player: Add "phase" ability

This adds an action that, while held, temporarily prevents the
player-character from colliding with enemies or coins.

The new action is bound to:

- Player 1: Backspace
- Player 2: Tab
- Gamepad: Xbox X / PlayStation Square

As with the other new actions, the function call to implement this is
commented out.

Author: wjt

project.godot

@@ -65,6 +65,12 @@ player_2_teleport={
 , Object(InputEventJoypadButton,"resource_local_to_scene":false,"resource_name":"","device":1,"button_index":1,"pressure":0.0,"pressed":true,"script":null)
 ]
 }
+player_2_phase={
+"deadzone": 0.2,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":4194306,"key_label":0,"unicode":0,"location":0,"echo":false,"script":null)
+, Object(InputEventJoypadButton,"resource_local_to_scene":false,"resource_name":"","device":1,"button_index":2,"pressure":0.0,"pressed":true,"script":null)
+]
+}
 player_1_jump={
 "deadzone": 0.5,
 "events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":4194320,"physical_keycode":0,"key_label":0,"unicode":0,"location":0,"echo":false,"script":null)
@@ -92,6 +98,12 @@ player_1_teleport={
 , Object(InputEventJoypadButton,"resource_local_to_scene":false,"resource_name":"","device":0,"button_index":1,"pressure":0.0,"pressed":true,"script":null)
 ]
 }
+player_1_phase={
+"deadzone": 0.5,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":4194308,"key_label":0,"unicode":0,"location":0,"echo":false,"script":null)
+, Object(InputEventJoypadButton,"resource_local_to_scene":false,"resource_name":"","device":0,"button_index":2,"pressure":0.0,"pressed":true,"script":null)
+]
+}
 
 [layer_names]
 

scripts/actions.gd

@@ -13,6 +13,7 @@ const ACTIONS = [
 	&"left",
 	&"right",
 	&"teleport",
+	&"phase",
 ]
 
 # Dictionary[Global.Player, Dictionary[StringName, StringName]]

scripts/player.gd

@@ -148,11 +148,36 @@ func _teleport(input_direction: float) -> void:
 		_teleport_sfx.play()
 
 
+## If the "phase" action is pressed, make the player-character invulnerable, but also unable to
+## interact with coins.
+func _phase() -> void:
+	# Check if the player is holding the "phase" action button.
+	if Input.is_action_just_pressed(Actions.lookup(player, "phase")):
+		# While phasing, disable collisions on the PLAYER physics layer.
+		set_collision_layer_value(Global.PhysicsLayers.PLAYER, false)
+		set_collision_mask_value(Global.PhysicsLayers.PLAYER, false)
+
+		# Make the sprite semitransparent
+		_sprite.modulate.a = 0.5
+
+		# TODO: Is this ability too powerful? Should it have a timer/stamina so the player can only
+		# use it occasionally and for a short time?
+	elif Input.is_action_just_released(Actions.lookup(player, "phase")):
+		# Re-enable collisions on the PLAYER physics layer.
+		set_collision_layer_value(Global.PhysicsLayers.PLAYER, true)
+		set_collision_mask_value(Global.PhysicsLayers.PLAYER, true)
+
+		# Make the sprite opaque again
+		_sprite.modulate.a = 1
+
+
 func _physics_process(delta):
 	# Don't move if there are no lives left.
 	if Global.lives <= 0:
 		return
 
+	# _phase()
+
 	# Handle jump
 	if is_on_floor():
 		coyote_timer = (coyote_time + delta)