From df413c0b14a1f87b221f021ba83997e470a920a8 Mon Sep 17 00:00:00 2001
From: Howard Stearns <howard@highfidelity.io>
Date: Mon, 7 Dec 2015 09:31:06 -0800
Subject: [PATCH 01/11] Temporary debugging aids.

---
 libraries/shared/src/PIDController.cpp | 10 ++++++----
 libraries/shared/src/PIDController.h   |  5 +++--
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/libraries/shared/src/PIDController.cpp b/libraries/shared/src/PIDController.cpp
index a853553b89..36c670e66d 100644
--- a/libraries/shared/src/PIDController.cpp
+++ b/libraries/shared/src/PIDController.cpp
@@ -14,7 +14,7 @@
 #include "SharedLogging.h"
 #include "PIDController.h"
 
-float PIDController::update(float measuredValue, float dt, bool resetAccumulator) {
+float PIDController::update(float measuredValue, float dt, bool resetAccumulator, float fixme1, float fixme2) {
     const float error = getMeasuredValueSetpoint() - measuredValue;   // Sign is the direction we want measuredValue to go. Positive means go higher.
 
     const float p = getKP() * error; // term is Proportional to error
@@ -32,7 +32,7 @@ float PIDController::update(float measuredValue, float dt, bool resetAccumulator
         getControlledValueHighLimit());
 
     if (getIsLogging()) {  // if logging/reporting
-        updateHistory(measuredValue, dt, error, accumulatedError, changeInError, p, i, d, computedValue);
+        updateHistory(measuredValue, dt, error, accumulatedError, changeInError, p, i, d, computedValue, fixme1, fixme2);
     }
     Q_ASSERT(!isnan(computedValue));
     
@@ -43,7 +43,7 @@ float PIDController::update(float measuredValue, float dt, bool resetAccumulator
 }
 
 // Just for logging/reporting. Used when picking/verifying the operational parameters.
-void PIDController::updateHistory(float measuredValue, float dt, float error, float accumulatedError, float changeInError, float p, float i, float d, float computedValue) {
+void PIDController::updateHistory(float measuredValue, float dt, float error, float accumulatedError, float changeInError, float p, float i, float d, float computedValue, float fixme1, float fixme2) {
     // Don't report each update(), as the I/O messes with the results a lot.
     // Instead, add to history, and then dump out at once when full.
     // Typically, the first few values reported in each batch should be ignored.
@@ -59,16 +59,18 @@ void PIDController::updateHistory(float measuredValue, float dt, float error, fl
     next.i = i;
     next.d = d;
     next.computed = computedValue;
+    next.fixme1 = fixme1; next.fixme2 = fixme2;
     if (_history.size() == _history.capacity()) { // report when buffer is full
         reportHistory();
         _history.resize(0);
     }
 }
 void PIDController::reportHistory() {
-    qCDebug(shared) << _label << "measured dt FIXME || error accumulated changed || p i d controlled";
+    qCDebug(shared) << _label << "measured dt || error accumulated changed || p i d controlled";
     for (int i = 0; i < _history.size(); i++) {
         Row& row = _history[i];
         qCDebug(shared) << row.measured << row.dt <<
+        row.fixme1 << row.fixme2 <<
             "||" << row.error << row.accumulated << row.changed <<
             "||" << row.p << row.i << row.d << row.computed << 1.0f/row.computed;
     }
diff --git a/libraries/shared/src/PIDController.h b/libraries/shared/src/PIDController.h
index 0b2411530a..24e619b13b 100644
--- a/libraries/shared/src/PIDController.h
+++ b/libraries/shared/src/PIDController.h
@@ -28,7 +28,7 @@ class PIDController {
 public:
     // These are the main interfaces:
     void setMeasuredValueSetpoint(float newValue) { _measuredValueSetpoint = newValue; }
-    float update(float measuredValue, float dt, bool resetAccumulator = false); // returns the new computedValue
+    float update(float measuredValue, float dt, bool resetAccumulator = false, float fixme1=0, float fixme2=0); // returns the new computedValue
     void setHistorySize(QString label = QString(""), int size = 0) { _history.reserve(size); _history.resize(0); _label = label; } // non-empty does logging
 
     bool getIsLogging() { return _history.capacity(); }
@@ -64,10 +64,11 @@ public:
         float i;
         float d;
         float computed;
+        float fixme1; float fixme2;
     };
 protected:
     void reportHistory();
-    void updateHistory(float measured, float dt, float error, float accumulatedError, float changeInErro, float p, float i, float d, float computedValue);
+    void updateHistory(float measured, float dt, float error, float accumulatedError, float changeInErro, float p, float i, float d, float computedValue, float fixme1, float fixme2);
     float _measuredValueSetpoint { 0.0f };
     float _controlledValueLowLimit { 0.0f };
     float _controlledValueHighLimit { std::numeric_limits<float>::max() };

From 34de4d67d80f6e9337d3f28ce6bc3dcf29ffcfba Mon Sep 17 00:00:00 2001
From: Howard Stearns <howard@highfidelity.io>
Date: Mon, 7 Dec 2015 09:32:12 -0800
Subject: [PATCH 02/11] DisplayPlugin::getLastSynchronizedElapsed

---
 .../src/display-plugins/OpenGLDisplayPlugin.cpp             | 6 ++++++
 .../src/display-plugins/OpenGLDisplayPlugin.h               | 4 ++++
 libraries/plugins/src/plugins/DisplayPlugin.h               | 1 +
 3 files changed, 11 insertions(+)

diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
index d306c23dc0..4668f8ba1a 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
@@ -156,8 +156,10 @@ OpenGLDisplayPlugin::OpenGLDisplayPlugin() {
         _container->releaseOverlayTexture(texture);
     });
 
+    _synchronizedTimer.start();
     connect(&_timer, &QTimer::timeout, this, [&] {
         if (_active && _sceneTextureEscrow.depth() <= 1) {
+            _synchronizedTimer.start();
             emit requestRender();
         }
     });
@@ -279,6 +281,10 @@ void OpenGLDisplayPlugin::submitOverlayTexture(GLuint sceneTexture, const glm::u
 }
 
 void OpenGLDisplayPlugin::updateTextures() {
+    const qint64 elapsed =_synchronizedTimer.elapsed();
+    if (elapsed != 0) {
+        _lastSynchronizedElapsed = elapsed;
+    }
     _currentSceneTexture = _sceneTextureEscrow.fetchAndRelease(_currentSceneTexture);
     _currentOverlayTexture = _overlayTextureEscrow.fetchAndRelease(_currentOverlayTexture);
 }
diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
index ef78374994..4577777034 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
@@ -10,6 +10,7 @@
 #include "DisplayPlugin.h"
 
