Fix FPS counter

interface/resources/qml/Stats.qml

@@ -48,12 +48,22 @@ Item {
                     Text {
                         color: root.fontColor;
                         font.pixelSize: root.fontSize
-                        text: "Render Rate: " + root.renderrate
+                        text: "Render Rate: " + root.renderrate.toFixed(2);
                     }
                     Text {
                         color: root.fontColor;
                         font.pixelSize: root.fontSize
-                        text: "Present Rate: " + root.presentrate
+                        text: "Present Rate: " + root.presentrate.toFixed(2);
+                    }
+                    Text {
+                        color: root.fontColor;
+                        font.pixelSize: root.fontSize
+                        text: "Present New Rate: " + root.presentnewrate.toFixed(2);
+                    }
+                    Text {
+                        color: root.fontColor;
+                        font.pixelSize: root.fontSize
+                        text: "Present Drop Rate: " + root.presentdroprate.toFixed(2);
                     }
                     Text {
                         color: root.fontColor;

interface/src/Application.cpp

@@ -511,8 +511,6 @@ Application::Application(int& argc, char** argv, QElapsedTimer& startupTimer) :
     _sessionRunTimer(startupTimer),
     _previousSessionCrashed(setupEssentials(argc, argv)),
     _undoStackScriptingInterface(&_undoStack),
-    _frameCount(0),
-    _fps(60.0f),
     _physicsEngine(new PhysicsEngine(Vectors::ZERO)),
     _entityClipboardRenderer(false, this, this),
     _entityClipboard(new EntityTree()),
@@ -1332,7 +1330,7 @@ void Application::initializeGL() {
     _idleLoopStdev.reset();
 
     // update before the first render
-    update(1.0f / _fps);
+    update(0);
 
     InfoView::show(INFO_HELP_PATH, true);
 }
@@ -1463,7 +1461,6 @@ void Application::initializeUi() {
 }
 
 void Application::paintGL() {
-
     updateHeartbeat();
 
     // Some plugins process message events, potentially leading to
@@ -1481,24 +1478,7 @@ void Application::paintGL() {
         return;
     }
     _frameCount++;
-
-    // update fps moving average
-    uint64_t now = usecTimestampNow();
-    static uint64_t lastPaintBegin{ now };
-    uint64_t diff = now - lastPaintBegin;
-    float instantaneousFps = 0.0f;
-    if (diff != 0) {
-        instantaneousFps = (float)USECS_PER_SECOND / (float)diff;
-        _framesPerSecond.updateAverage(_lastInstantaneousFps);
-    }
-
-    lastPaintBegin = now;
-
-    // update fps once a second
-    if (now - _lastFramesPerSecondUpdate > USECS_PER_SECOND) {
-        _fps = _framesPerSecond.getAverage();
-        _lastFramesPerSecondUpdate = now;
-    }
+    _frameCounter.increment();
 
     PROFILE_RANGE_EX(__FUNCTION__, 0xff0000ff, (uint64_t)_frameCount);
     PerformanceTimer perfTimer("paintGL");
@@ -1655,7 +1635,7 @@ void Application::paintGL() {
         }
         // Update camera position
         if (!isHMDMode()) {
-            _myCamera.update(1.0f / _fps);
+            _myCamera.update(1.0f / _frameCounter.rate());
         }
     }
 
@@ -1752,8 +1732,6 @@ void Application::paintGL() {
             batch.resetStages();
         });
     }
-
-    _lastInstantaneousFps = instantaneousFps;
 }
 
 void Application::runTests() {
@@ -2625,32 +2603,19 @@ bool Application::acceptSnapshot(const QString& urlString) {
 static uint32_t _renderedFrameIndex { INVALID_FRAME };
 
 void Application::idle(uint64_t now) {
-
+    // NOTICE NOTICE NOTICE NOTICE
+    // Do not insert new code between here and the PROFILE_RANGE declaration 
+    // unless you know exactly what you're doing.  This idle function can be 
+    // called thousands per second or more, so any additional work that's done 
+    // here will have a serious impact on CPU usage.  Only add code after all 
+    // the thottling logic, i.e. after PROFILE_RANGE
+    // NOTICE NOTICE NOTICE NOTICE
     updateHeartbeat();
 
     if (_aboutToQuit || _inPaint) {
         return; // bail early, nothing to do here.
     }
 
