SupaLidlGame/Entities/UnwantedFrequency.cs

using Godot;
using SupaLidlGame.Extensions;

namespace SupaLidlGame.Entities;

public partial class UnwantedFrequency : Projectile
{
    [Export]
    public Characters.Character Homing { get; set; }

    [Export]
    public float HomingVelocity { get; set; } = 1;

    public Utils.Trail Trail { get; set; }
    public Node2D TrailRotation { get; set; }
    public Node2D TrailPosition { get; set; }
    public GpuParticles2D DeathParticles { get; set; }
    public Timer DeferDeathTimer { get; set; }

    private double _currentLifetime = 0;

    public override void _Ready()
    {
        TrailRotation = GetNode<Node2D>("TrailRotation");
        TrailPosition = TrailRotation.GetNode<Node2D>("TrailPosition");
        Trail = TrailPosition.GetNode<Utils.Trail>("Trail");
        DeferDeathTimer = GetNode<Timer>("DeferDeath");
        DeathParticles = GetNode<GpuParticles2D>("DeathParticles");
        Hitbox.Hit += (BoundingBoxes.BoundingBox box) =>
        {
            if (box is BoundingBoxes.Hurtbox && box.Faction != Hitbox.Faction)
            {
                Die();
            }
        };
        base._Ready();
    }

    public override void _Process(double delta)
    {
        _currentLifetime += delta;
        float radians = (float)_currentLifetime * 24;
        TrailRotation.Rotation = Direction.Angle();
        TrailPosition.Position = new Vector2(0, 4 * Mathf.Sin(radians));

        // home towards player
        if (Homing is not null)
        {
            var desired = GlobalPosition.DirectionTo(Homing.GlobalPosition);
            //var steer = (desired - Direction) * HomingVelocity * (float)delta;
            //float dTheta = Direction.AngleTo(dirToHoming);
            //float dTheta = Mathf.Acos(Direction.Dot(dirToHoming));

            //float max = (float)(delta * HomingRotationalVelocity);
            //float rotVel = Mathf.Clamp(dTheta, -max, max);

            Direction += (desired - Direction) * HomingVelocity * (float)delta;
        }

        base._Process(delta);
    }

    public override void Die()
    {
        IsDead = Trail.IsDead = Hitbox.IsDisabled = true;
        DeferDeathTimer.Timeout += () =>
        {
            QueueFree();
        };
        DeferDeathTimer.Start();
        DeathParticles.Emitting = true;
        GetNode<AudioStreamPlayer2D>("Sound").Stop();
        GetNode<AnimationPlayer>("AnimationPlayer").Play("death");
    }
}