feat: FPS Limiter (#1446)

* Add interpolation frame rate cap

* wip: reworked framelimiter

Based on my testing this is a bit more stable in frametimes.

* wip: efficiency improvement + windows build fix

Significantly improve efficiency by using a hybrid approach.

* wip: UI changes

* wip: end frame AFTER limiting

* wip: remove unused include

* wip: minor ui code change

Makes it easier to remove/add presets

* Simplify Limiter UI

- Change enableFrameInterpolation to an enum with off/capped/unlimited values
- Simplify the UI to use 2 settings (unlock framerate + a max value entry)

* wip: slight limiter simplification

* wip: implement review suggestions

* wip: fix syntax error

* wip: revert enum order + replace old checks

* Fix compile error

---------

Co-authored-by: SailorSnoW <sailorsnow@pm.me>
Co-authored-by: Loïs <49660929+SailorSnoW@users.noreply.github.com>
Co-authored-by: SuperDude88 <82904174+SuperDude88@users.noreply.github.com>
Co-authored-by: Luke Street <luke@street.dev>

include/dusk/frame_interpolation.h

@@ -4,6 +4,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
+#include "settings.h"
 
 class camera_process_class;
 class view_class;
@@ -18,7 +19,7 @@ void begin_record();
 void end_record();
 void begin_sim_tick();
 uint64_t sim_tick_seq();
-void begin_frame(bool enabled, bool is_sim_frame, float step);
+void begin_frame(FrameInterpMode mode, bool is_sim_frame, float step);
 void interpolate();
 float get_interpolation_step();
 

include/dusk/settings.h

@@ -34,6 +34,12 @@ enum class GyroMode : u8 {
     Mouse = 1,
 };
 
+enum class FrameInterpMode : u8 {
+    Off = 0,
+    Capped = 1,
+    Unlimited = 2,
+};
+
 namespace config {
 template <>
 struct ConfigEnumRange<BloomMode> {
@@ -58,7 +64,13 @@ struct ConfigEnumRange<GyroMode> {
     static constexpr auto min = GyroMode::Sensor;
     static constexpr auto max = GyroMode::Mouse;
 };
-}
+
+template <>
+struct ConfigEnumRange<FrameInterpMode> {
+    static constexpr auto min = FrameInterpMode::Off;
+    static constexpr auto max = FrameInterpMode::Unlimited;
+};
+}  // namespace config
 
 // Persistent user settings
 
@@ -72,6 +84,7 @@ struct UserSettings {
         ConfigVar<bool> lockAspectRatio;
         ConfigVar<bool> enableFpsOverlay;
         ConfigVar<int> fpsOverlayCorner;
+        ConfigVar<int> maxFrameRate;
     } video;
 
     struct {
@@ -124,7 +137,7 @@ struct UserSettings {
         ConfigVar<float> bloomMultiplier;
         ConfigVar<bool> disableWaterRefraction;
         ConfigVar<bool> enableTextureReplacements;
-        ConfigVar<bool> enableFrameInterpolation;
+        ConfigVar<FrameInterpMode> enableFrameInterpolation;
         ConfigVar<int> internalResolutionScale;
         ConfigVar<int> shadowResolutionMultiplier;
         ConfigVar<bool> enableDepthOfField;

include/dusk/time.h

@@ -17,16 +17,21 @@
 #include <shellapi.h>
 #include <intrin.h>
 #endif
+#ifdef __APPLE__
+#include <mach/mach_time.h>
+#endif
 
 class Limiter {
 public:
   using duration_t = Uint64;
 
-  void Reset() { m_oldTime = SDL_GetTicksNS(); }
+  void Reset() { 
+    m_oldTime = SDL_GetTicksNS(); 
+  }
 
-  void Sleep(duration_t targetFrameTime) {
+  duration_t Sleep(duration_t targetFrameTime) {
     if (targetFrameTime == 0) {
-      return;
+      return 0;
     }
 
     const Uint64 start = SDL_GetTicksNS();
@@ -41,6 +46,8 @@ public:
       }
     }
     Reset();
+
+    return adjustedSleepTime;
   }
 
