CoreTiming/VideoCommon: Add "Sync to Host Refresh Rate" setting.

Source/Core/Core/Config/MainSettings.cpp

@@ -324,6 +324,7 @@ const Info<int> MAIN_ISO_PATH_COUNT{{System::Main, "General", "ISOPaths"}, 0};
 const Info<std::string> MAIN_SKYLANDERS_PATH{{System::Main, "General", "SkylandersCollectionPath"},
                                              ""};
 const Info<bool> MAIN_TIME_TRACKING{{System::Main, "General", "EnablePlayTimeTracking"}, true};
+const Info<bool> MAIN_SYNC_REFRESH_RATE{{System::Main, "General", "SyncToHostRefreshRate"}, true};
 
 static Info<std::string> MakeISOPathConfigInfo(size_t idx)
 {

Source/Core/Core/Config/MainSettings.h

@@ -190,6 +190,7 @@ extern const Info<bool> MAIN_RENDER_WINDOW_AUTOSIZE;
 extern const Info<bool> MAIN_KEEP_WINDOW_ON_TOP;
 extern const Info<bool> MAIN_DISABLE_SCREENSAVER;
 extern const Info<bool> MAIN_TIME_TRACKING;
+extern const Info<bool> MAIN_SYNC_REFRESH_RATE;
 
 // Main.General
 

Source/Core/Core/CoreTiming.cpp

@@ -28,6 +28,7 @@
 #include "VideoCommon/PerformanceMetrics.h"
 #include "VideoCommon/VideoBackendBase.h"
 #include "VideoCommon/VideoConfig.h"
+#include "VideoCommon/VideoEvents.h"
 
 namespace CoreTiming
 {
@@ -103,6 +104,19 @@ void CoreTimingManager::Init()
 
   m_event_fifo_id = 0;
   m_ev_lost = RegisterEvent("_lost_event", &EmptyTimedCallback);
+
+  m_after_frame_hook = AfterPresentEvent::Register(
+      [this](const PresentInfo& info) {
+        const bool sync_to_host_active =
+            Config::Get(Config::MAIN_SYNC_REFRESH_RATE) && g_ActiveConfig.bVSyncActive;
+
+        const auto presentation_time = PresentationTime{.ticks = info.emulated_timestamp,
+                                                        .time = Clock::now(),
+                                                        .sync_to_host_active = sync_to_host_active};
+
+        m_last_presentation.Store(std::make_unique<PresentationTime>(presentation_time));
+      },
+      "CoreTiming AfterPresentEvent");
 }
 
 void CoreTimingManager::Shutdown()
@@ -112,6 +126,8 @@ void CoreTimingManager::Shutdown()
   ClearPendingEvents();
   UnregisterAllEvents();
   CPUThreadConfigCallback::RemoveConfigChangedCallback(m_registered_config_callback_id);
+  m_after_frame_hook.reset();
+  m_last_presentation = nullptr;
 }
 
 void CoreTimingManager::RefreshConfig()
@@ -201,6 +217,7 @@ void CoreTimingManager::DoState(PointerWrap& p)
     // The stave state has changed the time, so our previous Throttle targets are invalid.
     // Especially when global_time goes down; So we create a fake throttle update.
     ResetThrottle(m_globals.global_timer);
+    m_last_presentation = nullptr;
   }
 }
 
@@ -399,6 +416,14 @@ void CoreTimingManager::SleepUntil(TimePoint time_point)
 
 void CoreTimingManager::Throttle(const s64 target_cycle)
 {
+  // Adjust throttle based on last presentation if "Sync to Host Refresh Rate" was active.
+  const auto last_presentation = m_last_presentation.Exchange(nullptr);
+  if (last_presentation && last_presentation->sync_to_host_active)
+  {
+    m_throttle_last_cycle = last_presentation->ticks;
+    m_throttle_deadline = last_presentation->time;
+  }
+
   // Based on number of cycles and emulation speed, increase the target deadline
   const s64 cycles = target_cycle - m_throttle_last_cycle;
   m_throttle_last_cycle = target_cycle;

Source/Core/Core/CoreTiming.h

@@ -22,7 +22,9 @@
 #include <unordered_map>
 #include <vector>
 
+#include "Common/AtomicUniquePtr.h"
 #include "Common/CommonTypes.h"
+#include "Common/HookableEvent.h"
 #include "Common/SPSCQueue.h"
 #include "Common/Timer.h"
 #include "Core/CPUThreadConfigCallback.h"
@@ -219,6 +221,16 @@ private:
   std::atomic_bool m_use_precision_timer = false;
   Common::PrecisionTimer m_precision_cpu_timer;
   Common::PrecisionTimer m_precision_gpu_timer;
+
+  struct PresentationTime
+  {
+    u64 ticks;
+    Clock::time_point time;
+    bool sync_to_host_active;
+  };
+  Common::AtomicUniquePtr<PresentationTime> m_last_presentation;
+
+  Common::EventHook m_after_frame_hook;
 };
 
