Change Present to finish only after swap

src/citra/emu_window/emu_window_sdl2.cpp

@@ -227,6 +227,7 @@ void EmuWindow_SDL2::Present() {
     while (IsOpen()) {
         VideoCore::g_renderer->Present();
         SDL_GL_SwapWindow(render_window);
+        VideoCore::g_renderer->PresentComplete();
     }
     SDL_GL_MakeCurrent(render_window, nullptr);
 }

src/citra_qt/bootmanager.cpp

@@ -86,7 +86,7 @@ GRenderWindow::GRenderWindow(QWidget* parent, EmuThread* emu_thread)
     setWindowTitle(QStringLiteral("Citra %1 | %2-%3")
                        .arg(Common::g_build_name, Common::g_scm_branch, Common::g_scm_desc));
     setAttribute(Qt::WA_AcceptTouchEvents);
-
+    connect(this, &QOpenGLWidget::frameSwapped, this, &GRenderWindow::OnFrameSwapped);
     InputCommon::Init();
 }
 
@@ -104,6 +104,10 @@ void GRenderWindow::DoneCurrent() {
 
 void GRenderWindow::PollEvents() {}
 
+void OnFrameSwapped() {
+    VideoCore::g_renderer->PresentComplete();
+}
+
 // On Qt 5.0+, this correctly gets the size of the framebuffer (pixels).
 //
 // Older versions get the window size (density independent pixels),
@@ -294,6 +298,10 @@ void GRenderWindow::paintGL() {
     update();
 }
 
+void GRenderWindow::OnFrameSwapped() {
+    VideoCore::g_renderer->PresentComplete();
+}
+
 void GRenderWindow::showEvent(QShowEvent* event) {
     QWidget::showEvent(event);
 }

src/citra_qt/bootmanager.h

@@ -163,6 +163,7 @@ public slots:
     void OnEmulationStarting(EmuThread* emu_thread);
     void OnEmulationStopping();
     void OnFramebufferSizeChanged();
+    void OnFrameSwapped();
 
 signals:
     /// Emitted when the window is closed

src/video_core/renderer_base.h

@@ -34,6 +34,9 @@ public:
     /// Draws the latest frame to the window (Renderer specific implementation)
     virtual void Present() = 0;
 
+    /// Marks the presentation buffer as complete and swaps it back into the pool
+    virtual void PresentComplete() = 0;
+
     /// Prepares for video dumping (e.g. create necessary buffers, etc)
     virtual void PrepareVideoDumping() = 0;
 

src/video_core/renderer_opengl/renderer_opengl.cpp

@@ -794,6 +794,9 @@ void RendererOpenGL::Present() {
     /* insert fence for the main thread to block on */
     frame.present_sync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
     glFlush();
+}
+
+void RendererOpenGL::PresentComplete() {
     render_window.mailbox->PresentationComplete();
 }
 

src/video_core/renderer_opengl/renderer_opengl.h

@@ -60,6 +60,9 @@ public:
     /// context
     void Present() override;
 
+    /// Finializes the presentation and sets up the presentation frame to go back into the mailbox
+    void PresentComplete() override;
+
     /// Prepares for video dumping (e.g. create necessary buffers, etc)
     void PrepareVideoDumping() override;