   duration_t SleepTime(duration_t targetFrameTime) {
@@ -74,7 +81,6 @@ private:
     if (!initialized || numSleeps++ % 1000 == 0) {
       LARGE_INTEGER freq;
       if (QueryPerformanceFrequency(&freq) == 0) {
-        DuskLog.warn("QueryPerformanceFrequency failed: {}", GetLastError());
         return;
       }
       countPerNs = static_cast<double>(freq.QuadPart) / 1e9;
@@ -98,6 +104,33 @@ private:
 #endif
     } while (current.QuadPart - start.QuadPart < ticksToWait);
   }
+#elif defined (__APPLE__)
+  void NanoSleep(const duration_t duration) {
+      // Hybrid approach using Apple Mach
+      uint64_t start_mach = mach_absolute_time();
+
+      mach_timebase_info_data_t timebase_info;
+      mach_timebase_info(&timebase_info);
+
+      uint64_t total_mach_ticks = (duration * timebase_info.denom) / timebase_info.numer;
+      uint64_t target_mach = start_mach + total_mach_ticks;
+
+      uint64_t buffer_ns = 2'000'000ULL;
+      uint64_t buffer_mach_ticks = (buffer_ns * timebase_info.denom) / timebase_info.numer;
+
+      if (total_mach_ticks > buffer_mach_ticks) {
+          uint64_t sleep_until_mach = target_mach - buffer_mach_ticks;
+          mach_wait_until(sleep_until_mach);
+      }
+
+      while (mach_absolute_time() < target_mach) {
+#if defined(__aarch64__) || defined(__arm__)
+          asm volatile("yield" ::: "memory");  // Hardware hint, not a scheduler hint.
+#else
+          _mm_pause();
+#endif
+      }
+  }
 #else
   void NanoSleep(const duration_t duration) { SDL_DelayPrecise(duration); }
 #endif

libs/JSystem/src/JFramework/JFWDisplay.cpp

@@ -370,28 +370,28 @@ constexpr auto FRAME_PERIOD = std::chrono::duration_cast<std::chrono::nanosecond
 constexpr auto RETRACE_PERIOD = FRAME_PERIOD / 2;
 
 static void waitPrecise(Limiter& limiter, Limiter::duration_t targetNs) {
-    const auto sleepTime = limiter.SleepTime(targetNs);
+   const auto sleepTime = limiter.Sleep(targetNs);
     dusk::frameUsagePct =
         100.0f * (1.0f - static_cast<float>(sleepTime) / static_cast<float>(targetNs));
-    limiter.Sleep(targetNs);
 }
 #endif
 
 static void waitForTick(u32 p1, u16 p2) {
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation && !dusk::getTransientSettings().skipFrameRateLimit) {
+    static Limiter limiter;
-        dusk::frameUsagePct = 0.f;
+
-        return;
+    if (dusk::frame_interp::is_enabled() && !dusk::getTransientSettings().skipFrameRateLimit) {
+        dusk::frameUsagePct = 0.f; 
+        return; 
     }
+
     if (dusk::getTransientSettings().skipFrameRateLimit) {
         p1 = OS_TIMER_CLOCK / 120;
     }
     
-    #if TARGET_PC
     if (fopOvlpM_IsPeek() && dusk::getTransientSettings().stateShareLoadActive) {
         return;
     }
-    #endif
 
     ZoneScopedC(tracy::Color::DimGray);
 #endif

libs/JSystem/src/JStudio/JStudio/jstudio-object.cpp

@@ -655,7 +655,7 @@ value_or_fun:
 
 value:
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation && u <= 5 &&
+    if (dusk::frame_interp::is_enabled() && u <= 5 &&
         (operation == data::UNK_0x2 || operation == data::UNK_0x3 || operation == data::UNK_0x12))
     {
         dusk::frame_interp::request_presentation_sync();
@@ -666,7 +666,7 @@ value:
 
 value_n:
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation &&
+    if (dusk::frame_interp::is_enabled() &&
         (pN == TAdaptor_camera::sauVariableValue_3_POSITION_XYZ || pN == TAdaptor_camera::sauVariableValue_3_TARGET_POSITION_XYZ) &&
         (operation == data::UNK_0x2 || operation == data::UNK_0x3 || operation == data::UNK_0x12))
     {

src/d/actor/d_a_alink.cpp

@@ -5990,7 +5990,7 @@ void daAlink_c::setItemMatrix(int param_0) {
 
         mDoMtx_stack_c::XrotS(-0x8000);
 #ifdef TARGET_PC
-        if (dusk::getSettings().game.enableFrameInterpolation) {
+        if (dusk::frame_interp::is_enabled()) {
             Mtx boot_mtx;
             mDoMtx_concat(mpLinkModel->getAnmMtx(0x18), mDoMtx_stack_c::get(), boot_mtx);
             mpLinkBootModels[1]->setAnmMtx(1, boot_mtx);
@@ -19767,7 +19767,7 @@ int daAlink_c::draw() {
                 dComIfGd_getOpaListDark()->entryImm(mpHookChain, 0);
 
