add damage and health component

scripts/components/damage.gd

@@ -0,0 +1,7 @@
+class_name DamageComponent
+extends Node2D
+
+@export var damage: float = 0.25
+
+func deal_damage(target: HealthComponent):
+	target.decrease_health(damage)

scripts/components/health.gd

@@ -0,0 +1,53 @@
+class_name HealthComponent
+extends Node2D
+
+@export var health: float = 1.0
+@export var max_health: float = 1.0
+
+signal on_health_change(delta: float)
+signal on_death
+
+func _get_delta(value: float) -> float:
+	var old_value = health
+	return value - old_value
+
+func set_health(new_value: float):
+	var delta = _get_delta(new_value)
+	
+	if new_value >= max_health:
+		health = max_health
+		on_health_change.emit(delta)
+		return
+	
+	health = new_value
+	
+	if health <= 0:
+		on_death.emit()
+		return
+	
+	on_health_change.emit(delta)
+
+func decrease_health(value: float):
+	var delta = _get_delta(value)
+	
+	health -= value
+	
+	if health <= 0:
+		on_death.emit()
+		return
+		
+	on_health_change.emit(delta)
+	
+func increase_health(value: float):
+	var delta = _get_delta(value)
+	
+	health += value
+	
+	if health >= max_health:
+		health = max_health
+		on_health_change.emit(delta)
+		return
+	
+	health += value
+	on_health_change.emit(delta)
+