cirnogodot/Scripts/Bullet.cs

using Godot;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using Cirno.Scripts;
using Cirno.Scripts.Components;
using Cirno.Scripts.Resources;

public partial class Bullet : Area2D
{
	[Export]
	public float Speed = 1900f;
	
	public BulletOwner BulletOwner => _bulletInfo?.Owner ?? BulletOwner.None;
	
	public float Damage => _bulletInfo?.Damage ?? 1;

	public DamageType DamageType => _bulletInfo?.DamageType ?? DamageType.Neutral;

	private Vector2 _direction = Vector2.Right;
	
	private double _elapsedTime = 0f;
	private BulletInfo _bulletInfo;

	public BulletInfo BulletInfo => _bulletInfo;

	private List<ModifierWrapper> _modifiers = new();
	
	public void Initialize(BulletInfo bulletInfo)
	{
		_bulletInfo = bulletInfo;

		// Ugly hack to make instances unique
		_modifiers = _bulletInfo.TimeModifiers.Select(x => new ModifierWrapper()
		{
			TimeModifier = x.TimeModifier,
			Applied = x.Applied
		}).ToList();
		
	}
	
	private void ApplyTimeModifiers()
	{
		foreach (var modifier in _modifiers)
		{
			if (modifier.Applied)
			{
				continue;
			}
			if (_elapsedTime >= modifier.TimeModifier.TimeInSeconds)
			{
				GD.Print("Applied time modifier");
				switch (modifier.TimeModifier.ModifierType)
				{
					case TimeModifierType.SpeedChange:
						//_bulletInfo.Speed += modifier.Value;
						Speed = modifier.TimeModifier.Value;
						break;
					case TimeModifierType.RotationChange:
						RotateBullet(modifier.TimeModifier.Value);
						//Rotation += Mathf.DegToRad(modifier.Value);
						break;
					case TimeModifierType.FacePlayer:
						FacePlayer();
						break;
				}

				modifier.Applied = true;
			}
		}
	}
	
	private void RotateBullet(float degrees)
	{
		float radians = Mathf.DegToRad(degrees);
		_direction = _direction.Rotated(radians).Normalized(); // Rotate direction
		SetRotation(Rotation + radians);
		//Rotation = radians;
	}


	private void FacePlayer()
	{
		// TODO: cache player
		var player = GetTree().GetFirstNodeInGroup("Player") as Node2D;
		if (player != null)
		{
			_direction = (player.GlobalPosition - this.GlobalPosition).Normalized();
			//LookAt(player.GlobalPosition);
		}
	}


	//private void OnBodyEntered(Node body)
	//{
	// When a body is entered, invoke the event and pass the collided body
	//	BulletHit?.Invoke(body);

	// Then remove the bullet
	//	QueueFree();
	//}

	public void SetDirection(Vector2 direction)
	{
		var normalized = direction.Normalized();

		_direction = normalized;
		
		SetRotation(Mathf.Atan2(normalized.Y,normalized.X) + Mathf.Pi / 2);
		
		//Debug.WriteLine($"Bullet Shot at direction {direction.X} {direction.Y}");
	}

	// Called every frame. 'delta' is the elapsed time since the previous frame.
	public override void _Process(double delta)
	{
		_elapsedTime += delta;
		if (_bulletInfo != null)
		{
			ApplyTimeModifiers();
		}
		
		this.Position += ((float)(Speed * delta) * _direction);
	}

	private void _on_visible_on_screen_notifier_2d_screen_exited()
	{
		//Debug.WriteLine("Destroy bullet out of screen");
		Destroy();
	}

	private void _on_body_entered(Node2D body)
	{
		if (body.IsInGroup("Solid"))
		{
			//Debug.WriteLine("Collision");
			Destroy();
		}
		//// Do not Collide with body for purpose of destroying bullets
		// else if (body.IsInGroup("Destroyable"))
		// {
		// 	Debug.WriteLine("Collision with destroyable object body");
		// 	QueueFree();
		// }
		
	}

	private void _on_area_entered(Area2D area)
	{
		if (area.IsInGroup("Solid"))
		{
			Destroy();
			return;
		}

		if (area.IsInGroup("Destroyable") && area is IDestructible destructible)
		{
			//Debug.WriteLine("Collision with destroyable object area");
			
			destructible.Hit(Damage, DamageType);

			Destroy();
		}
	}

	public void Destroy()
	{
		if (_bulletInfo?.DestructionParticlesScene != null)
		{
			var particle = this.CreateSibling<AutodeleteParticle>(_bulletInfo.DestructionParticlesScene);

			particle.Init();
		}
		
		QueueFree();
	}
}

public enum BulletOwner
{
	None,
	Player,
	Enemy
}

public enum DamageType
{
	Neutral,
	Ballistic,
	Fire,
	Ice,
	Explosive,
	Acid
}