 #if TARGET_PC
-                if (dusk::getSettings().game.enableFrameInterpolation &&
+                if (dusk::frame_interp::is_enabled() &&
                     mEquipItem == dItemNo_IRONBALL_e &&
                     mIronBallChainPos != NULL && mIronBallChainAngle != NULL)
                 {

src/d/actor/d_a_b_gnd.cpp

@@ -397,7 +397,7 @@ static int daB_GND_Draw(b_gnd_class* i_this) {
         i_this->field_0x21e8.update(2, l_color, &a_this->tevStr);
         dComIfGd_set3DlineMat(&i_this->field_0x21e8);
 #if TARGET_PC
-        if (dusk::getSettings().game.enableFrameInterpolation) {
+        if (dusk::frame_interp::is_enabled()) {
             if (i_this->mReinsInterpCurrValid) {
                 memcpy(i_this->mReinsInterpPrev, i_this->mReinsInterpCurr, sizeof(i_this->mReinsInterpCurr));
                 memcpy(i_this->mReinsTexInterpPrev, i_this->mReinsTexInterpCurr, sizeof(i_this->mReinsTexInterpCurr));

src/d/actor/d_a_e_db.cpp

@@ -116,7 +116,7 @@ static int daE_DB_Draw(e_db_class* i_this) {
     i_this->stalkLine.update(12, l_color, &actor->tevStr);
     dComIfGd_set3DlineMat(&i_this->stalkLine);
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         if (i_this->mStalkLineInterpCurrValid) {
             memcpy(i_this->mStalkLineInterpPrev, i_this->mStalkLineInterpCurr, sizeof(i_this->mStalkLineInterpCurr));
             i_this->mStalkLineInterpPrevValid = true;

src/d/actor/d_a_e_hb.cpp

@@ -103,7 +103,7 @@ static int daE_HB_Draw(e_hb_class* i_this) {
     i_this->stalkLine.update(12, l_color, &actor->tevStr);
     dComIfGd_set3DlineMat(&i_this->stalkLine);
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         if (i_this->mStalkLineInterpCurrValid) {
             memcpy(i_this->mStalkLineInterpPrev, i_this->mStalkLineInterpCurr, sizeof(i_this->mStalkLineInterpCurr));
             i_this->mStalkLineInterpPrevValid = true;

src/d/actor/d_a_e_mb.cpp

@@ -105,7 +105,7 @@ static int daE_MB_Draw(e_mb_class* i_this) {
     i_this->mRopeMat.update(16, l_color, &a_this->tevStr);
     dComIfGd_set3DlineMat(&i_this->mRopeMat);
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         if (i_this->mRopeInterpCurrValid) {
             memcpy(i_this->mRopeInterpPrev, i_this->mRopeInterpCurr, sizeof(i_this->mRopeInterpCurr));
             i_this->mRopeInterpPrevValid = true;

src/d/actor/d_a_e_s1.cpp

@@ -161,7 +161,7 @@ static int daE_S1_Draw(e_s1_class* i_this) {
     dComIfGd_set3DlineMatDark(&i_this->mLineMat);
 
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         if (i_this->mHairInterpCurrValid) {
             memcpy(i_this->mHairInterpPrev, i_this->mHairInterpCurr, sizeof(i_this->mHairInterpCurr));
             i_this->mHairInterpPrevValid = true;

src/d/actor/d_a_e_wb.cpp

@@ -535,7 +535,7 @@ static int daE_WB_Draw(e_wb_class* i_this) {
         i_this->himo_tex.update(2, l_color, &actor->tevStr);
         dComIfGd_set3DlineMat(&i_this->himo_tex);
 #if TARGET_PC
-        if (dusk::getSettings().game.enableFrameInterpolation) {
+        if (dusk::frame_interp::is_enabled()) {
             if (i_this->himo_interp_curr_valid) {
                 memcpy(i_this->himo_mat_interp_prev, i_this->himo_mat_interp_curr, sizeof(i_this->himo_mat_interp_curr));
                 memcpy(i_this->himo_tex_interp_prev, i_this->himo_tex_interp_curr, sizeof(i_this->himo_tex_interp_curr));

src/d/actor/d_a_e_yd.cpp

@@ -107,7 +107,7 @@ static s32 daE_YD_Draw(e_yd_class* i_this) {
     i_this->mLineMat.update(12, l_color, &i_this->actor.tevStr);
     dComIfGd_set3DlineMat(&i_this->mLineMat);
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         if (i_this->mLineMatInterpCurrValid) {
             memcpy(i_this->mLineMatInterpPrev, i_this->mLineMatInterpCurr, sizeof(i_this->mLineMatInterpCurr));
             i_this->mLineMatInterpPrevValid = true;

src/d/actor/d_a_e_yg.cpp

@@ -191,7 +191,7 @@ static int daE_YG_Draw(e_yg_class* i_this) {
     dComIfGd_set3DlineMatDark(&i_this->mLineMat);
 
