Rendering

Rendering is a crucial part in the brainGDX framework. libgdx already provides commands to render textures, sprites, particles and animations on the screen. The problem is when it comes to more complex examples:'

• how to render a village with 25 different NPCs without writing 25 Java classes?
• how to change the appearance of game objects dynamically?
• how to disable rendering for a particular game object?
• how to easily add debug rendering for game objects?

The solutions are so called Renderer implementations. A Renderer describes how a game object should get rendered:

public class MyRenderer implements GameObjectRenderer {
    @Override
    public void init() {
        // is called when the renderer gets attached
    }

    @Override
    public void render(GameObject object, Batch batch, float delta) {
        // is called when the object should get rendered
    }
}

brainGDX already comes with various predefined renderers which you can use to describe the render behavior for your entities:

• QuadRenderer renders a quad.
• CircleRenderer renders a circle.
• SpriteRenderer renders a defined sprite.
• AnimationRenderer renders a defined animation.
• ParticleRenderer renders a particle effect onto the given renderer (decorator).

Registering a renderer

We need to register a renderer in order to display game objects on the screen:

// Retrieve the renderManager instance
RenderManager renderManager = context.getRenderManager();
// Registering a new renderer for game objects of type '1'
renderManager.register(1, new SpriteRenderer(Assets.Textures.PLAYER));

When running again you should see a red square on the screen.

To learn how to use the renderers, especially how to add actual game objects to your game continue with the next chapter.