From 442c03237340e5e2cce7e9f7d79679c176794dda Mon Sep 17 00:00:00 2001
From: Andrei Kortunov <andrei.kortunov@yandex.ru>
Date: Tue, 26 Sep 2023 14:39:38 +0400
Subject: [PATCH] Decouple rendering simulation time from Lua simulation time
 (bug 7576)

---
 apps/openmw/engine.cpp                  | 5 ++++-
 apps/openmw/mwworld/datetimemanager.hpp | 7 ++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/apps/openmw/engine.cpp b/apps/openmw/engine.cpp
index df89cd3eb6..ee2ce7ae3e 100644
--- a/apps/openmw/engine.cpp
+++ b/apps/openmw/engine.cpp
@@ -945,7 +945,7 @@ void OMW::Engine::go()
                               .count()
             * timeManager.getSimulationTimeScale();
 
-        mViewer->advance(timeManager.getSimulationTime());
+        mViewer->advance(timeManager.getRenderingSimulationTime());
 
         if (!frame(dt))
         {
@@ -954,7 +954,10 @@ void OMW::Engine::go()
         }
         timeManager.updateIsPaused();
         if (!timeManager.isPaused())
+        {
             timeManager.setSimulationTime(timeManager.getSimulationTime() + dt);
+            timeManager.setRenderingSimulationTime(timeManager.getRenderingSimulationTime() + dt);
+        }
 
         if (stats)
         {
diff --git a/apps/openmw/mwworld/datetimemanager.hpp b/apps/openmw/mwworld/datetimemanager.hpp
index f89894292f..af62d9ba3f 100644
--- a/apps/openmw/mwworld/datetimemanager.hpp
+++ b/apps/openmw/mwworld/datetimemanager.hpp
@@ -29,7 +29,11 @@ namespace MWWorld
         float getGameTimeScale() const { return mGameTimeScale; }
         void setGameTimeScale(float scale); // game time to simulation time ratio
 
-        // Simulation time (the number of seconds passed from the beginning of the game).
+        // Rendering simulation time (summary simulation time of rendering frames since application start).
+        double getRenderingSimulationTime() const { return mRenderingSimulationTime; }
+        void setRenderingSimulationTime(double t) { mRenderingSimulationTime = t; }
+
+        // World simulation time (the number of seconds passed from the beginning of the game).
         double getSimulationTime() const { return mSimulationTime; }
         void setSimulationTime(double t) { mSimulationTime = t; }
         float getSimulationTimeScale() const { return mSimulationTimeScale; }
@@ -64,6 +68,7 @@ namespace MWWorld
         float mGameHour = 0.f;
         float mGameTimeScale = 0.f;
         float mSimulationTimeScale = 1.0;
+        double mRenderingSimulationTime = 0.0;
         double mSimulationTime = 0.0;
         bool mPaused = false;
         std::set<std::string, std::less<>> mPausedTags;