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         if (i_this->mTentacleInterpCurrValid) {
             memcpy(i_this->mTentacleInterpPrev, i_this->mTentacleInterpCurr, sizeof(i_this->mTentacleInterpCurr));
             i_this->mTentacleInterpPrevValid = true;

src/d/actor/d_a_e_yh.cpp

@@ -135,7 +135,7 @@ static int daE_YH_Draw(e_yh_class* i_this) {
     i_this->mLine.update(12, l_color, &a_this->tevStr);
     dComIfGd_set3DlineMat(&i_this->mLine);
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         if (i_this->mLineInterpCurrValid) {
             memcpy(i_this->mLineInterpPrev, i_this->mLineInterpCurr, sizeof(i_this->mLineInterpCurr));
             i_this->mLineInterpPrevValid = true;

src/d/actor/d_a_horse.cpp

@@ -3165,7 +3165,7 @@ void daHorse_c::setReinPosNormalSubstance() {
 #if TARGET_PC
 void daHorse_c::lerpControlPoints(f32 alpha) {
     // FRAME INTERP NOTE: Currently only lerping points for Epona's reins. Need a more global solution.
-    if (!dusk::getSettings().game.enableFrameInterpolation || !s_horseReinSimPrevValid || !s_horseReinSimCurrValid) {
+    if (!dusk::frame_interp::is_enabled() || !s_horseReinSimPrevValid || !s_horseReinSimCurrValid) {
         return;
     }
     const int nCurr = s_horseReinSimNumCurr;

src/d/actor/d_a_obj_fchain.cpp

@@ -325,7 +325,7 @@ int daObjFchain_c::draw() {
         dComIfGd_getOpaListDark()->entryImm(&mShape, 0);
 
 #if TARGET_PC
-        if (dusk::getSettings().game.enableFrameInterpolation) {
+        if (dusk::frame_interp::is_enabled()) {
             if (mChainInterpCurrValid) {
                 memcpy(mChainInterpPrev, mChainInterpCurr, sizeof(mChainInterpCurr));
                 mChainInterpPrevValid = true;

src/d/actor/d_a_obj_klift00.cpp

@@ -493,7 +493,7 @@ int daObjKLift00_c::Draw() {
     dComIfGd_setList();
 
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         if (mChainInterpCurrValid) {
             memcpy(mChainInterpPrev, mChainInterpCurr, mNumChains * sizeof(cXyz));
             mChainInterpPrevValid = true;

src/d/actor/d_a_title.cpp

@@ -170,7 +170,7 @@ int daTitle_c::Execute() {
     }
 
 #ifdef TARGET_PC
-    if (!dusk::getSettings().game.enableFrameInterpolation) {
+    if (!dusk::frame_interp::is_enabled()) {
 #endif
         dMenu_Collect3D_c::setViewPortOffsetY(0.0f);
 #ifdef TARGET_PC
@@ -354,7 +354,7 @@ void daTitle_c::fastLogoDispInit() {
     mProcID = 5;
 
 #ifdef TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         dusk::frame_interp::request_presentation_sync();
     }
 #endif

src/d/d_camera.cpp

@@ -10431,7 +10431,7 @@ bool dCamera_c::eventCamera(s32 param_0) {
 #endif
 
 #if TARGET_PC
-        if (dusk::getSettings().game.enableFrameInterpolation) {
+        if (dusk::frame_interp::is_enabled()) {
             switch (var_r29) {
                 case 3:
                 case 4:
@@ -11322,7 +11322,7 @@ static int camera_execute(camera_process_class* i_this) {
 #ifdef TARGET_PC
     widezoom_correction(i_this, i_this->mCamera.TrimHeight());
 
