video_core: add null backend

src/yuzu/bootmanager.cpp

@@ -237,8 +237,7 @@ private:
     GRenderWindow* render_window;
 };
 
-class OpenGLRenderWidget : public RenderWidget {
-public:
+struct OpenGLRenderWidget : public RenderWidget {
     explicit OpenGLRenderWidget(GRenderWindow* parent) : RenderWidget(parent) {
         windowHandle()->setSurfaceType(QWindow::OpenGLSurface);
     }
@@ -251,13 +250,16 @@ private:
     std::unique_ptr<Core::Frontend::GraphicsContext> context;
 };
 
-class VulkanRenderWidget : public RenderWidget {
-public:
+struct VulkanRenderWidget : public RenderWidget {
     explicit VulkanRenderWidget(GRenderWindow* parent) : RenderWidget(parent) {
         windowHandle()->setSurfaceType(QWindow::VulkanSurface);
     }
 };
 
+struct NullRenderWidget : public RenderWidget {
+    explicit NullRenderWidget(GRenderWindow* parent) : RenderWidget(parent) {}
+};
+
 static Core::Frontend::WindowSystemType GetWindowSystemType() {
     // Determine WSI type based on Qt platform.
     QString platform_name = QGuiApplication::platformName();
@@ -874,6 +876,9 @@ bool GRenderWindow::InitRenderTarget() {
             return false;
         }
         break;
+    case Settings::RendererBackend::Null:
+        InitializeNull();
+        break;
     }
 
     // Update the Window System information with the new render target
@@ -970,6 +975,11 @@ bool GRenderWindow::InitializeVulkan() {
     return true;
 }
 
+void GRenderWindow::InitializeNull() {
+    child_widget = new NullRenderWidget(this);
+    main_context = std::make_unique<DummyContext>();
+}
+
 bool GRenderWindow::LoadOpenGL() {
     auto context = CreateSharedContext();
     auto scope = context->Acquire();

src/yuzu/bootmanager.h

@@ -218,6 +218,7 @@ private:
 
     bool InitializeOpenGL();
     bool InitializeVulkan();
+    void InitializeNull();
     bool LoadOpenGL();
     QStringList GetUnsupportedGLExtensions() const;
 

src/yuzu/configuration/configure_graphics.cpp

@@ -260,6 +260,7 @@ void ConfigureGraphics::ApplyConfiguration() {
             Settings::values.renderer_backend.SetValue(GetCurrentGraphicsBackend());
             switch (GetCurrentGraphicsBackend()) {
             case Settings::RendererBackend::OpenGL:
+            case Settings::RendererBackend::Null:
                 Settings::values.shader_backend.SetGlobal(false);
                 Settings::values.vulkan_device.SetGlobal(true);
                 Settings::values.shader_backend.SetValue(shader_backend);
@@ -348,6 +349,10 @@ void ConfigureGraphics::UpdateAPILayout() {
         ui->device_widget->setVisible(true);
         ui->backend_widget->setVisible(false);
         break;
+    case Settings::RendererBackend::Null:
+        ui->device_widget->setVisible(false);
+        ui->backend_widget->setVisible(false);
+        break;
     }
 }
 

src/yuzu/configuration/configure_graphics.ui

@@ -139,6 +139,11 @@
                   <string notr="true">Vulkan</string>
                  </property>
                 </item>
+                <item>
+                 <property name="text">
+                  <string>None</string>
+                 </property>
+                </item>
                </widget>
               </item>
              </layout>

