[VK]: Support for frame interpolation on PC and improve it's logic

I also suspect that frame interpolation hasn't been ever working, as it needs frame_skip_threshold and it was only being initialized if frame_skipping was on (actually a disabled and useless option, thats why i also nuked it), and the toggle was very messy with jni.

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"),
@@ -68,8 +67,6 @@ enum class BooleanSetting(override val key: String) : AbstractBooleanSetting {
     USE_LRU_CACHE("use_lru_cache");
 
     external fun isRaiiEnabled(): Boolean
-//  external fun isFrameSkippingEnabled(): Boolean
-    external fun isFrameInterpolationEnabled(): Boolean
 
     override fun getBoolean(needsGlobal: Boolean): Boolean =
         NativeConfig.getBoolean(key, needsGlobal)

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

@@ -234,15 +234,6 @@ 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(
                 SwitchSetting(
                     dockedModeSetting,

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

@@ -479,8 +479,6 @@
     <string name="display">Display</string>
     <string name="processing">Post-Processing</string>
 
-    <string name="frame_skipping">WIP: Frameskip</string>
-    <string name="frame_skipping_description">Toggle frame skipping to improve performance by reducing the number of rendered frames. This feature is still being worked on and will be enabled in future releases.</string>
     <string name="renderer_accuracy">Accuracy level</string>
     <string name="renderer_resolution">Resolution (Handheld/Docked)</string>
     <string name="renderer_vsync">VSync mode</string>

src/common/settings.h

@@ -322,12 +322,8 @@ struct Values {
     SwitchableSetting<int> vulkan_device{linkage, 0, "vulkan_device", Category::Renderer,
                                          Specialization::RuntimeList};
     SwitchableSetting<bool> enable_raii{linkage, false, "enable_raii", Category::Renderer};
-#ifdef __ANDROID__
     SwitchableSetting<bool> frame_interpolation{linkage, true, "frame_interpolation", Category::Renderer,
                                                 Specialization::RuntimeList};
-    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/renderer_vulkan/renderer_vulkan.cpp

@@ -38,9 +38,7 @@
 #include "video_core/vulkan_common/vulkan_memory_allocator.h"
 #include "video_core/vulkan_common/vulkan_surface.h"
 #include "video_core/vulkan_common/vulkan_wrapper.h"
-#ifdef __ANDROID__
-#include <jni.h>
-#endif
+
 namespace Vulkan {
 namespace {
 
@@ -189,144 +187,97 @@ RendererVulkan::~RendererVulkan() {
     void(device.GetLogical().WaitIdle());
 }
 
-#ifdef __ANDROID__
-class BooleanSetting {
-    public:
-//        static BooleanSetting FRAME_SKIPPING;
-        static BooleanSetting FRAME_INTERPOLATION;
-        explicit BooleanSetting(bool initial_value = false) : value(initial_value) {}
-
-        [[nodiscard]] bool getBoolean() const {
-            return value;
-        }
-
-        void setBoolean(bool new_value) {
-            value = new_value;
-        }
+void RendererVulkan::InterpolateFrames(Frame* prev_frame, Frame* interpolated_frame) {
+    if (!prev_frame || !interpolated_frame || !prev_frame->image || !interpolated_frame->image) {
+        return;
+    }
 
-    private:
-        bool value;
+    const auto& framebuffer_layout = render_window.GetFramebufferLayout();
+    // Fixed aggressive downscale (50%)
+    VkExtent2D dst_extent{
+        .width = framebuffer_layout.width / 2,
+        .height = framebuffer_layout.height / 2
     };
 
-    // Initialize static members
-//    BooleanSetting BooleanSetting::FRAME_SKIPPING(false);
-    BooleanSetting BooleanSetting::FRAME_INTERPOLATION(false);
-
-//    extern "C" JNIEXPORT jboolean JNICALL
-//    Java_org_yuzu_yuzu_1emu_features_settings_model_BooleanSetting_isFrameSkippingEnabled(JNIEnv* env, jobject /* this */) {
-//        return static_cast<jboolean>(BooleanSetting::FRAME_SKIPPING.getBoolean());
-//    }
-
-    extern "C" JNIEXPORT jboolean JNICALL
-    Java_org_yuzu_yuzu_1emu_features_settings_model_BooleanSetting_isFrameInterpolationEnabled(JNIEnv* env, jobject /* this */) {
-        return static_cast<jboolean>(BooleanSetting::FRAME_INTERPOLATION.getBoolean());
+    // Check if we need to recreate the destination frame
+    bool needs_recreation = false;  // Only recreate when necessary
+    if (!interpolated_frame->image_view) {
+        needs_recreation = true;  // Need to create initially
+    } else {
+        // Check if dimensions have changed
+        if (interpolated_frame->framebuffer) {
+            needs_recreation = (framebuffer_layout.width / 2 != dst_extent.width) ||
+                                (framebuffer_layout.height / 2 != dst_extent.height);
+        } else {
+            needs_recreation = true;
+        }
     }
 