 #include <QtCore/QTimer>
+#include <QElapsedTimer>
 
 #include <GLMHelpers.h>
 #include <SimpleMovingAverage.h>
@@ -30,6 +31,7 @@ public:
     virtual void submitSceneTexture(uint32_t frameIndex, uint32_t sceneTexture, const glm::uvec2& sceneSize) override;
     virtual void submitOverlayTexture(uint32_t overlayTexture, const glm::uvec2& overlaySize) override;
     virtual float presentRate() override;
+    virtual qint64 getLastSynchronizedElapsed() { return _lastSynchronizedElapsed; }
 
     virtual glm::uvec2 getRecommendedRenderSize() const override {
         return getSurfacePixels();
@@ -68,6 +70,8 @@ protected:
     virtual void internalPresent();
 
     mutable QTimer _timer;
+    QElapsedTimer _synchronizedTimer;
+    qint64 _lastSynchronizedElapsed { 0 };
     ProgramPtr _program;
     ShapeWrapperPtr _plane;
 
diff --git a/libraries/plugins/src/plugins/DisplayPlugin.h b/libraries/plugins/src/plugins/DisplayPlugin.h
index 83afbc9402..6fc6062214 100644
--- a/libraries/plugins/src/plugins/DisplayPlugin.h
+++ b/libraries/plugins/src/plugins/DisplayPlugin.h
@@ -58,6 +58,7 @@ public:
     /// By default, all HMDs are stereo
     virtual bool isStereo() const { return isHmd(); }
     virtual bool isThrottled() const { return false; }
+    virtual qint64 getLastSynchronizedElapsed() { return 0; }
 
     // Rendering support
 

From 1d4cc7c9847bbf615b40e9647e7a13e564e6f181 Mon Sep 17 00:00:00 2001
From: Howard Stearns <howard@highfidelity.io>
Date: Mon, 7 Dec 2015 10:01:46 -0800
Subject: [PATCH 03/11] Checkpoint exploring use of getLastSynchronizedElapsed
 and fixing paintWait (which may go away).

---
 interface/src/Application.cpp | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 9e98b51442..3af0e6d39b 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -1126,9 +1126,9 @@ void Application::paintGL() {
     // Time between previous paintGL call and this one, which can vary not only with vSync misses, but also with QT timing.
     // We're using this as a proxy for the time between vsync and displayEnd, below. (Not exact, but tends to be the same over time.)
     // This is not the same as update(deltaTime), because the latter attempts to throttle to 60hz and also clamps to 1/4 second.
-    const float actualPeriod = diff / (float)USECS_PER_SECOND; // same as 1/instantaneousFps but easier for compiler to optimize
+    //const float actualPeriod = diff / (float)USECS_PER_SECOND; // same as 1/instantaneousFps but easier for compiler to optimize
     // Note that _lastPaintWait (stored at end of last call) is for the same paint cycle.
-    float deducedNonVSyncPeriod = actualPeriod - _lastPaintWait + _marginForDeducedFramePeriod; // plus a some non-zero time for machinery we can't measure
+    float deducedNonVSyncPeriod = (float) getActiveDisplayPlugin()->getLastSynchronizedElapsed() / (float) MSECS_PER_SECOND; /*actualPeriod - _lastPaintWait + _marginForDeducedFramePeriod; // plus a some non-zero time for machinery we can't measure
     // We don't know how much time to allow for that, but if we went over the target period, we know it's at least the portion
     // of paintWait up to the next vSync. This gives us enough of a penalty so that when actualPeriod crosses two cycles,
     // the key part (and not an exagerated part) of _lastPaintWait is accounted for.
@@ -1136,7 +1136,7 @@ void Application::paintGL() {
     if (_lastPaintWait > EPSILON && actualPeriod > targetPeriod) {
         // Don't use C++ remainder(). It's authors are mathematically insane.
         deducedNonVSyncPeriod += fmod(actualPeriod, _lastPaintWait);
-    }
+    }*/
     _lastDeducedNonVSyncFps = 1.0f / deducedNonVSyncPeriod;
     _lastInstantaneousFps = instantaneousFps;
 
@@ -1375,6 +1375,7 @@ void Application::paintGL() {
     }
 
     // deliver final composited scene to the display plugin
+    uint64_t displayStart = usecTimestampNow();
     {
         PROFILE_RANGE(__FUNCTION__ "/pluginOutput");
         PerformanceTimer perfTimer("pluginOutput");
@@ -1396,7 +1397,6 @@ void Application::paintGL() {
         Q_ASSERT(!_lockedFramebufferMap.contains(finalTexture));
         _lockedFramebufferMap[finalTexture] = scratchFramebuffer;
 
-        uint64_t displayStart = usecTimestampNow();
         Q_ASSERT(QOpenGLContext::currentContext() == _offscreenContext->getContext());
         {
             PROFILE_RANGE(__FUNCTION__ "/pluginSubmitScene");
@@ -1404,10 +1404,6 @@ void Application::paintGL() {
             displayPlugin->submitSceneTexture(_frameCount, finalTexture, toGlm(size));
         }
         Q_ASSERT(QOpenGLContext::currentContext() == _offscreenContext->getContext());
-
-        uint64_t displayEnd = usecTimestampNow();
-        const float displayPeriodUsec = (float)(displayEnd - displayStart); // usecs
-        _lastPaintWait = displayPeriodUsec / (float)USECS_PER_SECOND;
     }
 
     {
@@ -1418,6 +1414,9 @@ void Application::paintGL() {
             batch.resetStages();
         });
     }
+    uint64_t displayEnd = usecTimestampNow();
+    const float displayPeriodUsec = (float)(displayEnd - displayStart); // usecs
+    _lastPaintWait = displayPeriodUsec / (float)USECS_PER_SECOND;
 }
 
 void Application::runTests() {

From 17ecf9b6b70e027ecd9656bbea59418bfbc029ec Mon Sep 17 00:00:00 2001
From: Howard Stearns <howard@highfidelity.io>
Date: Mon, 7 Dec 2015 11:26:56 -0800
Subject: [PATCH 04/11] debugging

---
 interface/src/avatar/AvatarManager.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 7aa5073921..35b5db7946 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -111,7 +111,7 @@ void AvatarManager::init() {
     _renderDistanceController.setKP(0.0008f); // Usually about 0.6 of largest that doesn't oscillate when other parameters 0.
     _renderDistanceController.setKI(0.0006f); // Big enough to bring us to target with the above KP.
     _renderDistanceController.setKD(0.000001f); // A touch of kd increases the speed by which we get there.
-
+    a_renderDistanceController.setHistorySize("av", 240); //FIXME
 }
 
 void AvatarManager::updateMyAvatar(float deltaTime) {
@@ -152,7 +152,7 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     // goes up, the render cutoff distance gets closer, the number of rendered avatars is less, and frame rate
     // goes up.
     const float deduced = qApp->getLastDeducedNonVSyncFps();
-    const float distance = 1.0f / _renderDistanceController.update(deduced, deltaTime);
+    const float distance = 1.0f / _renderDistanceController.update(deduced, deltaTime, false, qApp->getLastPaintWait(), qApp->getLastInstanteousFps());
     _renderDistanceAverage.updateAverage(distance);
     _renderDistance = _renderDistanceAverage.getAverage();
     int renderableCount = 0;

