Describe the bug

While the DemoScene is active, if pressing BackSpace to go back to TitleScene, and then press ENTER to go to DemoScene, the default active Camera is not 'active'.

Light

In the context of a 2D platform game, the Decors need to be lighted with some specific colors or dimmed to match required ambiance.

It is time to add some Light to our game framework.

A light can be an AMBIANT light, a POINT light or a CONE Light, having an identified target.

The Light class must extend the GameEntity object, and add required new attributes.

Goals

To be able to simulate rain effect, add an new component to manage multiple particles as drop.
The same component will be reused to add stars as background.

ParticleEntity

The ParticleEntity will add child entities to a GameEntity. Using already existing Behavior to animate child particles.

An implementation of a Behavior will allow rain animation with wind effect : the RainParticleBehavior.
The wind parameter (a Vector2D) will be defined in the World object.

Add a CollisionEngine to support collision detection and resolution on Tile and GameEntity.

The World play Area must be split into partitions to enhance performances of collision detection.

As PhysicEngine already provides some solid module, we can add new Water simulation.

To serve this new feature, we introduce the Influence concept, a defined area in the play area, changing the locally the physic properties though applying a specific Material or some forces.

public class Influencer extends GameEntity{
  Reclangle2D  area;
}

and the PhysicEngine will apply those modification to impacted GameEntity, the ones contained by the Influencer#area.

In a second Time, we will add a WaterEntity, embedding the Influencer characteristics and waves visual animation.

The WaterEntity is an Influencer with drawing capability to draw some vertical vectors for the water surface. The width of the water surface is divided into equals spacer, and on each spacer edge, we draw a point at top of a vertical vector.

The water is animated by changing the vector length, according to object colliding the water/Influence object: a wave is generated from the colliding place through the two horizontal opposite directions.

In the DemoScene, the rain effect is already active with RainEffectBehavior on ParticlesEntity.

I'd like to ad Wind to be applied to rain drops and make the wind blows in some random direction,
but with parameterized controls like:

• maximum force,
• min and max direction angle,
• a maximum delay between 2 direction changes.

This must be implemented through new scene behavior WindyWeatherBehavior, applying new parameter on the World#wind attribute, used by the RainEffectBehavior.