feat(renderer): Add frame skipping and interpolation logic

- Further Implemented frame skipping functionality to improve performance on lower-end devices by skipping alternate frames.
- Added interpolation logic to create additional frames, resulting in smoother gameplay when frame interpolation is enabled.
- Introduced new settings for toggling frame skipping and interpolation in the renderer configuration.

src/android/app/src/main/java/org/uzuy/uzuy_emu/features/settings/model/BooleanSetting.kt

@@ -29,7 +29,8 @@ enum class BooleanSetting(override val key: String) : AbstractBooleanSetting {
     SHOW_THERMAL_OVERLAY("show_thermal_overlay"),
     CORE_USE_MULTI_CORE("use_multi_core"),
     SYNC_CORE_SPEED("sync_core_speed"),
-    FRAME_SKIPPING("frame_skipping");
+    FRAME_SKIPPING("frame_skipping"),
+    FRAME_INTERPOLATION("frame_interpolation");
 
     override fun getBoolean(needsGlobal: Boolean): Boolean =
         NativeConfig.getBoolean(key, needsGlobal)

src/android/app/src/main/java/org/uzuy/uzuy_emu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -177,6 +177,7 @@ private fun addPhoenixHacksSubmenu(sl: ArrayList<SettingsItem>) {
 
         // Add settings using keys directly
         add(BooleanSetting.FRAME_SKIPPING.key)
+        add(BooleanSetting.FRAME_INTERPOLATION.key)
         add(BooleanSetting.CORE_USE_MULTI_CORE.key)
         add(BooleanSetting.SYNC_CORE_SPEED.key)
         add(IntSetting.RENDERER_SHADER_BACKEND.key)
@@ -187,6 +188,25 @@ private fun addPhoenixHacksSubmenu(sl: ArrayList<SettingsItem>) {
     }
 }
 
+    private val useInterpolationSetting = object : AbstractBooleanSetting {
+    override val key = BooleanSetting.FRAME_INTERPOLATION.key
+
+    override fun getBoolean(needsGlobal: Boolean): Boolean {
+        return BooleanSetting.FRAME_INTERPOLATION.getBoolean(needsGlobal)
+    }
+
+    override fun setBoolean(value: Boolean) {
+        BooleanSetting.FRAME_INTERPOLATION.setBoolean(value)
+    }
+
+    override val defaultValue = BooleanSetting.FRAME_INTERPOLATION.defaultValue
+
+    override fun getValueAsString(needsGlobal: Boolean): String =
+        BooleanSetting.FRAME_INTERPOLATION.getValueAsString(needsGlobal)
+
+    override fun reset() = BooleanSetting.FRAME_INTERPOLATION.reset()
+    }
+
     private val useSyncCoreSpeedSetting = object : AbstractBooleanSetting {
     override val key = BooleanSetting.SYNC_CORE_SPEED.key
 
@@ -226,34 +246,26 @@ private fun addPhoenixHacksSubmenu(sl: ArrayList<SettingsItem>) {
     }
 
     private val frameSkippingSetting = object : AbstractBooleanSetting {
-    override val key = "frame_skipping"
+        override val key = BooleanSetting.FRAME_SKIPPING.key
 
-    override fun getBoolean(needsGlobal: Boolean): Boolean {
-        return BooleanSetting.FRAME_SKIPPING.getBoolean(needsGlobal)
+        override fun getBoolean(needsGlobal: Boolean): Boolean {
+            return BooleanSetting.FRAME_SKIPPING.getBoolean(needsGlobal)
+        }
+
+        override fun setBoolean(value: Boolean) {
+            BooleanSetting.FRAME_SKIPPING.setBoolean(value)
+        }
+
+        override val defaultValue = BooleanSetting.FRAME_SKIPPING.defaultValue
+
+        override fun getValueAsString(needsGlobal: Boolean): String =
+            BooleanSetting.FRAME_SKIPPING.getValueAsString(needsGlobal)
+
+        override fun reset() = BooleanSetting.FRAME_SKIPPING.reset()
     }
 
