From df16444e3599772dbd9c34806d22bd20cd12e78c Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Tue, 16 Mar 2021 02:25:33 +1000
Subject: [PATCH] Add skip presenting duplicate frames option

---
 android/app/src/main/res/values/arrays.xml    | 12 ++++++
 android/app/src/main/res/values/strings.xml   |  1 +
 .../src/main/res/xml/advanced_preferences.xml | 12 +++---
 src/core/gpu.cpp                              | 10 ++++-
 src/core/gpu.h                                | 11 +++--
 src/core/host_display.cpp                     |  4 ++
 src/core/host_display.h                       | 16 ++++----
 src/core/host_interface.cpp                   |  3 +-
 src/core/settings.cpp                         | 40 ++++++++++++++++++-
 src/core/settings.h                           |  8 +++-
 src/core/types.h                              |  9 +++++
 src/duckstation-qt/displaysettingswidget.cpp  | 16 ++++++--
 src/duckstation-qt/displaysettingswidget.ui   | 19 +++++----
 src/frontend-common/common_host_interface.cpp | 20 +++++++---
 src/frontend-common/d3d11_host_display.cpp    |  1 +
 src/frontend-common/fullscreen_ui.cpp         | 10 +++--
 src/frontend-common/opengl_host_display.cpp   |  1 +
 src/frontend-common/vulkan_host_display.cpp   |  1 +
 18 files changed, 152 insertions(+), 42 deletions(-)

diff --git a/android/app/src/main/res/values/arrays.xml b/android/app/src/main/res/values/arrays.xml
index 01a9ae0c5..bcbead1f9 100644
--- a/android/app/src/main/res/values/arrays.xml
+++ b/android/app/src/main/res/values/arrays.xml
@@ -485,4 +485,16 @@
         <item>Port2Only</item>
         <item>BothPorts</item>
     </string-array>
+    <string-array name="settings_display_frame_pacing_entries">
+        <item>Always Display All Frames</item>
+        <item>Display All Frames When Possible</item>
+        <item>Skip Duplicate Frames</item>
+        <item>Clamp To Max FPS</item>
+    </string-array>
+    <string-array name="settings_display_frame_pacing_values">
+        <item>DisplayAllFrames</item>
+        <item>DisplayAllFramesWhenPossible</item>
+        <item>SkipDuplicateFrames</item>
+        <item>ClampToMaxFPS</item>
+    </string-array>
 </resources>
diff --git a/android/app/src/main/res/values/strings.xml b/android/app/src/main/res/values/strings.xml
index 861f7bc3e..554f88b5b 100644
--- a/android/app/src/main/res/values/strings.xml
+++ b/android/app/src/main/res/values/strings.xml
@@ -276,4 +276,5 @@
     <string name="controller_settings_category_ports">Ports</string>
     <string name="controller_settings_main_port_format">Port %d</string>
     <string name="controller_settings_sub_port_format">Port %1$d%2$c</string>
+    <string name="settings_display_frame_pacing">Frame Pacing</string>
 </resources>
diff --git a/android/app/src/main/res/xml/advanced_preferences.xml b/android/app/src/main/res/xml/advanced_preferences.xml
index 96b41425a..316a47a0f 100644
--- a/android/app/src/main/res/xml/advanced_preferences.xml
+++ b/android/app/src/main/res/xml/advanced_preferences.xml
@@ -56,11 +56,13 @@
             app:summary="@string/settings_summary_general_sync_to_host_refresh_rate"
             app:dependency="Display/VSync"
             app:iconSpaceReserved="false" />
-        <SwitchPreferenceCompat
-            app:key="Display/DisplayAllFrames"
-            app:title="@string/settings_display_all_frames"
-            app:defaultValue="false"
-            app:summary="@string/settings_summary_display_all_frames"
+        <ListPreference
+            app:key="Display/FramePacingMode"
+            app:entries="@array/settings_display_frame_pacing_entries"
+            app:entryValues="@array/settings_display_frame_pacing_values"
+            app:title="@string/settings_display_frame_pacing"
+            app:defaultValue="DisplayAllFramesWhenPossible"
+            app:useSimpleSummaryProvider="true"
             app:iconSpaceReserved="false" />
         <ListPreference
             app:key="Display/MaxFPS"
diff --git a/src/core/gpu.cpp b/src/core/gpu.cpp
index 638ba9479..5dacce4d1 100644
--- a/src/core/gpu.cpp
+++ b/src/core/gpu.cpp
@@ -855,7 +855,14 @@ void GPU::CRTCTickEvent(TickCount ticks)
 