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         dusk::frame_interp::add_interpolation_callback([](bool _, void* pUserWork) {
             const auto i_this = static_cast<camera_process_class*>(pUserWork);
             const auto camera = &i_this->mCamera;

src/d/d_menu_dmap.cpp

@@ -991,7 +991,7 @@ void dMenu_DmapBg_c::draw() {
             -35.0f + (local_224.x - local_218.x),
             -35.0f + (local_224.y - local_218.y));
 #if TARGET_PC
-        if (!dusk::getSettings().game.enableFrameInterpolation) {
+        if (!dusk::frame_interp::is_enabled()) {
             field_0xdda = 0;
         }
 #else
@@ -2624,7 +2624,7 @@ void dMenu_Dmap_c::zoomIn_proc() {
 
 void dMenu_Dmap_c::zoomOut_init_proc() {
 #if TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         mpDrawBg->resetScrollArrowMask();
     }
 #endif

src/d/d_menu_fmap.cpp

@@ -1146,7 +1146,7 @@ void dMenu_Fmap_c::zoom_spot_to_region_init() {
     field_0x1ec = 1.0f;
 #if TARGET_PC
     // Frame interp note: field_0x122d used to be set every draw, causing flickering. Do it here instead.
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         mpDraw2DBack->resetScrollArrowMask();
     }
 #endif

src/d/d_menu_fmap2D.cpp

@@ -437,7 +437,7 @@ void dMenu_Fmap2DBack_c::draw() {
     if (field_0x122d) {
         mpMeterHaihai->drawHaihai(field_0x122d);
 #if TARGET_PC
-        if (!dusk::getSettings().game.enableFrameInterpolation) {
+        if (!dusk::frame_interp::is_enabled()) {
             field_0x122d = 0;
         }
 #else

src/dusk/config.cpp

@@ -56,6 +56,23 @@ static T sanitizeEnumValue(const ConfigVar<T>& cVar, T value) {
 
 template<ConfigValue T>
 void ConfigImpl<T>::loadFromJson(ConfigVar<T>& cVar, const json& jsonValue) {
+    if constexpr (std::is_enum_v<T>) {
+        if (jsonValue.is_boolean()) {
+            using Underlying = std::underlying_type_t<T>;
+            const bool b = jsonValue.get<bool>();
+
+            Underlying raw;
+            if constexpr (std::is_same_v<T, dusk::FrameInterpMode>) {
+                raw = b ? static_cast<Underlying>(2) : static_cast<Underlying>(0);
+            } else {
+                raw = b ? static_cast<Underlying>(1) : static_cast<Underlying>(0);
+            }
+
+            cVar.setValue(sanitizeEnumValue(cVar, static_cast<T>(raw)), false);
+            return;
+        }
+    }
+
     cVar.setValue(sanitizeEnumValue(cVar, jsonValue.get<T>()), false);
 }
 
@@ -158,6 +175,7 @@ namespace dusk::config {
     template class ConfigImpl<dusk::DiscVerificationState>;
     template class ConfigImpl<dusk::GameLanguage>;
     template class ConfigImpl<dusk::GyroMode>;
+    template class ConfigImpl<dusk::FrameInterpMode>;
 }
 
 void dusk::config::Register(ConfigVarBase& configVar) {

src/dusk/frame_interpolation.cpp

@@ -142,8 +142,8 @@ uint64_t sim_tick_seq() {
     return g_sim_tick_seq;
 }
 
-void begin_frame(bool enabled, bool is_sim_frame, float step) {
+void begin_frame(FrameInterpMode mode, bool is_sim_frame, float step) {
-    g_enabled = enabled;
+    g_enabled = mode != FrameInterpMode::Off;
     g_is_sim_frame = is_sim_frame;
     g_step = std::clamp(step, 0.0f, 1.0f);
 }

src/dusk/game_clock.cpp

@@ -4,6 +4,7 @@
 #include <chrono>
 #include <cmath>
 #include <unordered_map>
+#include <dusk/frame_interpolation.h>
 
 namespace dusk::game_clock {
 
@@ -45,7 +46,8 @@ MainLoopPacer advance_main_loop() {
     MainLoopPacer out{};
     out.presentation_dt_seconds = presentation_dt;
 
-    const bool should_interpolate = dusk::getSettings().game.enableFrameInterpolation &&
+    const bool should_interpolate = dusk::getSettings().game.enableFrameInterpolation.getValue() !=
+                                        dusk::FrameInterpMode::Off &&
                                     !dusk::getTransientSettings().skipFrameRateLimit;
     out.is_interpolating = should_interpolate;
     out.sim_pace = sim_pace();

src/dusk/settings.cpp

@@ -10,6 +10,7 @@ UserSettings g_userSettings = {
         .lockAspectRatio {"video.lockAspectRatio", false},
         .enableFpsOverlay {"game.enableFpsOverlay", false},
         .fpsOverlayCorner {"game.fpsOverlayCorner", 0},
+        .maxFrameRate {"video.maxFrameRate", 240},
     },
 
