Implement hysteresis for setting monitor brightness

AdaptiveBrightness/AdaptiveBrightness.ui

@@ -60,6 +60,9 @@
              <layout class="QGridLayout" name="gridLayout_9">
               <item row="1" column="1">
                <widget class="QSlider" name="monitorMaxBrightnessSlider">
+                <property name="value">
+                 <number>50</number>
+                </property>
                 <property name="orientation">
                  <enum>Qt::Horizontal</enum>
                 </property>
@@ -74,6 +77,9 @@
               </item>
               <item row="0" column="1">
                <widget class="QSlider" name="monitorMinBrightnessSlider">
+                <property name="value">
+                 <number>50</number>
+                </property>
                 <property name="orientation">
                  <enum>Qt::Horizontal</enum>
                 </property>
@@ -117,6 +123,9 @@
              <layout class="QGridLayout" name="gridLayout_2">
               <item row="0" column="0">
                <widget class="QSlider" name="monitorBrightnessSlider">
+                <property name="value">
+                 <number>50</number>
+                </property>
                 <property name="orientation">
                  <enum>Qt::Horizontal</enum>
                 </property>
@@ -160,6 +169,9 @@
            </item>
            <item row="0" column="1">
             <widget class="QSlider" name="monitorOverallMinBrightnessSlider">
+             <property name="value">
+              <number>50</number>
+             </property>
              <property name="orientation">
               <enum>Qt::Horizontal</enum>
              </property>
@@ -184,6 +196,9 @@
            </item>
            <item row="1" column="1">
             <widget class="QSlider" name="monitorOverallMaxBrightnessSlider">
+             <property name="value">
+              <number>50</number>
+             </property>
              <property name="orientation">
               <enum>Qt::Horizontal</enum>
              </property>
@@ -243,6 +258,9 @@
           <layout class="QGridLayout" name="gridLayout">
            <item row="0" column="0">
             <widget class="QSlider" name="monitorOverallBrightnessSlider">
+             <property name="value">
+              <number>50</number>
+             </property>
              <property name="orientation">
               <enum>Qt::Horizontal</enum>
              </property>

AdaptiveBrightness/main_window.cpp

@@ -5,6 +5,7 @@
 
 #include <cmath>
 
+#include <QAbstractButton>
 #include <QCloseEvent>
 #include <QGroupBox>
 #include <QSlider>
@@ -18,7 +19,7 @@
 #include "sensor_driver.hpp"
 #include "utils.hpp"
 
-MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
+MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent), m_mtx(QMutex::RecursionMode::Recursive)
 {
     qDebug(ltr("Creating main window"));
 
@@ -28,6 +29,7 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
     enumMonitors();
 
     setupMonitorsTab();
+    setupSensorsTab();
 
     setupTrayIcon();
 
@@ -52,6 +54,8 @@ void MainWindow::closeEvent(QCloseEvent* event)
 
 void MainWindow::enumSensors()
 {
+    m_sensors.clear();
+
     auto sensors = enumerateSensors();
 
     for(auto& sensor: sensors) {
@@ -61,15 +65,20 @@ void MainWindow::enumSensors()
 
 void MainWindow::enumMonitors()
 {
+    m_mtx.lock();
+
     m_ui.monitorDropdown->clear();
+    m_monitors.clear();
 
     auto monitors = enumerateMonitors();
 
     for(auto& monitor: monitors) {
         const auto currentBrightness = monitor.getBrightness();
-        m_ui.monitorDropdown->addItem(monitor.getName());
         m_monitors.push_back({std::move(monitor), 0.f, 1.f, currentBrightness, false});
+        m_ui.monitorDropdown->addItem(m_monitors.back().driver.getName());
     }
+
+    m_mtx.unlock();
 }
 
