[GPU]: Implement a working Frame-Skip into Android

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/BooleanSetting.kt

@@ -51,7 +51,6 @@ enum class BooleanSetting(override val key: String) : AbstractBooleanSetting {
 
     ENABLE_RAII("enable_raii"),
     FRAME_INTERPOLATION("frame_interpolation"),
-//    FRAME_SKIPPING("frame_skipping"),
 
     PERF_OVERLAY_BACKGROUND("perf_overlay_background"),
     SHOW_PERFORMANCE_OVERLAY("show_performance_overlay"),

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/IntSetting.kt

@@ -42,6 +42,7 @@ enum class IntSetting(override val key: String) : AbstractIntSetting {
     RENDERER_SAMPLE_SHADING_FRACTION("sample_shading_fraction"),
     FAST_CPU_TIME("fast_cpu_time"),
     CPU_TICKS("cpu_ticks"),
+    FRAME_SKIPPING("frame_skipping"),
     FAST_GPU_TIME("fast_gpu_time"),
     BAT_TEMPERATURE_UNIT("bat_temperature_unit"),
     CABINET_APPLET("cabinet_applet_mode"),

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/view/SettingsItem.kt

@@ -242,15 +242,15 @@ abstract class SettingsItem(
                     descriptionId = R.string.frame_interpolation_description
                 )
             )
-
-//            put(
-//                SwitchSetting(
-//                    BooleanSetting.FRAME_SKIPPING,
-//                    titleId = R.string.frame_skipping,
-//                    descriptionId = R.string.frame_skipping_description
-//                )
-//            )
-
+            put(
+                SingleChoiceSetting(
+                    IntSetting.FRAME_SKIPPING,
+                    titleId = R.string.frame_skipping,
+                    descriptionId = R.string.frame_skipping_description,
+                    choicesId = R.array.frameSkippingNames,
+                    valuesId = R.array.frameSkippingValues
+                )
+            )
             put(
                 SwitchSetting(
                     dockedModeSetting,

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -450,6 +450,7 @@ class SettingsFragmentPresenter(
             add(BooleanSetting.RENDERER_EARLY_RELEASE_FENCES.key)
             add(BooleanSetting.BUFFER_REORDER_DISABLE.key)
             add(BooleanSetting.FRAME_INTERPOLATION.key)
+            add(IntSetting.FRAME_SKIPPING.key)
             add(BooleanSetting.RENDERER_FAST_GPU.key)
             add(IntSetting.FAST_GPU_TIME.key)
             add(IntSetting.RENDERER_SHADER_BACKEND.key)

src/android/app/src/main/res/values/arrays.xml

@@ -21,6 +21,18 @@
         <item>1</item>
     </integer-array>
 
+    <string-array name="frameSkippingNames">
+        <item>@string/disabled</item>
+        <item>1</item>
+        <item>2</item>
+    </string-array>
+
+    <integer-array name="frameSkippingValues">
+        <item>0</item>
+        <item>1</item>
+        <item>2</item>
+    </integer-array>
+
     <string-array name="memoryNames">
         <item>@string/memory_4gb</item>
         <item>@string/memory_6gb</item>

src/common/settings.h

@@ -325,9 +325,9 @@ struct Values {
 #ifdef __ANDROID__
     SwitchableSetting<bool> frame_interpolation{linkage, true, "frame_interpolation", Category::Renderer,
                                                 Specialization::RuntimeList};
+#endif
     SwitchableSetting<bool> frame_skipping{linkage, false, "frame_skipping", Category::Renderer,
                                            Specialization::RuntimeList};
-#endif
     SwitchableSetting<bool> use_disk_shader_cache{linkage, true, "use_disk_shader_cache",
                                                   Category::Renderer};
     SwitchableSetting<SpirvOptimizeMode, true> optimize_spirv_output{linkage,

src/video_core/gpu.cpp

@@ -223,17 +223,23 @@ struct GPU::Impl {
         system.GetPerfStats().EndGameFrame();
     }
 
