#include <windows.h>
#include <cstdio>
#include <stdarg.h>


HINSTANCE g_hInst;
HWND	  g_hWnd;

#define WNDWIDTH  400
#define WNDHEIGHT 400
#define WNDTYPE	  WS_OVERLAPPEDWINDOW

const char g_szClass[]     = "FrameClass";
const char g_szCaptation[] = "Frame Captation";

//entry point

int PASCAL WinMain(HINSTANCE hInst, HINSTANCE hPrev,
				   LPSTR szCmdLine, int nCmdShow);

void AppError(BOOL Fatal, char *Text, ...);

long FAR PASCAL WindowProc(HWND hWnd, UINT uMsg,
							 WPARAM wParam, LPARAM lParam);

//register and unregister classes

bool RegisterWindowsClasses(HINSTANCE hInst);
bool UnregisterWindowsClasses(HINSTANCE hInst);

//creates window

HWND CreateMainWindow(HINSTANCE hInst);

//funktions to init, shutdown, and handel per-frame funktions

BOOL DoInit();
BOOL DoShutDown();
BOOL DoPreFrame();
BOOL DoPostFrame();


int PASCAL WinMain(HINSTANCE hInst, HINSTANCE hPrev,
				   LPSTR szCmdLine, int CmdShow)
{
	MSG  Msg;
	
	g_hInst = hInst;

	//register window 

	if((RegisterWindowsClasses(hInst)) == FALSE)
		return FALSE;
	
	//create window

	if((g_hWnd = CreateMainWindow(hInst)) == NULL)
		return FALSE;
	
	if(DoInit() == TRUE)
	{
		ZeroMemory(&Msg, sizeof(MSG));
		
		while(Msg.message != WM_QUIT)
		{
			if(PeekMessage(&Msg, NULL, 0, 0, PM_REMOVE))
			{
				TranslateMessage(&Msg);
				DispatchMessage(&Msg);
			}
			else
			{
				//do preframe rendering

				if(DoPreFrame() == FALSE)
					break;
				
				//do postframe rendering

				if(DoPostFrame() == FALSE)
					break;
			}
		}
	}
	DoShutDown();

	//unregister class

	UnregisterWindowsClasses(hInst);

	return TRUE;
}

BOOL RegisterWindowsClassex(HINSTANCE hInst)
{
	WNDCLASSEX wcex;
	
	//create and register window

	wcex.cbSize			= sizeof(wcex);
	wcex.style			= CS_CLASSDC;
	wcex.lpfnWndProc	= WindowProc;
	wcex.cbClsExtra		= 0;
	wcex.cbWndExtra		= 0;
	wcex.hInstance		= hInst;
	wcex.hIcon			= LoadIcon(NULL, IDI_APPLICATION);
	wcex.hCursor		= LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground	= NULL;
	wcex.lpszMenuName	= NULL;
	wcex.lpszClassName	= g_szClass;
	wcex.hIconSm		= LoadIcon(NULL, IDI_APPLICATION);
	if(!RegisterClassEx(&wcex))
		return FALSE;

	return TRUE;
}


BOOL UnregisterWindowClasses(HINSTANCE hInst)
{
	UnregisterClass(g_szClass, hInst);

	return TRUE;
}

HWND CreateMainWindow(HINSTANCE hInst)
{
	HWND hWnd;

	hWnd = CreateWindow(g_szClass, g_szCaptation, WNDTYPE, 0, 0, 
						WNDWIDTH, WNDHEIGHT, 
						NULL, NULL, hInst, NULL);
	if(!hWnd)
		return NULL;

	ShowWindow(hWnd, SW_NORMAL);
	UpdateWindow(hWnd);

	return hWnd;
}

void AppError(BOOL Fatal, char *Text, ...)
{
	char CaptationText[12];
	char ErrorText[2048];
	va_list valist;

	if(Fatal == FALSE)
		strcpy(CaptationText, "ERROR");
	else
		strcpy(CaptationText, "FATAL ERROR");

	//build variable text buffer

	va_start(valist, Text);
	vsprintf(ErrorText, Text, valist);
	va_end(valist);

	//display the message

	MessageBox(NULL, ErrorText, CaptationText, MB_OK | MB_ICONEXCLAMATION);

	if(Fatal == TRUE)
		PostQuitMessage(0);
}

long FAR PASCAL WindowProc(HWND hWnd, UINT uMsg,
						   WPARAM wParam, LPARAM lParam)
{
	switch(uMsg)
	{
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	}
	
	return DefWindowProc(hWnd, uMsg, wParam, lParam);
}

BOOL DoInit()
{
	/*
	performe application init functions here,
	souch as those who setup grafics sound etc...
	return true for succes
	*/
	return TRUE;
}

BOOL DoShutDown()
{
	/*
	performe application shutdowns here souch as shuting
	down grafics sound etc...
	returns true for succes
	*/

	return TRUE;
}

BOOL DoPreFrame()
{
	/*
	performe pre-frame proccesing here, souch as setting up timer...
	return true for succes.
	*/
	return TRUE;
}

BOOL DoFrame()
{
	/*
	performe rendering and souch,
	true if succes
	*/
	return TRUE;
}

BOOL DoPostFrame()
{
	/*
	performe postframe proccesing souch as synching
	*/
	return TRUE;
}