         // flush any pending draws and "scan out" the image
         FlushRender();
-        UpdateDisplay();
+        if (IsInterlacedDisplayEnabled() || m_crtc_state.display_changed ||
+            g_settings.display_frame_pacing_mode != DisplayFramePacingMode::SkipDuplicateFrames ||
+            g_settings.debugging.show_vram)
+        {
+          m_crtc_state.display_changed = false;
+          UpdateDisplay();
+        }
+
         System::FrameDone();
 
         // switch fields early. this is needed so we draw to the correct one.
@@ -1073,6 +1080,7 @@ void GPU::WriteGP1(u32 value)
       Log_DebugPrintf("Display address start <- 0x%08X", new_value);
 
       System::IncrementInternalFrameNumber();
+      m_crtc_state.display_changed = true;
       if (m_crtc_state.regs.display_address_start != new_value)
       {
         SynchronizeCRTC();
diff --git a/src/core/gpu.h b/src/core/gpu.h
index 41424c41e..e61c6cc69 100644
--- a/src/core/gpu.h
+++ b/src/core/gpu.h
@@ -484,7 +484,13 @@ protected:
         BitField<u32, u16, 0, 10> Y1;
         BitField<u32, u16, 10, 10> Y2;
       };
-    } regs;
+    };
+
+    bool in_hblank;
+    bool in_vblank;
+    bool display_changed;
+
+    Regs regs;
 
     u16 dot_clock_divider;
 
@@ -523,9 +529,6 @@ protected:
 
     TickCount fractional_dot_ticks; // only used when timer0 is enabled
 
-    bool in_hblank;
-    bool in_vblank;
-
     u8 interlaced_field; // 0 = odd, 1 = even
     u8 interlaced_display_field;
     u8 active_line_lsb;
diff --git a/src/core/host_display.cpp b/src/core/host_display.cpp
index 141fcad5e..ae86918ff 100644
--- a/src/core/host_display.cpp
+++ b/src/core/host_display.cpp
@@ -5,6 +5,7 @@
 #include "common/log.h"
 #include "common/string_util.h"
 #include "common/timer.h"
+#include "settings.h"
 #include "host_interface.h"
 #include "stb_image.h"
 #include "stb_image_resize.h"
@@ -27,6 +28,9 @@ void HostDisplay::SetDisplayMaxFPS(float max_fps)
 
 bool HostDisplay::ShouldSkipDisplayingFrame()
 {
+  if (!m_display_duplicate_frames && !m_display_changed)
+    return true;
+
   if (m_display_frame_interval == 0.0f)
     return false;
 
diff --git a/src/core/host_display.h b/src/core/host_display.h
index 1c683eb74..a2c59d036 100644
--- a/src/core/host_display.h
+++ b/src/core/host_display.h
@@ -8,7 +8,7 @@
 #include <tuple>
 #include <vector>
 
-enum class HostDisplayPixelFormat : u32
+enum class HostDisplayPixelFormat : u8
 {
   Unknown,
   RGBA8,
@@ -46,7 +46,7 @@ public:
     OpenGLES
   };
 