From 2974241796d847e1a5c13fa7ab54d50918d04a93 Mon Sep 17 00:00:00 2001
From: howard-stearns <howard.stearns@gmail.com>
Date: Mon, 7 Dec 2015 15:49:29 -0800
Subject: [PATCH 05/11] typo

---
 interface/src/avatar/AvatarManager.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 35b5db7946..0f96ca9af0 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -111,7 +111,7 @@ void AvatarManager::init() {
     _renderDistanceController.setKP(0.0008f); // Usually about 0.6 of largest that doesn't oscillate when other parameters 0.
     _renderDistanceController.setKI(0.0006f); // Big enough to bring us to target with the above KP.
     _renderDistanceController.setKD(0.000001f); // A touch of kd increases the speed by which we get there.
-    a_renderDistanceController.setHistorySize("av", 240); //FIXME
+    _renderDistanceController.setHistorySize("av", 240); //FIXME
 }
 
 void AvatarManager::updateMyAvatar(float deltaTime) {

From b007617c8555dca32206fe1c69f26abfd2fe6b13 Mon Sep 17 00:00:00 2001
From: howard-stearns <howard.stearns@gmail.com>
Date: Mon, 7 Dec 2015 16:56:59 -0800
Subject: [PATCH 06/11] Remove unneeded DisplayPlugin stuff.

---
 .../src/display-plugins/OpenGLDisplayPlugin.cpp             | 6 ------
 .../src/display-plugins/OpenGLDisplayPlugin.h               | 4 ----
 2 files changed, 10 deletions(-)

diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
index b010414396..8e02077600 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
@@ -151,7 +151,6 @@ OpenGLDisplayPlugin::OpenGLDisplayPlugin() {
         _container->releaseOverlayTexture(texture);
     });
 
-    _synchronizedTimer.start();
     connect(&_timer, &QTimer::timeout, this, [&] {
 #ifdef Q_OS_MAC
         // On Mac, QT thread timing is such that we can miss one or even two cycles quite often, giving a render rate (including update/simulate)
@@ -161,7 +160,6 @@ OpenGLDisplayPlugin::OpenGLDisplayPlugin() {
 #else
         if (_active && _sceneTextureEscrow.depth() < 1) {
 #endif
-            _synchronizedTimer.start();
             emit requestRender();
         }
     });
@@ -283,10 +281,6 @@ void OpenGLDisplayPlugin::submitOverlayTexture(GLuint sceneTexture, const glm::u
 }
 
 void OpenGLDisplayPlugin::updateTextures() {
-    const qint64 elapsed =_synchronizedTimer.elapsed();
-    if (elapsed != 0) {
-        _lastSynchronizedElapsed = elapsed;
-    }
     _currentSceneTexture = _sceneTextureEscrow.fetchAndRelease(_currentSceneTexture);
     _currentOverlayTexture = _overlayTextureEscrow.fetchAndRelease(_currentOverlayTexture);
 }
diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
index 4577777034..ef78374994 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
@@ -10,7 +10,6 @@
 #include "DisplayPlugin.h"
 
 #include <QtCore/QTimer>
-#include <QElapsedTimer>
 
 #include <GLMHelpers.h>
 #include <SimpleMovingAverage.h>
@@ -31,7 +30,6 @@ public:
     virtual void submitSceneTexture(uint32_t frameIndex, uint32_t sceneTexture, const glm::uvec2& sceneSize) override;
     virtual void submitOverlayTexture(uint32_t overlayTexture, const glm::uvec2& overlaySize) override;
     virtual float presentRate() override;
-    virtual qint64 getLastSynchronizedElapsed() { return _lastSynchronizedElapsed; }
 
     virtual glm::uvec2 getRecommendedRenderSize() const override {
         return getSurfacePixels();
@@ -70,8 +68,6 @@ protected:
     virtual void internalPresent();
 
     mutable QTimer _timer;
-    QElapsedTimer _synchronizedTimer;
-    qint64 _lastSynchronizedElapsed { 0 };
     ProgramPtr _program;
     ShapeWrapperPtr _plane;
 

From 9512c3f73da0033a6c094606bd6bb824c60e4b7f Mon Sep 17 00:00:00 2001
From: howard-stearns <howard.stearns@gmail.com>
Date: Mon, 7 Dec 2015 16:58:59 -0800
Subject: [PATCH 07/11]  Debugging.  Please enter the commit message for your
 changes. Lines starting

---
 interface/src/Application.cpp          | 19 +++++++++----------
 interface/src/Application.h            |  1 +
 interface/src/avatar/Avatar.cpp        |  4 ++--
 interface/src/avatar/AvatarManager.cpp | 21 +++++++++++++++++----
 libraries/shared/src/PIDController.cpp |  2 +-
 5 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 6e4f3de649..521921faea 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -1117,6 +1117,8 @@ void Application::paintGL() {
     _inPaint = true;
     Finally clearFlagLambda([this] { _inPaint = false; });
 
+    _lastPaintWait = (float)(now - _paintWaitStart) / (float)USECS_PER_SECOND;
+    _lastInstantaneousFps = instantaneousFps;
     // Some LOD-like controls need to know a smoothly varying "potential" frame rate that doesn't
     // include time waiting for vsync, and which can report a number above target if we've got the headroom.
     // For example, if we're shooting for 75fps and paintWait is 3.3333ms (= 75% * 13.33ms), our deducedNonVSyncFps
@@ -1126,20 +1128,20 @@ void Application::paintGL() {
     // Time between previous paintGL call and this one, which can vary not only with vSync misses, but also with QT timing.
     // We're using this as a proxy for the time between vsync and displayEnd, below. (Not exact, but tends to be the same over time.)
     // This is not the same as update(deltaTime), because the latter attempts to throttle to 60hz and also clamps to 1/4 second.
-    //const float actualPeriod = diff / (float)USECS_PER_SECOND; // same as 1/instantaneousFps but easier for compiler to optimize
+/*    const float actualPeriod = diff / (float)USECS_PER_SECOND; // same as 1/instantaneousFps but easier for compiler to optimize
     // Note that _lastPaintWait (stored at end of last call) is for the same paint cycle.
-    float deducedNonVSyncPeriod = (float) getActiveDisplayPlugin()->getLastSynchronizedElapsed() / (float) MSECS_PER_SECOND; /*actualPeriod - _lastPaintWait + _marginForDeducedFramePeriod; // plus a some non-zero time for machinery we can't measure
+    float deducedNonVSyncPeriod = actualPeriod - _lastPaintWait + _marginForDeducedFramePeriod; // plus a some non-zero time for machinery we can't measure
     // We don't know how much time to allow for that, but if we went over the target period, we know it's at least the portion
     // of paintWait up to the next vSync. This gives us enough of a penalty so that when actualPeriod crosses two cycles,
     // the key part (and not an exagerated part) of _lastPaintWait is accounted for.
     const float targetPeriod = getTargetFramePeriod();
     if (_lastPaintWait > EPSILON && actualPeriod > targetPeriod) {
         // Don't use C++ remainder(). It's authors are mathematically insane.
-        deducedNonVSyncPeriod += fmod(actualPeriod, _lastPaintWait);
-    }*/
+        deducedNonVSyncPeriod += fmod(targetPeriod, _lastPaintWait);
+    }
     _lastDeducedNonVSyncFps = 1.0f / deducedNonVSyncPeriod;
-    _lastInstantaneousFps = instantaneousFps;
-
+    */
+ 
     auto displayPlugin = getActiveDisplayPlugin();
     // FIXME not needed anymore?
     _offscreenContext->makeCurrent();
@@ -1375,7 +1377,6 @@ void Application::paintGL() {
     }
 