-    // These tasks need to be done on our first idle, because we don't want the showing of
-    // overlay subwindows to do a showDesktop() until after the first time through
-    static bool firstIdle = true;
-    if (firstIdle) {
-        firstIdle = false;
-        auto offscreenUi = DependencyManager::get<OffscreenUi>();
-        connect(offscreenUi.data(), &OffscreenUi::showDesktop, this, &Application::showDesktop);
-        _overlayConductor.setEnabled(Menu::getInstance()->isOptionChecked(MenuOption::Overlays));
-    }
-
-    // If the offscreen Ui has something active that is NOT the root, then assume it has keyboard focus.
-    auto offscreenUi = DependencyManager::get<OffscreenUi>();
-    if (_keyboardDeviceHasFocus && offscreenUi && offscreenUi->getWindow()->activeFocusItem() != offscreenUi->getRootItem()) {
-        _keyboardMouseDevice->pluginFocusOutEvent();
-        _keyboardDeviceHasFocus = false;
-    } else if (offscreenUi && offscreenUi->getWindow()->activeFocusItem() == offscreenUi->getRootItem()) {
-        _keyboardDeviceHasFocus = true;
-    }
-
     auto displayPlugin = getActiveDisplayPlugin();
     // depending on whether we're throttling or not.
     // Once rendering is off on another thread we should be able to have Application::idle run at start(0) in
@@ -2684,8 +2649,36 @@ void Application::idle(uint64_t now) {
         return;
     }
 
+    // NOTICE NOTICE NOTICE NOTICE
+    // do NOT add new code above this line unless you want it to be executed potentially 
+    // thousands of times per second
+    // NOTICE NOTICE NOTICE NOTICE
+
     PROFILE_RANGE(__FUNCTION__);
 
+    // These tasks need to be done on our first idle, because we don't want the showing of
+    // overlay subwindows to do a showDesktop() until after the first time through
+    static bool firstIdle = true;
+    if (firstIdle) {
+        firstIdle = false;
+        auto offscreenUi = DependencyManager::get<OffscreenUi>();
+        connect(offscreenUi.data(), &OffscreenUi::showDesktop, this, &Application::showDesktop);
+        _overlayConductor.setEnabled(Menu::getInstance()->isOptionChecked(MenuOption::Overlays));
+    }
+
+
+
+    // If the offscreen Ui has something active that is NOT the root, then assume it has keyboard focus.
+    auto offscreenUi = DependencyManager::get<OffscreenUi>();
+    if (_keyboardDeviceHasFocus && offscreenUi && offscreenUi->getWindow()->activeFocusItem() != offscreenUi->getRootItem()) {
+        _keyboardMouseDevice->pluginFocusOutEvent();
+        _keyboardDeviceHasFocus = false;
+    } else if (offscreenUi && offscreenUi->getWindow()->activeFocusItem() == offscreenUi->getRootItem()) {
+        _keyboardDeviceHasFocus = true;
+    }
+
+
+
     // We're going to execute idle processing, so restart the last idle timer
     _lastTimeUpdated.start();
 
@@ -2694,14 +2687,7 @@ void Application::idle(uint64_t now) {
     Stats::getInstance()->updateStats();
     AvatarInputs::getInstance()->update();
 
-    {
-        static uint64_t lastIdleStart{ now };
-        uint64_t idleStartToStartDuration = now - lastIdleStart;
-        if (idleStartToStartDuration != 0) {
-            _simsPerSecond.updateAverage((float)USECS_PER_SECOND / (float)idleStartToStartDuration);
-        }
-        lastIdleStart = now;
-    }
+    _simCounter.increment();
 
     PerformanceTimer perfTimer("idle");
     // Drop focus from _keyboardFocusedItem if no keyboard messages for 30 seconds
@@ -2757,30 +2743,6 @@ void Application::idle(uint64_t now) {
     emit checkBackgroundDownloads();
 }
 
