Player shield

In this section, you’ll add a shield to the player and a display element to the HUD showing the current shield level.

First, add the following to the top of the player.gd script:

signal shield_changed
@export var max_shield = 100.0
@export var shield_regen = 5.0
var shield = 0: set = set_shield
func set_shield(value):
    value = min(value, max_shield)
    shield = value
    shield_changed.emit(shield / max_shield)
    if shield <= 0:
        lives -= 1
        explode()

The shield variable works similarly to lives, emitting a signal whenever it changes. Since the value will be added to by the shield’s regeneration, you need to make sure it doesn’t go above the max_shield value. Then, when you emit the shield_changed signal, you pass the ratio of shield / max_shield rather than...