Animate Window_Message during transitions

Emulates the RPG_RT behavior for EasyRPG#1706 Tests 17 & 18

src/game_message.cpp

@@ -196,6 +196,12 @@ int Game_Message::WordWrap(const std::string& line, const int limit, const std::
 	return line_count;
 }
 
+void Game_Message::AdvanceAnimationFrames(int frames) {
+	if (window) {
+		window->AdvanceAnimationFrames(frames);
+	}
+}
+
 void Game_Message::Update() {
 	if (window) {
 		window->Update();

src/game_message.h

@@ -39,6 +39,9 @@ namespace Game_Message {
 
 	void Update();
 
+	/** Calls AdvanceAnimationFrames() on the Window_Message */
+	void AdvanceAnimationFrames(int frames);
+
 	/** Reset the face graphic. */
 	void ClearFace();
 

src/scene_map.cpp

@@ -187,15 +187,16 @@ void Scene_Map::TransitionOut(SceneType next_scene) {
 	}
 
 	if (next_scene == Scene::Battle) {
-		Graphics::GetTransition().Init((Transition::TransitionType)Game_System::GetTransition(Game_System::Transition_BeginBattleErase), this, 32, true);
+		InitTransitionOut((Transition::TransitionType)Game_System::GetTransition(Game_System::Transition_BeginBattleErase), 32);
 		Graphics::GetTransition().AppendBefore(Color(255, 255, 255, 255), 12, 2);
 		return;
 	}
 	if (next_scene == Scene::Gameover) {
-		Graphics::GetTransition().Init(Transition::TransitionFadeOut, this, 32, true);
+		InitTransitionOut(Transition::TransitionFadeOut, 32);
 		return;
 	}
-	Scene::TransitionOut(next_scene);
+
+	InitTransitionOut(Transition::TransitionFadeOut, 6);
 }
 
 void Scene_Map::DrawBackground() {
@@ -324,7 +325,7 @@ void Scene_Map::StartPendingTeleport(TeleportParams tp) {
 	request->Start();
 
 	if (!Graphics::IsTransitionErased() && tt.GetType() != TeleportTarget::eVehicleHackTeleport && tp.erase_screen) {
-		Graphics::GetTransition().Init((Transition::TransitionType)Game_System::GetTransition(Game_System::Transition_TeleportErase), this, 32, true);
+		InitTransitionOut((Transition::TransitionType)Game_System::GetTransition(Game_System::Transition_TeleportErase), 32);
 	}
 
 	AsyncNext([=]() { FinishPendingTeleport(tp); });
@@ -450,7 +451,7 @@ void Scene_Map::OnAsyncSuspend(F&& f, AsyncOp aop, bool is_preupdate) {
 
 	if (aop.GetType() == AsyncOp::eEraseScreen) {
 		auto tt = static_cast<Transition::TransitionType>(aop.GetTransitionType());
-		Graphics::GetTransition().Init(tt, this, 32, true);
+		InitTransitionOut(tt, 32);
 		if (!is_preupdate) {
 			// RPG_RT behavior: EraseScreen commands performed during pre-update don't stick.
 			screen_erased_by_event = true;
@@ -471,7 +472,7 @@ void Scene_Map::OnAsyncSuspend(F&& f, AsyncOp aop, bool is_preupdate) {
 		Game_System::BgmFade(800);
 
 		// FIXME: Is 36 correct here?
-		Graphics::GetTransition().Init(Transition::TransitionFadeOut, Scene::instance.get(), 36, true);
+		InitTransitionOut(Transition::TransitionFadeOut, 36);
 
 		AsyncNext([=]() { StartInn(); });
 		return;
@@ -515,3 +516,15 @@ void Scene_Map::UpdateInn() {
 		FinishInn();
 	}
 }
+
+void Scene_Map::InitTransitionOut(Transition::TransitionType tt, int frames) {
+	// In rare cases where a message and a transition are triggered on the same frame, RPG_RT
+	// will still animate the message box open/close and the transition effect will show
+	// the resulting message box state. This can affect interpreter timing so we try to emulate it.
+	// See #1706 Tests 17 and 18
+	auto cb = [this](int frames) {
+		message_window->AdvanceAnimationFrames(frames);
+	};
+	Graphics::GetTransition().Init(tt, this, frames, true, cb);
+}
+

src/scene_map.h

@@ -24,6 +24,7 @@
 #include "window_message.h"
 #include "window_varlist.h"
 #include "game_map.h"
+#include "transition.h"
 