-  enum class Alignment
+  enum class Alignment : u8
   {
     LeftOrTop,
     Center,
@@ -135,6 +135,7 @@ public:
   const float GetDisplayAspectRatio() const { return m_display_aspect_ratio; }
 
   void SetDisplayMaxFPS(float max_fps);
+  void SetDisplayDuplicateFrames(bool enabled) { m_display_duplicate_frames = enabled; }
   bool ShouldSkipDisplayingFrame();
 
   void ClearDisplayTexture()
@@ -267,7 +268,7 @@ protected:
   float m_display_frame_interval = 0.0f;
 
   void* m_display_texture_handle = nullptr;
-  HostDisplayPixelFormat m_display_texture_format = HostDisplayPixelFormat::Count;
+  std::unique_ptr<HostDisplayTexture> m_cursor_texture;
   s32 m_display_texture_width = 0;
   s32 m_display_texture_height = 0;
   s32 m_display_texture_view_x = 0;
@@ -276,13 +277,14 @@ protected:
   s32 m_display_texture_view_height = 0;
 
   s32 m_display_top_margin = 0;
-  Alignment m_display_alignment = Alignment::Center;
-
-  std::unique_ptr<HostDisplayTexture> m_cursor_texture;
   float m_cursor_texture_scale = 1.0f;
 
-  bool m_display_linear_filtering = false;
+  HostDisplayPixelFormat m_display_texture_format = HostDisplayPixelFormat::Count;
+  Alignment m_display_alignment = Alignment::Center;
+
   bool m_display_changed = false;
+  bool m_display_linear_filtering = false;
   bool m_display_integer_scaling = false;
   bool m_display_stretch = false;
+  bool m_display_duplicate_frames = false;
 };
diff --git a/src/core/host_interface.cpp b/src/core/host_interface.cpp
index bbb65fe1f..8fb82afa4 100644
--- a/src/core/host_interface.cpp
+++ b/src/core/host_interface.cpp
@@ -539,6 +539,8 @@ void HostInterface::SetDefaultSettings(SettingsInterface& si)
   si.SetIntValue("Display", "LineEndOffset", 0);
   si.SetStringValue("Display", "AspectRatio",
                     Settings::GetDisplayAspectRatioName(Settings::DEFAULT_DISPLAY_ASPECT_RATIO));
+  si.SetStringValue("Display", "FramePacingMode",
+                    Settings::GetDisplayFramePacingModeName(Settings::DEFAULT_DISPLAY_FRAME_PACING_MODE));
   si.SetBoolValue("Display", "Force4_3For24Bit", false);
   si.SetBoolValue("Display", "LinearFiltering", true);
   si.SetBoolValue("Display", "IntegerScaling", false);
@@ -551,7 +553,6 @@ void HostInterface::SetDefaultSettings(SettingsInterface& si)
   si.SetBoolValue("Display", "ShowResolution", false);
   si.SetBoolValue("Display", "Fullscreen", false);
   si.SetBoolValue("Display", "VSync", true);
-  si.SetBoolValue("Display", "DisplayAllFrames", false);
   si.SetStringValue("Display", "PostProcessChain", "");
   si.SetFloatValue("Display", "MaxFPS", 0.0f);
 
