yuzu: Drop SDL2 and Qt frontend Vulkan requirements

Create Vulkan instances and surfaces from the Vulkan backend.

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
@@ -127,6 +149,13 @@ public:
         config = val;
     }
 
+    /**
+     * 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.