[D3D12] Window output

src/xenia/gpu/d3d12/d3d12_graphics_system.h

@@ -14,6 +14,7 @@
 
 #include "xenia/gpu/command_processor.h"
 #include "xenia/gpu/graphics_system.h"
+#include "xenia/ui/d3d12/d3d12_context.h"
 
 namespace xe {
 namespace gpu {
@@ -30,10 +31,24 @@ class D3D12GraphicsSystem : public GraphicsSystem {
                  ui::Window* target_window) override;
   void Shutdown() override;
 
+  void AwaitFrontBufferUnused();
+
+  // Draws a texture covering the entire viewport to the render target currently
+  // bound on the specified command list (in D3D12Context::kSwapChainFormat).
+  // This changes the current pipeline, graphics root signature and primitive
+  // topology.
+  void StretchTextureToFrontBuffer(D3D12_GPU_DESCRIPTOR_HANDLE handle,
+                                   ID3D12GraphicsCommandList* command_list);
+
  private:
   std::unique_ptr<CommandProcessor> CreateCommandProcessor() override;
 
   void Swap(xe::ui::UIEvent* e) override;
+
+  ui::d3d12::D3D12Context* display_context_ = nullptr;
+
+  ID3D12RootSignature* stretch_root_signature_ = nullptr;
+  ID3D12PipelineState* stretch_pipeline_ = nullptr;
 };
 
 }  // namespace d3d12