I have no idea what this means. But here is the code that it supposely is happening in.

//=======================================================================================
// d3dApp.cpp by Frank Luna (C) 2008 All Rights Reserved.
//=======================================================================================

#include "d3dApp.h"
#include <stream>

LRESULT CALLBACK
MainWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    static D3DApp* app = 0;

    switch( msg )
    {
        case WM_CREATE:
        {
            // Get the 'this' pointer we passed to CreateWindow via the lpParam parameter.
            CREATESTRUCT* cs = (CREATESTRUCT*)lParam;
            app = (D3DApp*)cs->lpCreateParams;
            return 0;
        }
    }

    // Don't start processing messages until after WM_CREATE.
    if( app )
        return app->msgProc(msg, wParam, lParam);
    else
        return DefWindowProc(hwnd, msg, wParam, lParam);
}

D3DApp::D3DApp(HINSTANCE hInstance)
{
    mhAppInst   = hInstance;
    mhMainWnd   = 0;
    mAppPaused  = false;
    mMinimized  = false;
    mMaximized  = false;
    mResizing   = false;

    mFrameStats = L"";

    md3dDevice          = 0;
    mSwapChain          = 0;
    mDepthStencilBuffer = 0;
    mRenderTargetView   = 0;
    mDepthStencilView   = 0;
    mFont               = 0;

    mMainWndCaption = L"D3D10 Application";
    md3dDriverType  = D3D10_DRIVER_TYPE_HARDWARE;
    mClearColor     = D3DXCOLOR(0.0f, 0.0f, 1.0f, 1.0f);
    mClientWidth    = 800;
    mClientHeight   = 600;
}

D3DApp::~D3DApp()
{
    ReleaseCOM(mRenderTargetView);
    ReleaseCOM(mDepthStencilView);
    ReleaseCOM(mSwapChain);
    ReleaseCOM(mDepthStencilBuffer);
    ReleaseCOM(md3dDevice);
    ReleaseCOM(mFont);
}

HINSTANCE D3DApp::getAppInst()
{
    return mhAppInst;
}

HWND D3DApp::getMainWnd()
{
    return mhMainWnd;
}

int D3DApp::run()
{
    MSG msg = {0};

    mTimer.reset();

    while(msg.message != WM_QUIT)
    {
        // If there are Window messages then process them.
        if(PeekMessage( &msg, 0, 0, 0, PM_REMOVE ))
        {
            TranslateMessage( &msg );
            DispatchMessage( &msg );
        }
        // Otherwise, do animation/game stuff.
        else
        {   
            mTimer.tick();

            if( !mAppPaused )
                updateScene(mTimer.getDeltaTime()); 
            else
                Sleep(50);

            drawScene();
        }
    }
    return (int)msg.wParam;
}

void D3DApp::initApp()
{
    initMainWindow();
    initDirect3D();

    D3DX10_FONT_DESC fontDesc;
    fontDesc.Height          = 24;
    fontDesc.Width           = 0;
    fontDesc.Weight          = 0;
    fontDesc.MipLevels       = 1;
    fontDesc.Italic          = false;
    fontDesc.CharSet         = DEFAULT_CHARSET;
    fontDesc.OutputPrecision = OUT_DEFAULT_PRECIS;
    fontDesc.Quality         = DEFAULT_QUALITY;
    fontDesc.PitchAndFamily  = DEFAULT_PITCH | FF_DONTCARE;
    wcscpy(fontDesc.FaceName, L"Times New Roman");

    D3DX10CreateFontIndirect(md3dDevice, &fontDesc, &mFont);
}

void D3DApp::onResize()
{
    // Release the old views, as they hold references to the buffers we
    // will be destroying.  Also release the old depth/stencil buffer.

    ReleaseCOM(mRenderTargetView);
    ReleaseCOM(mDepthStencilView);
    ReleaseCOM(mDepthStencilBuffer);


    // Resize the swap chain and recreate the render target view.

    HR(mSwapChain->ResizeBuffers(1, mClientWidth, mClientHeight, DXGI_FORMAT_R8G8B8A8_UNORM, 0));
    ID3D10Texture2D* backBuffer;
    HR(mSwapChain->GetBuffer(0, __uuidof(ID3D10Texture2D), reinterpret_cast<void**>(&backBuffer)));
    HR(md3dDevice->CreateRenderTargetView(backBuffer, 0, &mRenderTargetView));
    ReleaseCOM(backBuffer);


    // Create the depth/stencil buffer and view.

