bool Draw()
{
    Device->Clear(0, 0, D3DCLEAR_TARGET, WHITE, 1, 0);
    Device->BeginScene();

    DrawEnvironment(Device,Environment);

    Device->EndScene();
    if (FAILED(Device->Present(0,0,0,0)))
    {
        while(Device->TestCooperativeLevel() == D3DERR_DEVICELOST) Sleep(100);
        D3DPRESENT_PARAMETERS D3dPresParams = GetDeviceParams(Window);
        if (FAILED(Device->Reset(&D3dPresParams)))
            return true;
    }

    return false;
}

LPDIRECT3DVERTEXBUFFER9 CreateEnvironment(LPDIRECT3DDEVICE9 D3dDevice)
{
    LPDIRECT3DVERTEXBUFFER9     Buffer      = 0;
    ENV_VERTEX*                 Vertices    = 0;

    Vertices = new (std::nothrow) ENV_VERTEX[40];

    for (UINT i=0, ii=-10; i<10; i+=2, ii+=2)
    {
        Vertices[i].P = D3DXVECTOR3((float)ii,0,10);
        Vertices[i+1].P = D3DXVECTOR3((float)ii,0,-10);
    }

    for (UINT i=10, ii=10; i<20; i+=2, ii-=2)
    {
        Vertices[i].P = D3DXVECTOR3((float)ii,0,10);
        Vertices[i+1].P = D3DXVECTOR3((float)ii,0,-10);
    }

    for (UINT i=20, ii=-10; i<30; i+=2, ii+=2)
    {
        Vertices[i].P = D3DXVECTOR3(10,0,(float)ii);
        Vertices[i+1].P = D3DXVECTOR3(-10,0,(float)ii);
    }

    for (UINT i=30, ii=10; i<40; i+=2, ii-=2)
    {
        Vertices[i].P = D3DXVECTOR3(10,0,(float)ii);
        Vertices[i+1].P = D3DXVECTOR3(-10,0,(float)ii);
    }

    for (UINT i=0; i<40; ++i)
        Vertices[i].C = GREY;

    if (FAILED(D3dDevice->CreateVertexBuffer(40*sizeof(ENV_VERTEX), 0, ENVFVF, D3DPOOL_MANAGED, &Buffer, 0)))
        return 0;

    VOID* Address;
    Buffer->Lock(0,0,&Address,0);
    memcpy(Address,Vertices,40*sizeof(ENV_VERTEX));
    Buffer->Unlock();

    SAFE_ARRAY_DELETE(Vertices);

    return Buffer;
}

void DrawEnvironment(LPDIRECT3DDEVICE9 D3dDevice, LPDIRECT3DVERTEXBUFFER9 Buffer)
{
    D3dDevice->SetFVF(ENVFVF);
    D3dDevice->SetStreamSource(0,Buffer,0,sizeof(ENV_VERTEX));
    D3dDevice->DrawPrimitive(D3DPT_LINELIST,0,20);
}