-float Application::getAverageSimsPerSecond() {
-    uint64_t now = usecTimestampNow();
-
-    if (now - _lastSimsPerSecondUpdate > USECS_PER_SECOND) {
-        _simsPerSecondReport = _simsPerSecond.getAverage();
-        _lastSimsPerSecondUpdate = now;
-    }
-    return _simsPerSecondReport;
-}
-
-void Application::setAvatarSimrateSample(float sample) {
-    _avatarSimsPerSecond.updateAverage(sample);
-}
-
-float Application::getAvatarSimrate() {
-    uint64_t now = usecTimestampNow();
-
-    if (now - _lastAvatarSimsPerSecondUpdate > USECS_PER_SECOND) {
-        _avatarSimsPerSecondReport = _avatarSimsPerSecond.getAverage();
-        _lastAvatarSimsPerSecondUpdate = now;
-    }
-    return _avatarSimsPerSecondReport;
-}
-
 void Application::setLowVelocityFilter(bool lowVelocityFilter) {
     controller::InputDevice::setLowVelocityFilter(lowVelocityFilter);
 }
@@ -3051,7 +3013,7 @@ void Application::updateLOD() const {
     PerformanceTimer perfTimer("LOD");
     // adjust it unless we were asked to disable this feature, or if we're currently in throttleRendering mode
     if (!isThrottleRendering()) {
-        DependencyManager::get<LODManager>()->autoAdjustLOD(_fps);
+        DependencyManager::get<LODManager>()->autoAdjustLOD(_frameCounter.rate());
     } else {
         DependencyManager::get<LODManager>()->resetLODAdjust();
     }
@@ -3482,8 +3444,7 @@ void Application::update(float deltaTime) {
     // AvatarManager update
     {
         PerformanceTimer perfTimer("AvatarManger");
-
-        qApp->setAvatarSimrateSample(1.0f / deltaTime);
+        _avatarSimCounter.increment();
 
         {
             PROFILE_RANGE_EX("OtherAvatars", 0xffff00ff, (uint64_t)getActiveDisplayPlugin()->presentCount());
@@ -3805,7 +3766,8 @@ void Application::queryOctree(NodeType_t serverType, PacketType packetType, Node
 bool Application::isHMDMode() const {
     return getActiveDisplayPlugin()->isHmd();
 }
-float Application::getTargetFrameRate() { return getActiveDisplayPlugin()->getTargetFrameRate(); }
+
+float Application::getTargetFrameRate() const { return getActiveDisplayPlugin()->getTargetFrameRate(); }
 
 QRect Application::getDesirableApplicationGeometry() const {
     QRect applicationGeometry = getWindow()->geometry();

interface/src/Application.h

@@ -39,6 +39,7 @@
 #include <StDev.h>
 #include <ViewFrustum.h>
 #include <AbstractUriHandler.h>
+#include <shared/RateCounter.h>
 
 #include "avatar/MyAvatar.h"
 #include "Bookmarks.h"
@@ -155,10 +156,9 @@ public:
 
     bool isForeground() const { return _isForeground; }
 
-    uint32_t getFrameCount() const { return _frameCount; }
-    float getFps() const { return _fps; }
-    float getTargetFrameRate(); // frames/second
-    float getLastInstanteousFps() const { return _lastInstantaneousFps; }
+    size_t getFrameCount() const { return _frameCount; }
+    float getFps() const { return _frameCounter.rate(); }
+    float getTargetFrameRate() const; // frames/second
 
     float getFieldOfView() { return _fieldOfView.get(); }
     void setFieldOfView(float fov);
@@ -216,10 +216,9 @@ public:
     const QRect& getMirrorViewRect() const { return _mirrorViewRect; }
 
     void updateMyAvatarLookAtPosition();
-    float getAvatarSimrate();
-    void setAvatarSimrateSample(float sample);
 
-    float getAverageSimsPerSecond();
+    float getAvatarSimrate() const { return _avatarSimCounter.rate(); }
+    float getAverageSimsPerSecond() const { return _simCounter.rate(); }
 
 signals:
     void svoImportRequested(const QString& url);
@@ -396,12 +395,15 @@ private:
     QUndoStack _undoStack;
     UndoStackScriptingInterface _undoStackScriptingInterface;
 
+    uint32_t _frameCount { 0 };
+
     // Frame Rate Measurement
-    int _frameCount;
-    float _fps;
+    RateCounter<> _frameCounter;
+    RateCounter<> _avatarSimCounter;
+    RateCounter<> _simCounter;
+
     QElapsedTimer _timerStart;
     QElapsedTimer _lastTimeUpdated;
-    float _lastInstantaneousFps { 0.0f };
 
     ShapeManager _shapeManager;
     PhysicalEntitySimulation _entitySimulation;
@@ -488,12 +490,6 @@ private:
 