    D3D10_TEXTURE2D_DESC depthStencilDesc;

    depthStencilDesc.Width     = mClientWidth;
    depthStencilDesc.Height    = mClientHeight;
    depthStencilDesc.MipLevels = 1;
    depthStencilDesc.ArraySize = 1;
    depthStencilDesc.Format    = DXGI_FORMAT_D24_UNORM_S8_UINT;
    depthStencilDesc.SampleDesc.Count   = 1; // multisampling must match
    depthStencilDesc.SampleDesc.Quality = 0; // swap chain values.
    depthStencilDesc.Usage          = D3D10_USAGE_DEFAULT;
    depthStencilDesc.BindFlags      = D3D10_BIND_DEPTH_STENCIL;
    depthStencilDesc.CPUAccessFlags = 0; 
    depthStencilDesc.MiscFlags      = 0;

    HR(md3dDevice->CreateTexture2D(&depthStencilDesc, 0, &mDepthStencilBuffer));
    HR(md3dDevice->CreateDepthStencilView(mDepthStencilBuffer, 0, &mDepthStencilView));


    // Bind the render target view and depth/stencil view to the pipeline.

    md3dDevice->OMSetRenderTargets(1, &mRenderTargetView, mDepthStencilView);


    // Set the viewport transform.

    D3D10_VIEWPORT vp;
    vp.TopLeftX = 0;
    vp.TopLeftY = 0;
    vp.Width    = mClientWidth;
    vp.Height   = mClientHeight;
    vp.MinDepth = 0.0f;
    vp.MaxDepth = 1.0f;

    md3dDevice->RSSetViewports(1, &vp);
}

void D3DApp::updateScene(float dt)
{
    // Code computes the average frames per second, and also the 
    // average time it takes to render one frame.

    static int frameCnt = 0;
    static float t_base = 0.0f;

    frameCnt++;

    // Compute averages over one second period.
    if( (mTimer.getGameTime() - t_base) >= 1.0f )
    {
        float fps = (float)frameCnt; // fps = frameCnt / 1
        float mspf = 1000.0f / fps;

        std::wostringstream outs;   
        outs.precision(6);
        outs << L"FPS: " << fps << L"\n" 
             << "Milliseconds: Per Frame: " << mspf;
        mFrameStats = outs.str();

        // Reset for next average.
        frameCnt = 0;
        t_base  += 1.0f;
    }
}

void D3DApp::drawScene()
{
    md3dDevice->ClearRenderTargetView(mRenderTargetView, mClearColor);
    md3dDevice->ClearDepthStencilView(mDepthStencilView, D3D10_CLEAR_DEPTH|D3D10_CLEAR_STENCIL, 1.0f, 0);
}

LRESULT D3DApp::msgProc(UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch( msg )
    {
    // WM_ACTIVATE is sent when the window is activated or deactivated.  
    // We pause the game when the window is deactivated and unpause it 
    // when it becomes active.  
    case WM_ACTIVATE:
        if( LOWORD(wParam) == WA_INACTIVE )
        {
            mAppPaused = true;
            mTimer.stop();
        }
        else
        {
            mAppPaused = false;
            mTimer.start();
        }
        return 0;

    // WM_SIZE is sent when the user resizes the window.  
    case WM_SIZE:
        // Save the new client area dimensions.
        mClientWidth  = LOWORD(lParam);
        mClientHeight = HIWORD(lParam);
        if( md3dDevice )
        {
            if( wParam == SIZE_MINIMIZED )
            {
                mAppPaused = true;
                mMinimized = true;
                mMaximized = false;
            }
            else if( wParam == SIZE_MAXIMIZED )
            {
                mAppPaused = false;
                mMinimized = false;
                mMaximized = true;
                onResize();
            }
            else if( wParam == SIZE_RESTORED )
            {

                // Restoring from minimized state?
                if( mMinimized )
                {
                    mAppPaused = false;
                    mMinimized = false;
                    onResize();
                }

                // Restoring from maximized state?
                else if( mMaximized )
                {
                    mAppPaused = false;
                    mMaximized = false;
                    onResize();
                }
                else if( mResizing )
                {
                    // If user is dragging the resize bars, we do not resize 
                    // the buffers here because as the user continuously 
                    // drags the resize bars, a stream of WM_SIZE messages are
                    // sent to the window, and it would be pointless (and slow)
                    // to resize for each WM_SIZE message received from dragging
                    // the resize bars.  So instead, we reset after the user is 
                    // done resizing the window and releases the resize bars, which 
                    // sends a WM_EXITSIZEMOVE message.
                }
                else // API call such as SetWindowPos or mSwapChain->SetFullscreenState.
                {
                    onResize();
                }
            }
        }
        return 0;