 /**
  * Scene Map class.
@@ -91,6 +92,8 @@ class Scene_Map: public Scene {
 	void UpdateInn();
 	void FinishInn();
 
+	void InitTransitionOut(Transition::TransitionType tt, int frames);
+
 	template <typename F> void AsyncNext(F&& f);
 	template <typename F> void OnAsyncSuspend(F&& f, AsyncOp aop, bool is_preupdate);
 

src/transition.cpp

@@ -29,6 +29,7 @@
 #include "baseui.h"
 #include "drawable.h"
 #include "drawable_mgr.h"
+#include "game_message.h"
 
 Transition::Transition() : Drawable(TypeTransition, Priority_Transition, true)
 {
@@ -45,7 +46,7 @@ void Transition::AppendBefore(Color color, int duration, int iterations) {
 	total_frames += flash_duration * flash_iterations;
 }
 
-void Transition::Init(TransitionType type, Scene *linked_scene, int duration, bool erase) {
+void Transition::Init(TransitionType type, Scene *linked_scene, int duration, bool erase, const TransitionCallback& cb) {
 	// FIXME: Break this dependency on DisplayUI
 	if (!black_screen && DisplayUi) {
 		black_screen = Bitmap::Create(DisplayUi->GetWidth(), DisplayUi->GetHeight(), Color(0, 0, 0, 255));
@@ -61,6 +62,15 @@ void Transition::Init(TransitionType type, Scene *linked_scene, int duration, bo
 		return;
 	}
 
+	if (transition_type == TransitionErase) {
+		duration = 1;
+	}
+
+	// Note: This must be called before we grab the screen!
+	if (cb) {
+		cb(duration);
+	}
+
 	frozen_screen = Graphics::SnapToBitmap(GetZ());
 	screen1 = erase ? frozen_screen : old_frozen_screen? old_frozen_screen : black_screen;
 	screen2 = erase ? black_screen : frozen_screen;
@@ -73,7 +83,7 @@ void Transition::Init(TransitionType type, Scene *linked_scene, int duration, bo
 	current_frame = 0;
 	flash_iterations = 0;
 	flash_duration = 0;
-	total_frames = transition_type == TransitionErase ? 1 : duration;
+	total_frames = duration;
 
 	SetAttributesTransitions();
 }

src/transition.h

@@ -73,6 +73,8 @@ class Transition : public Drawable {
 		TransitionNone
 	};
 
+	using TransitionCallback = std::function<void(int)>;
+
 	Transition();
 
 	/**
@@ -83,7 +85,7 @@ class Transition : public Drawable {
 	 * @param duration transition duration.
 	 * @param erase erase screen flag.
 	 */
-	void Init(TransitionType type, Scene *linked_scene, int duration, bool erase = false);
+	void Init(TransitionType type, Scene *linked_scene, int duration, bool erase = false, const TransitionCallback& cb = {});
 
 	void AppendBefore(Color color, int duration, int iterations);
 

src/window_message.cpp

@@ -360,6 +360,21 @@ void Window_Message::ResetWindow() {
 
 }
 
+void Window_Message::AdvanceAnimationFrames(int frames) {
+	if (frames == 0) {
+		return;
+	}
+
+	close_started_this_frame = false;
+
+	while (frames > 0) {
+		bool was_closing = IsClosing();
+		Window::Update();
+		close_finished_this_frame = was_closing && !IsClosing();
+		--frames;
+	}
+}
+
 void Window_Message::Update() {
 	if (IsOpening()) { DebugLog("%d: MSG OPENING"); }
 	if (IsClosing()) { DebugLog("%d: MSG CLOSING"); }

src/window_message.h

@@ -88,11 +88,19 @@ class Window_Message: public Window_Selectable {
 
 	void Update() override;
 
+	/**
+	 * Force the window animations to advance by a number of frames.
+	 * This is exercised by some edge cases with transitions
+	 * 
+	 * @params frames number of frames of the transition.
+	 */
+	void AdvanceAnimationFrames(int frames);
+
 	/**
 	 * Continues outputting more text. Also handles the
 	 * CommandCode parsing.
 	 */
-	virtual void UpdateMessage();
+	void UpdateMessage();
 
 	/**
 	 * Stub. For choice.