feat: Improve FSR2 UI with dropdown quality mode and conditional FSR sharpness

- Convert FSR2 quality mode from number input to dropdown with 4 options
- Disable and grey out FSR sharpness slider when FSR2 is selected
- Add proper enum-based settings for FSR2 quality modes
- Update both Vulkan and OpenGL FSR2 implementations
- Connect UI state changes automatically

Provides better UX by using appropriate controls and preventing confusion
between FSR 1.0 and FSR 2.0 sharpening options.

Signed-off-by: Zephyron <zephyron@citron-emu.org>

src/citron/configuration/configure_graphics.cpp

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: 2016 Citra Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <algorithm>
@@ -288,6 +289,11 @@ void ConfigureGraphics::Setup(const ConfigurationShared::Builder& builder) {
             continue;
         }
 
+        // Store reference to the FSR sharpness widget for later use
+        if (setting->Id() == Settings::values.fsr_sharpening_slider.Id()) {
+            fsr_sharpness_widget = widget;
+        }
+
         if (setting->Id() == Settings::values.renderer_backend.Id()) {
             // Add the renderer combobox now so it's at the top
             api_grid_layout->addWidget(widget);
@@ -366,6 +372,41 @@ void ConfigureGraphics::Setup(const ConfigurationShared::Builder& builder) {
         api_grid_layout->addWidget(widget);
     }
 
+    // Set up FSR sharpness slider conditional enabling
+    if (fsr_sharpness_widget) {
+        // Create a function to update the enabled state based on scaling filter
+        auto update_fsr_sharpness_enabled = [this]() {
+            if (fsr_sharpness_widget) {
+                const auto scaling_filter = Settings::values.scaling_filter.GetValue();
+                const bool fsr2_selected = (scaling_filter == Settings::ScalingFilter::Fsr2);
+                fsr_sharpness_widget->setEnabled(!fsr2_selected);
+
+                // Grey out the widget when disabled
+                if (fsr2_selected) {
+                    fsr_sharpness_widget->setStyleSheet(QStringLiteral("QWidget { color: gray; }"));
+                } else {
+                    fsr_sharpness_widget->setStyleSheet(QStringLiteral(""));
+                }
+            }
+        };
+
+        // Initial state
+        update_fsr_sharpness_enabled();
+
+        // Connect to scaling filter changes
+        if (!Settings::IsConfiguringGlobal()) {
+            // Find the scaling filter widget and connect to its changes
+            for (const auto& [id, widget] : hold_graphics) {
+                if (id == Settings::values.scaling_filter.Id()) {
+                    auto* config_widget = static_cast<ConfigurationShared::Widget*>(widget);
+                    QObject::connect(config_widget->combobox, QOverload<int>::of(&QComboBox::activated),
+                                   [update_fsr_sharpness_enabled]() { update_fsr_sharpness_enabled(); });
+                    break;
+                }
+            }
+        }
+    }
+
     // Background color is too specific to build into the new system, so we manage it here
     // (3 settings, all collected into a single widget with a QColor to manage on top)
     if (Settings::IsConfiguringGlobal()) {

src/citron/configuration/configure_graphics.h

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: 2016 Citra Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
@@ -113,4 +114,5 @@ private:
     QWidget* shader_backend_widget;
     QComboBox* aspect_ratio_combobox;
     QComboBox* resolution_combobox;
+    QWidget* fsr_sharpness_widget;
 };