     // deliver final composited scene to the display plugin
-    uint64_t displayStart = usecTimestampNow();
     {
         PROFILE_RANGE(__FUNCTION__ "/pluginOutput");
         PerformanceTimer perfTimer("pluginOutput");
@@ -1415,9 +1416,7 @@ void Application::paintGL() {
             batch.resetStages();
         });
     }
-    uint64_t displayEnd = usecTimestampNow();
-    const float displayPeriodUsec = (float)(displayEnd - displayStart); // usecs
-    _lastPaintWait = displayPeriodUsec / (float)USECS_PER_SECOND;
+    _paintWaitStart = usecTimestampNow();
 }
 
 void Application::runTests() {
diff --git a/interface/src/Application.h b/interface/src/Application.h
index ce33f051ef..197d9a7a60 100644
--- a/interface/src/Application.h
+++ b/interface/src/Application.h
@@ -443,6 +443,7 @@ private:
     QElapsedTimer _lastTimeUpdated;
     float _lastInstantaneousFps { 0.0f };
     float _lastPaintWait { 0.0f };
+    uint64_t _paintWaitStart { 0 };
     float _lastDeducedNonVSyncFps { 0.0f };
     float _marginForDeducedFramePeriod{ 0.002f }; // 2ms, adjustable
 
diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 2c8d970336..4558e6046d 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -174,14 +174,14 @@ void Avatar::simulate(float deltaTime) {
             _shouldSkipRender = false;
             _skeletonModel.setVisibleInScene(true, qApp->getMain3DScene());
             if (!isControllerLogging) {  // Test for isMyAvatar is prophylactic. Never occurs in current code.
-                qCDebug(interfaceapp) << "Rerendering" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for distance" << renderDistance;
+                //qCDebug(interfaceapp) << "Rerendering" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for distance" << renderDistance;
             }
         }
     } else if (distance > renderDistance * (1.0f + SKIP_HYSTERESIS_PROPORTION)) {
         _shouldSkipRender = true;
         _skeletonModel.setVisibleInScene(false, qApp->getMain3DScene());
         if (!isControllerLogging) {
-            qCDebug(interfaceapp) << "Unrendering" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for distance" << renderDistance;
+            //qCDebug(interfaceapp) << "Unrendering" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for distance" << renderDistance;
         }
     }
 
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index ba483a80ca..0b5551555c 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -111,7 +111,7 @@ void AvatarManager::init() {
     _renderDistanceController.setKP(0.0008f); // Usually about 0.6 of largest that doesn't oscillate when other parameters 0.
     _renderDistanceController.setKI(0.0006f); // Big enough to bring us to target with the above KP.
     _renderDistanceController.setKD(0.000001f); // A touch of kd increases the speed by which we get there.
-    _renderDistanceController.setHistorySize("av", 240); //FIXME
+    //_renderDistanceController.setHistorySize("av", 240); //FIXME
 }
 
 void AvatarManager::updateMyAvatar(float deltaTime) {
@@ -130,7 +130,7 @@ void AvatarManager::updateMyAvatar(float deltaTime) {
         _lastSendAvatarDataTime = now;
     }
 }
-
+#include "InterfaceLogging.h"
 void AvatarManager::updateOtherAvatars(float deltaTime) {
     // lock the hash for read to check the size
     QReadLocker lock(&_hashLock);
@@ -151,8 +151,21 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     // The measured value is frame rate. When the controlled value (1 / render cutoff distance)
     // goes up, the render cutoff distance gets closer, the number of rendered avatars is less, and frame rate
     // goes up.
-    const float deduced = qApp->getLastDeducedNonVSyncFps();
-    const float distance = 1.0f / _renderDistanceController.update(deduced, deltaTime, false, qApp->getLastPaintWait(), qApp->getLastInstanteousFps());
+    const float targetFps = 60.0f;
+    const float instantaneousFps = qApp->getLastInstanteousFps();
+    const float paintWait = qApp->getLastPaintWait();
+    const float actual = 1.0f / instantaneousFps;
+    const float firstAdjusted = actual - paintWait + 0.002f;
+    const float machinery = (paintWait > 0.0001f) ? fmod(1.0f / targetFps, paintWait) : 0.0f;
+    const float secondAdjusted = firstAdjusted + machinery;
+    const float deduced = 1.0f / secondAdjusted;
+    qCDebug(interfaceapp) << "dump " << instantaneousFps << (1000.0f * paintWait)
+        << "(" << paintWait << actual
+        << "(" << firstAdjusted << machinery << secondAdjusted
+        << ")" << deduced << ")";
+
+    //const float deduced = qApp->getLastDeducedNonVSyncFps();
+    const float distance = 1.0f / _renderDistanceController.update(deduced, deltaTime, false, paintWait, instantaneousFps);
     _renderDistanceAverage.updateAverage(distance);
     _renderDistance = _renderDistanceAverage.getAverage();
     int renderableCount = 0;
diff --git a/libraries/shared/src/PIDController.cpp b/libraries/shared/src/PIDController.cpp
index 36c670e66d..3607c281ec 100644
--- a/libraries/shared/src/PIDController.cpp
+++ b/libraries/shared/src/PIDController.cpp
@@ -70,7 +70,7 @@ void PIDController::reportHistory() {
     for (int i = 0; i < _history.size(); i++) {
         Row& row = _history[i];
         qCDebug(shared) << row.measured << row.dt <<
-        row.fixme1 << row.fixme2 <<
+        (row.fixme1 * 1000.0f) << (row.fixme2) <<
             "||" << row.error << row.accumulated << row.changed <<
             "||" << row.p << row.i << row.d << row.computed << 1.0f/row.computed;
     }

From faec4639b1d8b93f090799b80f084f8f7ac0fc25 Mon Sep 17 00:00:00 2001
From: Howard Stearns <howard@highfidelity.io>
Date: Tue, 8 Dec 2015 09:14:40 -0800
Subject: [PATCH 08/11] cap