diff --git a/src/core/settings.cpp b/src/core/settings.cpp
index 061477cf9..e38287203 100644
--- a/src/core/settings.cpp
+++ b/src/core/settings.cpp
@@ -227,7 +227,11 @@ void Settings::Load(SettingsInterface& si)
   display_show_vps = si.GetBoolValue("Display", "ShowVPS", false);
   display_show_speed = si.GetBoolValue("Display", "ShowSpeed", false);
   display_show_resolution = si.GetBoolValue("Display", "ShowResolution", false);
-  display_all_frames = si.GetBoolValue("Display", "DisplayAllFrames", false);
+  display_frame_pacing_mode =
+    ParseDisplayFramePacingMode(
+      si.GetStringValue("Display", "FramePacingMode", GetDisplayFramePacingModeName(DEFAULT_DISPLAY_FRAME_PACING_MODE))
+        .c_str())
+      .value_or(DEFAULT_DISPLAY_FRAME_PACING_MODE);
   video_sync_enabled = si.GetBoolValue("Display", "VSync", true);
   display_post_process_chain = si.GetStringValue("Display", "PostProcessChain", "");
   display_max_fps = si.GetFloatValue("Display", "MaxFPS", 0.0f);
@@ -387,6 +391,7 @@ void Settings::Save(SettingsInterface& si) const
   si.SetIntValue("Display", "LineEndOffset", display_line_end_offset);
   si.SetBoolValue("Display", "Force4_3For24Bit", display_force_4_3_for_24bit);
   si.SetStringValue("Display", "AspectRatio", GetDisplayAspectRatioName(display_aspect_ratio));
+  si.SetStringValue("Display", "FramePacingMode", GetDisplayAspectRatioName(display_aspect_ratio));
   si.SetBoolValue("Display", "LinearFiltering", display_linear_filtering);
   si.SetBoolValue("Display", "IntegerScaling", display_integer_scaling);
   si.SetBoolValue("Display", "Stretch", display_stretch);
@@ -396,7 +401,6 @@ void Settings::Save(SettingsInterface& si) const
   si.SetBoolValue("Display", "ShowVPS", display_show_vps);
   si.SetBoolValue("Display", "ShowSpeed", display_show_speed);
   si.SetBoolValue("Display", "ShowResolution", display_show_resolution);
-  si.SetBoolValue("Display", "DisplayAllFrames", display_all_frames);
   si.SetBoolValue("Display", "VSync", video_sync_enabled);
   if (display_post_process_chain.empty())
     si.DeleteValue("Display", "PostProcessChain");
@@ -778,6 +782,38 @@ float Settings::GetDisplayAspectRatioValue(DisplayAspectRatio ar)
   return s_display_aspect_ratio_values[static_cast<int>(ar)];
 }
 
+static std::array<const char*, 4> s_display_frame_pacing_mode_names = {
+  {"DisplayAllFrames", "DisplayAllFramesWhenPossible", "SkipDuplicateFrames", "ClampToMaxFPS"}};
+static std::array<const char*, 4> s_display_frame_pacing_mode_display_names = {
+  {TRANSLATABLE("DisplayFramePacingMode", "Display All Frames"),
+   TRANSLATABLE("DisplayFramePacingMode", "Display All Frames When Possible"),
+   TRANSLATABLE("DisplayFramePacingMode", "Skip Duplicate Frames"),
+   TRANSLATABLE("DisplayFramePacingMode", "Clamp To Max FPS")}};
+
+std::optional<DisplayFramePacingMode> Settings::ParseDisplayFramePacingMode(const char* str)
+{
+  int index = 0;
+  for (const char* name : s_display_frame_pacing_mode_names)
+  {
+    if (StringUtil::Strcasecmp(name, str) == 0)
+      return static_cast<DisplayFramePacingMode>(index);
+
+    index++;
+  }
+
+  return std::nullopt;
+}
+
+const char* Settings::GetDisplayFramePacingModeName(DisplayFramePacingMode mode)
+{
+  return s_display_frame_pacing_mode_names[static_cast<int>(mode)];
+}
+
+const char* Settings::GetDisplayFramePacingModeDisplayName(DisplayFramePacingMode mode)
+{
+  return s_display_frame_pacing_mode_display_names[static_cast<int>(mode)];
+}
+
 static std::array<const char*, 3> s_audio_backend_names = {{
   "Null",
   "Cubeb",
diff --git a/src/core/settings.h b/src/core/settings.h
index 1531bb11e..f503a243d 100644
--- a/src/core/settings.h
+++ b/src/core/settings.h
@@ -127,6 +127,7 @@ struct Settings
   bool gpu_pgxp_depth_buffer = false;
   DisplayCropMode display_crop_mode = DisplayCropMode::None;
   DisplayAspectRatio display_aspect_ratio = DisplayAspectRatio::Auto;
+  DisplayFramePacingMode display_frame_pacing_mode = DisplayFramePacingMode::DisplayAllFramesWhenPossible;
   s16 display_active_start_offset = 0;
   s16 display_active_end_offset = 0;
   s8 display_line_start_offset = 0;
@@ -142,7 +143,6 @@ struct Settings
   bool display_show_vps = false;
   bool display_show_speed = false;
   bool display_show_resolution = false;
-  bool display_all_frames = false;
   bool video_sync_enabled = true;
   float display_max_fps = 0.0f;
   float gpu_pgxp_tolerance = -1.0f;
@@ -317,6 +317,10 @@ struct Settings
   static const char* GetDisplayAspectRatioName(DisplayAspectRatio ar);
   static float GetDisplayAspectRatioValue(DisplayAspectRatio ar);
 