+    void ResetFrameCounter() {
+        frame_count.store(0, std::memory_order_relaxed);
+    }
+
     /// Performs any additional setup necessary in order to begin GPU emulation.
     /// This can be used to launch any necessary threads and register any necessary
     /// core timing events.
     void Start() {
         Settings::UpdateGPUAccuracy();
+        ResetFrameCounter();
         gpu_thread.StartThread(*renderer, renderer->Context(), *scheduler);
     }
 
     void NotifyShutdown() {
         std::unique_lock lk{sync_mutex};
         shutting_down.store(true, std::memory_order::relaxed);
+        ResetFrameCounter();
         sync_cv.notify_all();
     }
 
@@ -291,10 +297,16 @@ struct GPU::Impl {
 
     void RequestComposite(std::vector<Tegra::FramebufferConfig>&& layers,
                           std::vector<Service::Nvidia::NvFence>&& fences) {
+        // Increment frame counter
+        const u64 current_frame = frame_count.fetch_add(1, std::memory_order_relaxed) + 1;
+        const u32 frame_skip_value = Settings::values.frame_skipping.GetValue();
+        const bool skip_frame = frame_skip_value > 0 &&
+                                (current_frame % (static_cast<u64>(frame_skip_value) + 1) != 0);
+
         size_t num_fences{fences.size()};
         size_t current_request_counter{};
         {
-            std::unique_lock<std::mutex> lk(request_swap_mutex);
+            std::unique_lock<std::mutex> lk{request_swap_mutex};
             if (free_swap_counters.empty()) {
                 current_request_counter = request_swap_counters.size();
                 request_swap_counters.emplace_back(num_fences);
@@ -305,24 +317,34 @@ struct GPU::Impl {
             }
         }
         const auto wait_fence =
-            RequestSyncOperation([this, current_request_counter, &layers, &fences, num_fences] {
+            RequestSyncOperation([this, current_request_counter, &layers, &fences, num_fences, skip_frame] {
                 auto& syncpoint_manager = host1x.GetSyncpointManager();
                 if (num_fences == 0) {
+                    if (!skip_frame) {
                         renderer->Composite(layers);
+                    } else {
+                        system.GetPerfStats().EndGameFrame();
                     }
-                const auto executer = [this, current_request_counter, layers_copy = layers]() {
+                } else {
+                    const auto executer = [this, current_request_counter, layers_copy = std::move(layers), skip_frame]() {
                         {
-                        std::unique_lock<std::mutex> lk(request_swap_mutex);
+                            std::unique_lock<std::mutex> lk{request_swap_mutex};
                             if (--request_swap_counters[current_request_counter] != 0) {
                                 return;
                             }
                             free_swap_counters.push_back(current_request_counter);
                         }
+                        // Handle frame skipping in executer
+                        if (!skip_frame) {
                             renderer->Composite(layers_copy);
+                        } else {
+                            system.GetPerfStats().EndGameFrame();
+                        }
                     };
                     for (size_t i = 0; i < num_fences; i++) {
                         syncpoint_manager.RegisterGuestAction(fences[i].id, fences[i].value, executer);
                     }
+                }
             });
         gpu_thread.TickGPU();
         WaitForSyncOperation(wait_fence);
@@ -353,6 +375,8 @@ struct GPU::Impl {
     /// When true, we are about to shut down emulation session, so terminate outstanding tasks
     std::atomic_bool shutting_down{};
 
+    std::atomic<u64> frame_count{0};
+
     std::array<std::atomic<u32>, Service::Nvidia::MaxSyncPoints> syncpoints{};
 
     std::array<std::list<u32>, Service::Nvidia::MaxSyncPoints> syncpt_interrupts;

src/video_core/gpu.h

@@ -220,6 +220,9 @@ public:
 
     std::vector<u8> GetAppletCaptureBuffer();
 
+    // Reset frame counter
+    void ResetFrameCounter();
+
     /// Performs any additional setup necessary in order to begin GPU emulation.
     /// This can be used to launch any necessary threads and register any necessary
     /// core timing events.