     EntityItemID _keyboardFocusedItem;
     quint64 _lastAcceptedKeyPress = 0;
-
-    SimpleMovingAverage _framesPerSecond{10};
-    quint64 _lastFramesPerSecondUpdate = 0;
-    SimpleMovingAverage _simsPerSecond{10};
-    int _simsPerSecondReport = 0;
-    quint64 _lastSimsPerSecondUpdate = 0;
     bool _isForeground = true; // starts out assumed to be in foreground
     bool _inPaint = false;
     bool _isGLInitialized { false };

interface/src/ui/Stats.cpp

@@ -117,11 +117,15 @@ void Stats::updateStats(bool force) {
     // we need to take one avatar out so we don't include ourselves
     STAT_UPDATE(avatarCount, avatarManager->size() - 1);
     STAT_UPDATE(serverCount, (int)nodeList->size());
-    STAT_UPDATE(renderrate, (int)qApp->getFps());
+    STAT_UPDATE(renderrate, qApp->getFps());
     if (qApp->getActiveDisplayPlugin()) {
-        STAT_UPDATE(presentrate, (int)round(qApp->getActiveDisplayPlugin()->presentRate()));
+        STAT_UPDATE(presentrate, qApp->getActiveDisplayPlugin()->presentRate());
+        STAT_UPDATE(presentnewrate, qApp->getActiveDisplayPlugin()->newFramePresentRate());
+        STAT_UPDATE(presentdroprate, qApp->getActiveDisplayPlugin()->droppedFrameRate());
     } else {
         STAT_UPDATE(presentrate, -1);
+        STAT_UPDATE(presentnewrate, -1);
+        STAT_UPDATE(presentdroprate, -1);
     }
     STAT_UPDATE(simrate, (int)qApp->getAverageSimsPerSecond());
     STAT_UPDATE(avatarSimrate, (int)qApp->getAvatarSimrate());

interface/src/ui/Stats.h

@@ -32,8 +32,10 @@ class Stats : public QQuickItem {
     Q_PROPERTY(float audioPacketlossDownstream READ getAudioPacketLossDownstream)
 
     STATS_PROPERTY(int, serverCount, 0)
-    STATS_PROPERTY(int, renderrate, 0)
-    STATS_PROPERTY(int, presentrate, 0)
+    STATS_PROPERTY(float, renderrate, 0)
+    STATS_PROPERTY(float, presentrate, 0)
+    STATS_PROPERTY(float, presentnewrate, 0)
+    STATS_PROPERTY(float, presentdroprate, 0)
     STATS_PROPERTY(int, simrate, 0)
     STATS_PROPERTY(int, avatarSimrate, 0)
     STATS_PROPERTY(int, avatarCount, 0)
@@ -117,6 +119,8 @@ signals:
     void serverCountChanged();
     void renderrateChanged();
     void presentrateChanged();
+    void presentnewrateChanged();
+    void presentdroprateChanged();
     void simrateChanged();
     void avatarSimrateChanged();
     void avatarCountChanged();

libraries/display-plugins/src/display-plugins/Basic2DWindowOpenGLDisplayPlugin.cpp

@@ -30,8 +30,6 @@ bool Basic2DWindowOpenGLDisplayPlugin::internalActivate() {
             }
         }, true, false);
 
-    updateFramerate();
-
     return Parent::internalActivate();
 }
 

libraries/display-plugins/src/display-plugins/Basic2DWindowOpenGLDisplayPlugin.h

@@ -20,7 +20,7 @@ class Basic2DWindowOpenGLDisplayPlugin : public OpenGLDisplayPlugin {
 public:
     virtual const QString& getName() const override { return NAME; }
 
-    virtual float getTargetFrameRate() override { return  _framerateTarget ? (float) _framerateTarget : TARGET_FRAMERATE_Basic2DWindowOpenGL; }
+    virtual float getTargetFrameRate() const override { return  _framerateTarget ? (float) _framerateTarget : TARGET_FRAMERATE_Basic2DWindowOpenGL; }
 
     virtual bool internalActivate() override;
 

libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp

@@ -30,6 +30,7 @@
 #include <CursorManager.h>
 #include "CompositorHelper.h"
 