+  static std::optional<DisplayFramePacingMode> ParseDisplayFramePacingMode(const char* str);
+  static const char* GetDisplayFramePacingModeName(DisplayFramePacingMode mode);
+  static const char* GetDisplayFramePacingModeDisplayName(DisplayFramePacingMode mode);
+
   static std::optional<AudioBackend> ParseAudioBackend(const char* str);
   static const char* GetAudioBackendName(AudioBackend backend);
   static const char* GetAudioBackendDisplayName(AudioBackend backend);
@@ -364,6 +368,8 @@ struct Settings
 
   static constexpr DisplayCropMode DEFAULT_DISPLAY_CROP_MODE = DisplayCropMode::Overscan;
   static constexpr DisplayAspectRatio DEFAULT_DISPLAY_ASPECT_RATIO = DisplayAspectRatio::Auto;
+  static constexpr DisplayFramePacingMode DEFAULT_DISPLAY_FRAME_PACING_MODE =
+    DisplayFramePacingMode::DisplayAllFramesWhenPossible;
   static constexpr ControllerType DEFAULT_CONTROLLER_1_TYPE = ControllerType::DigitalController;
   static constexpr ControllerType DEFAULT_CONTROLLER_2_TYPE = ControllerType::None;
   static constexpr MemoryCardType DEFAULT_MEMORY_CARD_1_TYPE = MemoryCardType::PerGameTitle;
diff --git a/src/core/types.h b/src/core/types.h
index 30a383aee..f94065936 100644
--- a/src/core/types.h
+++ b/src/core/types.h
@@ -110,6 +110,15 @@ enum class DisplayAspectRatio : u8
   Count
 };
 
