileset.tsx"))) {
  tileLayer = generator.addTileLayer(RenderType.GROUND, (x, y) -> {
    if (x == y) {
      // draw a diagonal in another tile color
      return 2;
    }

    // fill the entire map with this tile
    return 1;
  });

  // set an explicit tile at a location
  tileLayer.setTile(10, 10, 3);

  // add a collision box to the map
  generator.add(new CollisionBox(0, 50, 100, 10));

  generatedMap = generator.getMap();
}