Make third Champ challenge with placeholder player script

[wjt]

From discussion with @jgbourque, who I'm sure will correct me if I'm wrong: the third challenge of Champ should be where the majority of "gaps" for participants should be. In particular, this should be where the player-character is not an instance of player.tscn, but a much simplified CharacterBody2D with a simple script attached with obvious gaps & bugs, e.g.:

• No sprinting
• Diagonal movement is faster than up/down/left/right because the two axes of the input vector are calculated separately with Input.get_axis() rather than together with Input.get_vector
• Placeholders for abilities like "walk on water"

This means that there can't be a collectible thread in this level - because interacting with in-world objects is a complex feature of the "real" player script. To work around this and still have a goal in the level, I suggest placing a teleporter at the end of the challenge, or even near the start so the challenge is wholly optional. (Teleporters are just Area2Ds that wait for a body in the correct physics layer to enter them - no player logic required.) But this is why @jgbourque suggests putting this as the final challenge in the quest.

[jgbourque]

Thanks for the scene to scene connection idea here Will. @felixwalberg Let me know if you need any help prepping the third "mini game" or scene to be inspiration for learner submissions!

Just to add: The scene should still be playable gameplay wise Felix just with some clear "placeholders" for assets or learner contributions. Missing sound effects, decorative assets or NPCs that are just gray or collision shapes without an image. Let's do this in a few places for variety but no need to gray out the entire scene! I noticed you already generalized the playable character which is great. There should definitely be an option to design and or animate the protagonist!

[wjt]

@felixwalberg I was thinking about whether you could actually use the existing stealth challenge guards with a custom CharacterBody2D for the player-character. The answer is no but it's not for a particularly interesting reason: the detection callbacks check if body is Player and short-circuit if not.

threadbare/scenes/game_elements/characters/enemies/guard/components/guard.gd

Lines 456 to 483 in 8f55c06

	func _on_instant_detection_area_body_entered(body: Node2D) -> void:
	if not body is Player:
	return
	state = State.ALERTED
	player_detected.emit(body as Player)
	func _on_detection_area_body_entered(body: Node2D) -> void:
	if not body is Player:
	return
	_player = body as Player
	if _is_sight_to_point_blocked(body.global_position):
	return
	if player_instantly_detected_on_sight:
	state = State.ALERTED
	player_detected.emit(_player)
	else:
	state = State.DETECTING
	func _on_detection_area_body_exited(body: Node2D) -> void:
	if not body is Player:
	return
	_player = null
	last_seen_position = body.global_position
	if state == State.DETECTING:
	guard_movement.stop_moving()
	state = State.INVESTIGATING

I think we could reasonably make the following changes:

• In guard.gd, change the signal player_detected signature to signal player_detected(player: Node2D), and var _player to be a Node2D, then remove all the is Player / as Player typechecks in the file. (I think this is legitimate anyway - you could imagine wanting to have guards be able to detect an NPC too.)
• Then there's stealth_game_logic.gd, which is the only user of that player_detected signal. It calls defeat() on the detected node in response to the signal. In fact that's all it does! So we move the typecheck into that callback instead, and rather than checking the type, check for the method:

func _on_player_detected(player: Node2D) -> void:
	if player.has_method(&"defeat"):
		player.defeat()

That should be enough - you could I think then use the vanilla guards & stealth_game_logic script in a scene where the player-character is a different, hand-rolled CharacterBody2D.

[wjt]

I implemented those two changes in #1811 - with those I was able to replace the player.tscn instance in a stealth challenge with a handrolled CharacterBody2D that is placed into the correct layer and has a defeat() method that just prints "oh no", and it worked as expected. @felixwalberg please take a look at #1811 - I think it will help you with this task!