-    override fun setBoolean(value: Boolean) {
-        BooleanSetting.FRAME_SKIPPING.setBoolean(value)
-        NativeLibrary.setFrameSkipping(value)  // Ensure this toggles the frame skipping in Vulkan renderer
-    }
-
-    override val defaultValue = BooleanSetting.FRAME_SKIPPING.defaultValue
-
-    override fun getValueAsString(needsGlobal: Boolean): String = getBoolean(needsGlobal).toString()
-
-    override fun reset() = setBoolean(defaultValue)
-    }
-
-private fun addPhoenixHacksSettings(sl: ArrayList<SettingsItem>) {
+    private fun addPhoenixHacksSettings(sl: ArrayList<SettingsItem>) {
     sl.apply {
-        // Add the multi-core setting to Phoenix Hacks submenu
-        add(
-            SwitchSetting(
-                frameSkippingSetting,
-                titleId = R.string.frame_skipping,
-                descriptionId = R.string.frame_skipping_description
-            )
-        )
         add(
             SwitchSetting(
                 useSyncCoreSpeedSetting,
@@ -268,7 +280,20 @@ private fun addPhoenixHacksSettings(sl: ArrayList<SettingsItem>) {
                 descriptionId = R.string.use_multi_core_description
             )
         )
-        // Add the new settings
+        add(
+            SwitchSetting(
+                frameSkippingSetting,
+                titleId = R.string.frame_skipping,
+                descriptionId = R.string.frame_skipping_description
+            )
+        )
+        add(
+            SwitchSetting(
+                useInterpolationSetting,  // The interpolation setting object you've created
+                titleId = R.string.frame_interpolation,  // Use appropriate string resources for the title
+                descriptionId = R.string.frame_interpolation_description  // Description resource for the interpolation setting
+            )
+        )
         add(
             SingleChoiceSetting(
                 IntSetting.RENDERER_SHADER_BACKEND,

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

@@ -390,9 +390,15 @@
     <string name="sync_core_speed">Sync Core Speed</string>
     <string name="sync_core_speed_description">Synchronizes the CPU core speed with the game\'s maximum rendering speed.</string>
 
+    <string name="frame_interpolation">Frame Interpolation</string>
+    <string name="frame_interpolation_description">Enable or disable frame interpolation for smoother transitions between frames.</string>
+
+    <string name="frame_skipping">Frame Skipping</string>
+    <string name="frame_skipping_description">Enables frame skipping to improve performance by skipping certain frames during rendering.</string>
+
     <!-- Miscellaneous -->
-    <string name="preferences_phoenix_hacks">🐦‍🔥 Phoenix Hacks</string>
-    <string name="preferences_phoenix_hacks_description">Enable or adjust Phoenix-specific hacks</string>
+    <string name="preferences_phoenix_hacks">🐦‍🔥 Phoenix Tweaks</string>
+    <string name="preferences_phoenix_hacks_description">Enable or adjust Phoenix-specific tweaks</string>
     <string name="slider_default">Default</string>
     <string name="ini_saved">Saved settings</string>
     <string name="gameid_saved">Saved settings for %1$s</string>

src/common/settings.h

@@ -210,10 +210,12 @@ struct Values {
                                              true,
                                              true,
                                              &use_speed_limit};
-    SwitchableSetting<bool> sync_core_speed{linkage, false, "sync_core_speed", Category::Core, Specialization::Default};
+    SwitchableSetting<bool> sync_core_speed{linkage, true, "sync_core_speed", Category::Core, Specialization::Default};
 
     // Frame-Skipping (Experimental)
-    SwitchableSetting<bool> frame_skipping{linkage, false, "frame_skipping", Category::Core, Specialization::Default};
+    SwitchableSetting<bool> frame_skipping{linkage, false, "frame_skipping", Category::Renderer, Specialization::Default};
+    // Frame Interpolation (Experimental)
+    SwitchableSetting<bool> frame_interpolation{linkage, false, "frame_interpolation", Category::Renderer, Specialization::Default};
 
     // Cpu
     SwitchableSetting<CpuBackend, true> cpu_backend{linkage,

src/uzuy/configuration/shared_translation.cpp

@@ -189,6 +189,10 @@ std::unique_ptr<TranslationMap> InitializeTranslations(QWidget* parent) {
        tr("Enables frame skipping to improve performance in cases where the emulator cannot maintain the target frame rate. "
           "Frame skipping will cause some frames to be skipped to maintain smoother gameplay at the cost of visual fluidity. "
           "This is especially useful on lower-end hardware."));
+    INSERT(Settings, frame_interpolation, tr("Enable Frame Interpolation"),
+       tr("Enables frame interpolation to smooth out transitions between frames for a more fluid visual experience. "
+          "This can be useful when the emulator's frame rate is lower than the target frame rate, creating smoother movement at the cost of input lag or visual accuracy. "
+          "Recommended for higher-end hardware or when fluidity is prioritized over precision."));
 
