Add a transition effect test scene

[wjt]

I find the labels for these effects counter-intuitive, and having
written this test tool I understand why.

[wjt]

Try setting both to LEFT_TO_RIGHT_WIPE. I think the in-effect is as expected but the out-effect is inverted from what I would expect.

[github-actions]

Play this branch at https://play.threadbare.game/branches/endlessm/wjt/add-a-transition-effect-test-scene/.

(This launches the game from the start, not directly at the change(s) in this pull request.)

[wjt]

Effectively we have to invert the sense of the transition on the way out (but not the way in!) for it to match the label.

This would do it:

diff --git a/scenes/globals/scene_switcher/transitions/transitions.gd b/scenes/globals/scene_switcher/transitions/transitions.gd
index 5bf48b78f..1564049c1 100644
--- a/scenes/globals/scene_switcher/transitions/transitions.gd
+++ b/scenes/globals/scene_switcher/transitions/transitions.gd
@@ -24,6 +29,19 @@ var _current_tween: Tween
 @onready var transition_mask: ColorRect = $TransitionMask
 
 
+static func _invert(effect: Effect) -> Effect:
+	match effect:
+		Effect.LEFT_TO_RIGHT_WIPE:
+			return Effect.RIGHT_TO_LEFT_WIPE
+		Effect.RIGHT_TO_LEFT_WIPE:
+			return Effect.LEFT_TO_RIGHT_WIPE
+		Effect.TOP_TO_BOTTOM_WIPE:
+			return Effect.BOTTOM_TO_TOP_WIPE
+		Effect.BOTTOM_TO_TOP_WIPE:
+			return Effect.TOP_TO_BOTTOM_WIPE
+		_:
+			return effect
+
 func _input(_event: InputEvent) -> void:
 	if visible:
 		get_viewport().set_input_as_handled()
@@ -64,21 +82,21 @@ func _do_tween(
 
 
 func _leave_scene(
-	_transition_effect: Effect = Effect.FADE,
+	transition_effect: Effect = Effect.FADE,
 	duration: float = 1.0,
 	easing: Tween.EaseType = Tween.EaseType.EASE_OUT,
 	transition_type: Tween.TransitionType = Tween.TransitionType.TRANS_QUAD
 ) -> void:
-	await _do_tween(0.0, _transition_effect, duration, easing, transition_type)
+	await _do_tween(0.0, _invert(transition_effect), duration, easing, transition_type)
 
 
 func _introduce_scene(
-	_transition_effect: Effect = Effect.FADE,
+	transition_effect: Effect = Effect.FADE,
 	duration: float = 1.0,
 	easing: Tween.EaseType = Tween.EaseType.EASE_IN,
 	transition_type: Tween.TransitionType = Tween.TransitionType.TRANS_QUAD
 ) -> void:
-	await _do_tween(1.0, _transition_effect, duration, easing, transition_type)
+	await _do_tween(1.0, transition_effect, duration, easing, transition_type)
 
 
 func do_transition(

[wjt]

https://play.threadbare.game/branches/endlessm/wjt/add-a-transition-effect-test-scene/#res://scenes/globals/scene_switcher/transitions/transition_test.tscn

[manuq]

https://play.threadbare.game/branches/endlessm/wjt/add-a-transition-effect-test-scene/#res://scenes/globals/scene_switcher/transitions/transition_test.tscn

This is amazing! With sound effects even :)

Yes I agree, is all inverted.