libretro: Additional work

- Reliable resolution switching.
 - Hook up logging.
 - Memory cards and controller type settings.
 - Save state support.
 - Direct3D support.

src/duckstation-libretro/libretro_d3d11_host_display.h

@@ -0,0 +1,27 @@
+#pragma once
+#include "common/d3d11/texture.h"
+#include "frontend-common/d3d11_host_display.h"
+#include "libretro.h"
+
+class LibretroD3D11HostDisplay final : public FrontendCommon::D3D11HostDisplay
+{
+public:
+  LibretroD3D11HostDisplay();
+  ~LibretroD3D11HostDisplay();
+
+  static bool RequestHardwareRendererContext(retro_hw_render_callback* cb);
+
+  bool CreateRenderDevice(const WindowInfo& wi, std::string_view adapter_name, bool debug_device) override;
+  void DestroyRenderDevice();
+
+  void ResizeRenderWindow(s32 new_window_width, s32 new_window_height) override;
+
+  void SetVSync(bool enabled) override;
+
+  bool Render() override;
+
+private:
+  bool CheckFramebufferSize(u32 width, u32 height);
+
+  D3D11::Texture m_framebuffer;
+};