---
 interface/src/avatar/AvatarManager.cpp | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 0b5551555c..b101c106a2 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -111,7 +111,7 @@ void AvatarManager::init() {
     _renderDistanceController.setKP(0.0008f); // Usually about 0.6 of largest that doesn't oscillate when other parameters 0.
     _renderDistanceController.setKI(0.0006f); // Big enough to bring us to target with the above KP.
     _renderDistanceController.setKD(0.000001f); // A touch of kd increases the speed by which we get there.
-    //_renderDistanceController.setHistorySize("av", 240); //FIXME
+    _renderDistanceController.setHistorySize("av", 240); //FIXME
 }
 
 void AvatarManager::updateMyAvatar(float deltaTime) {
@@ -155,17 +155,23 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     const float instantaneousFps = qApp->getLastInstanteousFps();
     const float paintWait = qApp->getLastPaintWait();
     const float actual = 1.0f / instantaneousFps;
-    const float firstAdjusted = actual - paintWait + 0.002f;
-    const float machinery = (paintWait > 0.0001f) ? fmod(1.0f / targetFps, paintWait) : 0.0f;
+    const float target = 1.0f / targetFps;
+    const float firstAdjusted = actual - paintWait /*+ 0.002f*/;
+    const float machinery = (paintWait > target) ? fmod(paintWait, target) : 0.0f;
     const float secondAdjusted = firstAdjusted + machinery;
     const float deduced = 1.0f / secondAdjusted;
-    qCDebug(interfaceapp) << "dump " << instantaneousFps << (1000.0f * paintWait)
+    const float modulus = (instantaneousFps >= targetFps) ?
+                            (1.0f + floor(instantaneousFps / targetFps)) :
+                            (1.0f / floor(targetFps / instantaneousFps));
+    const float cap = modulus * targetFps;
+    const float capped = glm::min(cap, deduced);
+    /*qCDebug(interfaceapp) << "dump " << instantaneousFps << (1000.0f * paintWait)
         << "(" << paintWait << actual
         << "(" << firstAdjusted << machinery << secondAdjusted
-        << ")" << deduced << ")";
+        << ")" << deduced << ")";*/
 
     //const float deduced = qApp->getLastDeducedNonVSyncFps();
-    const float distance = 1.0f / _renderDistanceController.update(deduced, deltaTime, false, paintWait, instantaneousFps);
+    const float distance = 1.0f / _renderDistanceController.update(capped, deltaTime, false, paintWait, instantaneousFps);
     _renderDistanceAverage.updateAverage(distance);
     _renderDistance = _renderDistanceAverage.getAverage();
     int renderableCount = 0;

From 5b41d4da1caae89d6517c2d6641405994cb7b0c0 Mon Sep 17 00:00:00 2001
From: howard-stearns <howard.stearns@gmail.com>
Date: Tue, 8 Dec 2015 15:30:23 -0800
Subject: [PATCH 09/11] Snapshot of "working" version.

---
 interface/src/Application.cpp                   |  9 +++++++--
 interface/src/avatar/AvatarManager.cpp          | 17 +++++++----------
 .../src/display-plugins/OpenGLDisplayPlugin.cpp |  3 ++-
 .../src/display-plugins/OpenGLDisplayPlugin.h   |  3 +++
 libraries/plugins/src/plugins/DisplayPlugin.h   |  2 +-
 5 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 1718389a5f..9de395dc57 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -1086,6 +1086,7 @@ void Application::paintGL() {
 
     // update fps moving average
     uint64_t now = usecTimestampNow();
+    qint64 sinceSync = getActiveDisplayPlugin()->getTimeSinceSync();
     static uint64_t lastPaintBegin{ now };
     uint64_t diff = now - lastPaintBegin;
     float instantaneousFps = 0.0f;
@@ -1122,8 +1123,8 @@ void Application::paintGL() {
     _inPaint = true;
     Finally clearFlagLambda([this] { _inPaint = false; });
 
-    _lastPaintWait = (float)(now - _paintWaitStart) / (float)USECS_PER_SECOND;
-    _lastInstantaneousFps = instantaneousFps;
+    //_lastPaintWait = (float)(now - _paintWaitStart) / (float)USECS_PER_SECOND;
+    //_lastInstantaneousFps = instantaneousFps;
     // Some LOD-like controls need to know a smoothly varying "potential" frame rate that doesn't
     // include time waiting for vsync, and which can report a number above target if we've got the headroom.
     // For example, if we're shooting for 75fps and paintWait is 3.3333ms (= 75% * 13.33ms), our deducedNonVSyncFps
@@ -1422,6 +1423,10 @@ void Application::paintGL() {
         });
     }
     _paintWaitStart = usecTimestampNow();
+    _lastPaintWait = (float)sinceSync / (float)MSECS_PER_SECOND;
+    _lastInstantaneousFps = instantaneousFps;
+    _lastDeducedNonVSyncFps = 1.0f / (((_paintWaitStart - now) / (float)USECS_PER_SECOND) + ((float)sinceSync / (float)MSECS_PER_SECOND));
+   // qCDebug(interfaceapp) << "pw/now/sync" << _paintWaitStart << now << sinceSync << "period" << (((_paintWaitStart - now) / (float)USECS_PER_SECOND) + ((float)sinceSync / (float)MSECS_PER_SECOND)) << "hz" << _lastDeducedNonVSyncFps;
 }
 
 void Application::runTests() {
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index b101c106a2..c0485bdebb 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -154,24 +154,21 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     const float targetFps = 60.0f;
     const float instantaneousFps = qApp->getLastInstanteousFps();
     const float paintWait = qApp->getLastPaintWait();
-    const float actual = 1.0f / instantaneousFps;
+    const float deduced = qApp->getLastDeducedNonVSyncFps();
+    /*const float actual = 1.0f / instantaneousFps;
     const float target = 1.0f / targetFps;
-    const float firstAdjusted = actual - paintWait /*+ 0.002f*/;
-    const float machinery = (paintWait > target) ? fmod(paintWait, target) : 0.0f;
-    const float secondAdjusted = firstAdjusted + machinery;
-    const float deduced = 1.0f / secondAdjusted;
     const float modulus = (instantaneousFps >= targetFps) ?
-                            (1.0f + floor(instantaneousFps / targetFps)) :
-                            (1.0f / floor(targetFps / instantaneousFps));
+            (1.0f + floor(instantaneousFps / targetFps)) :
+            (1.0f / floor(targetFps / instantaneousFps));
     const float cap = modulus * targetFps;
-    const float capped = glm::min(cap, deduced);
+    const float deduced = instantaneousFps + ((cap - instantaneousFps) * (paintWait / target));*/
     /*qCDebug(interfaceapp) << "dump " << instantaneousFps << (1000.0f * paintWait)
         << "(" << paintWait << actual
         << "(" << firstAdjusted << machinery << secondAdjusted
-        << ")" << deduced << ")";*/
+        << ")" << deduced << modulus << cap << capped << ")";*/
 
