Add "Separate Windows" LayoutOption (#6177)

src/citra/emu_window/emu_window_sdl2.cpp

@@ -135,18 +135,8 @@ void EmuWindow_SDL2::Fullscreen() {
     SDL_MaximizeWindow(render_window);
 }
 
-EmuWindow_SDL2::EmuWindow_SDL2(bool fullscreen) {
+EmuWindow_SDL2::EmuWindow_SDL2(bool fullscreen, bool is_secondary) : EmuWindow(is_secondary) {
     // Initialize the window
-    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMECONTROLLER) < 0) {
-        LOG_CRITICAL(Frontend, "Failed to initialize SDL2: {}! Exiting...", SDL_GetError());
-        exit(1);
-    }
-
-    InputCommon::Init();
-    Network::Init();
-
-    SDL_SetMainReady();
-
     if (Settings::values.use_gles) {
         SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
         SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
@@ -201,6 +191,7 @@ EmuWindow_SDL2::EmuWindow_SDL2(bool fullscreen) {
         exit(1);
     }
 
+    render_window_id = SDL_GetWindowID(render_window);
     auto gl_load_func = Settings::values.use_gles ? gladLoadGLES2Loader : gladLoadGLLoader;
 
     if (!gl_load_func(static_cast<GLADloadproc>(SDL_GL_GetProcAddress))) {
@@ -211,19 +202,26 @@ EmuWindow_SDL2::EmuWindow_SDL2(bool fullscreen) {
     OnResize();
     OnMinimalClientAreaChangeRequest(GetActiveConfig().min_client_area_size);
     SDL_PumpEvents();
-    LOG_INFO(Frontend, "Citra Version: {} | {}-{}", Common::g_build_fullname, Common::g_scm_branch,
-             Common::g_scm_desc);
-    Settings::LogSettings();
 }
 
 EmuWindow_SDL2::~EmuWindow_SDL2() {
     core_context.reset();
-    Network::Shutdown();
-    InputCommon::Shutdown();
     SDL_GL_DeleteContext(window_context);
     SDL_Quit();
 }
 
+void EmuWindow_SDL2::InitializeSDL2() {
+    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMECONTROLLER) < 0) {
+        LOG_CRITICAL(Frontend, "Failed to initialize SDL2: {}! Exiting...", SDL_GetError());
+        exit(1);
+    }
+
+    InputCommon::Init();
+    Network::Init();
+
+    SDL_SetMainReady();
+}
+
 std::unique_ptr<Frontend::GraphicsContext> EmuWindow_SDL2::CreateSharedContext() const {
     return std::make_unique<SharedContext_SDL2>();
 }
@@ -240,7 +238,7 @@ void EmuWindow_SDL2::Present() {
     SDL_GL_MakeCurrent(render_window, window_context);
     SDL_GL_SetSwapInterval(1);
     while (IsOpen()) {
-        VideoCore::g_renderer->TryPresent(100);
+        VideoCore::g_renderer->TryPresent(100, is_secondary);
         SDL_GL_SwapWindow(render_window);
     }
     SDL_GL_MakeCurrent(render_window, nullptr);
@@ -248,9 +246,14 @@ void EmuWindow_SDL2::Present() {
 
 void EmuWindow_SDL2::PollEvents() {
     SDL_Event event;
+    std::vector<SDL_Event> other_window_events;
 
     // SDL_PollEvent returns 0 when there are no more events in the event queue
     while (SDL_PollEvent(&event)) {
+        if (event.window.windowID != render_window_id) {
+            other_window_events.push_back(event);
+            continue;
+        }
         switch (event.type) {
         case SDL_WINDOWEVENT:
             switch (event.window.event) {
@@ -299,16 +302,13 @@ void EmuWindow_SDL2::PollEvents() {
             break;
         }
     }
-
-    const u32 current_time = SDL_GetTicks();
-    if (current_time > last_time + 2000) {
-        const auto results = Core::System::GetInstance().GetAndResetPerfStats();
-        const auto title =
-            fmt::format("Citra {} | {}-{} | FPS: {:.0f} ({:.0f}%)", Common::g_build_fullname,
-                        Common::g_scm_branch, Common::g_scm_desc, results.game_fps,
-                        results.emulation_speed * 100.0f);
-        SDL_SetWindowTitle(render_window, title.c_str());
-        last_time = current_time;
+    for (auto& e : other_window_events) {
+        // This is a somewhat hacky workaround to re-emit window events meant for another window
+        // since SDL_PollEvent() is global but we poll events per window.
+        SDL_PushEvent(&e);
+    }
+    if (!is_secondary) {
+        UpdateFramerateCounter();
     }
 }
 
@@ -323,3 +323,16 @@ void EmuWindow_SDL2::DoneCurrent() {
 void EmuWindow_SDL2::OnMinimalClientAreaChangeRequest(std::pair<u32, u32> minimal_size) {
     SDL_SetWindowMinimumSize(render_window, minimal_size.first, minimal_size.second);
 }
+
+void EmuWindow_SDL2::UpdateFramerateCounter() {
+    const u32 current_time = SDL_GetTicks();
+    if (current_time > last_time + 2000) {
+        const auto results = Core::System::GetInstance().GetAndResetPerfStats();
+        const auto title =
+            fmt::format("Citra {} | {}-{} | FPS: {:.0f} ({:.0f}%)", Common::g_build_fullname,
+                        Common::g_scm_branch, Common::g_scm_desc, results.game_fps,
+                        results.emulation_speed * 100.0f);
+        SDL_SetWindowTitle(render_window, title.c_str());
+        last_time = current_time;
+    }
+}

src/citra/emu_window/emu_window_sdl2.h

@@ -29,9 +29,11 @@ private:
 
 class EmuWindow_SDL2 : public Frontend::EmuWindow {
 public:
-    explicit EmuWindow_SDL2(bool fullscreen);
+    explicit EmuWindow_SDL2(bool fullscreen, bool is_secondary);
     ~EmuWindow_SDL2();
 
+    static void InitializeSDL2();
+
     void Present();
 
     /// Polls window events
@@ -88,12 +90,18 @@ private:
     /// Called when a configuration change affects the minimal size of the window
     void OnMinimalClientAreaChangeRequest(std::pair<u32, u32> minimal_size) override;
 
+    /// Called when polling to update framerate
+    void UpdateFramerateCounter();
+
     /// Is the window still open?
     bool is_open = true;
 
     /// Internal SDL2 render window
     SDL_Window* render_window;
 
+    /// Internal SDL2 window ID
+    int render_window_id{};
+
     /// Fake hidden window for the core context
     SDL_Window* dummy_window;