feat: add weapons

- add fire pattern (base interface for all weapons)
- add shotgun and cannon pattern
- add basic projectile
- add input map for shoot

scripts/spaceship.gd

@@ -4,8 +4,15 @@ extends CharacterBody2D
 @export var friction := 0.98
 @export var max_speed := 1000.0
 
+@onready var weapons = get_children().filter(func(c): return c is Weapon)
+
 
 func _physics_process(delta: float) -> void:
+	handle_move(delta)
+	handle_shoot()
+
+
+func handle_move(delta: float) -> void:
 	var direction = Input.get_vector("move_left", "move_right", "move_up", "move_down")
 
 	velocity += direction * thrust * delta
@@ -13,3 +20,9 @@ func _physics_process(delta: float) -> void:
 
 	velocity = velocity.limit_length(max_speed)
 	move_and_slide()
+
+
+func handle_shoot() -> void:
+	if Input.is_action_just_pressed("shoot"):
+		for w in weapons:
+			w.shoot()

scripts/weapon.gd

@@ -0,0 +1,17 @@
+class_name Weapon
+extends Node2D
+
+@export var projectile_scene: PackedScene
+@export var fire_pattern: FirePattern
+
+
+func shoot() -> void:
+	fire_pattern.fire(global_position, -global_transform.y, spawn_projectile)
+
+
+func spawn_projectile(pos: Vector2, dir: Vector2):
+	var proj = projectile_scene.instantiate()
+	proj.global_position = pos
+	proj.direction = dir
+	get_tree().current_scene.get_parent().add_child(proj)
+	return proj

scripts/weapon/cannon_pattern.gd

@@ -0,0 +1,6 @@
+class_name CannonPattern
+extends FirePattern
+
+
+func fire(pos: Vector2, dir: Vector2, spawn: Callable) -> void:
+	spawn.call(pos, dir)

scripts/weapon/fire_pattern.gd

@@ -0,0 +1,6 @@
+class_name FirePattern
+extends Resource
+
+
+func fire(_pos: Vector2, _dir: Vector2, _spawn: Callable) -> void:
+	pass

scripts/weapon/projectile.gd

@@ -0,0 +1,12 @@
+extends Area2D
+
+@export var speed := 600.0
+var direction: Vector2 = Vector2.RIGHT
+
+
+func _physics_process(delta):
+	global_position += direction * speed * delta
+
+
+func _on_visible_on_screen_enabler_2d_screen_exited() -> void:
+	queue_free()

scripts/weapon/shotgun_pattern.gd

@@ -0,0 +1,12 @@
+class_name ShotgunPattern
+extends FirePattern
+
+@export var bullets := 5
+@export var spread := 0.25
+
+
+func fire(pos: Vector2, dir: Vector2, spawn: Callable) -> void:
+	for i in range(bullets):
+		var angle := randf_range(-spread, spread)
+		var new_dir := dir.rotated(angle)
+		spawn.call(pos, new_dir)