     .audio = {
@@ -59,7 +60,7 @@ UserSettings g_userSettings = {
         .bloomMultiplier {"game.bloomMultiplier", 1.0f},
         .disableWaterRefraction {"game.disableWaterRefraction", false},
         .enableTextureReplacements {"game.enableTextureReplacements", true},
-        .enableFrameInterpolation {"game.enableFrameInterpolation", false},
+        .enableFrameInterpolation {"game.enableFrameInterpolation", FrameInterpMode::Off},
         .internalResolutionScale {"game.internalResolutionScale", 0},
         .shadowResolutionMultiplier {"game.shadowResolutionMultiplier", 1},
         .enableDepthOfField {"game.enableDepthOfField", true},
@@ -178,6 +179,7 @@ void registerSettings() {
     Register(g_userSettings.video.lockAspectRatio);
     Register(g_userSettings.video.enableFpsOverlay);
     Register(g_userSettings.video.fpsOverlayCorner);
+    Register(g_userSettings.video.maxFrameRate);
 
     // Audio
     Register(g_userSettings.audio.masterVolume);

src/dusk/ui/preset.cpp

@@ -40,7 +40,7 @@ void applyPresetDusk() {
     s.game.enableQuickTransform.setValue(true);
     s.game.instantSaves.setValue(true);
     s.game.midnasLamentNonStop.setValue(true);
-    s.game.enableFrameInterpolation.setValue(true);
+    s.game.enableFrameInterpolation.setValue(FrameInterpMode::Unlimited);
     s.game.sunsSong.setValue(true);
     s.game.bloomMode.setValue(BloomMode::Dusk);
     s.game.internalResolutionScale.setValue(0);

src/dusk/ui/settings.cpp

@@ -59,6 +59,12 @@ constexpr std::array kFpsOverlayCornerNames = {
     "Bottom Right",
 };
 
+constexpr std::array kInterpolationModes = {
+    "Off",
+    "Capped",
+    "Unlimited",
+};
+
 constexpr std::array kGyroInputModeLabels = {
     "Sensor",
     "Mouse",
@@ -357,7 +363,7 @@ const Rml::String kBloomHelpText =
 const Rml::String kBloomBrightnessHelpText =
     "Configure bloom intensity. Higher values make bright areas glow more strongly.";
 const Rml::String kUnlockFramerateHelpText =
-    "Uses inter-frame interpolation to enable higher frame rates.<br/><br/>May introduce minor "
+    "<br/>Uses inter-frame interpolation to enable higher frame rates.<br/><br/>May introduce minor "
     "visual artifacts or animation glitches.";
 
 int float_setting_percent(ConfigVar<float>& var) {
@@ -440,6 +446,31 @@ SelectButton& config_percent_select(Pane& leftPane, Pane& rightPane, ConfigVar<f
     return button;
 }
 
+SelectButton& config_int_select(Pane& leftPane, Pane& rightPane, ConfigVar<int>& var,
+    Rml::String key, Rml::String helpText, int min, int max, int step = 5,
+    std::function<bool()> isDisabled = {}, std::string suffix = "") {
+    auto& button = leftPane.add_child<NumberButton>(NumberButton::Props{
+        .key = std::move(key),
+        .getValue = [&var] { return var; },
+        .setValue =
+            [&var, min, max](int value) {
+                var.setValue(std::clamp(value, min, max));
+                config::Save();
+            },
+        .isDisabled = std::move(isDisabled),
+        .isModified = [&var] { return var.getValue() != var.getDefaultValue(); },
+        .min = min,
+        .max = max,
+        .step = step,
+        .suffix = suffix,
+    });
+    leftPane.register_control(button, rightPane, [helpText = std::move(helpText)](Pane& pane) {
+        pane.clear();
+        pane.add_text(helpText);
+    });
+    return button;
+}
+
 template <typename T>
 void graphics_tuner_control(Window& window, Pane& leftPane, Pane& rightPane, ConfigVar<T>& var,
     const GraphicsTunerProps& props, bool prelaunch) {
@@ -803,11 +834,39 @@ SettingsWindow::SettingsWindow(bool prelaunch) : mPrelaunch(prelaunch) {
                 .helpText = "Enable installed texture replacements.",
                 .onChange = [](bool value) { aurora_set_texture_replacements_enabled(value); },
             });
-        config_bool_select(leftPane, rightPane, getSettings().game.enableFrameInterpolation,
+        leftPane.register_control(
-            {
+            leftPane.add_select_button({
                 .key = "Unlock Framerate",
-                .helpText = kUnlockFramerateHelpText,
+                .getValue =
+                    [] {
+                        return kInterpolationModes[static_cast<u8>(getSettings().game.enableFrameInterpolation.getValue())];
+                    },
+                .isModified =
+                    [] {
+                        return getSettings().game.enableFrameInterpolation.getValue() !=
+                               getSettings().game.enableFrameInterpolation.getDefaultValue();
+                    },
+            }),
+            rightPane, [](Pane& pane) {
+                for (int i = 0; i < kInterpolationModes.size(); i++) {
+                    pane.add_button({
+                            .text = kInterpolationModes[i],
+                            .isSelected =
+                                [i] {
+                                    return getSettings().game.enableFrameInterpolation.getValue() == static_cast<FrameInterpMode>(i);
+                                },
+                        })
+                        .on_pressed([i] {
+                            mDoAud_seStartMenu(kSoundItemChange);
+                            getSettings().game.enableFrameInterpolation.setValue(static_cast<FrameInterpMode>(i));
+                            config::Save();
+                        });
+                }
+                pane.add_rml(kUnlockFramerateHelpText);
             });
+        config_int_select(leftPane, rightPane, getSettings().video.maxFrameRate,
+            "Framerate Cap", "Limit the framerate to the specified value.", 30, 540, 1,
+            [] { return getSettings().game.enableFrameInterpolation.getValue() != FrameInterpMode::Capped; });
         config_bool_select(leftPane, rightPane, getSettings().game.enableDepthOfField,
             {
                 .key = "Enable Depth of Field",

