3 files changed, 69 insertions, 14 deletions

diff --git a/src/core/frontend/emu_window.h b/src/core/frontend/emu_window.h
index 72294d4d8..13aa14934 100644
--- a/src/core/frontend/emu_window.h
+++ b/src/core/frontend/emu_window.h
@@ -12,6 +12,15 @@
 
 namespace Core::Frontend {
 
+/// Information for the Graphics Backends signifying what type of screen pointer is in
+/// WindowInformation
+enum class WindowSystemType {
+    Headless,
+    Windows,
+    X11,
+    Wayland,
+};
+
 /**
  * Represents a drawing context that supports graphics operations.
  */
@@ -76,6 +85,23 @@ public:
         std::pair<unsigned, unsigned> min_client_area_size;
     };
 
+    /// Data describing host window system information
+    struct WindowSystemInfo {
+        // Window system type. Determines which GL context or Vulkan WSI is used.
+        WindowSystemType type = WindowSystemType::Headless;
+
+        // Connection to a display server. This is used on X11 and Wayland platforms.
+        void* display_connection = nullptr;
+
+        // Render surface. This is a pointer to the native window handle, which depends
+        // on the platform. e.g. HWND for Windows, Window for X11. If the surface is
+        // set to nullptr, the video backend will run in headless mode.
+        void* render_surface = nullptr;
+
+        // Scale of the render surface. For hidpi systems, this will be >1.
+        float render_surface_scale = 1.0f;
+    };
+
     /// Polls window events
     virtual void PollEvents() = 0;
 
@@ -87,10 +113,6 @@ public:
     /// Returns if window is shown (not minimized)
     virtual bool IsShown() const = 0;
 
-    /// Retrieves Vulkan specific handlers from the window
-    virtual void RetrieveVulkanHandlers(void* get_instance_proc_addr, void* instance,
-                                        void* surface) const = 0;
-
     /**
      * Signal that a touch pressed event has occurred (e.g. mouse click pressed)
      * @param framebuffer_x Framebuffer x-coordinate that was pressed
@@ -128,6 +150,13 @@ public:
     }
 
     /**
+     * Returns system information about the drawing area.
+     */
+    const WindowSystemInfo& GetWindowInfo() const {
+        return window_info;
+    }
+
+    /**
      * Gets the framebuffer layout (width, height, and screen regions)
      * @note This method is thread-safe
      */
@@ -142,7 +171,7 @@ public:
     void UpdateCurrentFramebufferLayout(unsigned width, unsigned height);
 
 protected:
-    EmuWindow();
+    explicit EmuWindow();
     virtual ~EmuWindow();
 
     /**
@@ -179,6 +208,8 @@ protected:
         client_area_height = size.second;
     }
 
+    WindowSystemInfo window_info;
+
 private:
     /**
      * Handler called when the minimal client area was requested to be changed via SetConfig.
diff --git a/src/core/hle/service/nvflinger/buffer_queue.cpp b/src/core/hle/service/nvflinger/buffer_queue.cpp
index ad0e4ff73..f1e3d832a 100644
--- a/src/core/hle/service/nvflinger/buffer_queue.cpp
+++ b/src/core/hle/service/nvflinger/buffer_queue.cpp
@@ -28,6 +28,7 @@ void BufferQueue::SetPreallocatedBuffer(u32 slot, const IGBPBuffer& igbp_buffer)
     buffer.slot = slot;
     buffer.igbp_buffer = igbp_buffer;
     buffer.status = Buffer::Status::Free;
+    free_buffers.push_back(slot);
 
     queue.emplace_back(buffer);
     buffer_wait_event.writable->Signal();
@@ -35,16 +36,37 @@ void BufferQueue::SetPreallocatedBuffer(u32 slot, const IGBPBuffer& igbp_buffer)
 
 std::optional<std::pair<u32, Service::Nvidia::MultiFence*>> BufferQueue::DequeueBuffer(u32 width,
                                                                                        u32 height) {
-    auto itr = std::find_if(queue.begin(), queue.end(), [&](const Buffer& buffer) {
-        // Only consider free buffers. Buffers become free once again after they've been Acquired
-        // and Released by the compositor, see the NVFlinger::Compose method.
-        if (buffer.status != Buffer::Status::Free) {
-            return false;
-        }
 
-        // Make sure that the parameters match.
-        return buffer.igbp_buffer.width == width && buffer.igbp_buffer.height == height;
-    });
+    if (free_buffers.empty()) {
+        return {};
+    }
+
+    auto f_itr = free_buffers.begin();
+    auto itr = queue.end();
+
+    while (f_itr != free_buffers.end()) {
+        auto slot = *f_itr;
+        itr = std::find_if(queue.begin(), queue.end(), [&](const Buffer& buffer) {
+            // Only consider free buffers. Buffers become free once again after they've been
+            // Acquired and Released by the compositor, see the NVFlinger::Compose method.
+            if (buffer.status != Buffer::Status::Free) {
+                return false;
+            }
+
+            if (buffer.slot != slot) {
+                return false;
+            }
+
+            // Make sure that the parameters match.
+            return buffer.igbp_buffer.width == width && buffer.igbp_buffer.height == height;
+        });
+
+        if (itr != queue.end()) {
+            free_buffers.erase(f_itr);
+            break;
+        }
+        ++f_itr;
+    }
 
     if (itr == queue.end()) {
         return {};
@@ -99,6 +121,7 @@ void BufferQueue::ReleaseBuffer(u32 slot) {
     ASSERT(itr != queue.end());
     ASSERT(itr->status == Buffer::Status::Acquired);
     itr->status = Buffer::Status::Free;
+    free_buffers.push_back(slot);
 
     buffer_wait_event.writable->Signal();
 }
diff --git a/src/core/hle/service/nvflinger/buffer_queue.h b/src/core/hle/service/nvflinger/buffer_queue.h
index f3edb6dfb..d5f31e567 100644
--- a/src/core/hle/service/nvflinger/buffer_queue.h
+++ b/src/core/hle/service/nvflinger/buffer_queue.h
@@ -102,6 +102,7 @@ private:
     u32 id;
     u64 layer_id;
 
+    std::list<u32> free_buffers;
     std::vector<Buffer> queue;
     std::list<u32> queue_sequence;
     Kernel::EventPair buffer_wait_event;