[D3D, C++] Błąd podczas kompilacji kodu: 'undefined reference to `WinMain@16''

#include <d3d8.h>

LPDIRECT3D8 g_pD3D = NULL;
LPDIRECT3DDEVICE8 g_pd3dDevice = NULL;

HRESULT InitD3D( HWND hWnd )
{
    if( NULL ==( g_pD3D = Direct3DCreate8( D3D_SDK_VERSION ) ) )
         return E_FAIL;
   
    D3DDISPLAYMODE d3ddm;
    if( FAILED( g_pD3D->GetAdapterDisplayMode( D3DADAPTER_DEFAULT, & d3ddm ) ) )
         return E_FAIL;
   
    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory( & d3dpp, sizeof( d3dpp ) );
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = d3ddm.Format;
   
    if( FAILED( g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
    D3DCREATE_SOFTWARE_VERTEXPROCESSING, & d3dpp, & g_pd3dDevice ) ) )
         return E_FAIL;
   
    return S_OK;
}

void Cleanup()
{
    if( g_pd3dDevice != NULL )
         g_pd3dDevice->Release();
   
    if( g_pD3D != NULL )
         g_pD3D->Release();
   
}

void Render()
{
    if( NULL == g_pd3dDevice )
         return;
   
    g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB( 0, 0, 255 ), 1.0f, 0 );
    g_pd3dDevice->BeginScene();
    g_pd3dDevice->EndScene();
   
    g_pd3dDevice->Present( NULL, NULL, NULL, NULL );
}