17.6. Projectiles

Shoot

Dans cet état le boss tire une série de projectiles en spirale. Afin de représenter cette attaque, nous aurons besoin d'une nouvelle attaque ProjectileAttack. Pour l'effet de spiral, il est simplement question d'appliquer une rotation de manière incrémentale au vecteur de direction du boss et de s'en servir pour créer le projectile.

Étapes à suivre

1. Ajoutez la classe ProjectileAttack
2. Ajoutez la classe ShootState

/* ProjectileAttack.java */
package com.tutorialquest.entities;
// import ..

public class ProjectileAttack extends PhysicalObject implements IAttack
{
    public static float SPEED = 50f;
    public static Vector2 SIZE = new Vector2(16, 16);
    private static final int NUM_HITS = 3;

    private int hits = 0;
    private Vector2 direction;
    private Sprite sprite;
    private List<PhysicalObject> collisionResults = new LinkedList<>();
    private float damage;
    private float knockback;
    private float speed = 1f;

    @Override
    public float getDamage() {
        return damage;
    }

    @Override
    public float getKnockback() {
        return knockback;
    }

    @Override
    public Vector2 getDirection() {
        return direction;
    }

    public ProjectileAttack(
        Vector2 position,
        Vector2 direction,
        float damage,
        float knockback,
        float speed)
    {
        super(position);
        this.sprite = new Sprite("objects/projectile.png", SIZE);
        this.collider = new Collider(SIZE, Collider.FLAG_ENEMY);
        this.direction = direction;
        this.damage = damage;
        this.knockback = knockback;
        this.speed = speed;
        this.locomotionVelocity
            .set(direction)
            .scl(speed);
    }

    @Override
    public void update(float deltaTime) {
        super.update(deltaTime);
        updateVelocity(deltaTime);
        move();
        sprite.update(deltaTime);
        collisionResults.clear();
        if(collider.getObjectCollisions(
            this,
            velocity.x,
            velocity.y,
            Collider.FLAG_AVATAR,
            collisionResults))
        {
            collisionResults.iterator().next().onAttacked(this);
            destroy();
            return;
        }

        if(collider.isColliding(this, velocity, Collider.FLAG_NONE))
        {
            destroy();
        }
    }

    public void destroy()
    {
        Game.level.remove(this);
    }

    @Override
    public void render(SpriteBatch spriteBatch) {
        super.render(spriteBatch);
        sprite.render(spriteBatch, position);
    }

    @Override
    public void onAttacked(IAttack attack)
    {
        sprite.flash();
        onPushed(this, attack.getDirection().scl(attack.getKnockback()));
        hits++;
        if(hits >= NUM_HITS) 
        {
            Game.level.remove(this);
        }
    }
}

/* ShootState.java */
package com.tutorialquest.entities;
// import ..

public class ShootState extends BossState {

    public static final float ROTATION_SPEED = 30f;

    @Override
    public String getName() {
        return "Shoot Spiral";
    }

    public ShootState(
        Boss boss, 
        StateMachine stateMachine, 
        int id, 
        float probability, 
        float timeLimit, 
        int timeoutState) 
    {
        super(
            boss, 
            stateMachine, 
            id, 
            probability, 
            timeLimit, 
            timeoutState);
    }

    @Override
    public boolean update(float deltaTime) {
        if (!super.update(deltaTime)) return false;

        fireRateTime += deltaTime;
        if (fireRateTime >= Boss.FIRE_RATE) {
            fireRateTime = 0;
            Game.level.add(
                new ProjectileAttack(
                    new Vector2()
                        .add(boss.direction)
                        .scl(Boss.PROJECTILE_DISTANCE)
                        .add(boss.position),
                    boss.direction.cpy(),
                    Boss.PROJECTILE_DAMAGE,
                    Boss.PROJECTILE_KNOCKBACK,
                    Boss.PROJECTILE_SPEED)
            );

            boss.direction
                .rotate(ROTATION_SPEED)
                .nor();
        }

        return true;
    }

    @Override
    public void enter() {
        super.enter();
        boss.direction = new Vector2(1, 0);
        boss.playAnimation(Boss.SpriteUtils.SHOOT, true, true);
    }
}