    // WM_EXITSIZEMOVE is sent when the user grabs the resize bars.
    case WM_ENTERSIZEMOVE:
        mAppPaused = true;
        mResizing  = true;
        mTimer.stop();
        return 0;

    // WM_EXITSIZEMOVE is sent when the user releases the resize bars.
    // Here we reset everything based on the new window dimensions.
    case WM_EXITSIZEMOVE:
        mAppPaused = false;
        mResizing  = false;
        mTimer.start();
        onResize();
        return 0;

    // WM_DESTROY is sent when the window is being destroyed.
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;

    // The WM_MENUCHAR message is sent when a menu is active and the user presses 
    // a key that does not correspond to any mnemonic or accelerator key. 
    case WM_MENUCHAR:
        // Don't beep when we alt-enter.
        return MAKELRESULT(0, MNC_CLOSE);

    // Catch this message so to prevent the window from becoming too small.
    case WM_GETMINMAXINFO:
        ((MINMAXINFO*)lParam)->ptMinTrackSize.x = 200;
        ((MINMAXINFO*)lParam)->ptMinTrackSize.y = 200; 
        return 0;
    }

    return DefWindowProc(mhMainWnd, msg, wParam, lParam);
}


void D3DApp::initMainWindow()
{
    WNDCLASS wc;
    wc.style         = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc   = MainWndProc; 
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance     = mhAppInst;
    wc.hIcon         = LoadIcon(0, IDI_APPLICATION);
    wc.hCursor       = LoadCursor(0, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);
    wc.lpszMenuName  = 0;
    wc.lpszClassName = L"D3DWndClassName";

    if( !RegisterClass(&wc) )
    {
        MessageBox(0, L"RegisterClass FAILED", 0, 0);
        PostQuitMessage(0);
    }

    // Compute window rectangle dimensions based on requested client area dimensions.
    RECT R = { 0, 0, mClientWidth, mClientHeight };
    AdjustWindowRect(&R, WS_OVERLAPPEDWINDOW, false);
    int width  = R.right - R.left;
    int height = R.bottom - R.top;

    mhMainWnd = CreateWindow(L"D3DWndClassName", mMainWndCaption.c_str(), 
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, width, height, 0, 0, mhAppInst, this); 
    if( !mhMainWnd )
    {
        MessageBox(0, L"CreateWindow FAILED", 0, 0);
        PostQuitMessage(0);
    }

    ShowWindow(mhMainWnd, SW_SHOW);
    UpdateWindow(mhMainWnd);
}

void D3DApp::initDirect3D()
{
    // Fill out a DXGI_SWAP_CHAIN_DESC to describe our swap chain.

    DXGI_SWAP_CHAIN_DESC sd;
    sd.BufferDesc.Width  = mClientWidth;
    sd.BufferDesc.Height = mClientHeight;
    sd.BufferDesc.RefreshRate.Numerator = 60;
    sd.BufferDesc.RefreshRate.Denominator = 1;
    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    sd.BufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
    sd.BufferDesc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;

    // No multisampling.
    sd.SampleDesc.Count   = 1;
    sd.SampleDesc.Quality = 0;

    sd.BufferUsage  = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    sd.BufferCount  = 1;
    sd.OutputWindow = mhMainWnd;
    sd.Windowed     = true;
    sd.SwapEffect   = DXGI_SWAP_EFFECT_DISCARD;
    sd.Flags        = 0;


    // Create the device.

    UINT createDeviceFlags = 0;
#if defined(DEBUG) || defined(_DEBUG)  
    createDeviceFlags |= D3D10_CREATE_DEVICE_DEBUG;
#endif

    HR( D3D10CreateDeviceAndSwapChain(
            0,                 //default adapter
            md3dDriverType,
            0,                 // no software device
            createDeviceFlags, 
            D3D10_SDK_VERSION,
            &sd,
            &mSwapChain,
            &md3dDevice) );


    // The remaining steps that need to be carried out for d3d creation
    // also need to be executed every time the window is resized.  So
    // just call the onResize method here to avoid code duplication.

    onResize();
}