From 70a3ae02455cb223504acdf644bbc27bff28b69f Mon Sep 17 00:00:00 2001
From: WarmUpTill <WarmUpTill@web.de>
Date: Sun, 8 May 2022 03:49:22 +0200
Subject: [PATCH] Fix waiting for transition to complete with fixed duration
 transitions

---
 src/macro-action-scene-switch.cpp | 73 ++++++++++++++++++++++++++-----
 1 file changed, 63 insertions(+), 10 deletions(-)

diff --git a/src/macro-action-scene-switch.cpp b/src/macro-action-scene-switch.cpp
index 33a8b1d5..607e6d78 100644
--- a/src/macro-action-scene-switch.cpp
+++ b/src/macro-action-scene-switch.cpp
@@ -2,6 +2,8 @@
 #include "headers/advanced-scene-switcher.hpp"
 #include "headers/utility.hpp"
 
+using namespace std::chrono_literals;
+
 const std::string MacroActionSwitchScene::id = "scene_switch";
 
 bool MacroActionSwitchScene::_registered = MacroActionFactory::Register(
@@ -9,7 +11,21 @@ bool MacroActionSwitchScene::_registered = MacroActionFactory::Register(
 	{MacroActionSwitchScene::Create, MacroActionSwitchSceneEdit::Create,
 	 "AdvSceneSwitcher.action.switchScene"});
 
-void waitForTransitionChange(int duration)
+void waitForTransitionChange(OBSWeakSource &transition)
+{
+	const auto time = 100ms;
+	obs_source_t *source = obs_weak_source_get_source(transition);
+	std::unique_lock<std::mutex> lock(switcher->m);
+	bool stillTransitioning = true;
+	while (stillTransitioning && !switcher->abortMacroWait) {
+		switcher->macroTransitionCv.wait_for(lock, time);
+		float t = obs_transition_get_time(source);
+		stillTransitioning = t < 1.0f && t > 0.0f;
+	}
+	obs_source_release(source);
+}
+
+void waitForTransitionChangeFixedDuration(int duration)
 {
 	duration += 200; // It seems to be necessary to add a small buffer
 	auto time = std::chrono::high_resolution_clock::now() +
@@ -25,7 +41,7 @@ void waitForTransitionChange(int duration)
 	}
 }
 
-int getTransitionOverrideDuration(OBSWeakSource scene)
+int getTransitionOverrideDuration(OBSWeakSource &scene)
 {
 	int duration = 0;
 	obs_source_t *source = obs_weak_source_get_source(scene);
@@ -39,11 +55,41 @@ int getTransitionOverrideDuration(OBSWeakSource scene)
 	return duration;
 }
 
-int getExpectedTransitionDuration(OBSWeakSource scene, double duration)
+bool isUsingFixedLengthTransition(OBSWeakSource &transition)
 {
-	int overrideDuration = getTransitionOverrideDuration(scene);
-	if (overrideDuration && !switcher->transitionOverrideOverride) {
-		return overrideDuration;
+	obs_source_t *source = obs_weak_source_get_source(transition);
+	bool ret = obs_transition_fixed(source);
+	obs_source_release(source);
+	return ret;
+}
+
+OBSWeakSource getOverrideTransition(OBSWeakSource &scene)
+{
+	OBSWeakSource transition;
+	obs_source_t *source = obs_weak_source_get_source(scene);
+	obs_data_t *data = obs_source_get_private_settings(source);
+	transition = GetWeakTransitionByName(
+		obs_data_get_string(data, "transition"));
+	obs_data_release(data);
+	obs_source_release(source);
+	return transition;
+}
+
+int getExpectedTransitionDuration(OBSWeakSource &scene, OBSWeakSource &t,
+				  double duration)
+{
+	OBSWeakSource transition = t;
+	if (!switcher->transitionOverrideOverride) {
+		auto overrideTransition = getOverrideTransition(scene);
+		if (overrideTransition) {
+			transition = overrideTransition;
+			if (!isUsingFixedLengthTransition(transition)) {
+				return getTransitionOverrideDuration(scene);
+			}
+		}
+	}
+	if (isUsingFixedLengthTransition(transition)) {
+		return -1; // no API is available to access the fixed duration
 	}
 	if (duration != 0) {
 		return duration * 1000;
@@ -54,12 +100,19 @@ int getExpectedTransitionDuration(OBSWeakSource scene, double duration)
 bool MacroActionSwitchScene::PerformAction()
 {
 	auto scene = _scene.GetScene();
-	switchScene({scene, _transition.GetTransition(),
-		     (int)(_duration.seconds * 1000)},
+	auto transition = _transition.GetTransition();
+	switchScene({scene, transition, (int)(_duration.seconds * 1000)},
 		    obs_frontend_preview_program_mode_active());
 	if (_blockUntilTransitionDone && scene) {
-		waitForTransitionChange(getExpectedTransitionDuration(
-			scene, _duration.seconds));
+		const int expectedTransitionDuration =
+			getExpectedTransitionDuration(scene, transition,
+						      _duration.seconds);
+		if (expectedTransitionDuration < 0) {
+			waitForTransitionChange(transition);
+		} else {
+			waitForTransitionChangeFixedDuration(
+				expectedTransitionDuration);
+		}
 		return !switcher->abortMacroWait;
 	}
 	return true;