 void MainWindow::loadIcons()
@@ -110,26 +119,16 @@ void MainWindow::loadIcons()
 void MainWindow::setupMonitorsTab()
 {
     connect(m_ui.monitorDropdown, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &MainWindow::updateCurrentMonitorGUI);
-
+    connect(m_ui.monitorEnumerateButton, &QAbstractButton::clicked, [this](bool) { enumMonitors(); });
-    m_ui.monitorBrightnessSlider->setDisabled(true);
+    connect(m_ui.monitorResetButton, &QAbstractButton::clicked, [this](bool) { resetAllMonitorSettings(); });
-    m_ui.monitorOverallBrightnessSlider->setDisabled(true);
-
-    m_ui.monitorOverrideCheck->setChecked(false);
-    connect(m_ui.monitorOverrideCheck, &QCheckBox::stateChanged,
-            [this](int state) { m_ui.monitorBrightnessSlider->setEnabled(state == Qt::CheckState::Checked); });
-
-    m_ui.monitorOverallOverrideCheck->setChecked(false);
-    connect(m_ui.monitorOverallOverrideCheck, &QCheckBox::stateChanged,
-            [this](int state) { m_ui.monitorOverallBrightnessSlider->setEnabled(state == Qt::CheckState::Checked); });
-
-    connect(m_ui.monitorBrightnessSlider, &QSlider::valueChanged, [this](int value) {
-        const auto newBrightness = utils::map(value, 0, 100, 0.f, 1.f);
-        qDebug(ltr("Overriding brightness with %1").arg(newBrightness));
-        m_brightness = newBrightness;
-    });
 
     setupLimitsSlider();
     setupOverallLimitsSlider();
+
+    setupBrightness();
+    setupOverallBrightness();
+
+    resetAllMonitorSettings();
 }
 
 void MainWindow::setupLimitsSlider()
@@ -141,7 +140,6 @@ void MainWindow::setupLimitsSlider()
         }
         const auto curIdx = m_ui.monitorDropdown->currentIndex();
         m_monitors[curIdx].minBrightness = utils::map(value, 0, 100, 0.f, 1.f);
-        updateCurrentMonitorGUI(curIdx);
     });
     connect(m_ui.monitorMaxBrightnessSlider, &QSlider::valueChanged, [this](int value) {
         m_ui.monitorMaxBrightnessValueLabel->setText(tr("%1%").arg(value, 3));
@@ -150,7 +148,6 @@ void MainWindow::setupLimitsSlider()
         }
         const auto curIdx = m_ui.monitorDropdown->currentIndex();
         m_monitors[curIdx].maxBrightness = utils::map(value, 0, 100, 0.f, 1.f);
-        updateCurrentMonitorGUI(curIdx);
     });
 }
 
