Fixed window creation behavior in Win32 Framebuffer

It now creates the correct window size from the start and doesn't move the
window to (0,0) after showing it. This is much more natural and correct.

Also refactored and cleaned the related code somewhat.

src/framebuffer/fbw.cpp

@@ -113,9 +113,8 @@ CWinDisplay::~CWinDisplay() {
 // Comments				:
 void	CWinDisplay::main() {
 	WNDCLASSEX	wcex;
-	RECT		clientRect,windowRect;
-	int			nw,nh;
 	MSG			msg;
+  const char *szPixieWndClass = "PixieWinDisplay";
 
 	hInst							= (HINSTANCE) GetModuleHandle(NULL);
 
@@ -130,36 +129,37 @@ void	CWinDisplay::main() {
 	wcex.hCursor					= LoadCursor(NULL,IDC_ARROW);
 	wcex.hbrBackground				= NULL;
 	wcex.lpszMenuName				= NULL;
-	wcex.lpszClassName				= "WinDisplay";
+	wcex.lpszClassName				= szPixieWndClass;
 	wcex.hIconSm					= LoadIcon(NULL,IDI_APPLICATION);
 
 	RegisterClassEx(&wcex);
 
+  // Make a non-resizable window style.
+  DWORD dwStyle = WS_OVERLAPPEDWINDOW & ~(WS_THICKFRAME | WS_MAXIMIZEBOX);
+
+  // Size of our desired client area.
+  RECT rc = { 0, 0, width, height };
+
+  // Compute the correct window size given our style.
+  AdjustWindowRect(&rc, dwStyle, FALSE);
+
   // Create the window (non-resizable).
-  hWnd = CreateWindow("WinDisplay", name,
-    WS_OVERLAPPEDWINDOW & ~(WS_THICKFRAME | WS_MAXIMIZEBOX), CW_USEDEFAULT,
-    0, width, height, NULL, NULL, hInst, NULL);
+  hWnd = CreateWindow(szPixieWndClass, name,
+    dwStyle, CW_USEDEFAULT, CW_USEDEFAULT, rc.right - rc.left,
+    rc.bottom - rc.top, NULL, NULL, hInst, NULL);
 
 	if (!hWnd)	{
 		active	=	FALSE;
 		return;	// Nothing to do
 	}
 
+  // Associate a pointer to our instance with this window.
   SetWindowLongPtr(hWnd, GWLP_USERDATA, (LONG_PTR)this);
 
 	// Show the window
 	ShowWindow(hWnd,SW_SHOW);
 	UpdateWindow(hWnd);
 
-	// Adjust the size of the window so that we display the entire picture
-	GetWindowRect(hWnd,&windowRect);
-	GetClientRect(hWnd,&clientRect);
-
-	nw	=	width	+	(windowRect.right - windowRect.left) - (clientRect.right - clientRect.left);
-	nh	=	height	+	(windowRect.bottom - windowRect.top) - (clientRect.bottom - clientRect.top);
-
-	SetWindowPos(hWnd,NULL,0,0,nw,nh,SWP_SHOWWINDOW);
-
 	// Set up the bitmap
 	info.bmiHeader.biSize			= sizeof(BITMAPINFOHEADER);
 	info.bmiHeader.biWidth			= width;