+enum class DisplayFramePacingMode : u8
+{
+  DisplayAllFrames,
+  DisplayAllFramesWhenPossible,
+  SkipDuplicateFrames,
+  ClampToFPS,
+  Count
+};
+
 enum class AudioBackend : u8
 {
   Null,
diff --git a/src/duckstation-qt/displaysettingswidget.cpp b/src/duckstation-qt/displaysettingswidget.cpp
index 9a9312108..d82dfab40 100644
--- a/src/duckstation-qt/displaysettingswidget.cpp
+++ b/src/duckstation-qt/displaysettingswidget.cpp
@@ -28,6 +28,9 @@ DisplaySettingsWidget::DisplaySettingsWidget(QtHostInterface* host_interface, QW
   SettingWidgetBinder::BindWidgetToEnumSetting(m_host_interface, m_ui.displayCropMode, "Display", "CropMode",
                                                &Settings::ParseDisplayCropMode, &Settings::GetDisplayCropModeName,
                                                Settings::DEFAULT_DISPLAY_CROP_MODE);
+  SettingWidgetBinder::BindWidgetToEnumSetting(
+    m_host_interface, m_ui.framePacingMode, "Display", "FramePacingMode", &Settings::ParseDisplayFramePacingMode,
+    &Settings::GetDisplayFramePacingModeName, Settings::DEFAULT_DISPLAY_FRAME_PACING_MODE);
   SettingWidgetBinder::BindWidgetToEnumSetting(m_host_interface, m_ui.gpuDownsampleMode, "GPU", "DownsampleMode",
                                                &Settings::ParseDownsampleModeName, &Settings::GetDownsampleModeName,
                                                Settings::DEFAULT_GPU_DOWNSAMPLE_MODE);
@@ -39,8 +42,6 @@ DisplaySettingsWidget::DisplaySettingsWidget(QtHostInterface* host_interface, QW
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.internalResolutionScreenshots, "Display",
                                                "InternalResolutionScreenshots", false);
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.vsync, "Display", "VSync");
-  SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.displayAllFrames, "Display", "DisplayAllFrames",
-                                               false);
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.gpuThread, "GPU", "UseThread", true);
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.threadedPresentation, "GPU",
                                                "ThreadedPresentation", true);
@@ -112,7 +113,7 @@ DisplaySettingsWidget::DisplaySettingsWidget(QtHostInterface* host_interface, QW
     m_ui.vsync, tr("VSync"), tr("Checked"),
     tr("Enable this option to match DuckStation's refresh rate with your current monitor or screen. "
        "VSync is automatically disabled when it is not possible (e.g. running at non-100% speed)."));
-  dialog->registerWidgetHelp(m_ui.displayAllFrames, tr("Optimal Frame Pacing"), tr("Unchecked"),
+  dialog->registerWidgetHelp(m_ui.framePacingMode, tr("Optimal Frame Pacing"), tr("Unchecked"),
                              tr("Enable this option will ensure every frame the console renders is displayed to the "
                                 "screen, for optimal frame pacing. If you are having difficulties maintaining full "
                                 "speed, or are getting audio glitches, try disabling this option."));
@@ -140,7 +141,7 @@ DisplaySettingsWidget::DisplaySettingsWidget(QtHostInterface* host_interface, QW
   {
     QCheckBox* cb = new QCheckBox(tr("Use Blit Swap Chain"), m_ui.basicGroupBox);
     SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, cb, "Display", "UseBlitSwapChain", false);
-    m_ui.basicCheckboxGridLayout->addWidget(cb, 2, 0, 1, 1);
+    m_ui.basicCheckboxGridLayout->addWidget(cb, 1, 1, 1, 1);
     dialog->registerWidgetHelp(cb, tr("Use Blit Swap Chain"), tr("Unchecked"),
                                tr("Uses a blit presentation model instead of flipping when using the Direct3D 11 "
                                   "renderer. This usually results in slower performance, but may be required for some "
@@ -171,6 +172,13 @@ void DisplaySettingsWidget::setupAdditionalUi()
       qApp->translate("DisplayCropMode", Settings::GetDisplayCropModeDisplayName(static_cast<DisplayCropMode>(i))));
   }
 
