Refactored and documented item codes.

items/consumables/bow/bow.gd

@@ -5,14 +5,17 @@ extends ActiveItem
 func actually_collect():
 		player.set_cooldown(cooldown)
 
-
 func activate():
 	player.activate_cooldown()
+	
+	# Spawn an arrow on activation
 	var arrow : Area2D = arrow_scene.instantiate()
 	get_tree().get_root().add_child(arrow)
 	arrow.position = player.position
 	arrow.rotation = player.rotation
 	arrow.direction = player.earth_aligner.global_from_local(Vector2(player.facing, 0))
+	
+	# Make sure the arrow sprite faces the right direction
 	if(player.facing == -1):
 		arrow.get_node("Sprite2D").scale.x = - arrow.get_node("Sprite2D").scale.x
 	$SoundBowRelease.play()

items/consumables/heal_item/heal_item.gd

@@ -3,6 +3,6 @@ extends Item
 
 func collect() -> bool:
 	if(player.current_hp < player.max_hp):
-		player.current_hp = min(player.max_hp, player.current_hp + heal_amount)
+		player.current_hp += heal_amount
 		return true
 	return false

items/consumables/horizontal_dash/horizontal_dash.gd

@@ -6,22 +6,26 @@ var dash_dir
 
 func _process(delta: float) -> void:
 	super(delta)
+	# While the dash is active, move the player in the
+	# (absolute!) direction fixed at the start of the dash
 	if dash_timer != null and dash_timer.time_left > 0:
 		player.reset_to_velocity = player.earth_aligner.local_from_global(dash_dir)
 
-
 func actually_collect():
 	player.set_cooldown(cooldown)
 	
 func activate():
 	$DashSound.play()
 	player.activate_cooldown()
-	player.air_jumps_current = min(player.air_jumps_current + 1, player.air_jumps_max)
+	# The dash refills one air jump if possible and provides iframes.
+	player.air_jumps_current += 1
 	dash_timer = get_tree().create_timer(dash_time)
 	dash_dir = player.earth_aligner.global_from_local(Vector2.RIGHT * player.facing * 1600)
 	player.inv_time = max(player.inv_time, dash_time)
 
 func remove(reset_player_active = true):
+	# If the item is removed during the dash, clear the active item slot,
+	# but only remove the item from the scene afterwards.
 	if(dash_timer != null):
 		if reset_player_active:
 			player.active_item = null

items/consumables/updash/updash.gd

@@ -8,12 +8,15 @@ func actually_collect():
 func activate():
 	$UpdashSound.play()
 	player.activate_cooldown()
+	# Drop the player for a moment, then boost upwards.
 	player.reset_to_velocity = Vector2(0,1)
 	timer = get_tree().create_timer(0.1)
 	await timer.timeout
 	player.reset_to_velocity = Vector2(0, -2400)
 
 func remove(reset_player_active = true):
+	# If the item is removed during the dash startup, clear the active item slot,
+	# but only remove the item from the scene afterwards.
 	if reset_player_active:
 		player.active_item = null
 	if timer != null and timer.time_left > 0:

items/generic/active_item.gd

@@ -7,6 +7,10 @@ class_name ActiveItem extends Item
 @export var uses = 1:
 	set(new_uses):
 		uses = new_uses
+		refresh_uses_ui()
+
+func refresh_uses_ui():
+	# Set the amount and type of child nodes active_item_uses has according to num_uses.
 	if active_item_uses != null:
 		while active_item_uses.get_children().size() > uses:
 			active_item_uses.remove_child(active_item_uses.get_child(0))
@@ -14,15 +18,17 @@ class_name ActiveItem extends Item
 			while active_item_uses.get_children().size() < uses:
 				active_item_uses.add_child(uses_left_icon.instantiate())
 
+# Called when the active item is touched. It will only be collected if
+# the player has space, in which case actually_collect() is called.
 func collect() -> bool:
 	if (player.active_item == null or (player.active_item.item_name == item_name and player.active_item.uses < uses)):
 		player.active_item = self
 		uses = uses
 		actually_collect()
-		
 		return true
 	return false
 
+# Intended to be overridden by item classes.
 func actually_collect():
 	pass
 
@@ -33,9 +39,11 @@ func trigger_activation():
 		if uses == 0:
 			remove()
 
+# Intended to be overridden by item classes.
 func activate():
-	assert(false)
+	pass
 
+# When removed, also removes the reference from the player and removes the uses.
 func remove(reset_player_active = true):
 	if player.active_item == self:
 		uses = 0

items/generic/item.gd

@@ -6,6 +6,8 @@ var collected = false
 
 func _process(_delta: float) -> void:
 	if(is_instance_valid(player) and overlaps_body(player)):
+		# Attempt to collect the item. If successful, play the collect animation
+		# and attach the item to the player.
 		if(self.has_method("collect") and collect()):
 			set_deferred("monitoring", false)
 			set_deferred("monitorable", false)
@@ -13,10 +15,12 @@ func _process(_delta: float) -> void:
 			collect_animation()
 			collected = true
 
+# Placeholder for a proper animation.
 func collect_animation():
 	self.visible = false
 	if self.has_node("AudioStreamPlayer2D"): $AudioStreamPlayer2D.play()
 
+# Intended to be overridden by item classes.
 func collect():
 	push_error("Please specify item collection behavior")
 	return false

items/rare_items/healthup/healthup.gd

@@ -4,5 +4,5 @@ extends Item
 
 func collect() -> bool:
 	player.max_hp += max_health_increase
-	player.current_hp = min(player.max_hp, player.current_hp + heal_amount)
+	player.current_hp += max_health_increase
 	return true

items/unique_items/backslash/backslash.gd

@@ -3,6 +3,7 @@ extends Item
 @export var sword : PackedScene
 
 func collect() -> bool:
+	# Give the player a new sword facing towards th back.
 	var sword_instance = sword.instantiate()
 	player.add_child(sword_instance)
 	sword_instance.facing_mult = -1

player/player.gd

@@ -22,7 +22,9 @@ var base_hspeed = 150.0;
 var ground_jump_strength = 1400;
 var air_jump_strength = 1100;
 var air_jumps_max = 1;
-var air_jumps_current = 1;
+var air_jumps_current = 1:
+	set(air_jumps_new):
+		air_jumps_current = min(air_jumps_new, air_jumps_max)
 
 # HP and Iframes
 signal health_changed(new_health : int)
@@ -31,11 +33,19 @@ signal player_died
 
 var current_hp = 5:
 	set(new_hp):
-		current_hp = new_hp
+		new_hp = min(new_hp, max_hp)
+		if new_hp <= 0:
+			new_hp = 0
+			die()
+		if new_hp != current_hp:
 			health_changed.emit(current_hp)
+			current_hp = new_hp
 @export var max_hp = 5:
 	set(new_max_hp):
 		max_hp = new_max_hp
+		if max_hp <= 0:
+			max_hp = 0
+			die()
 		max_hp_changed.emit(max_hp)
 var hit_invulnerability = 0.8
 var inv_time = 0;
@@ -185,8 +195,6 @@ func hurt(dmg: int, dir: Vector2 = Vector2.ZERO):
 		if Status.affects("Vulnerable", self): dmg += 1
 		$AudioStreamPlayer2D.play()
 		current_hp -= dmg
-		if(current_hp <= 0):
-			die()
 		inv_time = hit_invulnerability
 		reset_to_velocity = Vector2(-sign(earth_aligner.local_from_global(dir).x)*knockback_strength, -damage_knockup)
 		return true