Instant Buff Pickup Animation

Purpose

The float animation that occurs after a player picks up a HP booster/HP deplete buff. Common in games and helps the player keep track of what is happening when one of these buffs are collected.

Implementation

Key Components

• BuffFactory Creates the floating animation as an Entity
• ForestGameArea Holds the spawning function to spawn the animation onto the map
• BuffManager Handles the spawning/despawning of the animation on the map
• FloatTask Handles the floating movement of the animation

The BuffFactory class handles the instantiation of the Entity.

public static Entity createBuffAnimation(BuffManager.BuffPickup pickup, BuffManager manager) {
    /* Get the texture for the pickup */
    String texture = manager.getPickupTexture(pickup);
    AITaskComponent buffComponent = new AITaskComponent().addTask(new FloatTask(new Vector2(0f, 3f)));

    Entity buffPickup = new Entity().addComponent(new TextureRenderComponent(texture))
            .addComponent(new PhysicsComponent().setBodyType(BodyDef.BodyType.DynamicBody))
            .addComponent(new PhysicsMovementComponent())
            .addComponent(buffComponent);

The buffPickup entity has an AITaskComponent with a FloatTask, which allows the entity to float the range specified in the constructor, through utilising a MovementTask

@Override
public void start() {
    super.start();
    startPos = owner.getEntity().getPosition();
    movementTask = new MovementTask(getTarget());
    movementTask.create(owner);
    movementTask.start();
}

The different types of animations are stored in a LinkedHashMap with the key entry being the BuffPickup type and the second being a list of 2 integers. The first is whether the buff has been collided with and the second is whether the animation has spawned onto the map. Both use 0 to represent false and 1 to represent true.

private LinkedHashMap<BuffPickup, List<Integer>> buffPickups;

public BuffManager(MainGameScreen mainGame, GameArea currentMap) {
    this.buffPickups.put(BuffPickup.positive, Arrays.asList(0, 0));
    this.buffPickups.put(BuffPickup.negative, Arrays.asList(0, 0));
}

The values in the list are updated when a player collides with the right buff.

public void selectBuffFunctionality(BuffTypes type, Entity buff,
        BuffInformation buffInfo) {

    /* PlayerBuffs functions to call when there is a new instant buff */
    switch (type) {
        case B_HP_UP:
            this.buffPickups.get(BuffPickup.positive).set(0, 1);
            return;
}

They are also updated in the spawnPickup function, which handles the spawning and despawning of the animation and is called in the update function.

private void spawnPickup() {
    for (BuffPickup pickup: this.buffPickups.keySet()) {
        if (this.buffPickups.get(pickup).get(0) == 1) {
            pickupCreationTime = ServiceLocator.getTimeSource().getTime();
            buffPickup = mainGame.getCurrentMap().spawnBuffDebuffPickup(pickup, this);
            this.buffPickups.get(pickup).set(0, 0);
            this.buffPickups.get(pickup).set(1, 1);
        }
        if (this.buffPickups.get(pickup).get(1) == 1) {
            if (ServiceLocator.getTimeSource().getTimeSince(pickupCreationTime) >= 1.5 * SECONDS) {
                removeBuff(buffPickup);
                this.buffPickups.get(pickup).set(1, 0);
            }
        }
    }
}

public void update() {
    spawnPickup();
}

Usage

To add another animation type, add the type to the BuffPickup enum.

public enum BuffPickup {
    positive, negative
}

And in the constructor method, add the type into the LinkedHashMap

public BuffManager(MainGameScreen mainGame, GameArea currentMap) {
    this.buffPickups.put(BuffPickup.positive, Arrays.asList(0, 0));
}