     //const float deduced = qApp->getLastDeducedNonVSyncFps();
-    const float distance = 1.0f / _renderDistanceController.update(capped, deltaTime, false, paintWait, instantaneousFps);
+    const float distance = 1.0f / _renderDistanceController.update(deduced, deltaTime, false, paintWait, instantaneousFps);
     _renderDistanceAverage.updateAverage(distance);
     _renderDistance = _renderDistanceAverage.getAverage();
     int renderableCount = 0;
diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
index 9a0db0ad97..b59ac24b52 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
@@ -168,8 +168,9 @@ OpenGLDisplayPlugin::OpenGLDisplayPlugin() {
         // This is likely to be mooted by further planned changes.
         if (_active && _sceneTextureEscrow.depth() <= 1) {
 #else
-        if (_active && _sceneTextureEscrow.depth() < 1) {
+        if (_active && _sceneTextureEscrow.depth() <= 1) {
 #endif
+            _sinceSync.start();
             emit requestRender();
         }
     });
diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
index ef78374994..4231c8ff7f 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
@@ -10,6 +10,7 @@
 #include "DisplayPlugin.h"
 
 #include <QtCore/QTimer>
+#include <QElapsedTimer.h>
 
 #include <GLMHelpers.h>
 #include <SimpleMovingAverage.h>
@@ -40,6 +41,7 @@ public:
     }
 
     virtual QImage getScreenshot() const override;
+    virtual quint64 getTimeSinceSync() { return _sinceSync.elapsed(); }
 
 protected:
     friend class PresentThread;
@@ -82,6 +84,7 @@ protected:
     GLTextureEscrow _sceneTextureEscrow;
 
     bool _vsyncSupported { false };
+    QElapsedTimer _sinceSync;
 };
 
 
diff --git a/libraries/plugins/src/plugins/DisplayPlugin.h b/libraries/plugins/src/plugins/DisplayPlugin.h
index 6fc6062214..c2e10dcc02 100644
--- a/libraries/plugins/src/plugins/DisplayPlugin.h
+++ b/libraries/plugins/src/plugins/DisplayPlugin.h
@@ -58,7 +58,7 @@ public:
     /// By default, all HMDs are stereo
     virtual bool isStereo() const { return isHmd(); }
     virtual bool isThrottled() const { return false; }
-    virtual qint64 getLastSynchronizedElapsed() { return 0; }
+    virtual quint64 getTimeSinceSync() { return 0; }
 
     // Rendering support
 

From 32e4967ee0a66e8b2f9eba8a06e53b5d553b0d19 Mon Sep 17 00:00:00 2001
From: howard-stearns <howard.stearns@gmail.com>
Date: Tue, 8 Dec 2015 16:38:05 -0800
Subject: [PATCH 10/11] cleanup

---
 interface/src/Application.cpp                 | 37 ++++---------------
 interface/src/Application.h                   | 10 +----
 interface/src/avatar/Avatar.cpp               |  4 +-
 interface/src/avatar/AvatarManager.cpp        | 23 ++----------
 .../display-plugins/OpenGLDisplayPlugin.cpp   |  3 +-
 .../src/display-plugins/OpenGLDisplayPlugin.h |  3 --
 libraries/plugins/src/plugins/DisplayPlugin.h |  1 -
 libraries/shared/src/PIDController.cpp        |  8 ++--
 libraries/shared/src/PIDController.h          |  5 +--
 9 files changed, 20 insertions(+), 74 deletions(-)

diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index f56231ada8..78882342df 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -1086,7 +1086,6 @@ void Application::paintGL() {
 
     // update fps moving average
     uint64_t now = usecTimestampNow();
-    qint64 sinceSync = getActiveDisplayPlugin()->getTimeSinceSync();
     static uint64_t lastPaintBegin{ now };
     uint64_t diff = now - lastPaintBegin;
     float instantaneousFps = 0.0f;
@@ -1123,31 +1122,6 @@ void Application::paintGL() {
     _inPaint = true;
     Finally clearFlagLambda([this] { _inPaint = false; });
 
-    //_lastPaintWait = (float)(now - _paintWaitStart) / (float)USECS_PER_SECOND;
-    //_lastInstantaneousFps = instantaneousFps;
-    // Some LOD-like controls need to know a smoothly varying "potential" frame rate that doesn't
-    // include time waiting for vsync, and which can report a number above target if we've got the headroom.
-    // For example, if we're shooting for 75fps and paintWait is 3.3333ms (= 75% * 13.33ms), our deducedNonVSyncFps
-    // would be 100fps. In principle, a paintWait of zero would have deducedNonVSyncFps=75.
-    // Here we make a guess for deducedNonVSyncFps = 1 / deducedNonVSyncPeriod.
-    //
-    // Time between previous paintGL call and this one, which can vary not only with vSync misses, but also with QT timing.
-    // We're using this as a proxy for the time between vsync and displayEnd, below. (Not exact, but tends to be the same over time.)
-    // This is not the same as update(deltaTime), because the latter attempts to throttle to 60hz and also clamps to 1/4 second.
-/*    const float actualPeriod = diff / (float)USECS_PER_SECOND; // same as 1/instantaneousFps but easier for compiler to optimize
-    // Note that _lastPaintWait (stored at end of last call) is for the same paint cycle.
-    float deducedNonVSyncPeriod = actualPeriod - _lastPaintWait + _marginForDeducedFramePeriod; // plus a some non-zero time for machinery we can't measure
-    // We don't know how much time to allow for that, but if we went over the target period, we know it's at least the portion
-    // of paintWait up to the next vSync. This gives us enough of a penalty so that when actualPeriod crosses two cycles,
-    // the key part (and not an exagerated part) of _lastPaintWait is accounted for.
-    const float targetPeriod = getTargetFramePeriod();
-    if (_lastPaintWait > EPSILON && actualPeriod > targetPeriod) {
-        // Don't use C++ remainder(). It's authors are mathematically insane.
-        deducedNonVSyncPeriod += fmod(targetPeriod, _lastPaintWait);
-    }
-    _lastDeducedNonVSyncFps = 1.0f / deducedNonVSyncPeriod;
-    */
- 
     auto displayPlugin = getActiveDisplayPlugin();
     // FIXME not needed anymore?
     _offscreenContext->makeCurrent();
@@ -1422,11 +1396,14 @@ void Application::paintGL() {
             batch.resetStages();
         });
     }
-    _paintWaitStart = usecTimestampNow();
-    _lastPaintWait = (float)sinceSync / (float)MSECS_PER_SECOND;
+
+    // Some LOD-like controls need to know a smoothly varying "potential" frame rate that doesn't
+    // include time waiting for sync, and which can report a number above target if we've got the headroom.
+    // In my tests, the following is mostly less than 0.5ms, and never more than 3ms. I don't think its worth measuring during runtime.
+    static const float paintWaitAndQTTimerAllowance = 0.001; // seconds
+    // Store both values now for use by next cycle.
     _lastInstantaneousFps = instantaneousFps;
-    _lastDeducedNonVSyncFps = 1.0f / (((_paintWaitStart - now) / (float)USECS_PER_SECOND) + ((float)sinceSync / (float)MSECS_PER_SECOND));
-   // qCDebug(interfaceapp) << "pw/now/sync" << _paintWaitStart << now << sinceSync << "period" << (((_paintWaitStart - now) / (float)USECS_PER_SECOND) + ((float)sinceSync / (float)MSECS_PER_SECOND)) << "hz" << _lastDeducedNonVSyncFps;
+    _lastUnsynchronizedFps = 1.0f / (((usecTimestampNow() - now) / (float)USECS_PER_SECOND) + paintWaitAndQTTimerAllowance);
 }
 