     // Renderer (Advanced Graphics)
     INSERT(Settings, async_presentation, tr("Enable asynchronous presentation (Vulkan only)"),

src/video_core/renderer_vulkan/renderer_vulkan.cpp

@@ -124,6 +124,12 @@ RendererVulkan::RendererVulkan(Core::TelemetrySession& telemetry_session_,
       rasterizer(render_window, gpu, device_memory, device, memory_allocator, state_tracker,
                  scheduler),
       applet_frame() {
+    // Move frame skipping initialization here
+    frame_skipping_enabled = Settings::values.frame_skipping.GetValue();
+
+    // Initialize frame interpolation here
+    frame_interpolation_enabled = Settings::values.frame_interpolation.GetValue();
+
     if (Settings::values.renderer_force_max_clock.GetValue() && device.ShouldBoostClocks()) {
         turbo_mode.emplace(instance, dld);
         scheduler.RegisterOnSubmit([this] { turbo_mode->QueueSubmitted(); });
@@ -139,80 +145,83 @@ RendererVulkan::~RendererVulkan() {
     void(device.GetLogical().WaitIdle());
 }
 
-void RendererVulkan::Composite(std::span<const Tegra::FramebufferConfig> framebuffers) {
-    if (frame_skip_interval > 0 && (frame_counter % (frame_skip_interval + 1)) == 0) {
-        frame_counter++;
-        is_frame_skipped = true;  // Mark this frame as skipped
-        return;  // Skip this frame
+void RendererVulkan::InterpolateFrames(Frame* prev_frame, Frame* next_frame, Frame* interpolated_frame, float interpolation_factor) {
+    if (prev_frame && next_frame && interpolated_frame) {
+        // Implement further interpolation logic here, e.g., linear interpolation, spherical interpolation, etc.
+        for (size_t i = 0; i < interpolated_frame->data.size(); ++i) {
+            interpolated_frame->data[i] = (1.0f - interpolation_factor) * prev_frame->data[i] +
+                                           interpolation_factor * next_frame->data[i];
+        }
     }
+}
 
-    frame_counter++;
+bool frame_skipping_enabled = false;
+bool frame_interpolation_enabled = false;
+
+void RendererVulkan::Composite(std::span<const Tegra::FramebufferConfig> framebuffers) {
+    static int frame_counter = 0;  // Track frame count
+    static Frame* prev_frame = nullptr;  // Track the previous frame
+    Frame* interpolated_frame = nullptr;
+
+    // Frame skipping logic
+    if (frame_skipping_enabled) {
+        // Skip rendering every other frame
+        if (++frame_counter % 2 != 0) {
+            return;  // Skip this frame
+        }
+    }
 
     if (framebuffers.empty()) {
         return;
     }
 
     SCOPE_EXIT {
-            render_window.OnFrameDisplayed();
+        render_window.OnFrameDisplayed();
     };
 
-    RenderAppletCaptureLayer(framebuffers);
+    // Check if frame interpolation is enabled
+    if (frame_interpolation_enabled && prev_frame != nullptr) {
+        // Allocate or retrieve a new frame for interpolation
+        interpolated_frame = present_manager.GetRenderFrame();
 
-    if (!render_window.IsShown()) {
-        return;
+        // Calculate interpolation factor (e.g., halfway between frames = 0.5)
+        float interpolation_factor = 0.5f;
+
+        // Interpolate between prev_frame and the current frame
+        InterpolateFrames(prev_frame, present_manager.GetRenderFrame(), interpolated_frame, interpolation_factor);
+
+        // Render the interpolated frame instead of the current frame
+        blit_swapchain.DrawToFrame(rasterizer, interpolated_frame, framebuffers,
+                                   render_window.GetFramebufferLayout(), swapchain.GetImageCount(),
+                                   swapchain.GetImageViewFormat());
+
+        scheduler.Flush(*interpolated_frame->render_ready);
+        present_manager.Present(interpolated_frame);
+
+    } else {
+        // Render the current frame as normal if interpolation is disabled
+        RenderAppletCaptureLayer(framebuffers);
+
+        if (!render_window.IsShown()) {
+            return;
+        }
+
+        RenderScreenshot(framebuffers);
+        Frame* frame = present_manager.GetRenderFrame();
+        blit_swapchain.DrawToFrame(rasterizer, frame, framebuffers,
+                                   render_window.GetFramebufferLayout(), swapchain.GetImageCount(),
+                                   swapchain.GetImageViewFormat());
+        scheduler.Flush(*frame->render_ready);
+        present_manager.Present(frame);
     }
 
