VideoCommon: Add a hidden setting to cap immediate XFB swaps to one per VI.

Source/Core/Core/Config/GraphicsSettings.cpp

@@ -194,6 +194,7 @@ const Info<bool> GFX_HACK_SKIP_XFB_COPY_TO_RAM{{System::GFX, "Hacks", "XFBToText
 const Info<bool> GFX_HACK_DISABLE_COPY_TO_VRAM{{System::GFX, "Hacks", "DisableCopyToVRAM"}, false};
 const Info<bool> GFX_HACK_DEFER_EFB_COPIES{{System::GFX, "Hacks", "DeferEFBCopies"}, true};
 const Info<bool> GFX_HACK_IMMEDIATE_XFB{{System::GFX, "Hacks", "ImmediateXFBEnable"}, false};
+const Info<bool> GFX_HACK_CAP_IMMEDIATE_XFB{{System::GFX, "Hacks", "CapImmediateXFB"}, false};
 const Info<bool> GFX_HACK_SKIP_DUPLICATE_XFBS{{System::GFX, "Hacks", "SkipDuplicateXFBs"}, true};
 const Info<bool> GFX_HACK_EARLY_XFB_OUTPUT{{System::GFX, "Hacks", "EarlyXFBOutput"}, true};
 const Info<bool> GFX_HACK_COPY_EFB_SCALED{{System::GFX, "Hacks", "EFBScaledCopy"}, true};

Source/Core/Core/Config/GraphicsSettings.h

@@ -168,6 +168,7 @@ extern const Info<bool> GFX_HACK_SKIP_XFB_COPY_TO_RAM;
 extern const Info<bool> GFX_HACK_DISABLE_COPY_TO_VRAM;
 extern const Info<bool> GFX_HACK_DEFER_EFB_COPIES;
 extern const Info<bool> GFX_HACK_IMMEDIATE_XFB;
+extern const Info<bool> GFX_HACK_CAP_IMMEDIATE_XFB;
 extern const Info<bool> GFX_HACK_SKIP_DUPLICATE_XFBS;
 extern const Info<bool> GFX_HACK_EARLY_XFB_OUTPUT;
 extern const Info<bool> GFX_HACK_COPY_EFB_SCALED;

Source/Core/VideoCommon/Present.cpp

@@ -95,8 +95,13 @@ static void TryToSnapToXFBSize(int& width, int& height, int xfb_width, int xfb_h
 
 Presenter::Presenter()
 {
+  auto& video_events = GetVideoEvents();
+
   m_config_changed =
-      GetVideoEvents().config_changed_event.Register([this](u32 bits) { ConfigChanged(bits); });
+      video_events.config_changed_event.Register([this](u32 bits) { ConfigChanged(bits); });
+
+  m_end_field_hook = video_events.vi_end_field_event.Register(
+      [this] { m_immediate_swap_happened_this_field.store(false, std::memory_order_relaxed); });
 }
 
 Presenter::~Presenter()
@@ -109,6 +114,8 @@ bool Presenter::Initialize()
 {
   UpdateDrawRectangle();
 
+  m_immediate_swap_happened_this_field.store(false, std::memory_order_relaxed);
+
   if (!g_gfx->IsHeadless())
   {
     SetBackbuffer(g_gfx->GetSurfaceInfo());
@@ -214,6 +221,12 @@ void Presenter::ViSwap(u32 xfb_addr, u32 fb_width, u32 fb_stride, u32 fb_height,
 
 void Presenter::ImmediateSwap(u32 xfb_addr, u32 fb_width, u32 fb_stride, u32 fb_height)
 {
+  if (m_immediate_swap_happened_this_field.exchange(true, std::memory_order_relaxed) &&
+      Config::Get(Config::GFX_HACK_CAP_IMMEDIATE_XFB))
+  {
+    return;
+  }
+
   const u64 ticks = m_next_swap_estimated_ticks;
 
   FetchXFB(xfb_addr, fb_width, fb_stride, fb_height, ticks);
@@ -984,6 +997,8 @@ void Presenter::DoState(PointerWrap& p)
     m_next_swap_estimated_ticks = m_last_xfb_ticks;
     m_next_swap_estimated_time = Clock::now();
 
+    m_immediate_swap_happened_this_field.store(false, std::memory_order_relaxed);
+
     ImmediateSwap(m_last_xfb_addr, m_last_xfb_width, m_last_xfb_stride, m_last_xfb_height);
   }
 }

Source/Core/VideoCommon/Present.h

@@ -169,6 +169,7 @@ private:
   u32 m_last_xfb_height = MAX_XFB_HEIGHT;
 
   Common::EventHook m_config_changed;
+  Common::EventHook m_end_field_hook;
 
   // Updates state for the SmoothEarlyPresentation setting if enabled.
   // Returns the desired presentation time regardless.
@@ -181,6 +182,8 @@ private:
   // Can be used for presentation of ImmediateXFB swaps which don't have timing information.
   u64 m_next_swap_estimated_ticks = 0;
   TimePoint m_next_swap_estimated_time{Clock::now()};
+
+  std::atomic_bool m_immediate_swap_happened_this_field{};
 };
 
 }  // namespace VideoCommon