@@ -178,6 +175,57 @@ void MainWindow::setupOverallLimitsSlider()
     });
 }
 
+void MainWindow::setupBrightness()
+{
+    m_ui.monitorBrightnessSlider->setDisabled(true);
+
+    connect(m_ui.monitorBrightnessSlider, &QSlider::valueChanged, [this](int value) {
+        m_ui.monitorBrightnessValueLabel->setText(tr("%1%").arg(value, 3));
+        const auto newBrightness = utils::map(value, 0, 100, 0.f, 1.f);
+        qDebug(ltr("Overriding brightness with %1").arg(newBrightness));
+        const auto curIdx = m_ui.monitorDropdown->currentIndex();
+        m_monitors[curIdx].brightness = newBrightness;
+    });
+
+    m_ui.monitorOverrideCheck->setChecked(false);
+    connect(m_ui.monitorOverrideCheck, &QCheckBox::stateChanged, [this](int state) {
+        m_ui.monitorBrightnessSlider->setEnabled(state == Qt::CheckState::Checked);
+        const auto curIdx = m_ui.monitorDropdown->currentIndex();
+        m_monitors[curIdx].manualOverride = state == Qt::CheckState::Checked;
+    });
+}
+
+void MainWindow::setupOverallBrightness()
+{
+    m_ui.monitorOverallBrightnessSlider->setDisabled(true);
+
+    connect(m_ui.monitorOverallBrightnessSlider, &QSlider::valueChanged, [this](int value) {
+        m_ui.monitorOverallBrightnessValueLabel->setText(tr("%1%").arg(value, 3));
+        const auto newBrightness = utils::map(value, 0, 100, 0.f, 1.f);
+        qDebug(ltr("Overriding overall brightness with %1").arg(newBrightness));
+        for(auto& monitor: m_monitors) {
+            if(monitor.manualOverride) {
+                monitor.brightness = newBrightness;
+            }
+        }
+        updateCurrentMonitorGUI(m_ui.monitorDropdown->currentIndex());
+    });
+
+    m_ui.monitorOverallOverrideCheck->setChecked(false);
+    connect(m_ui.monitorOverallOverrideCheck, &QCheckBox::stateChanged, [this](int state) {
+        m_ui.monitorOverallBrightnessSlider->setEnabled(state == Qt::CheckState::Checked);
+        for(auto& monitor: m_monitors) {
+            monitor.manualOverride = state == Qt::CheckState::Checked;
+        }
+        updateCurrentMonitorGUI(m_ui.monitorDropdown->currentIndex());
+    });
+}
+
+void MainWindow::setupSensorsTab()
+{
+    m_ui.tabs->removeTab(1);
+}
+
 void MainWindow::setupTrayIcon()
 {
     loadIcons();
@@ -229,26 +277,29 @@ void MainWindow::setupCallbackTimer()
     qDebug(ltr("Callback timer started"));
 }
 
+void MainWindow::resetAllMonitorSettings()
+{
+    m_ui.monitorOverallMinBrightnessSlider->setValue(0);
+    m_ui.monitorOverallMaxBrightnessSlider->setValue(100);
+    m_ui.monitorOverallOverrideCheck->setCheckState(Qt::CheckState::Unchecked);
+}
+
 void MainWindow::updateCurrentMonitorGUI(int index)
 {
-    const auto brightness = utils::map(m_monitors[index].brightness, 0.f, 1.f, 0, 100);
+    if(index == -1) {
-    const auto minimum = utils::map(m_monitors[index].minBrightness, 0.f, 1.f, 0, 100);
+        return;
-    const auto maximum = utils::map(m_monitors[index].maxBrightness, 0.f, 1.f, 0, 100);
+    }
-
-    m_ui.monitorMinBrightnessSlider->setValue(minimum);
-    m_ui.monitorMinBrightnessValueLabel->setText(QString("%1%").arg(minimum, 3));
-
-    m_ui.monitorMaxBrightnessSlider->setValue(maximum);
-    m_ui.monitorMaxBrightnessValueLabel->setText(QString("%1%").arg(maximum, 3));
-
-    m_ui.monitorBrightnessSlider->setValue(brightness);
-    m_ui.monitorBrightnessValueLabel->setText(QString("%1%").arg(brightness, 3));
 
+    m_ui.monitorMinBrightnessSlider->setValue(utils::map(m_monitors[index].minBrightness, 0.f, 1.f, 0, 100));
+    m_ui.monitorMaxBrightnessSlider->setValue(utils::map(m_monitors[index].maxBrightness, 0.f, 1.f, 0, 100));
+    m_ui.monitorBrightnessSlider->setValue(utils::map(m_monitors[index].brightness, 0.f, 1.f, 0, 100));
     m_ui.monitorOverrideCheck->setChecked(m_monitors[index].manualOverride);
 }
 
 void MainWindow::updateState()
 {
+    m_mtx.lock();
+
     qDebug(ltr("Updating state"));
 
     bool sensorError = false;
@@ -273,34 +324,22 @@ void MainWindow::updateState()
         return true;
     };
 