-    if (is_frame_skipped && previous_frame_buffer.has_value()) {
-        // Interpolate between the previous frame and the current frame
-        InterpolateFrame(previous_frame_buffer.value(), framebuffers);
-        is_frame_skipped = false;
-    }
-
-    // Capture current frame buffer for future interpolation
-    vk::Buffer current_frame_buffer = RenderToBuffer(framebuffers, render_window.GetFramebufferLayout(),
-                                                     VK_FORMAT_B8G8R8A8_UNORM, layout.width * layout.height * 4);
-    previous_frame_buffer = current_frame_buffer;
-
-    RenderScreenshot(framebuffers);
-    Frame* frame = present_manager.GetRenderFrame();
-    blit_swapchain.DrawToFrame(rasterizer, frame, framebuffers,
-                               render_window.GetFramebufferLayout(), swapchain.GetImageCount(),
-                               swapchain.GetImageViewFormat());
-    scheduler.Flush(*frame->render_ready);
-    present_manager.Present(frame);
+    // Save the current frame as the previous frame for the next call
+    prev_frame = present_manager.GetRenderFrame();
 
     gpu.RendererFrameEndNotify();
     rasterizer.TickFrame();
 }
 
-void RendererVulkan::InterpolateFrame(vk::Buffer& previous_frame, std::span<const Tegra::FramebufferConfig> framebuffers) {
-    // Allocate a buffer for the interpolated frame
-    vk::Buffer interpolated_frame_buffer = RenderToBuffer(framebuffers, render_window.GetFramebufferLayout(),
-                                                          VK_FORMAT_B8G8R8A8_UNORM, layout.width * layout.height * 4);
-
-    // Perform the interpolation here (simplified linear blending)
-    // In reality, you'd need to read from both frame buffers and blend the pixel values
-    scheduler.Record([&](vk::CommandBuffer cmdbuf) {
-        // For simplicity, assume a 50-50 blend between previous and current frames
-        // More complex interpolation can be implemented by reading pixel data and manually blending
-
-        // vkCmdCopyBuffer and other Vulkan operations to blend the previous and current frames
-        // Here you would implement your actual blending logic
-        BlitBuffer(cmdbuf, previous_frame, interpolated_frame_buffer);  // Pseudo-code function for blending
-    });
-
-    scheduler.Finish();  // Ensure the interpolation finishes before presenting
-
-    // Present the interpolated frame
-    present_manager.PresentInterpolatedFrame(interpolated_frame_buffer);
-}
-
-void RendererVulkan::BlitBuffer(vk::CommandBuffer cmdbuf, vk::Buffer& src, vk::Buffer& dst) {
-    // This is a placeholder for Vulkan operations that blend two frame buffers.
-    // Vulkan commands would go here, such as vkCmdCopyBuffer, and shader operations
-    // that blend the contents of src and dst.
-}
-
 void RendererVulkan::Report() const {
     using namespace Common::Literals;
     const std::string vendor_name{device.GetVendorName()};

src/video_core/renderer_vulkan/renderer_vulkan.h

@@ -58,6 +58,8 @@ public:
         return device.GetDriverName();
     }
 
+    void InterpolateFrames(Frame* prev_frame, Frame* next_frame, Frame* interpolated_frame, float interpolation_factor);
+
 private:
     void Report() const;
 
@@ -92,11 +94,8 @@ private:
 
     Frame applet_frame;
 
-    std::optional<vk::Buffer> previous_frame_buffer;  // Store previous frame buffer for interpolation
-    bool is_frame_skipped = false;                    // Flag to check if the previous frame was skipped
-
-    int frame_skip_interval = 0;  // Number of frames to skip (0 means no skipping)
-    int frame_counter = 0;        // Keeps track of the current frame number
+    bool frame_skipping_enabled;
+    bool frame_interpolation_enabled;
 };
 
 } // namespace Vulkan