+
 #if THREADED_PRESENT
 
 // FIXME, for display plugins that don't block on something like vsync, just 
@@ -415,25 +416,18 @@ void OpenGLDisplayPlugin::updateTextures() {
     if (_sceneTextureEscrow.fetchAndReleaseWithGpuWait(_currentSceneTexture)) {
 #endif
         updateFrameData();
-    }
+        _newFrameRate.increment();
+    } 
 
     _overlayTextureEscrow.fetchSignaledAndRelease(_currentOverlayTexture);
 }
 
 void OpenGLDisplayPlugin::updateFrameData() {
     Lock lock(_mutex);
+    auto previousFrameIndex = _currentRenderFrameIndex;
     _currentRenderFrameIndex = _sceneTextureToFrameIndexMap[_currentSceneTexture];
-}
-
-void OpenGLDisplayPlugin::updateFramerate() {
-    uint64_t now = usecTimestampNow();
-    static uint64_t lastSwapEnd { now };
-    uint64_t diff = now - lastSwapEnd;
-    lastSwapEnd = now;
-    if (diff != 0) {
-        Lock lock(_mutex);
-        _usecsPerFrame.updateAverage(diff);
-    }
+    auto skippedCount = (_currentRenderFrameIndex - previousFrameIndex) - 1;
+    _droppedFrameRate.increment(skippedCount);
 }
 
 void OpenGLDisplayPlugin::compositeOverlay() {
@@ -545,19 +539,20 @@ void OpenGLDisplayPlugin::present() {
         compositeLayers();
         // Take the composite framebuffer and send it to the output device
         internalPresent();
-        updateFramerate();
+        _presentRate.increment();
     }
 }
 
-float OpenGLDisplayPlugin::presentRate() {
-    float result { -1.0f }; 
-    {
-        Lock lock(_mutex);
-        result = _usecsPerFrame.getAverage();
-    }
-    result = 1.0f / result; 
-    result *= USECS_PER_SECOND;
-    return result;
+float OpenGLDisplayPlugin::newFramePresentRate() const {
+    return _newFrameRate.rate();
+}
+
+float OpenGLDisplayPlugin::droppedFrameRate() const {
+    return _droppedFrameRate.rate();
+}
+
+float OpenGLDisplayPlugin::presentRate() const {
+    return _presentRate.rate();
 }
 
 void OpenGLDisplayPlugin::drawUnitQuad() {

libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h

@@ -10,6 +10,7 @@
 #include "DisplayPlugin.h"
 
 #include <condition_variable>
+#include <memory>
 
 #include <QtCore/QTimer>
 #include <QtGui/QImage>
@@ -18,6 +19,7 @@
 #include <SimpleMovingAverage.h>
 #include <gl/OglplusHelpers.h>
 #include <gl/GLEscrow.h>
+#include <shared/RateCounter.h>
 
 #define THREADED_PRESENT 1
 
@@ -41,7 +43,6 @@ public:
 
     void submitSceneTexture(uint32_t frameIndex, const gpu::TexturePointer& sceneTexture) override;
     void submitOverlayTexture(const gpu::TexturePointer& overlayTexture) override;
-    float presentRate() override;
 
     glm::uvec2 getRecommendedRenderSize() const override {
         return getSurfacePixels();
@@ -53,6 +54,12 @@ public:
 
     QImage getScreenshot() const override;
 
+    float presentRate() const override;
+
+    float newFramePresentRate() const override;
+
+    float droppedFrameRate() const override;
+
 protected:
 #if THREADED_PRESENT
     friend class PresentThread;
@@ -88,7 +95,6 @@ protected:
 
     void present();
     void updateTextures();
-    void updateFramerate();
     void drawUnitQuad();
     void swapBuffers();
     void eyeViewport(Eye eye) const;
@@ -101,7 +107,9 @@ protected:
     ShapeWrapperPtr _plane;
 
     mutable Mutex _mutex;
-    SimpleMovingAverage _usecsPerFrame { 10 };
+    RateCounter<> _droppedFrameRate;
+    RateCounter<> _newFrameRate;
+    RateCounter<> _presentRate;
     QMap<gpu::TexturePointer, uint32_t> _sceneTextureToFrameIndexMap;
     uint32_t _currentRenderFrameIndex { 0 };
 

libraries/plugins/src/plugins/DisplayPlugin.h

@@ -66,7 +66,7 @@ public:
     /// By default, all HMDs are stereo
     virtual bool isStereo() const { return isHmd(); }
     virtual bool isThrottled() const { return false; }
-    virtual float getTargetFrameRate() { return 0.0f; }
+    virtual float getTargetFrameRate() const { return 0.0f; }
 
