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How To: Create a Device and Immediate Context

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This topics shows how to initialize a device. Initializing a device is one of the first tasks that your application must complete before you can render your scene.

To create a device and immediate context

Fill out the DXGI_SWAP_CHAIN_DESC structure with information about buffer formats and dimensions. For more information, see Creating a Swap Chain.

The following code example demonstrates how to fill in the DXGI_SWAP_CHAIN_DESC structure.

DXGI_SWAP_CHAIN_DESC sd;
ZeroMemory( &sd, sizeof( sd ) );
sd.BufferCount = 1;
sd.BufferDesc.Width = 640;
sd.BufferDesc.Height = 480;
sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
sd.BufferDesc.RefreshRate.Numerator = 60;
sd.BufferDesc.RefreshRate.Denominator = 1;
sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
sd.OutputWindow = g_hWnd;
sd.SampleDesc.Count = 1;
sd.SampleDesc.Quality = 0;
sd.Windowed = TRUE;

Using the DXGI_SWAP_CHAIN_DESC structure from step one, call D3D11CreateDeviceAndSwapChain to initialize the device and swap chain at the same time.

D3D_FEATURE_LEVEL  FeatureLevelsRequested = D3D_FEATURE_LEVEL_11_0;
UINT               numLevelsRequested = 1;
D3D_FEATURE_LEVEL  FeatureLevelsSupported;

if( FAILED (hr = D3D11CreateDeviceAndSwapChain( NULL, 
                D3D_DRIVER_TYPE_HARDWARE, 
                NULL, 
                0,
                &FeatureLevelsRequested, 
                numFeatureLevelsRequested, 
                D3D11_SDK_VERSION, 
                &sd, 
                &g_pSwapChain, 
                &g_pd3dDevice, 
                &FeatureLevelsSupported,
                &g_pImmediateContext )))
{
    return hr;
}

Note

If you request a D3D_FEATURE_LEVEL_11_1 device on a computer with only the Direct3D 11.0 runtime, D3D11CreateDeviceAndSwapChain immediately exits with E_INVALIDARG. To safely request all possible feature levels on a computer with the DirectX 11.0 or DirectX 11.1 runtime, use this code:

const D3D_FEATURE_LEVEL lvl[] = { D3D_FEATURE_LEVEL_11_1, D3D_FEATURE_LEVEL_11_0,
D3D_FEATURE_LEVEL_10_1, D3D_FEATURE_LEVEL_10_0,
D3D_FEATURE_LEVEL_9_3, D3D_FEATURE_LEVEL_9_2, D3D_FEATURE_LEVEL_9_1 };

UINT createDeviceFlags = 0;
#ifdef _DEBUG
createDeviceFlags |= D3D11_CREATE_DEVICE_DEBUG;
#endif


ID3D11Device* device = nullptr;
HRESULT hr = D3D11CreateDeviceAndSwapChain( nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, createDeviceFlags, lvl, _countof(lvl), D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3ddevice, &FeatureLevelsSupported, &g_pImmediateContext );
if ( hr == E_INVALIDARG )
{
hr = D3D11CreateDeviceAndSwapChain( nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, createDeviceFlags, &lvl[1], _countof(lvl) - 1, D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3ddevice, &FeatureLevelsSupported, &g_pImmediateContext );
}


if (FAILED(hr))
return hr;

 

Create a render-target view by calling ID3D11Device::CreateRenderTargetView and bind the back-buffer as a render target by calling ID3D11DeviceContext::OMSetRenderTargets.

ID3D11Texture2D* pBackBuffer;

// Get a pointer to the back buffer
hr = g_pSwapChain->GetBuffer( 0, __uuidof( ID3D11Texture2D ),
( LPVOID* )&pBackBuffer );


// Create a render-target view
g_pd3dDevice->CreateRenderTargetView( pBackBuffer, NULL,
&g_pRenderTargetView );


// Bind the view
g_pImmediateContext->OMSetRenderTargets( 1, &g_pRenderTargetView, NULL );

Create a viewport to define which parts of the render target will be visible. Define the viewport using the D3D11_VIEWPORT structure and set the viewport using the ID3D11DeviceContext::RSSetViewports method.

C++ 
    // Setup the viewport
    D3D11_VIEWPORT vp;
    vp.Width = 640;
    vp.Height = 480;
    vp.MinDepth = 0.0f;
    vp.MaxDepth = 1.0f;
    vp.TopLeftX = 0;
    vp.TopLeftY = 0;
    g_pImmediateContext->RSSetViewports( 1, &vp );

Devices

How to Use Direct3D 11

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