-    void RendererVulkan::InterpolateFrames(Frame* prev_frame, Frame* interpolated_frame) {
-        if (!prev_frame || !interpolated_frame || !prev_frame->image || !interpolated_frame->image) {
-            return;
-        }
+    if (needs_recreation) {
+        interpolated_frame->image = CreateWrappedImage(memory_allocator, dst_extent, swapchain.GetImageViewFormat());
+        interpolated_frame->image_view = CreateWrappedImageView(device, interpolated_frame->image, swapchain.GetImageViewFormat());
+        interpolated_frame->framebuffer = blit_swapchain.CreateFramebuffer(
+            Layout::FramebufferLayout{dst_extent.width, dst_extent.height},
+            *interpolated_frame->image_view,
+            swapchain.GetImageViewFormat());
+    }
 
-        const auto& framebuffer_layout = render_window.GetFramebufferLayout();
-        // Fixed aggressive downscale (50%)
-        VkExtent2D dst_extent{
-            .width = framebuffer_layout.width / 2,
-            .height = framebuffer_layout.height / 2
+    scheduler.RequestOutsideRenderPassOperationContext();
+    scheduler.Record([&](vk::CommandBuffer cmdbuf) {
+        // Transition images to transfer layouts
+        TransitionImageLayout(cmdbuf, *prev_frame->image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);
+        TransitionImageLayout(cmdbuf, *interpolated_frame->image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);
+
+        // Perform the downscale blit
+        VkImageBlit blit_region{};
+        blit_region.srcSubresource = {VK_IMAGE_ASPECT_COLOR_BIT, 0, 0, 1};
+        blit_region.srcOffsets[0] = {0, 0, 0};
+        blit_region.srcOffsets[1] = {
+            static_cast<int32_t>(framebuffer_layout.width),
+            static_cast<int32_t>(framebuffer_layout.height),
+            1
+        };
+        blit_region.dstSubresource = {VK_IMAGE_ASPECT_COLOR_BIT, 0, 0, 1};
+        blit_region.dstOffsets[0] = {0, 0, 0};
+        blit_region.dstOffsets[1] = {
+            static_cast<int32_t>(dst_extent.width),
+            static_cast<int32_t>(dst_extent.height),
+            1
         };
 
-        // Check if we need to recreate the destination frame
-        bool needs_recreation = false;  // Only recreate when necessary
-        if (!interpolated_frame->image_view) {
-            needs_recreation = true;  // Need to create initially
-        } else {
-            // Check if dimensions have changed
-            if (interpolated_frame->framebuffer) {
-                needs_recreation = (framebuffer_layout.width / 2 != dst_extent.width) ||
-                                  (framebuffer_layout.height / 2 != dst_extent.height);
-            } else {
-                needs_recreation = true;
-            }
-        }
-
-        if (needs_recreation) {
-            interpolated_frame->image = CreateWrappedImage(memory_allocator, dst_extent, swapchain.GetImageViewFormat());
-            interpolated_frame->image_view = CreateWrappedImageView(device, interpolated_frame->image, swapchain.GetImageViewFormat());
-            interpolated_frame->framebuffer = blit_swapchain.CreateFramebuffer(
-                Layout::FramebufferLayout{dst_extent.width, dst_extent.height},
-                *interpolated_frame->image_view,
-                swapchain.GetImageViewFormat());
-        }
+        // Using the wrapper's BlitImage with proper parameters
+        cmdbuf.BlitImage(
+            *prev_frame->image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
+            *interpolated_frame->image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
+            blit_region, VK_FILTER_NEAREST
+        );
 