-    const auto setAllMonitorsBrightness = [this](float& brightness) {
+    auto brightness = NAN;
-        if(m_monitors.empty()) {
-            return false;
-        }
 
-        bool errorOccurred = false;
+    if(!getAverageSensorValue(brightness)) {
-        for(auto& monitor: m_monitors) {
-            if(!monitor.driver.setBrightness(brightness)) {
-                errorOccurred = true;
-            }
-        }
-        return !errorOccurred;
-    };
-
-    if(!getAverageSensorValue(m_brightness)) {
         enumSensors();
         qInfo(ltr("At least one sensor became invalid, re-enumerating sensors found %1 valid sensor(s)").arg(m_sensors.size()));
         sensorError = true;
     }
 
-    const auto iconBrightness = utils::map(m_brightness, 0.f, 1.f, size_t{0}, size_t{8});
+    if(!setMonitorBrightness(brightness)) {
-
-    if(!setAllMonitorsBrightness(m_brightness)) {
         enumMonitors();
         qInfo(ltr("At least one monitor became invalid, re-enumerating monitors found %1 valid monitor(s)").arg(m_monitors.size()));
         monitorError = true;
     }
 
+    const auto iconBrightness = utils::map(brightness, 0.f, 1.f, size_t{0}, size_t{8});
+
     if(!sensorError && !monitorError && m_trayIcon) {
         m_trayIcon->setIcon(*m_sensorStateIcons[iconBrightness]);
     }
@@ -312,10 +351,80 @@ void MainWindow::updateState()
     }
 
     if(m_trayIcon) {
-        m_trayIcon->setToolTip(tr("AdaptiveBrightness - %1%").arg(m_brightness * 100, 0, 'f', 0));
+        m_trayIcon->setToolTip(tr("AdaptiveBrightness - %1%").arg(brightness * 100, 0, 'f', 0));
     }
 
-    m_ui.monitorBrightnessSlider->setValue(utils::map(m_brightness, 0.f, 1.f, 0, 100));
+    m_mtx.unlock();
+}
+
+bool MainWindow::setMonitorBrightness(float& brightness)
+{
+    constexpr auto hysteresis = [](const auto& lowThreshold, const auto& highThreshold, const auto& currentValue, const auto& newValue) {
+        if(newValue > highThreshold || newValue < lowThreshold)
+            return newValue;
+        return currentValue;
+    };
+
+    if(m_monitors.empty()) {
+        return false;
+    }
+
+    bool errorOccurred = false;
+    bool allMonitorsSameBrightness = true;
+
+    for(size_t i = 0; i < m_monitors.size(); ++i) {
+        const auto updateMonitorBrightness = [&] {
+            const auto brightnessRange = m_monitors[i].maxBrightness - m_monitors[i].minBrightness;
+            const auto hysteresisDelta = m_monitors[i].manualOverride ? 0.f : m_monitors[i].HYSTERESIS_THRESHOLD * brightnessRange;
+            const auto lowThreshold = std::clamp(m_monitors[i].prevBrightness - hysteresisDelta, m_monitors[i].minBrightness, m_monitors[i].maxBrightness);
+            const auto highThreshold = std::clamp(m_monitors[i].prevBrightness + hysteresisDelta, m_monitors[i].minBrightness, m_monitors[i].maxBrightness);
+            if(hysteresis(lowThreshold, highThreshold, m_monitors[i].prevBrightness, m_monitors[i].brightness) != m_monitors[i].prevBrightness) {
+                qDebug(ltr("Setting monitor %1 brightness from %2 to %3")
+                           .arg(i)
+                           .arg(m_monitors[i].prevBrightness, 0, 'f', 2)
+                           .arg(m_monitors[i].brightness, 0, 'f', 2));
+                m_monitors[i].prevBrightness = m_monitors[i].brightness;
+                return m_monitors[i].driver.setBrightness(m_monitors[i].brightness);
+            }
+            else {
+                qDebug(ltr("Hysteresis prevented setting monitor %1 brightness from %2 to %3")
+                           .arg(i)
+                           .arg(m_monitors[i].prevBrightness, 0, 'f', 2)
+                           .arg(m_monitors[i].brightness, 0, 'f', 2));
+            }
+            return true;
+        };
+
+        if(!std::isnan(brightness) && !m_monitors[i].manualOverride) {
+            m_monitors[i].brightness = brightness;
+        }
+
+        m_monitors[i].brightness = std::clamp(m_monitors[i].brightness, m_monitors[i].minBrightness, m_monitors[i].maxBrightness);
+
+        if(i > 0 && m_monitors[i - 1].brightness != m_monitors[i].brightness) {
+            allMonitorsSameBrightness = false;
+        }
+
+        if(!updateMonitorBrightness()) {
+            errorOccurred = true;
+        }
+        else if(m_ui.monitorDropdown->currentIndex() == static_cast<int>(i)) {
+            updateCurrentMonitorGUI(static_cast<int>(i));
+        }
+    }
+
+    if(!errorOccurred) {
+        auto avgBrightness = 0.f;
+        std::for_each(m_monitors.begin(), m_monitors.end(), [&avgBrightness](const auto& mon) { avgBrightness += mon.brightness; });
+        avgBrightness /= m_monitors.size();
+        brightness = avgBrightness;
+    }
+
+    if(allMonitorsSameBrightness) {
+        m_ui.monitorOverallBrightnessSlider->setValue(utils::map(brightness, 0.f, 1.f, 0, 100));
+    }
+
+    return !errorOccurred;
 }
 