+  for (u32 i = 0; i < static_cast<u32>(DisplayFramePacingMode::Count); i++)
+  {
+    m_ui.framePacingMode->addItem(
+      qApp->translate("DisplayFramePacingMode",
+                      Settings::GetDisplayFramePacingModeDisplayName(static_cast<DisplayFramePacingMode>(i))));
+  }
+
   for (u32 i = 0; i < static_cast<u32>(GPUDownsampleMode::Count); i++)
   {
     m_ui.gpuDownsampleMode->addItem(
diff --git a/src/duckstation-qt/displaysettingswidget.ui b/src/duckstation-qt/displaysettingswidget.ui
index c8385b2e1..8db2b9a1a 100644
--- a/src/duckstation-qt/displaysettingswidget.ui
+++ b/src/duckstation-qt/displaysettingswidget.ui
@@ -62,7 +62,17 @@
       <item row="2" column="1">
        <widget class="QComboBox" name="fullscreenMode"/>
       </item>
-      <item row="3" column="0" colspan="2">
+      <item row="3" column="0">
+       <widget class="QLabel" name="label_7">
+        <property name="text">
+         <string>Frame Pacing Mode:</string>
+        </property>
+       </widget>
+      </item>
+      <item row="3" column="1">
+       <widget class="QComboBox" name="framePacingMode"/>
+      </item>
+      <item row="4" column="0" colspan="2">
        <layout class="QGridLayout" name="basicCheckboxGridLayout">
         <item row="0" column="0">
          <widget class="QCheckBox" name="gpuThread">
@@ -85,13 +95,6 @@
           </property>
          </widget>
         </item>
-        <item row="1" column="1">
-         <widget class="QCheckBox" name="displayAllFrames">
-          <property name="text">
-           <string>Optimal Frame Pacing</string>
-          </property>
-         </widget>
-        </item>
        </layout>
       </item>
      </layout>
diff --git a/src/frontend-common/common_host_interface.cpp b/src/frontend-common/common_host_interface.cpp
index c35e574d0..1953b90c0 100644
--- a/src/frontend-common/common_host_interface.cpp
+++ b/src/frontend-common/common_host_interface.cpp
@@ -792,7 +792,8 @@ void CommonHostInterface::UpdateSpeedLimiterState()
                          g_settings.turbo_speed :
                          (m_fast_forward_enabled ? g_settings.fast_forward_speed : g_settings.emulation_speed);
   m_throttler_enabled = (target_speed != 0.0f);
-  m_display_all_frames = !m_throttler_enabled || g_settings.display_all_frames;
+  m_display_all_frames =
+    (!m_throttler_enabled || (g_settings.display_frame_pacing_mode == DisplayFramePacingMode::DisplayAllFrames));
 
   bool syncing_to_host = false;
   if (g_settings.sync_to_host_refresh_rate && g_settings.audio_resampling && target_speed == 1.0f && m_display &&
@@ -815,12 +816,18 @@ void CommonHostInterface::UpdateSpeedLimiterState()
     !System::IsRunning() || (m_throttler_enabled && g_settings.audio_sync_enabled && !is_non_standard_speed);
   const bool video_sync_enabled =
     !System::IsRunning() || (m_throttler_enabled && g_settings.video_sync_enabled && !is_non_standard_speed);
-  const float max_display_fps = (!System::IsValid() || m_throttler_enabled) ? 0.0f : g_settings.display_max_fps;
+  const float max_display_fps = (g_settings.display_frame_pacing_mode != DisplayFramePacingMode::ClampToFPS &&
+                                 (!System::IsValid() || m_throttler_enabled)) ?
+                                  0.0f :
+                                  g_settings.display_max_fps;
+  const bool display_duplicate_frames =
+    (g_settings.display_frame_pacing_mode != DisplayFramePacingMode::SkipDuplicateFrames) || !System::IsRunning();
   Log_InfoPrintf("Target speed: %f%%", target_speed * 100.0f);
   Log_InfoPrintf("Syncing to %s%s", audio_sync_enabled ? "audio" : "",
                  (audio_sync_enabled && video_sync_enabled) ? " and video" : (video_sync_enabled ? "video" : ""));
-  Log_InfoPrintf("Max display fps: %f (%s)", max_display_fps,
-                 m_display_all_frames ? "displaying all frames" : "skipping displaying frames when needed");
+  Log_InfoPrintf("Max display fps: %f", max_display_fps);
+  Log_InfoPrint(m_display_all_frames ? "Displaying all frames" : "Skipping displaying frames when needed");
+  Log_InfoPrint(display_duplicate_frames ? "Displaying duplicate frames" : "Skipping displaying duplicate frames");
 
   if (System::IsValid())
   {
@@ -979,7 +986,10 @@ void CommonHostInterface::OnSystemDestroyed()
 {
   // Restore present-all-frames behavior.
   if (m_display)
+  {
     m_display->SetDisplayMaxFPS(0.0f);
+    m_display->SetDisplayDuplicateFrames(true);
+  }
 
