UFO_animation Function

Purpose

The purpose of UFO animation is to Increase the difficulty of the game, When the player is close to ufo for a certain distance, ufo will chase the player.

Design

Implementation

Key Components

• ufo_animation.atlas This file sets up different animation effects for obstacles.
• UfoAnimationController This class listens to events relevant to a ufo state and plays the animation when one of the events is triggered.
• ObstacleFactory Create ufo obstacle by creatUFO(), createUFO can add tasks and animation effects to UFO.

Code of ufo_animation.atlas

ufo_animation-01.png
size: 8334, 7500
format: RGBA8888
filter: Nearest,Nearest
repeat: none
ufo
  rotate: false
  xy: 166, 705
  size: 1237, 1667
  orig: 1237, 1667
  offset: 0, 0
  index: 0
default
  rotate: false
  xy: 166, 705
  size: 1237, 1667
  orig: 1237, 1667
  offset: 0, 0
  index: 0
hit_ufo
  rotate: false
  xy: 166, 705
  size: 1237, 1667
  orig: 1237, 1667
  offset: 0, 0
  index: 0
hit_ufo
  rotate: false
  xy: 1831, 705
  size: 1237, 1667
  orig: 1237, 1667
  offset: 0, 0
  index: 1
hit_ufo
  rotate: false
  xy: 3498, 705
  size: 1237, 1667
  orig: 1237, 1667
  offset: 0, 0
  index: 2
hit_ufo
  rotate: false
  xy: 5165, 705
  size: 1237, 1667
  orig: 1237, 1667
  offset: 0, 0
  index: 3

Code of add tasks in the createUFO()

AITaskComponent aiComponent =
     new AITaskComponent()
         .addTask(new WanderTask(new Vector2(3f, 2f), 0f))
         .addTask(new ChaseTask(target, 2,2f,2.5f));
ufo.addComponent(aiComponent);

Code of add animation in the createUFO()

AnimationRenderComponent animator =
     new AnimationRenderComponent(
          ServiceLocator.getResourceService().getAsset("images/ufo_animation.atlas", TextureAtlas.class));
animator.addAnimation("hit_ufo", 0.5f, Animation.PlayMode.LOOP_REVERSED);
animator.addAnimation("ufo", 0.5f, Animation.PlayMode.LOOP);
ufo.addComponent(animator);
ufo.addComponent(new UfoAnimationController());
ufo.getComponent(AnimationRenderComponent.class).scaleEntity();

Code of UfoAnimationController.java

public class UfoAnimationController extends Component {
    AnimationRenderComponent animator;

    @Override
    public void create() {
        super.create();
        animator = this.entity.getComponent(AnimationRenderComponent.class);
        entity.getEvents().addListener("wanderStart", this::animateWander);
        entity.getEvents().addListener("chaseStart", this::animateChase);
    }

   void animateWander() {
       animator.startAnimation("ufo");
    }

   void animateChase() {
       animator.startAnimation("hit_ufo");
   }
}

UML