continue idling while minimized

interface/src/Application.cpp

@@ -2530,6 +2530,11 @@ bool Application::event(QEvent* event) {
 
         isPaintingThrottled = false;
 
+        return true;
+    } else if ((int)event->type() == (int)Idle) {
+        float nsecsElapsed = (float)_lastTimeUpdated.nsecsElapsed();
+        idle(nsecsElapsed);
+
         return true;
     }
 
@@ -6499,10 +6504,22 @@ void Application::activeChanged(Qt::ApplicationState state) {
 }
 
 void Application::windowMinimizedChanged(bool minimized) {
+    // initialize the _minimizedWindowTimer
+    static std::once_flag once;
+    std::call_once(once, [&] {
+        connect(&_minimizedWindowTimer, &QTimer::timeout, this, [] {
+            QCoreApplication::postEvent(QCoreApplication::instance(), new QEvent(static_cast<QEvent::Type>(Idle)), Qt::HighEventPriority);
+        });
+    });
+
+    // avoid rendering to the display plugin but continue posting Idle events,
+    // so that physics continues to simulate and the deadlock watchdog knows we're alive
     if (!minimized && !getActiveDisplayPlugin()->isActive()) {
+        _minimizedWindowTimer.stop();
         getActiveDisplayPlugin()->activate();
     } else if (minimized && getActiveDisplayPlugin()->isActive()) {
         getActiveDisplayPlugin()->deactivate();
+        _minimizedWindowTimer.start(THROTTLED_SIM_FRAME_PERIOD_MS);
     }
 }
 

interface/src/Application.h

@@ -138,6 +138,7 @@ public:
     enum Event {
         Present = DisplayPlugin::Present,
         Paint = Present + 1,
+        Idle = Paint + 1,
         Lambda = Paint + 1
     };
 
@@ -536,6 +537,7 @@ private:
     RateCounter<> _avatarSimCounter;
     RateCounter<> _simCounter;
 
+    QTimer _minimizedWindowTimer;
     QElapsedTimer _timerStart;
     QElapsedTimer _lastTimeUpdated;