Adding physics

We are going to add a physics world to our game and set it up with gravity. We will also make a physics body for the player character and add platforms. Finally, we will make the character move based on the tilt of our Android device. The physics extension should be already included in your game project since Chapter 1, Setting Up an AndEngine Project.

First, we must remove the code that we added in Chapter 5, Basic Interactions, when we were learning about modifiers, because we don't want the entity to be controlled by touch or drag-and-drop. We want it to be controlled by physics and gravity.

The following code snippet shows how the relevant parts of the cleaned up version of the GameScene class should look. The populate() method will be limited only to this code.

@Override
public void populate() {
  createBackground();
  createPlayer();
  createHUD();
  engine.enableAccelerationSensor(activity, this);
}

The onAccelerationChanged() method should look like the following code...