 void Application::runTests() {
diff --git a/interface/src/Application.h b/interface/src/Application.h
index 197d9a7a60..17d609ee0c 100644
--- a/interface/src/Application.h
+++ b/interface/src/Application.h
@@ -163,11 +163,8 @@ public:
     float const HMD_TARGET_FRAME_RATE = 75.0f;
     float const DESKTOP_TARGET_FRAME_RATE = 60.0f;
     float getTargetFrameRate() { return isHMDMode() ? HMD_TARGET_FRAME_RATE : DESKTOP_TARGET_FRAME_RATE; }
-    float getTargetFramePeriod() { return isHMDMode() ? 1.0f / HMD_TARGET_FRAME_RATE : 1.0f / DESKTOP_TARGET_FRAME_RATE; } // same as 1/getTargetFrameRate, but w/compile-time division
     float getLastInstanteousFps() const { return _lastInstantaneousFps; }
-    float getLastPaintWait() const { return _lastPaintWait; };
-    float getLastDeducedNonVSyncFps() const { return _lastDeducedNonVSyncFps; }
-    void setMarginForDeducedFramePeriod(float newValue) { _marginForDeducedFramePeriod = newValue; }
+    float getLastUnsynchronizedFps() const { return _lastUnsynchronizedFps; }
 
     float getFieldOfView() { return _fieldOfView.get(); }
     void setFieldOfView(float fov);
@@ -442,10 +439,7 @@ private:
     QElapsedTimer _timerStart;
     QElapsedTimer _lastTimeUpdated;
     float _lastInstantaneousFps { 0.0f };
-    float _lastPaintWait { 0.0f };
-    uint64_t _paintWaitStart { 0 };
-    float _lastDeducedNonVSyncFps { 0.0f };
-    float _marginForDeducedFramePeriod{ 0.002f }; // 2ms, adjustable
+    float _lastUnsynchronizedFps { 0.0f };
 
     ShapeManager _shapeManager;
     PhysicalEntitySimulation _entitySimulation;
diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index e3b7cd5735..e2b92cc06f 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -174,14 +174,14 @@ void Avatar::simulate(float deltaTime) {
             _shouldSkipRender = false;
             _skeletonModel.setVisibleInScene(true, qApp->getMain3DScene());
             if (!isControllerLogging) {  // Test for isMyAvatar is prophylactic. Never occurs in current code.
-                //qCDebug(interfaceapp) << "Rerendering" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for distance" << renderDistance;
+                qCDebug(interfaceapp) << "Rerendering" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for distance" << renderDistance;
             }
         }
     } else if (distance > renderDistance * (1.0f + SKIP_HYSTERESIS_PROPORTION)) {
         _shouldSkipRender = true;
         _skeletonModel.setVisibleInScene(false, qApp->getMain3DScene());
         if (!isControllerLogging) {
-            //qCDebug(interfaceapp) << "Unrendering" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for distance" << renderDistance;
+            qCDebug(interfaceapp) << "Unrendering" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for distance" << renderDistance;
         }
     }
 
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index c0485bdebb..59af6b18df 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -111,7 +111,6 @@ void AvatarManager::init() {
     _renderDistanceController.setKP(0.0008f); // Usually about 0.6 of largest that doesn't oscillate when other parameters 0.
     _renderDistanceController.setKI(0.0006f); // Big enough to bring us to target with the above KP.
     _renderDistanceController.setKD(0.000001f); // A touch of kd increases the speed by which we get there.
-    _renderDistanceController.setHistorySize("av", 240); //FIXME
 }
 
 void AvatarManager::updateMyAvatar(float deltaTime) {
@@ -130,7 +129,7 @@ void AvatarManager::updateMyAvatar(float deltaTime) {
         _lastSendAvatarDataTime = now;
     }
 }
-#include "InterfaceLogging.h"
+
 void AvatarManager::updateOtherAvatars(float deltaTime) {
     // lock the hash for read to check the size
     QReadLocker lock(&_hashLock);
@@ -151,24 +150,8 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     // The measured value is frame rate. When the controlled value (1 / render cutoff distance)
     // goes up, the render cutoff distance gets closer, the number of rendered avatars is less, and frame rate
     // goes up.
-    const float targetFps = 60.0f;
-    const float instantaneousFps = qApp->getLastInstanteousFps();
-    const float paintWait = qApp->getLastPaintWait();
-    const float deduced = qApp->getLastDeducedNonVSyncFps();
-    /*const float actual = 1.0f / instantaneousFps;
-    const float target = 1.0f / targetFps;
-    const float modulus = (instantaneousFps >= targetFps) ?
-            (1.0f + floor(instantaneousFps / targetFps)) :
-            (1.0f / floor(targetFps / instantaneousFps));
-    const float cap = modulus * targetFps;
-    const float deduced = instantaneousFps + ((cap - instantaneousFps) * (paintWait / target));*/
-    /*qCDebug(interfaceapp) << "dump " << instantaneousFps << (1000.0f * paintWait)
-        << "(" << paintWait << actual
-        << "(" << firstAdjusted << machinery << secondAdjusted
-        << ")" << deduced << modulus << cap << capped << ")";*/
-
-    //const float deduced = qApp->getLastDeducedNonVSyncFps();
-    const float distance = 1.0f / _renderDistanceController.update(deduced, deltaTime, false, paintWait, instantaneousFps);
+    const float deduced = qApp->getLastUnsynchronizedFps();
+    const float distance = 1.0f / _renderDistanceController.update(deduced, deltaTime);
     _renderDistanceAverage.updateAverage(distance);
     _renderDistance = _renderDistanceAverage.getAverage();
     int renderableCount = 0;
diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
index b59ac24b52..9a0db0ad97 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.cpp
@@ -168,9 +168,8 @@ OpenGLDisplayPlugin::OpenGLDisplayPlugin() {
         // This is likely to be mooted by further planned changes.
         if (_active && _sceneTextureEscrow.depth() <= 1) {
 #else
-        if (_active && _sceneTextureEscrow.depth() <= 1) {
+        if (_active && _sceneTextureEscrow.depth() < 1) {
 #endif
-            _sinceSync.start();
             emit requestRender();
         }
     });
diff --git a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
index 4231c8ff7f..ef78374994 100644
--- a/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
+++ b/libraries/display-plugins/src/display-plugins/OpenGLDisplayPlugin.h
@@ -10,7 +10,6 @@
 #include "DisplayPlugin.h"
 
