RogueTank/Scripts/Actors/EnemyTank.cs

using Godot;
using RogueTank.Combat;
using RogueTank.Util;

namespace RogueTank.Actors;

public partial class EnemyTank : CharacterBody2D, IDamageable
{
    [Signal] public delegate void DiedEventHandler(EnemyTank who);

    public float MoveSpeed { get; set; } = 110f;
    public float MaxHp { get; set; } = 30f;
    public float Hp { get; private set; } = 30f;
    public float ContactDamage { get; set; } = 8f;

    public Node2D? Target { get; set; }

    private Sprite2D _sprite = null!;

    public override void _Ready()
    {
        Hp = MaxHp;
        _sprite = new Sprite2D
        {
            Texture = PixelArt.MakeTankTexture(16, new Color(0.75f, 0.2f, 0.2f), new Color(0.95f, 0.7f, 0.2f)),
            Centered = true,
            TextureFilter = CanvasItem.TextureFilterEnum.Nearest
        };
        AddChild(_sprite);

        var col = new CollisionShape2D
        {
            Shape = new CircleShape2D { Radius = 7f }
        };
        AddChild(col);
    }

    public override void _PhysicsProcess(double delta)
    {
        if (Target == null || !IsInstanceValid(Target))
        {
            Velocity = Vector2.Zero;
            MoveAndSlide();
            return;
        }

        var dir = (Target.GlobalPosition - GlobalPosition);
        if (dir.Length() > 1f) dir = dir.Normalized();
        Velocity = dir * MoveSpeed;
        Rotation = Velocity.Angle();
        MoveAndSlide();

        // crude contact damage
        if (Target is PlayerTank p)
        {
            var dist = (p.GlobalPosition - GlobalPosition).Length();
            if (dist < 14f)
                p.TakeDamage(ContactDamage * (float)delta);
        }
    }

    public void TakeDamage(float amount)
    {
        Hp -= amount;
        if (Hp <= 0f)
        {
            EmitSignal(SignalName.Died, this);
            QueueFree();
        }
    }
}