qt: Show emulated notification LED

src/citra_qt/CMakeLists.txt

@@ -174,6 +174,8 @@ add_library(citra_qt STATIC EXCLUDE_FROM_ALL
     multiplayer/state.cpp
     multiplayer/state.h
     multiplayer/validation.h
+    notification_led.cpp
+    notification_led.h
     precompiled_headers.h
     qt_image_interface.cpp
     qt_image_interface.h

src/citra_qt/citra_qt.cpp

@@ -352,6 +352,8 @@ GMainWindow::GMainWindow(Core::System& system_)
     Camera::RegisterFactory("image", std::make_unique<Camera::StillImageCameraFactory>());
     Camera::RegisterFactory("qt", std::make_unique<Camera::QtMultimediaCameraFactory>(qt_cameras));
 
+    system.RegisterInfoLEDColorChanged([this]() { emit InfoLEDColorChanged(); });
+
     LoadTranslation();
 
     Pica::g_debug_context = Pica::DebugContext::Construct();
@@ -606,6 +608,20 @@ void GMainWindow::InitializeWidgets() {
     statusBar()->addPermanentWidget(multiplayer_state->GetStatusText());
     statusBar()->addPermanentWidget(multiplayer_state->GetStatusIcon());
 
+    QFrame* sep = new QFrame(this);
+    sep->setFrameShape(QFrame::VLine);
+    sep->setFrameShadow(QFrame::Sunken);
+    sep->setFixedHeight(16);
+    statusBar()->addPermanentWidget(sep);
+
+    notification_led = new LedWidget();
+    notification_led->setToolTip(tr("Emulated notification LED"));
+    statusBar()->addPermanentWidget(notification_led);
+    connect(this, &GMainWindow::InfoLEDColorChanged, this, [this] {
+        auto led_color = system.GetInfoLEDColor();
+        notification_led->setColor(QColor(led_color.r(), led_color.g(), led_color.b()));
+    });
+
     statusBar()->setVisible(true);
 
     // Removes an ugly inner border from the status bar widgets under Linux
@@ -1600,6 +1616,7 @@ void GMainWindow::ShutdownGame() {
     emu_speed_label->setVisible(false);
     game_fps_label->setVisible(false);
     emu_frametime_label->setVisible(false);
+    notification_led->setColor(QColor(0, 0, 0));
 
     UpdateSaveStates();
 

src/citra_qt/citra_qt.h

@@ -21,6 +21,7 @@
 #include <QTranslator>
 #include "citra_qt/compatibility_list.h"
 #include "citra_qt/hotkeys.h"
+#include "citra_qt/notification_led.h"
 #include "citra_qt/user_data_migration.h"
 #include "core/core.h"
 #include "core/savestate.h"
@@ -147,6 +148,7 @@ signals:
     void CIAInstallReport(Service::AM::InstallStatus status, QString filepath);
     void CompressFinished(bool is_compress, bool success);
     void CIAInstallFinished();
+    void InfoLEDColorChanged();
     // Signal that tells widgets to update icons to use the current theme
     void UpdateThemedIcons();
 
@@ -364,6 +366,8 @@ private:
 
     MultiplayerState* multiplayer_state = nullptr;
 
+    LedWidget* notification_led = nullptr;
+
     // Created before `config` to ensure that emu data directory
     // isn't created before the check is performed
     UserDataMigrator user_data_migrator;

src/citra_qt/notification_led.cpp

@@ -0,0 +1,87 @@
+// Copyright Citra Emulator Project / Azahar Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cmath>
+#include <QPainter>
+#include <QRadialGradient>
+#include "citra_qt/notification_led.h"
+
+LedWidget::LedWidget(QWidget* parent) : QWidget(parent), color(0, 0, 0) {
+    setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
+}
+
+QSize LedWidget::sizeHint() const {
+    return QSize(16, 16);
+}
+
+QSize LedWidget::minimumSizeHint() const {
+    return QSize(16, 16);
+}
+
+void LedWidget::setColor(const QColor& _color) {
+    if (color == _color)
+        return;
+
+    color = _color;
+    update();
+}
+
+QColor LedWidget::lerpColor(const QColor& a, const QColor& b, float t) {
+    t = std::clamp(t, 0.0f, 1.0f);
+
+    return QColor(int(a.red() + (b.red() - a.red()) * t),
+                  int(a.green() + (b.green() - a.green()) * t),
+                  int(a.blue() + (b.blue() - a.blue()) * t));
+}
+
+QColor LedWidget::blendLedColor(int r, int g, int b) const {
+    // Default "off" color
+    const QColor off_color(64, 64, 64);
+
+    // If completely off, just show gray and skip further calculations
+    if (r == 0 && g == 0 && b == 0)
+        return off_color;
+
+    // Normalize lit color so hue stays pure
+    int max_c = std::max({r, g, b});
+    QColor lit_color((r * 255) / max_c, (g * 255) / max_c, (b * 255) / max_c);
+
+    // Convert PWM duty to perceived brightness.
+    // This gives better results as LED RGB values
+    // are not linear.
+    constexpr float gamma = 2.4f;
+    float pwm = max_c / 255.0;
+    float t = std::powf(pwm, 1.f / gamma);
+
+    return lerpColor(off_color, lit_color, t * 0.8f);
+}
+
+void LedWidget::paintEvent(QPaintEvent*) {
+    QPainter p(this);
+    p.setRenderHint(QPainter::Antialiasing);
+
+    QRectF rect = this->rect().adjusted(0, 2, 0, -2);
+
+    qreal size = std::min(rect.width(), rect.height());
+    QRectF circle((rect.center().x() - size / 2.f) - 2, rect.center().y() - size / 2.f, size, size);
+
+    QPointF center = circle.center();
+    qreal radius = circle.width() / 2.f;
+
+    QColor base = blendLedColor(color.red(), color.green(), color.blue());
+
+    QRadialGradient g(center, radius);
+
+    QColor inner = base.lighter(135);
+    QColor outer = base.darker(125);
+
+    g.setColorAt(0.f, inner);
+    g.setColorAt(0.7f, base);
+    g.setColorAt(1.f, outer);
+
+    p.setPen(Qt::NoPen);
+    p.setBrush(g);
+    p.drawEllipse(circle);
+}

src/citra_qt/notification_led.h

@@ -0,0 +1,30 @@
+// Copyright Citra Emulator Project / Azahar Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <QColor>
+#include <QWidget>
+
+class LedWidget : public QWidget {
+    Q_OBJECT
+
+public:
+    explicit LedWidget(QWidget* parent = nullptr);
+
+    QSize sizeHint() const override;
+    QSize minimumSizeHint() const override;
+
+    void setColor(const QColor& color);
+
+protected:
+    void paintEvent(QPaintEvent* event) override;
+
+private:
+    QColor blendLedColor(int r, int g, int b) const;
+    static QColor lerpColor(const QColor& a, const QColor& b, float t);
+
+private:
+    QColor color;
+};