 #include <QtCore/QTimer>
-#include <QElapsedTimer.h>
 
 #include <GLMHelpers.h>
 #include <SimpleMovingAverage.h>
@@ -41,7 +40,6 @@ public:
     }
 
     virtual QImage getScreenshot() const override;
-    virtual quint64 getTimeSinceSync() { return _sinceSync.elapsed(); }
 
 protected:
     friend class PresentThread;
@@ -84,7 +82,6 @@ protected:
     GLTextureEscrow _sceneTextureEscrow;
 
     bool _vsyncSupported { false };
-    QElapsedTimer _sinceSync;
 };
 
 
diff --git a/libraries/plugins/src/plugins/DisplayPlugin.h b/libraries/plugins/src/plugins/DisplayPlugin.h
index c2e10dcc02..83afbc9402 100644
--- a/libraries/plugins/src/plugins/DisplayPlugin.h
+++ b/libraries/plugins/src/plugins/DisplayPlugin.h
@@ -58,7 +58,6 @@ public:
     /// By default, all HMDs are stereo
     virtual bool isStereo() const { return isHmd(); }
     virtual bool isThrottled() const { return false; }
-    virtual quint64 getTimeSinceSync() { return 0; }
 
     // Rendering support
 
diff --git a/libraries/shared/src/PIDController.cpp b/libraries/shared/src/PIDController.cpp
index 3607c281ec..78aa31e4c7 100644
--- a/libraries/shared/src/PIDController.cpp
+++ b/libraries/shared/src/PIDController.cpp
@@ -14,7 +14,7 @@
 #include "SharedLogging.h"
 #include "PIDController.h"
 
-float PIDController::update(float measuredValue, float dt, bool resetAccumulator, float fixme1, float fixme2) {
+float PIDController::update(float measuredValue, float dt, bool resetAccumulator) {
     const float error = getMeasuredValueSetpoint() - measuredValue;   // Sign is the direction we want measuredValue to go. Positive means go higher.
 
     const float p = getKP() * error; // term is Proportional to error
@@ -32,7 +32,7 @@ float PIDController::update(float measuredValue, float dt, bool resetAccumulator
         getControlledValueHighLimit());
 
     if (getIsLogging()) {  // if logging/reporting
-        updateHistory(measuredValue, dt, error, accumulatedError, changeInError, p, i, d, computedValue, fixme1, fixme2);
+        updateHistory(measuredValue, dt, error, accumulatedError, changeInError, p, i, d, computedValue);
     }
     Q_ASSERT(!isnan(computedValue));
     
@@ -43,7 +43,7 @@ float PIDController::update(float measuredValue, float dt, bool resetAccumulator
 }
 
 // Just for logging/reporting. Used when picking/verifying the operational parameters.
-void PIDController::updateHistory(float measuredValue, float dt, float error, float accumulatedError, float changeInError, float p, float i, float d, float computedValue, float fixme1, float fixme2) {
+void PIDController::updateHistory(float measuredValue, float dt, float error, float accumulatedError, float changeInError, float p, float i, float d, float computedValue) {
     // Don't report each update(), as the I/O messes with the results a lot.
     // Instead, add to history, and then dump out at once when full.
     // Typically, the first few values reported in each batch should be ignored.
@@ -59,7 +59,6 @@ void PIDController::updateHistory(float measuredValue, float dt, float error, fl
     next.i = i;
     next.d = d;
     next.computed = computedValue;
-    next.fixme1 = fixme1; next.fixme2 = fixme2;
     if (_history.size() == _history.capacity()) { // report when buffer is full
         reportHistory();
         _history.resize(0);
@@ -70,7 +69,6 @@ void PIDController::reportHistory() {
     for (int i = 0; i < _history.size(); i++) {
         Row& row = _history[i];
         qCDebug(shared) << row.measured << row.dt <<
-        (row.fixme1 * 1000.0f) << (row.fixme2) <<
             "||" << row.error << row.accumulated << row.changed <<
             "||" << row.p << row.i << row.d << row.computed << 1.0f/row.computed;
     }
diff --git a/libraries/shared/src/PIDController.h b/libraries/shared/src/PIDController.h
index 24e619b13b..0b2411530a 100644
--- a/libraries/shared/src/PIDController.h
+++ b/libraries/shared/src/PIDController.h
@@ -28,7 +28,7 @@ class PIDController {
 public:
     // These are the main interfaces:
     void setMeasuredValueSetpoint(float newValue) { _measuredValueSetpoint = newValue; }
-    float update(float measuredValue, float dt, bool resetAccumulator = false, float fixme1=0, float fixme2=0); // returns the new computedValue
+    float update(float measuredValue, float dt, bool resetAccumulator = false); // returns the new computedValue
     void setHistorySize(QString label = QString(""), int size = 0) { _history.reserve(size); _history.resize(0); _label = label; } // non-empty does logging
 
     bool getIsLogging() { return _history.capacity(); }
@@ -64,11 +64,10 @@ public:
         float i;
         float d;
         float computed;
-        float fixme1; float fixme2;
     };
 protected:
     void reportHistory();
-    void updateHistory(float measured, float dt, float error, float accumulatedError, float changeInErro, float p, float i, float d, float computedValue, float fixme1, float fixme2);
+    void updateHistory(float measured, float dt, float error, float accumulatedError, float changeInErro, float p, float i, float d, float computedValue);
     float _measuredValueSetpoint { 0.0f };
     float _controlledValueLowLimit { 0.0f };
     float _controlledValueHighLimit { std::numeric_limits<float>::max() };

From 270cfe8af7a63efebf603e908da887bb7fd32def Mon Sep 17 00:00:00 2001
From: Howard Stearns <howard@highfidelity.io>
Date: Wed, 9 Dec 2015 15:22:44 -0800
Subject: [PATCH 11/11] coding standards

---
 interface/src/Application.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 78882342df..a0842ca678 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -1400,7 +1400,7 @@ void Application::paintGL() {
     // Some LOD-like controls need to know a smoothly varying "potential" frame rate that doesn't
     // include time waiting for sync, and which can report a number above target if we've got the headroom.
     // In my tests, the following is mostly less than 0.5ms, and never more than 3ms. I don't think its worth measuring during runtime.
-    static const float paintWaitAndQTTimerAllowance = 0.001; // seconds
+    const float paintWaitAndQTTimerAllowance = 0.001f; // seconds
     // Store both values now for use by next cycle.
     _lastInstantaneousFps = instantaneousFps;
     _lastUnsynchronizedFps = 1.0f / (((usecTimestampNow() - now) / (float)USECS_PER_SECOND) + paintWaitAndQTTimerAllowance);