Замучил прямоугольник. Помогите разобраться.

HBITMAP GetBitmap (HDC hgraphdc, CONST RECT rect, HDC hmemdc)
{
HBITMAP hnew_bmp;
if (hnew_bmp) DeleteObject (hnew_bmp);
hnew_bmp = CreateCompatibleBitmap (hgraphdc, rect.right, rect.bottom);
SelectObject (hmemdc, hnew_bmp);
for (int j = rect.top; j < rect.bottom; j ++)
{
for (int i = rect.left; i < rect.right; i ++)
{
COLORREF pxl_clr = GetPixel (hgraphdc, i, j);
SetPixel (hmemdc, i, j, pxl_clr);
}
} 
return (hnew_bmp);
}//GetBitmap

int WINAPI WinMain (HINSTANCE hinstance, HINSTANCE hprevinstance, LPSTR lpcmdline, int ncmdshow)
//* * *
//* * *
//* * *
while (TRUE)
{
if (PeekMessage (&msg, NULL, 0, 0, PM_REMOVE))
{
if (msg.message == WM_QUIT)
break;
TranslateMessage (&msg);
DispatchMessage (&msg);
}// end if
//draw auto in the window-------------------------------------------------------
if (pressed_button == 300) // select auto
{
avto.LoadAvto (hmemdc, type_selector);
if (MOUSE_BUTTON & MK_LBUTTON)
{
avto.PlaceAvto (hmemdc);
}
MOUSE_BUTTON = NULL;
}
//move auto---------------------------------------------------------------------
if (pressed_button == 1200)
{
avto.StartMoving (hmemdc);
MOUSE_BUTTON = NULL;
}
//stop moving-------------------------------------------------------------------
if (pressed_button == 1300)
{
avto.StopMoving ();
 
MOUSE_BUTTON = NULL;
}
//------------------------------------------------------------------------------
//quit in window
if (KEYDOWN(VK_ESCAPE))
{
PostMessage (main_window_handle, WM_CLOSE, 0, 0);
}
 
//hold back the 30 fps
while ((GetTickCount() - start_time) < 33);
//===================================================================
}//while (TRUE)
 
DeleteDC (hmemdc);
ReleaseDC (main_window_handle, hgraphdc);
//===================================================================
 
return (msg.wParam);
}//WinMaim
//*******************************************************************
//Other functions*************************************************************
 
//class Avto Functions~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Avto::Avto()
{
avto_type = 20;
}//constructor
int Avto::LoadAvto (HDC hmemdc, int type_selector)
{
switch (type_selector)
{
case 1: 
{
avto_type = 10;
}break;
case 2: 
{
avto_type = 11;
}break;
case 3: 
{
avto_type = 12;
}break;
default: break;
}//switch
 
//load selected auto image
hbmp_avto = LoadBitmap (hinstance_app, MAKEINTRESOURCE(avto_type))
 
GetObject (hbmp_avto, sizeof(BITMAP), &bmp_avto)
SelectObject (hmemdc, hbmp_avto);
//place curent object into small window
StretchBlt (hgraphdc,
4,
293,
74,
74,
hmemdc,
0,
0,
bmp_avto.bmWidth,
bmp_avto.bmHeight,
SRCCOPY);
return (0);
}//int LoadAvto (int type_selector)
 
int Avto::PlaceAvto (HDC hmemdc)
{
 
avto_rect.left = MOUSE_XPOS;
avto_rect.top = MOUSE_YPOS;
avto_rect.right = MOUSE_XPOS + bmp_avto.bmWidth;
avto_rect.bottom = MOUSE_YPOS + bmp_avto.bmHeight;
//copy bacground before auto placed
hgroundrect = GetBitmap (hgraphdc, avto_rect, hmemdc);
SelectObject (hmemdc, hbmp_avto);
//place auto into window
BitBlt (hgraphdc,
avto_rect.left,
avto_rect.top,
avto_rect.right,
avto_rect.bottom,
hmemdc,
0, 0,
SRCCOPY);
 
return (0);
}//int Avto::PlaceAvto (HDC hmemdc)
int Avto::StartMoving (HDC hmemdc)
{
//select and place bacground
SelectObject (hmemdc, hgroundrect);
 
BitBlt (hgraphdc,
avto_rect.left,
avto_rect.top,
avto_rect.right,
avto_rect.bottom,
hmemdc,
0, 0,
SRCCOPY);
speed = 1;
boost = 1;
 
avto_rect.left += (speed * boost);
 
//load bacground 
hgroundrect = GetBitmap (hgraphdc, avto_rect, hmemdc);
SelectObject (hmemdc, hbmp_avto);
//place auto into window 
BitBlt (hgraphdc,
avto_rect.left,
avto_rect.top,
avto_rect.right,
avto_rect.bottom,
hmemdc,
0, 0,
SRCCOPY);
return (0); 
}
int Avto::StopMoving ()
{ 
speed += 0;
return (0); 
}
Avto::~Avto()
{
DeleteObject (hbmp_avto);
DeleteObject (hgroundrect);
}//destructor