 void MainWindow::trayIconClicked(QSystemTrayIcon::ActivationReason reason)

AdaptiveBrightness/main_window.hpp

@@ -8,6 +8,7 @@
 #include <QIcon>
 #include <QMainWindow>
 #include <QMenu>
+#include <QMutex>
 #include <QSlider>
 #include <QSystemTrayIcon>
 #include <QThread>
@@ -36,14 +37,22 @@ class MainWindow : public QMainWindow {
     void setupMonitorsTab();
     void setupLimitsSlider();
     void setupOverallLimitsSlider();
+    void setupBrightness();
+    void setupOverallBrightness();
+
+    void setupSensorsTab();
 
     void setupTrayIcon();
     void setupCallbackTimer();
 
+    void resetAllMonitorSettings();
+
     void updateCurrentMonitorGUI(int index);
 
     void updateState();
 
+    bool setMonitorBrightness(float& brightness);
+
     void trayIconClicked(QSystemTrayIcon::ActivationReason reason);
 
     Ui::MainWindow m_ui;
@@ -59,18 +68,20 @@ class MainWindow : public QMainWindow {
 
     QThread* m_timerThread = nullptr;
     QTimer* m_timer = nullptr;
-
+    QMutex m_mtx;
-    float m_brightness = 0.5f;
 
     struct SensorData {
         Sensor driver;
     };
 
     struct MonitorData {
+        static constexpr auto HYSTERESIS_THRESHOLD = 0.05f;
+
         Monitor driver;
         float minBrightness;
         float maxBrightness;
         float brightness;
+        float prevBrightness;
         bool manualOverride;
     };
 

firmware/README.md

@@ -56,7 +56,7 @@ Found DFU: [0483:df11] ver=2200, devnum=57, cfg=1, intf=0, path="2-13.2.2", alt=
 Found DFU: [0483:df11] ver=2200, devnum=57, cfg=1, intf=0, path="2-13.2.2", alt=0, name="@Internal Flash  /0x08000000/032*0001Kg", serial="FFFFFFFEFFFF"
 ```
 
-The firmware can then be flashing using:
+The firmware can then be flashed using:
 
 ```console
 $ dfu-util -a 0 -s 0x08000000 -D AdaptiveBrightnessFirmware.bin