   HostInterface::OnSystemDestroyed();
 
@@ -2697,7 +2707,7 @@ void CommonHostInterface::CheckForSettingsChanges(const Settings& old_settings)
         g_settings.emulation_speed != old_settings.emulation_speed ||
         g_settings.fast_forward_speed != old_settings.fast_forward_speed ||
         g_settings.display_max_fps != old_settings.display_max_fps ||
-        g_settings.display_all_frames != old_settings.display_all_frames ||
+        g_settings.display_frame_pacing_mode != old_settings.display_frame_pacing_mode ||
         g_settings.audio_resampling != old_settings.audio_resampling ||
         g_settings.sync_to_host_refresh_rate != old_settings.sync_to_host_refresh_rate)
     {
diff --git a/src/frontend-common/d3d11_host_display.cpp b/src/frontend-common/d3d11_host_display.cpp
index 12faaf857..5c4f195cd 100644
--- a/src/frontend-common/d3d11_host_display.cpp
+++ b/src/frontend-common/d3d11_host_display.cpp
@@ -706,6 +706,7 @@ bool D3D11HostDisplay::Render()
   else
     m_swap_chain->Present(BoolToUInt32(m_vsync), 0);
 
+  m_display_changed = false;
   return true;
 }
 
diff --git a/src/frontend-common/fullscreen_ui.cpp b/src/frontend-common/fullscreen_ui.cpp
index f90575c64..0d1a283de 100644
--- a/src/frontend-common/fullscreen_ui.cpp
+++ b/src/frontend-common/fullscreen_ui.cpp
@@ -1895,10 +1895,12 @@ void DrawSettingsWindow()
             break;
         }
 
-        settings_changed |= ToggleButton("Optimal Frame Pacing",
-                                         "Ensures every frame generated is displayed for optimal pacing. Disable if "
-                                         "you are having speed or sound issues.",
-                                         &s_settings_copy.display_all_frames);
+        settings_changed |=
+          EnumChoiceButton("Frame Pacing Mode",
+                           "Ensures every frame generated is displayed for optimal pacing. Disable if "
+                           "you are having speed or sound issues.",
+                           &s_settings_copy.display_frame_pacing_mode, &Settings::GetDisplayFramePacingModeDisplayName,
+                           DisplayFramePacingMode::Count);
 
         MenuHeading("Screen Display");
 
diff --git a/src/frontend-common/opengl_host_display.cpp b/src/frontend-common/opengl_host_display.cpp
index 2e2e7f7d1..d7b0a41d6 100644
--- a/src/frontend-common/opengl_host_display.cpp
+++ b/src/frontend-common/opengl_host_display.cpp
@@ -761,6 +761,7 @@ bool OpenGLHostDisplay::Render()
   RenderSoftwareCursor();
 
   m_gl_context->SwapBuffers();
+  m_display_changed = false;
   return true;
 }
 
diff --git a/src/frontend-common/vulkan_host_display.cpp b/src/frontend-common/vulkan_host_display.cpp
index 8d9529977..8d0cc96f9 100644
--- a/src/frontend-common/vulkan_host_display.cpp
+++ b/src/frontend-common/vulkan_host_display.cpp
@@ -636,6 +636,7 @@ bool VulkanHostDisplay::Render()
                                         m_swap_chain->GetRenderingFinishedSemaphore(), m_swap_chain->GetSwapChain(),
                                         m_swap_chain->GetCurrentImageIndex(), !m_swap_chain->IsVSyncEnabled());
   g_vulkan_context->MoveToNextCommandBuffer();
+  m_display_changed = false;
 
   return true;
 }