src/yuzu/main.cpp

@@ -1007,29 +1007,11 @@ void GMainWindow::InitializeWidgets() {
     renderer_status_button->setObjectName(QStringLiteral("RendererStatusBarButton"));
     renderer_status_button->setCheckable(true);
     renderer_status_button->setFocusPolicy(Qt::NoFocus);
-    connect(renderer_status_button, &QPushButton::toggled, [this](bool checked) {
-        renderer_status_button->setText(checked ? tr("VULKAN") : tr("OPENGL"));
-    });
-    renderer_status_button->toggle();
-
+    connect(renderer_status_button, &QPushButton::clicked, this, &GMainWindow::OnToggleGraphicsAPI);
+    UpdateAPIText();
+    renderer_status_button->setCheckable(true);
     renderer_status_button->setChecked(Settings::values.renderer_backend.GetValue() ==
                                        Settings::RendererBackend::Vulkan);
-    connect(renderer_status_button, &QPushButton::clicked, [this] {
-        if (emulation_running) {
-            return;
-        }
-        if (renderer_status_button->isChecked()) {
-            Settings::values.renderer_backend.SetValue(Settings::RendererBackend::Vulkan);
-        } else {
-            Settings::values.renderer_backend.SetValue(Settings::RendererBackend::OpenGL);
-            if (Settings::values.scaling_filter.GetValue() == Settings::ScalingFilter::Fsr) {
-                Settings::values.scaling_filter.SetValue(Settings::ScalingFilter::NearestNeighbor);
-                UpdateFilterText();
-            }
-        }
-
-        system->ApplySettings();
-    });
     statusBar()->insertPermanentWidget(0, renderer_status_button);
 
     statusBar()->setVisible(true);
@@ -3248,6 +3230,18 @@ void GMainWindow::OnToggleAdaptingFilter() {
     UpdateFilterText();
 }
 
+void GMainWindow::OnToggleGraphicsAPI() {
+    auto api = Settings::values.renderer_backend.GetValue();
+    if (api == Settings::RendererBackend::OpenGL) {
+        api = Settings::RendererBackend::Vulkan;
+    } else {
+        api = Settings::RendererBackend::OpenGL;
+    }
+    Settings::values.renderer_backend.SetValue(api);
+    renderer_status_button->setChecked(api == Settings::RendererBackend::Vulkan);
+    UpdateAPIText();
+}
+
 void GMainWindow::OnConfigurePerGame() {
     const u64 title_id = system->GetCurrentProcessProgramID();
     OpenPerGameConfiguration(title_id, current_game_path.toStdString());
@@ -3568,6 +3562,21 @@ void GMainWindow::UpdateDockedButton() {
     dock_status_button->setText(is_docked ? tr("DOCKED") : tr("HANDHELD"));
 }
 
+void GMainWindow::UpdateAPIText() {
+    const auto api = Settings::values.renderer_backend.GetValue();
+    switch (api) {
+    case Settings::RendererBackend::OpenGL:
+        renderer_status_button->setText(tr("OPENGL"));
+        break;
+    case Settings::RendererBackend::Vulkan:
+        renderer_status_button->setText(tr("VULKAN"));
+        break;
+    case Settings::RendererBackend::Null:
+        renderer_status_button->setText(tr("NULL"));
+        break;
+    }
+}
+
 void GMainWindow::UpdateFilterText() {
     const auto filter = Settings::values.scaling_filter.GetValue();
     switch (filter) {
@@ -3613,6 +3622,7 @@ void GMainWindow::UpdateAAText() {
 void GMainWindow::UpdateStatusButtons() {
     renderer_status_button->setChecked(Settings::values.renderer_backend.GetValue() ==
                                        Settings::RendererBackend::Vulkan);
+    UpdateAPIText();
     UpdateGPUAccuracyButton();
     UpdateDockedButton();
     UpdateFilterText();

src/yuzu/main.h

@@ -307,6 +307,7 @@ private slots:
     void OnTasStartStop();
     void OnTasRecord();
     void OnTasReset();
+    void OnToggleGraphicsAPI();
     void OnToggleDockedMode();
     void OnToggleGpuAccuracy();
     void OnToggleAdaptingFilter();
@@ -347,6 +348,7 @@ private:
     void UpdateWindowTitle(std::string_view title_name = {}, std::string_view title_version = {},
                            std::string_view gpu_vendor = {});
     void UpdateDockedButton();
+    void UpdateAPIText();
     void UpdateFilterText();
     void UpdateAAText();
     void UpdateStatusBar();