player: add health callbacks

Allows us to update the HUD on health change

player/player.gd

@@ -10,11 +10,12 @@ const gear_slots = ["1", "2", "3"]
 
 var starting_gear = preload("res://gears/ball.tscn")
 
-var health = 100
 var suspended = false
 var direction = Vector3.ZERO
 var target_velocity = Vector3.ZERO
 
+var _health = 100
+
 func resize_ui():
 	var hud_h = 200
 	var size = get_viewport().get_visible_rect().size
@@ -31,7 +32,7 @@ func make_hud():
 			continue
 		text += "%s (%s)\n" % [node.gear_name(), node.name]
 	text += "Holding " + $Pivot/Container/Gear.gear_name() + "\n"
-	text += str(health) + " hp"
+	text += str(health()) + " hp"
 	$HUD.text = text
 
 func message(string):
@@ -39,6 +40,19 @@ func message(string):
 	$Message.visible = true
 	$Message/VanishTimer.start()
 
+func harm(hp):
+	assert(hp >= 0)
+	_health -= hp
+	make_hud()
+
+func heal(hp):
+	assert(hp >= 0)
+	_health += hp
+	make_hud()
+
+func health():
+	return _health
+
 func die():
 	suspended = true
 	visible = false
@@ -55,7 +69,7 @@ func die():
 func respawn():
 	position = Vector3(spawn)
 	$CameraGimbal.reset()
-	health = 100
+	_health = 100
 	visible = true
 	suspended = false
 
@@ -159,7 +173,7 @@ func _physics_process(delta):
 	if suspended:
 		return
 
-	if health < 1 or position.y <= -1000:
+	if health() < 1 or position.y <= -1000:
 		die()
 
 	# UI and backpack keys