-        scheduler.RequestOutsideRenderPassOperationContext();
-        scheduler.Record([&](vk::CommandBuffer cmdbuf) {
-            // Transition images to transfer layouts
-            TransitionImageLayout(cmdbuf, *prev_frame->image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);
-            TransitionImageLayout(cmdbuf, *interpolated_frame->image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);
-
-            // Perform the downscale blit
-            VkImageBlit blit_region{};
-            blit_region.srcSubresource = {VK_IMAGE_ASPECT_COLOR_BIT, 0, 0, 1};
-            blit_region.srcOffsets[0] = {0, 0, 0};
-            blit_region.srcOffsets[1] = {
-                static_cast<int32_t>(framebuffer_layout.width),
-                static_cast<int32_t>(framebuffer_layout.height),
-                1
-            };
-            blit_region.dstSubresource = {VK_IMAGE_ASPECT_COLOR_BIT, 0, 0, 1};
-            blit_region.dstOffsets[0] = {0, 0, 0};
-            blit_region.dstOffsets[1] = {
-                static_cast<int32_t>(dst_extent.width),
-                static_cast<int32_t>(dst_extent.height),
-                1
-            };
-
-            // Using the wrapper's BlitImage with proper parameters
-            cmdbuf.BlitImage(
-                *prev_frame->image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
-                *interpolated_frame->image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
-                blit_region, VK_FILTER_NEAREST
-            );
-
-            // Transition back to general layout
-            TransitionImageLayout(cmdbuf, *prev_frame->image, VK_IMAGE_LAYOUT_GENERAL);
-            TransitionImageLayout(cmdbuf, *interpolated_frame->image, VK_IMAGE_LAYOUT_GENERAL);
-        });
-    }
-#endif
+        // Transition back to general layout
+        TransitionImageLayout(cmdbuf, *prev_frame->image, VK_IMAGE_LAYOUT_GENERAL);
+        TransitionImageLayout(cmdbuf, *interpolated_frame->image, VK_IMAGE_LAYOUT_GENERAL);
+    });
+}
 
 void RendererVulkan::Composite(std::span<const Tegra::FramebufferConfig> framebuffers) {
-    #ifdef __ANDROID__
-    static int frame_counter = 0;
-    static int target_fps = 60; // Target FPS (30 or 60)
-    int frame_skip_threshold = 1;
-
-    bool frame_skipping = false; //BooleanSetting::FRAME_SKIPPING.getBoolean();
-    bool frame_interpolation = BooleanSetting::FRAME_INTERPOLATION.getBoolean();
-    #endif
-
     if (framebuffers.empty()) {
         return;
     }
 
-    #ifdef __ANDROID__
-    if (frame_skipping) {
-        frame_skip_threshold = (target_fps == 30) ? 2 : 2;
-    }
+    bool frame_interpolation_enabled = Settings::values.frame_interpolation.GetValue();
 
-    frame_counter++;
-    if (frame_counter % frame_skip_threshold != 0) {
-        if (frame_interpolation && previous_frame) {
-            Frame* interpolated_frame = present_manager.GetRenderFrame();
-            InterpolateFrames(previous_frame, interpolated_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);
-        }
+    if (frame_interpolation_enabled && previous_frame) {
+        Frame* interpolated_frame = present_manager.GetRenderFrame();
+        InterpolateFrames(previous_frame, interpolated_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);
+
+        // Optionally, update previous_frame here if you want to chain interpolations
+        previous_frame = interpolated_frame;
         return;
     }
-    #endif
 
     SCOPE_EXIT {
         render_window.OnFrameDisplayed();
@@ -346,6 +297,11 @@ void RendererVulkan::Composite(std::span<const Tegra::FramebufferConfig> framebu
     scheduler.Flush(*frame->render_ready);
     present_manager.Present(frame);
 
+    // Store the current frame for interpolation on the next call
+    if (frame_interpolation_enabled) {
+        previous_frame = frame;
+    }
+
     gpu.RendererFrameEndNotify();
     rasterizer.TickFrame();
 }

src/yuzu/configuration/shared_translation.cpp

@@ -250,6 +250,12 @@ std::unique_ptr<TranslationMap> InitializeTranslations(QWidget* parent)
               "of available video memory for performance. Has no effect on integrated graphics. "
               "Aggressive mode may severely impact the performance of other applications such as "
               "recording software."));
+    INSERT(Settings,
+           frame_interpolation,
+           tr("Enhanced Frame Pacing"),
+           tr("Ensures smooth and consistent frame delivery by synchronizing the timing between frames, "
+              "reducing stuttering and uneven animation. Ideal for games that experience frame timing "
+              "instability or micro-stutters during gameplay."));
     INSERT(Settings,
            skip_cpu_inner_invalidation,
            tr("Skip CPU Inner Invalidation"),
@@ -333,14 +339,13 @@ std::unique_ptr<TranslationMap> InitializeTranslations(QWidget* parent)
            barrier_feedback_loops,
            tr("Barrier feedback loops"),
            tr("Improves rendering of transparency effects in specific games."));
-
-    // Renderer (Extensions)
     INSERT(Settings,
            enable_raii,
            tr("RAII"),
            tr("A method of automatic resource management in Vulkan "
               "that ensures proper release of resources "
               "when they are no longer needed, but may cause crashes in bundled games."));
+    // Renderer (Extensions)
     INSERT(Settings,
            dyna_state,
            tr("Extended Dynamic State"),