Game World

This chapter is about the GameWorld class provided via the GameContext of braingdx. Every screen has an own GameWorld object, available via the context.getGameWorld() method.

Game Objects

Worlds contain objects of type GameObject in order to make games alive:

// inside an AbstractScreen implementation
GameWorld world = context.getGameWorld();
// Creating a new game object in the world
GameObject object = world.addGameObject();
// Set the position of the game object in the world
object.setPosition(100, 200);

When running the game you will not see anything because the concept of game objects is virtual. Game objects exist in the game world but the game world does not know how to display them. Also the game objects itself have no information about rendering since they are stateful plain Java objects.

World bounds

By default a game world has infinite size in terms of bounds. However, when building a side scroller or space game you want to remove game objects as soon as they leave the screen/bounds of the world. braingdx provides a utility of so called World Bounds:

GameWorld world = context.getGameWorld();
// Set the world bounds to 1000px width and 2000px height
world.setBounds(new RectWorldBounds(1000, 2000));

As soon as a game object leaves the bounds completely it will get removed from the game world. Implement your own bounds implementation by implementing the WorldBounds interface.