game: add bullet and impacts

game/bullet.gd

@@ -0,0 +1,29 @@
+extends Node3D
+
+const SPEED = 80.0
+
+@onready var raycast = $bullet/RayCast3D
+@onready var bullet_decal = preload("res://bullet_decal.tscn")
+
+func _ready() -> void:
+	pass
+	
+func _process(delta: float) -> void:
+	var next_pos = position + transform.basis * Vector3(0,0,-SPEED) * delta
+	raycast.visible = true
+	raycast.target_position = raycast.position + raycast.transform.basis * Vector3(0,0,SPEED) * delta * 1.5
+	position = next_pos
+	
+	var collider = raycast.get_collider()
+	var col_point = raycast.get_collision_point()
+	if col_point and collider:
+		var b = bullet_decal.instantiate()
+		raycast.get_collider().add_child(b)
+		b.global_transform.origin = col_point
+		b.look_at(col_point + raycast.get_collision_normal(), Vector3.UP)
+		b.particles.emitting = true
+		b.smoke.emitting = true
+		queue_free()
+
+func _on_timer_timeout() -> void:
+	queue_free()