Merge pull request #4282 from zhaowenlan1779/frame-advance

core, citra_qt: add frame advancing to framelimiter

src/citra_qt/main.cpp

@@ -352,6 +352,10 @@ void GMainWindow::InitializeHotkeys() {
                                    Qt::ApplicationShortcut);
     hotkey_registry.RegisterHotkey("Main Window", "Decrease Speed Limit", QKeySequence("-"),
                                    Qt::ApplicationShortcut);
+    hotkey_registry.RegisterHotkey("Main Window", "Toggle Frame Advancing", QKeySequence("CTRL+A"),
+                                   Qt::ApplicationShortcut);
+    hotkey_registry.RegisterHotkey("Main Window", "Advance Frame", QKeySequence(Qt::Key_Backslash),
+                                   Qt::ApplicationShortcut);
     hotkey_registry.LoadHotkeys();
 
     connect(hotkey_registry.GetHotkey("Main Window", "Load File", this), &QShortcut::activated,
@@ -409,6 +413,10 @@ void GMainWindow::InitializeHotkeys() {
                     UpdateStatusBar();
                 }
             });
+    connect(hotkey_registry.GetHotkey("Main Window", "Toggle Frame Advancing", this),
+            &QShortcut::activated, ui.action_Enable_Frame_Advancing, &QAction::trigger);
+    connect(hotkey_registry.GetHotkey("Main Window", "Advance Frame", this), &QShortcut::activated,
+            ui.action_Advance_Frame, &QAction::trigger);
 }
 
 void GMainWindow::ShowUpdaterWidgets() {
@@ -540,6 +548,20 @@ void GMainWindow::ConnectMenuEvents() {
     connect(ui.action_Play_Movie, &QAction::triggered, this, &GMainWindow::OnPlayMovie);
     connect(ui.action_Stop_Recording_Playback, &QAction::triggered, this,
             &GMainWindow::OnStopRecordingPlayback);
+    connect(ui.action_Enable_Frame_Advancing, &QAction::triggered, this, [this] {
+        if (emulation_running) {
+            Core::System::GetInstance().frame_limiter.SetFrameAdvancing(
+                ui.action_Enable_Frame_Advancing->isChecked());
+            ui.action_Advance_Frame->setEnabled(ui.action_Enable_Frame_Advancing->isChecked());
+        }
+    });
+    connect(ui.action_Advance_Frame, &QAction::triggered, this, [this] {
+        if (emulation_running) {
+            ui.action_Enable_Frame_Advancing->setChecked(true);
+            ui.action_Advance_Frame->setEnabled(true);
+            Core::System::GetInstance().frame_limiter.AdvanceFrame();
+        }
+    });
 
     // Help
     connect(ui.action_FAQ, &QAction::triggered,
@@ -803,6 +825,9 @@ void GMainWindow::ShutdownGame() {
     // TODO(bunnei): This function is not thread safe, but it's being used as if it were
     Pica::g_debug_context->ClearBreakpoints();
 
+    // Frame advancing must be cancelled in order to release the emu thread from waiting
+    Core::System::GetInstance().frame_limiter.SetFrameAdvancing(false);
+
     emit EmulationStopping();
 
     // Wait for emulation thread to complete and delete it
@@ -823,6 +848,9 @@ void GMainWindow::ShutdownGame() {
     ui.action_Stop->setEnabled(false);
     ui.action_Restart->setEnabled(false);
     ui.action_Report_Compatibility->setEnabled(false);
+    ui.action_Enable_Frame_Advancing->setEnabled(false);
+    ui.action_Enable_Frame_Advancing->setChecked(false);
+    ui.action_Advance_Frame->setEnabled(false);
     render_window->hide();
     if (game_list->isEmpty())
         game_list_placeholder->show();
@@ -1110,6 +1138,7 @@ void GMainWindow::OnStartGame() {
     ui.action_Stop->setEnabled(true);
     ui.action_Restart->setEnabled(true);
     ui.action_Report_Compatibility->setEnabled(true);
+    ui.action_Enable_Frame_Advancing->setEnabled(true);
 
     discord_rpc->Update();
 }

src/citra_qt/main.ui

@@ -114,6 +114,9 @@
     <addaction name="action_Record_Movie"/>
     <addaction name="action_Play_Movie"/>
     <addaction name="action_Stop_Recording_Playback"/>
+    <addaction name="separator"/>
+    <addaction name="action_Enable_Frame_Advancing"/>
+    <addaction name="action_Advance_Frame"/>
    </widget>
    <widget class="QMenu" name="menu_Multiplayer">
     <property name="enabled">
@@ -276,6 +279,25 @@
     <string>Stop Recording / Playback</string>
    </property>
   </action>
+  <action name="action_Enable_Frame_Advancing">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="enabled">
+    <bool>false</bool>
+   </property>
+   <property name="text">
+    <string>Enable Frame Advancing</string>
+   </property>
+  </action>
+  <action name="action_Advance_Frame">
+   <property name="enabled">
+    <bool>false</bool>
+   </property>
+   <property name="text">
+    <string>Advance Frame</string>
+   </property>
+  </action>
   <action name="action_View_Lobby">
    <property name="enabled">
     <bool>true</bool>

src/core/perf_stats.cpp

@@ -74,6 +74,13 @@ double PerfStats::GetLastFrameTimeScale() {
 }
 
 void FrameLimiter::DoFrameLimiting(microseconds current_system_time_us) {
+    if (frame_advancing_enabled) {
+        // Frame advancing is enabled: wait on event instead of doing framelimiting
+        frame_advance_event.Wait();
+        frame_advance_event.Reset();
+        return;
+    }
+
     if (!Settings::values.use_frame_limit) {
         return;
     }
@@ -104,4 +111,20 @@ void FrameLimiter::DoFrameLimiting(microseconds current_system_time_us) {
     previous_walltime = now;
 }
 
+void FrameLimiter::SetFrameAdvancing(bool value) {
+    const bool was_enabled = frame_advancing_enabled.exchange(value);
+    if (was_enabled && !value) {
+        // Set the event to let emulation continue
+        frame_advance_event.Set();
+    }
+}
+
+void FrameLimiter::AdvanceFrame() {
+    if (!frame_advancing_enabled) {
+        // Start frame advancing
+        frame_advancing_enabled = true;
+    }
+    frame_advance_event.Set();
+}
+
 } // namespace Core

src/core/perf_stats.h

@@ -4,9 +4,11 @@
 
 #pragma once
 
+#include <atomic>
 #include <chrono>
 #include <mutex>
 #include "common/common_types.h"
+#include "common/thread.h"
 
 namespace Core {
 
@@ -70,6 +72,14 @@ public:
 
     void DoFrameLimiting(std::chrono::microseconds current_system_time_us);
 
+    /**
+     * Sets whether frame advancing is enabled or not.
+     * Note: The frontend must cancel frame advancing before shutting down in order
+     *       to resume the emu_thread.
+     */
+    void SetFrameAdvancing(bool value);
+    void AdvanceFrame();
+
 private:
     /// Emulated system time (in microseconds) at the last limiter invocation
     std::chrono::microseconds previous_system_time_us{0};
@@ -78,6 +88,12 @@ private:
 
     /// Accumulated difference between walltime and emulated time
     std::chrono::microseconds frame_limiting_delta_err{0};
+
+    /// Whether to use frame advancing (i.e. frame by frame)
+    std::atomic_bool frame_advancing_enabled;
+
+    /// Event to advance the frame when frame advancing is enabled
+    Common::Event frame_advance_event;
 };
 
 } // namespace Core