TetroGL: An OpenGL Game Tutorial in C++ for Win32 Platforms - Part 1

#include "Application.h"
#include "MainWindow.h"
#include <string>

// Disable the warnings for deprecated functions (strtok and stricmp)
#pragma warning(disable:4996)

CApplication::CApplication(HINSTANCE hInstance)
  : m_hInstance(hInstance), m_bFullScreen(false)
{
}

CApplication::~CApplication()
{
}

void CApplication::ParseCmdLine(LPSTR lpCmdLine)
{
	LPSTR lpArgument = strtok(lpCmdLine," ");
	while (lpArgument)
	{
		if (stricmp(lpArgument,"-fullscreen") == 0)
			m_bFullScreen = true;
		lpArgument = strtok(NULL," ");
	}
}

void CApplication::Run()
{
	// Create the main window first
	CMainWindow mainWindow(800,600,m_bFullScreen);

    MSG Message;
    Message.message = ~WM_QUIT;
	DWORD dwNextDeadLine = GetTickCount() + FRAME_TIME;
	DWORD dwSleep = FRAME_TIME;
	bool bUpdate = false;

	// Loop until a WM_QUIT message is received
    while (Message.message != WM_QUIT)
    {
		// Wait until a message comes in or until the timeout expires. The
		// timeout is recalculated so that this function will return at
		// least every FRAME_TIME msec.
		DWORD dwResult = MsgWaitForMultipleObjectsEx(0,NULL,dwSleep,QS_ALLEVENTS,0);
		if (dwResult != WAIT_TIMEOUT)
		{
			// If the function returned with no timeout, it means that at 
			// least one message has been received, so process all of them.
			while (PeekMessage(&Message, NULL, 0, 0, PM_REMOVE))
			{
				// If a message was waiting in the message queue, process it
				TranslateMessage(&Message);
				DispatchMessage(&Message);
			}

			// If the current time is close (or past) to the 
			// deadline, the application should be processed.
			if (GetTickCount() >= dwNextDeadLine)
				bUpdate = true;
			else
				bUpdate = false;
		}
		else
			// On a timeout, the application should be processed.
			bUpdate = true;

		// Check if the application should be processed
		if (bUpdate)
		{
			DWORD dwCurrentTime = GetTickCount();
			// Update the main window
			mainWindow.Update(dwCurrentTime);
			// Draw the main window
			mainWindow.Draw();

			dwNextDeadLine = dwNextDeadLine + FRAME_TIME;
		}

		// Process the sleep time, which is the difference
		// between the current time and the next deadline.
		dwSleep =  dwNextDeadLine - GetCurrentTime();
		// If the sleep time is larger than the frame time,
		// it probably means that the processing was stopped 
		// (e.g. the window was being moved,...), so recalculate
		// the next deadline.
		if (dwSleep>FRAME_TIME)
		{
			dwSleep = FRAME_TIME;
			dwNextDeadLine = GetCurrentTime() + FRAME_TIME;
		}
	}
}