purdy colors (clear backbuffer)

hw3d/App.cpp

@@ -21,5 +21,7 @@ int App::Go()
 
 void App::DoFrame()
 {
+	const float c = sin( timer.Peek() ) / 2.0f + 0.5f;
+	wnd.Gfx().ClearBuffer( c,c,1.0f );
 	wnd.Gfx().EndFrame();
 }
\ No newline at end of file

hw3d/App.h

 #pragma once
 #include "Window.h"
+#include "ChiliTimer.h"
 
 class App
 {
@@ -11,4 +12,5 @@ private:
 	void DoFrame();
 private:
 	Window wnd;
+	ChiliTimer timer;
 };
\ No newline at end of file

hw3d/Graphics.cpp

@@ -36,10 +36,23 @@ Graphics::Graphics( HWND hWnd )
 		nullptr,
 		&pContext
 	);
+	// gain access to texture subresource in swap chain (back buffer)
+	ID3D11Resource* pBackBuffer = nullptr;
+	pSwap->GetBuffer( 0,__uuidof(ID3D11Resource),reinterpret_cast<void**>(&pBackBuffer) );
+	pDevice->CreateRenderTargetView(
+		pBackBuffer,
+		nullptr,
+		&pTarget
+	);
+	pBackBuffer->Release();
 }
 
 Graphics::~Graphics()
 {
+	if( pTarget != nullptr )
+	{
+		pTarget->Release();
+	}
 	if( pContext != nullptr )
 	{
 		pContext->Release();

hw3d/Graphics.h

@@ -10,8 +10,14 @@ public:
 	Graphics& operator=( const Graphics& ) = delete;
 	~Graphics();
 	void EndFrame();
+	void ClearBuffer( float red,float green,float blue ) noexcept
+	{
+		const float color[] = { red,green,blue,1.0f };
+		pContext->ClearRenderTargetView( pTarget,color );
+	}
 private:
 	ID3D11Device* pDevice = nullptr;
 	IDXGISwapChain* pSwap = nullptr;
 	ID3D11DeviceContext* pContext = nullptr;
+	ID3D11RenderTargetView* pTarget = nullptr;
 };
\ No newline at end of file