src/m_Do/m_Do_ext.cpp

@@ -2410,7 +2410,7 @@ void mDoExt_3DlineMat0_c::draw() {
     }
 
 #if TARGET_PC
-    if (!dusk::getSettings().game.enableFrameInterpolation)
+    if (!dusk::frame_interp::is_enabled())
 #endif
     {
         field_0x16 ^= (u8)1;
@@ -2740,7 +2740,7 @@ void mDoExt_3DlineMat1_c::draw() {
     }
     GXSetTexCoordScaleManually(GX_TEXCOORD0, 0, 0, 0);
 #if TARGET_PC
-    if (!dusk::getSettings().game.enableFrameInterpolation)
+    if (!dusk::frame_interp::is_enabled())
 #endif
     {
         mIsDrawn ^= (u8)1;
@@ -2822,7 +2822,7 @@ void mDoExt_3DlineMat1_c::update(int param_0, f32 param_1, GXColor& param_2, u16
         }
 
 #if TARGET_PC
-        const cXyz& lineEye = (presentationEye != nullptr && dusk::getSettings().game.enableFrameInterpolation) ? *presentationEye : sp_3c->lookat.eye;
+        const cXyz& lineEye = (presentationEye != nullptr && dusk::frame_interp::is_enabled()) ? *presentationEye : sp_3c->lookat.eye;
         sp_13c = *local_r27 - lineEye;
 #else
         sp_13c = *local_r27 - sp_3c->lookat.eye;
@@ -2982,7 +2982,7 @@ void mDoExt_3DlineMat1_c::update(int param_0, GXColor& param_2, dKy_tevstr_c* pa
         local_r27 = sp_38[0].field_0x0;
         size_p = sp_38->field_0x4;
 #if TARGET_PC
-        if (presentationEye != nullptr && dusk::getSettings().game.enableFrameInterpolation && size_p == NULL) {
+        if (presentationEye != nullptr && dusk::frame_interp::is_enabled() && size_p == NULL) {
             sp_38 += 1;
             continue;
         }
@@ -3001,7 +3001,7 @@ void mDoExt_3DlineMat1_c::update(int param_0, GXColor& param_2, dKy_tevstr_c* pa
         local_f30 = sp_130.abs();
         local_f31 += local_f30 * 0.1f;
 #if TARGET_PC
-        const cXyz& lineEye = (presentationEye != nullptr && dusk::getSettings().game.enableFrameInterpolation) ? *presentationEye : stack_3c->lookat.eye;
+        const cXyz& lineEye = (presentationEye != nullptr && dusk::frame_interp::is_enabled()) ? *presentationEye : stack_3c->lookat.eye;
         sp_13c = local_r27[0] - lineEye;
 #else
         sp_13c = local_r27[0] - stack_3c->lookat.eye;
@@ -3077,7 +3077,7 @@ void mDoExt_3DlineMat1_c::update(int param_0, GXColor& param_2, dKy_tevstr_c* pa
 