src/citron/configuration/shared_translation.cpp

@@ -404,6 +404,13 @@ std::unique_ptr<ComboboxTranslationMap> ComboboxEnumeration(QWidget* parent) {
                               PAIR(AntiAliasing, Fxaa, tr("FXAA")),
                               PAIR(AntiAliasing, Smaa, tr("SMAA")),
                           }});
+    translations->insert({Settings::EnumMetadata<Settings::FSR2QualityMode>::Index(),
+                          {
+                              PAIR(FSR2QualityMode, Quality, tr("Quality")),
+                              PAIR(FSR2QualityMode, Balanced, tr("Balanced")),
+                              PAIR(FSR2QualityMode, Performance, tr("Performance")),
+                              PAIR(FSR2QualityMode, UltraPerformance, tr("Ultra Performance")),
+                          }});
     translations->insert({Settings::EnumMetadata<Settings::AspectRatio>::Index(),
                           {
                               PAIR(AspectRatio, R16_9, tr("Default (16:9)")),

src/common/settings.h

@@ -348,10 +348,10 @@ struct Values {
                                                        true,
                                                        true};
 
-    SwitchableSetting<int, true> fsr2_quality_mode{linkage,
+    SwitchableSetting<FSR2QualityMode, true> fsr2_quality_mode{linkage,
-                                                   2,  // Performance by default
+                                                               FSR2QualityMode::Performance,  // Performance by default
-                                                   0,  // Quality
+                                                               FSR2QualityMode::Quality,
-                                                   3,  // Ultra Performance
+                                                               FSR2QualityMode::UltraPerformance,
                                                                "fsr2_quality_mode",
                                                                Category::Renderer,
                                                                Specialization::Default,

src/common/settings_enums.h

@@ -151,6 +151,8 @@ ENUM(ScalingFilter, NearestNeighbor, Bilinear, Bicubic, Gaussian, ScaleForce, Fs
 
 ENUM(AntiAliasing, None, Fxaa, Smaa, MaxEnum);
 
+ENUM(FSR2QualityMode, Quality, Balanced, Performance, UltraPerformance);
+
 ENUM(AspectRatio, R16_9, R4_3, R21_9, R16_10, R32_9, Stretch);
 
 ENUM(ConsoleMode, Handheld, Docked);

src/video_core/renderer_opengl/present/fsr2.cpp

@@ -68,16 +68,16 @@ GLuint FSR2::Draw(ProgramManager& program_manager, GLuint texture, u32 input_ima
                      input_height, output_width, output_height, viewport_x, viewport_y);
 
                // FSR 2.0 uses a different sharpening calculation based on quality mode
-    const int quality_mode = Settings::values.fsr2_quality_mode.GetValue();
+           const auto quality_mode = Settings::values.fsr2_quality_mode.GetValue();
            const float sharpening = [quality_mode]() {
                switch (quality_mode) {
-        case 0: // Quality
+               case Settings::FSR2QualityMode::Quality:
                    return 0.2f;
-        case 1: // Balanced
+               case Settings::FSR2QualityMode::Balanced:
                    return 0.4f;
-        case 2: // Performance
+               case Settings::FSR2QualityMode::Performance:
                    return 0.6f;
-        case 3: // Ultra Performance
+               case Settings::FSR2QualityMode::UltraPerformance:
                    return 0.8f;
                default:
                    return 0.4f;

src/video_core/renderer_vulkan/present/fsr2.cpp

@@ -189,16 +189,16 @@ VkImageView FSR2::Draw(Scheduler& scheduler, size_t image_index, VkImage source_
                      viewport_y);
 
                // FSR 2.0 uses a different sharpening calculation based on quality mode
-    const int quality_mode = Settings::values.fsr2_quality_mode.GetValue();
+           const auto quality_mode = Settings::values.fsr2_quality_mode.GetValue();
            const float sharpening = [quality_mode]() {
                switch (quality_mode) {
-        case 0: // Quality
+               case Settings::FSR2QualityMode::Quality:
                    return 0.2f;
-        case 1: // Balanced
+               case Settings::FSR2QualityMode::Balanced:
                    return 0.4f;
-        case 2: // Performance
+               case Settings::FSR2QualityMode::Performance:
                    return 0.6f;
-        case 3: // Ultra Performance
+               case Settings::FSR2QualityMode::UltraPerformance:
                    return 0.8f;
                default:
                    return 0.4f;