ID3D10Device *Device = NULL;
IDXGISwapChain *SwapChain = NULL;
ID3D10RenderTargetView *RenderTargetView = NULL;

HRESULT InitDevice(HWND hwnd)
{
  HRESULT hr;  RECT rc;
  GetClientRect(hwnd, &rc);

  DXGI_SWAP_CHAIN_DESC sd;
  ZeroMemory(&sd, sizeof(sd));
    sd.BufferCount = 1;
    sd.BufferDesc.Width = (rc.right - rc.left);
    sd.BufferDesc.Height = (rc.bottom - rc.top);
    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 = hwnd;
    sd.SampleDesc.Count = 1;
    sd.SampleDesc.Quality = 0;
    sd.Windowed = TRUE;
  
  hr = D3D10CreateDeviceAndSwapChain(NULL, D3D10_DRIVER_TYPE_HARDWARE, NULL, D3D10_CREATE_DEVICE_DEBUG, 
                                       D3D10_SDK_VERSION, &sd, &SwapChain, &Device);
  if(FAILED(hr)) return hr;

  //create a render target view
    ID3D10Texture2D *buffer;
    hr = SwapChain->GetBuffer(0, __uuidof(ID3D10Texture2D), (LPVOID*)&buffer);
    if(FAILED(hr)) return hr;

    hr = Device->CreateRenderTargetView(buffer, NULL, &RenderTargetView);
    buffer->Release();
    if(FAILED(hr)) return hr;

  Device->OMSetRenderTargets(1, &RenderTargetView, NULL);

  //create the viewport
  D3D10_VIEWPORT vp;
    vp.Width = (rc.right - rc.left);
    vp.Height = (rc.bottom - rc.top);
    vp.MinDepth = 0.0f;
    vp.MaxDepth = 1.0f;
    vp.TopLeftX = 0;
    vp.TopLeftY = 0;
    Device->RSSetViewports(1, &vp);

  return S_OK;
}