Показать картину (bmp), растягивая ее на все окно (не нарушая пропорций)

#include <windows.h>
#include <tchar.h>
 
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
const TCHAR winName[] = _T("MainFrame");
const TCHAR regWndErr[] = _T("Ошибка регистрации окна");
const TCHAR createWndErr[] = _T("Ошибка создания окна");
 
 
int APIENTRY WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR lpCmdLine, int nShowMode){
 
 
    MSG msg;
    WNDCLASS wc;
 
    wc.hInstance = hInst;
    wc.lpszClassName = winName;
    wc.lpfnWndProc = WndProc;
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.lpszMenuName = NULL;
    wc.cbClsExtra = sizeof(&wc);
    wc.cbWndExtra = 0;
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW);
 
    if (!RegisterClass(&wc)) {
        MessageBox(NULL, regWndErr, regWndErr, MB_OK); return 0;
    }
 
    HWND hWnd;
 
    hWnd = CreateWindow(winName,_T("Каркас Wind приложения"),WS_OVERLAPPEDWINDOW,CW_USEDEFAULT, CW_USEDEFAULT,CW_USEDEFAULT, CW_USEDEFAULT,0, 0, hInst, 0);
    MessageBox(hWnd, GetCommandLine(), NULL, MB_OK);
 
    if (!hWnd) { MessageBox(NULL, createWndErr, createWndErr, MB_OK); return 0; }
    ShowWindow(hWnd, nShowMode);
 
    while (GetMessage(&msg, NULL, 0, 0)){
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}
 
 
 
LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam){
    PAINTSTRUCT ps;
    HDC hdc;
    
    
    
    
    static HDC memBit;
    static HBITMAP hBitmap;
    static BITMAP bm;
 
    static int caption, border;
 
 
    switch (msg){
    case WM_CREATE:
        caption = GetSystemMetrics(SM_CYCAPTION);
        border = GetSystemMetrics(SM_CXFIXEDFRAME);
 
        hBitmap = (HBITMAP)LoadImage(NULL, _T("F:\\Кондратьев\\13.bmp"), IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE | LR_CREATEDIBSECTION);
        if (hBitmap == NULL){
            MessageBox(hWnd, _T("file isn't find"), _T("file loading..."), MB_OK);
            DestroyWindow(hWnd);
            return 1;
        }
        GetObject(hBitmap, sizeof(bm), &bm);
        hdc = GetDC(hWnd);
        memBit = CreateCompatibleDC(hdc);
        SelectObject(memBit, hBitmap);
        ReleaseDC(hWnd, hdc);
        break;
 
    case WM_SIZE:
        MoveWindow(hWnd, 0, 0, bm.bmWidth + 2 * border, bm.bmHeight + caption + border, TRUE);
        break;
 
    case WM_PAINT:
        hdc = BeginPaint(hWnd, &ps);
        BitBlt(hdc, 0, 8, 0, 0, memBit, 0, 0, SRCCOPY);
        EndPaint(hWnd, &ps);
        break;
    case WM_DESTROY: PostQuitMessage(0); break;
    default: return DefWindowProc(hWnd, msg, wParam, lParam);
 
    }
    return 0;
}