Add "Separate Windows" LayoutOption (#6177)

src/citra/citra.cpp

@@ -35,6 +35,7 @@
 #include "core/loader/loader.h"
 #include "core/movie.h"
 #include "core/settings.h"
+#include "input_common/main.h"
 #include "network/network.h"
 #include "video_core/renderer_base.h"
 
@@ -359,11 +360,23 @@ int main(int argc, char** argv) {
     // Register generic image interface
     Core::System::GetInstance().RegisterImageInterface(std::make_shared<LodePNGImageInterface>());
 
-    std::unique_ptr<EmuWindow_SDL2> emu_window{std::make_unique<EmuWindow_SDL2>(fullscreen)};
-    Frontend::ScopeAcquireContext scope(*emu_window);
-    Core::System& system = Core::System::GetInstance();
+    EmuWindow_SDL2::InitializeSDL2();
 
-    const Core::System::ResultStatus load_result{system.Load(*emu_window, filepath)};
+    const auto emu_window{std::make_unique<EmuWindow_SDL2>(fullscreen, false)};
+    const bool use_secondary_window{Settings::values.layout_option ==
+                                    Settings::LayoutOption::SeparateWindows};
+    const auto secondary_window =
+        use_secondary_window ? std::make_unique<EmuWindow_SDL2>(false, true) : nullptr;
+
+    Frontend::ScopeAcquireContext scope(*emu_window);
+
+    LOG_INFO(Frontend, "Citra Version: {} | {}-{}", Common::g_build_fullname, Common::g_scm_branch,
+             Common::g_scm_desc);
+    Settings::LogSettings();
+
+    Core::System& system = Core::System::GetInstance();
+    const Core::System::ResultStatus load_result{
+        system.Load(*emu_window, filepath, secondary_window.get())};
 
     switch (load_result) {
     case Core::System::ResultStatus::ErrorGetLoader:
@@ -431,7 +444,12 @@ int main(int argc, char** argv) {
         system.VideoDumper().StartDumping(dump_video, layout);
     }
 
-    std::thread render_thread([&emu_window] { emu_window->Present(); });
+    std::thread main_render_thread([&emu_window] { emu_window->Present(); });
+    std::thread secondary_render_thread([&secondary_window] {
+        if (secondary_window) {
+            secondary_window->Present();
+        }
+    });
 
     std::atomic_bool stop_run;
     system.Renderer().Rasterizer()->LoadDiskResources(
@@ -440,7 +458,11 @@ int main(int argc, char** argv) {
                       total);
         });
 
-    while (emu_window->IsOpen()) {
+    const auto secondary_is_open = [&secondary_window] {
+        // if the secondary window isn't created, it shouldn't affect the main loop
+        return secondary_window ? secondary_window->IsOpen() : true;
+    };
+    while (emu_window->IsOpen() && secondary_is_open()) {
         const auto result = system.RunLoop();
 
         switch (result) {
@@ -454,13 +476,21 @@ int main(int argc, char** argv) {
             break;
         }
     }
-    render_thread.join();
+    emu_window->RequestClose();
+    if (secondary_window) {
+        secondary_window->RequestClose();
+    }
+    main_render_thread.join();
+    secondary_render_thread.join();
 
     Core::Movie::GetInstance().Shutdown();
     if (system.VideoDumper().IsDumping()) {
         system.VideoDumper().StopDumping();
     }
 
+    Network::Shutdown();
+    InputCommon::Shutdown();
+
     system.Shutdown();
 
     detached_tasks.WaitForAllTasks();

src/citra/default_ini.h

@@ -182,7 +182,11 @@ filter_mode =
 
 [Layout]
 # Layout for the screen inside the render window.
-# 0 (default): Default Top Bottom Screen, 1: Single Screen Only, 2: Large Screen Small Screen, 3: Side by Side
+# 0 (default): Default Top Bottom Screen
+# 1: Single Screen Only
+# 2: Large Screen Small Screen
+# 3: Side by Side
+# 4: Separate Windows
 layout_option =
 
 # Toggle custom layout (using the settings below) on or off.

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;