 #if TARGET_PC
 void mDoExt_3DlineMat1_c::refreshGeometryForPresentationEye(const cXyz& eye) {
-    if (!dusk::getSettings().game.enableFrameInterpolation) {
+    if (!dusk::frame_interp::is_enabled()) {
         return;
     }
     if (mInterpLineKind == 1) {

src/m_Do/m_Do_graphic.cpp

@@ -2063,7 +2063,7 @@ static void captureScreenPerspDrawInfo(JPADrawInfo& info) {
 static void drawItem3D() {
     ZoneScoped;
 #ifdef TARGET_PC
-    if (dusk::getSettings().game.enableFrameInterpolation) {
+    if (dusk::frame_interp::is_enabled()) {
         // FRAME INTERP NOTE: Title screen needs 0.0f while everything else that runs through this is -100.0f.
         if (fopAcM_SearchByName(fpcNm_TITLE_e) != nullptr) {
             dMenu_Collect3D_c::setViewPortOffsetY(0.0f);
@@ -2241,7 +2241,7 @@ int mDoGph_Painter() {
 #endif
             dKy_setLight();
 #if TARGET_PC
-            if (dusk::getSettings().game.enableFrameInterpolation) {
+            if (dusk::frame_interp::is_enabled()) {
                 dKy_setLight_again();
             }
 #endif
@@ -2296,7 +2296,7 @@ int mDoGph_Painter() {
             }
 
 #if TARGET_PC
-            if (dusk::getSettings().game.enableFrameInterpolation) {
+            if (dusk::frame_interp::is_enabled()) {
                 // FRAME INTERP NOTE: Currently only recalculating points for Epona's reins. Need a more global solution.
                 if (daHorse_c* horse = dComIfGp_getHorseActor()) {
                     horse->lerpControlPoints(dusk::frame_interp::get_interpolation_step());

src/m_Do/m_Do_main.cpp

@@ -28,6 +28,7 @@
 #include "d/d_s_logo.h"
 #include "d/d_s_menu.h"
 #include "d/d_s_play.h"
+#include "dusk/time.h"
 #include "f_ap/f_ap_game.h"
 #include "f_op/f_op_msg.h"
 #include "m_Do/m_Do_MemCard.h"
@@ -279,8 +280,9 @@ void main01(void) {
         const auto pacing = dusk::game_clock::advance_main_loop();
         if (pacing.is_interpolating) {
             if (pacing.sim_ticks_to_run > 0) {
-                dusk::frame_interp::begin_frame(true, true, 0.0f);
+                dusk::frame_interp::begin_frame(dusk::getSettings().game.enableFrameInterpolation, true, 0.0f);
                 dusk::frame_interp::set_ui_tick_pending(true);
+
                 for (int sim_tick = 0; sim_tick < pacing.sim_ticks_to_run; ++sim_tick) {
                     dusk::frame_interp::begin_sim_tick();
                     mDoCPd_c::read();
@@ -291,7 +293,7 @@ void main01(void) {
                 }
             }
 
-            dusk::frame_interp::begin_frame(true, false,
+            dusk::frame_interp::begin_frame(dusk::getSettings().game.enableFrameInterpolation, false,
                                             dusk::game_clock::sample_interpolation_step());
             dusk::frame_interp::interpolate();
             dusk::frame_interp::begin_presentation_camera();
@@ -301,7 +303,7 @@ void main01(void) {
             dusk::frame_interp::end_presentation_camera();
             dusk::frame_interp::set_ui_tick_pending(false);
         } else {
-            dusk::frame_interp::begin_frame(false, true, 0.0f);
+            dusk::frame_interp::begin_frame(dusk::FrameInterpMode::Off, true, 0.0f);
             dusk::frame_interp::set_ui_tick_pending(true);
 
             // Game Inputs
@@ -315,8 +317,26 @@ void main01(void) {
             mDoAud_Execute();
         }
 
+        static Limiter main_loop_limiter;
+        static double last_fps_setting = 0.0;
+        static Limiter::duration_t target_ns = 0;
+
+        if (dusk::getSettings().game.enableFrameInterpolation.getValue() == dusk::FrameInterpMode::Capped && !dusk::getTransientSettings().skipFrameRateLimit) {
+            double current_fps = dusk::getSettings().video.maxFrameRate.getValue();
+            if (current_fps != last_fps_setting) {
+                last_fps_setting = current_fps;
+                target_ns = static_cast<Limiter::duration_t>(1'000'000'000.0 / current_fps);
+            }
+
+            Limiter::duration_t sleepTime = main_loop_limiter.Sleep(target_ns);
+            dusk::frameUsagePct = 100.0f * (1.0f - static_cast<float>(sleepTime) / static_cast<float>(target_ns));
+        } else {
+            main_loop_limiter.Reset();
+        }
+
         aurora_end_frame();
 
+
         FrameMark;
 
 #ifdef DUSK_DISCORD