 }  // namespace CoreTiming

Source/Core/DolphinQt/Settings/AdvancedPane.cpp

@@ -88,6 +88,19 @@ void AdvancedPane::CreateLayout()
          "needed.<br><br><dolphin_emphasis>If unsure, leave this unchecked.</dolphin_emphasis>"));
   cpu_options_group_layout->addWidget(m_accurate_cpu_cache_checkbox);
 
+  auto* const timing_group = new QGroupBox(tr("Timing"));
+  main_layout->addWidget(timing_group);
+  auto* timing_group_layout = new QVBoxLayout{timing_group};
+  auto* const sync_to_host_refresh =
+      new ConfigBool{tr("Sync to Host Refresh Rate"), Config::MAIN_SYNC_REFRESH_RATE};
+  sync_to_host_refresh->SetDescription(
+      tr("Adjusts emulation speed to match host refresh rate when V-Sync is enabled."
+         "<br>This can make 59.94 FPS games run at 60 FPS."
+         "<br><br>Not needed or recommended for users with variable refresh rate displays."
+         "<br><br>Has no effect when Immediate XFB is in use."
+         "<br><br><dolphin_emphasis>If unsure, leave this unchecked.</dolphin_emphasis>"));
+  timing_group_layout->addWidget(sync_to_host_refresh);
+
   auto* clock_override = new QGroupBox(tr("Clock Override"));
   auto* clock_override_layout = new QVBoxLayout();
   clock_override->setLayout(clock_override_layout);

Source/Core/VideoBackends/Vulkan/VKGfx.cpp

@@ -16,6 +16,7 @@
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
 
+#include "Core/Config/MainSettings.h"
 #include "VideoBackends/Vulkan/CommandBufferManager.h"
 #include "VideoBackends/Vulkan/ObjectCache.h"
 #include "VideoBackends/Vulkan/StateTracker.h"
@@ -316,6 +317,9 @@ void VKGfx::PresentBackbuffer()
   // End drawing to backbuffer
   StateTracker::GetInstance()->EndRenderPass();
 
+  const bool wait_for_completion =
+      Config::Get(Config::MAIN_SYNC_REFRESH_RATE) && g_ActiveConfig.bVSyncActive;
+
   if (m_swap_chain->IsCurrentImageValid())
   {
     // Transition the backbuffer to PRESENT_SRC to ensure all commands drawing
@@ -327,12 +331,13 @@ void VKGfx::PresentBackbuffer()
     // Because this final command buffer is rendering to the swap chain, we need to wait for
     // the available semaphore to be signaled before executing the buffer. This final submission
     // can happen off-thread in the background while we're preparing the next frame.
-    g_command_buffer_mgr->SubmitCommandBuffer(true, false, true, m_swap_chain->GetSwapChain(),
+    g_command_buffer_mgr->SubmitCommandBuffer(true, wait_for_completion, true,
+                                              m_swap_chain->GetSwapChain(),
                                               m_swap_chain->GetCurrentImageIndex());
   }
   else
   {
-    g_command_buffer_mgr->SubmitCommandBuffer(true, false, true);
+    g_command_buffer_mgr->SubmitCommandBuffer(true, wait_for_completion, true);
   }
 
   // New cmdbuffer, so invalidate state.

Source/Core/VideoCommon/VideoBackendBase.cpp

@@ -97,7 +97,12 @@ void VideoBackendBase::Video_OutputXFB(u32 xfb_addr, u32 fb_width, u32 fb_stride
     auto& system = Core::System::GetInstance();
     system.GetFifo().SyncGPU(Fifo::SyncGPUReason::Swap);
 
-    const TimePoint presentation_time = system.GetCoreTiming().GetTargetHostTime(ticks);
+    const bool sync_to_host_refresh =
+        Config::Get(Config::MAIN_SYNC_REFRESH_RATE) && g_ActiveConfig.bVSyncActive;
+
+    const TimePoint presentation_time =
+        sync_to_host_refresh ? Clock::now() : system.GetCoreTiming().GetTargetHostTime(ticks);
+
     AsyncRequests::GetInstance()->PushEvent([=] {
       g_presenter->ViSwap(xfb_addr, fb_width, fb_stride, fb_height, ticks, presentation_time);
     });