     /// Returns a boolean value indicating whether the display is currently visible 
     /// to the user.  For monitor displays, false might indicate that a screensaver,
@@ -142,7 +142,12 @@ public:
     virtual void abandonCalibration() {}
     virtual void resetSensors() {}
     virtual float devicePixelRatio() { return 1.0f; }
-    virtual float presentRate() { return -1.0f; }
+    // Rate at which we present to the display device
+    virtual float presentRate() const { return -1.0f; }
+    // Rate at which new frames are being presented to the display device
+    virtual float newFramePresentRate() const { return -1.0f; }
+    // Rate at which rendered frames are being skipped
+    virtual float droppedFrameRate() const { return -1.0f; }
     uint32_t presentCount() const { return _presentedFrameIndex; }
 
     virtual void cycleDebugOutput() {}

libraries/shared/src/shared/RateCounter.h

@@ -0,0 +1,47 @@
+//
+//  Created by Bradley Austin Davis 2016/04/10
+//  Copyright 2013-2016 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#pragma once
+#ifndef hifi_Shared_RateCounter_h
+#define hifi_Shared_RateCounter_h
+
+#include <stdint.h>
+#include <functional>
+#include <QtCore/QElapsedTimer>
+
+#include "../SharedUtil.h"
+#include "../NumericalConstants.h"
+
+template <uint32_t INTERVAL = MSECS_PER_SECOND, uint8_t PRECISION = 2>
+class RateCounter {
+public:
+    void increment(size_t count = 1) {
+        auto now = usecTimestampNow();
+        auto currentIntervalMs = (uint32_t)((now - _start) / USECS_PER_MSEC);
+        if (currentIntervalMs > INTERVAL) {
+            float currentCount = _count;
+            float intervalSeconds = (float)currentIntervalMs / (float)MSECS_PER_SECOND;
+            _rate = roundf(currentCount / intervalSeconds * _scale) / _scale;
+        };
+        _count += count;
+    }
+
+    float rate() const { return _rate; }
+
+    uint8_t precision() const { return PRECISION; }
+
+    uint32_t interval() const { return INTERVAL; }
+
+private:
+    uint64_t _start { usecTimestampNow() };
+    size_t _count { 0 };
+    float _rate { 0 };
+    const float _scale { powf(10, PRECISION) };
+};
+
+#endif

plugins/oculus/src/OculusBaseDisplayPlugin.h

@@ -21,7 +21,7 @@ public:
     // Stereo specific methods
     virtual void resetSensors() override final;
     virtual void beginFrameRender(uint32_t frameIndex) override;
-    float getTargetFrameRate() override { return _hmdDesc.DisplayRefreshRate; }
+    float getTargetFrameRate() const override { return _hmdDesc.DisplayRefreshRate; }
     
 
 protected:

plugins/oculusLegacy/src/OculusLegacyDisplayPlugin.cpp

@@ -181,7 +181,7 @@ int OculusLegacyDisplayPlugin::getHmdScreen() const {
     return _hmdScreen;
 }
 
-float OculusLegacyDisplayPlugin::getTargetFrameRate() {
+float OculusLegacyDisplayPlugin::getTargetFrameRate() const {
     return TARGET_RATE_OculusLegacy;
 }
 

plugins/oculusLegacy/src/OculusLegacyDisplayPlugin.h

@@ -28,7 +28,7 @@ public:
     virtual void resetSensors() override;
     virtual void beginFrameRender(uint32_t frameIndex) override;
 
-    virtual float getTargetFrameRate() override;
+    virtual float getTargetFrameRate() const override;
 
 protected:
     virtual bool internalActivate() override;

plugins/openvr/src/OpenVrDisplayPlugin.h

@@ -21,7 +21,7 @@ public:
     virtual bool isSupported() const override;
     virtual const QString& getName() const override { return NAME; }
 
-    virtual float getTargetFrameRate() override { return TARGET_RATE_OpenVr; }
+    virtual float getTargetFrameRate() const override { return TARGET_RATE_OpenVr; }
 
     virtual void customizeContext() override;