#include <windows.h>

double time_factor;		// Time Scaling Factor
double time_span;		// time elapsed since last frame
LONGLONG last_time;		// Previous timer value	
LONGLONG cur_time;		// current timer value
int fps;			// number of frames per second
float dwTime;			// time elapsed since last second tick
int dwFramesDrawn;		// number of frames drawn since last second tick

LONGLONG perf_cnt;


HDC hdc;
HDC backbuffer_dc;

HBITMAP backbuffer;


char szBuffer [40];


LRESULT CALLBACK WinProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam);

int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprev, PSTR cmdline, int ishow)
{	
    HWND hwnd;
    MSG msg;
    WNDCLASSEX wndclassex = {0};
	
    char class_name[] = "fps";

    wndclassex.cbSize = sizeof(WNDCLASSEX);
    wndclassex.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
    wndclassex.lpfnWndProc = WinProc;
    wndclassex.hInstance = hinstance;
    wndclassex.hIcon = LoadIcon(hinstance,IDI_APPLICATION);
    wndclassex.hbrBackground = NULL;
    wndclassex.lpszClassName = class_name;
    wndclassex.hCursor = LoadCursor(NULL, IDC_ARROW);


    RegisterClassEx(&wndclassex);


    hwnd = CreateWindowEx(WS_EX_APPWINDOW, class_name, "fps test", WS_POPUP, CW_USEDEFAULT, CW_USEDEFAULT, 800, 600, NULL, NULL, hinstance, NULL);

		if(!hwnd)
		{
			UnregisterClass(class_name,hinstance);
				return EXIT_FAILURE;
		}

    ShowWindow(hwnd, ishow);
    UpdateWindow(hwnd);

	
	
	while(1)	// main window loop
	{
		if(PeekMessage(&msg,NULL,0,0,PM_REMOVE))
		{
			if(msg.message == WM_QUIT)
				break;
				
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
		else
		{
			QueryPerformanceCounter((LARGE_INTEGER *) &cur_time);
			
			if (cur_time>last_time)
			{
				time_span=(cur_time-last_time)*time_factor;
			
				dwTime+=time_span;
				dwFramesDrawn++;
		
				if (dwTime>=1.0f)
				{
					fps=dwFramesDrawn;
					dwFramesDrawn=0;
					dwTime=0;
				}
			
				BitBlt(backbuffer_dc,0,0,800,600,NULL,0,0,WHITENESS);
			
				TextOut (backbuffer_dc, 100, 100, szBuffer, sprintf (szBuffer, "fps: %d",fps));


								
				//backbuffer to the screen
				BitBlt(hdc,0,0,800,600,backbuffer_dc,0,0,SRCCOPY);
		
				last_time=cur_time;
		
			}
			else
				Sleep(0);
		}	// end of main window else
	}	// end of main window loop


	UnregisterClass(class_name,hinstance);

		return msg.wParam;
}


LRESULT CALLBACK WinProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam)
{
    PAINTSTRUCT ps;
			
	switch(message)
    {
	    case WM_CREATE:
	    {			
			//checking for QPC
			if (QueryPerformanceFrequency((LARGE_INTEGER *) &perf_cnt))
			{
				time_factor=1.0/perf_cnt;
				QueryPerformanceCounter((LARGE_INTEGER *) &last_time);
			}
			
			hdc = GetDC(hwnd);
			backbuffer_dc = CreateCompatibleDC(hdc);
			backbuffer = CreateCompatibleBitmap(hdc, 800, 600);
			
			backbuffer = (HBITMAP)SelectObject(backbuffer_dc,backbuffer);


			if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDYES)
			{
				//switching to the full screen display mode
				DEVMODE dmScreenSettings;								// device mode
				memset(&dmScreenSettings, 0, sizeof(dmScreenSettings));	// clear memory
				dmScreenSettings.dmSize=sizeof(dmScreenSettings);		// size of devmode structure
				dmScreenSettings.dmPelsWidth = 800;						// selected screen width
				dmScreenSettings.dmPelsHeight = 600;					// selected screen height
				dmScreenSettings.dmBitsPerPel = 32;						// selected bits per pixel
				dmScreenSettings.dmFields = DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;
		
				ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN);	    
			}
	    }
	    
	    case WM_KEYDOWN:
	    {
		    if (wparam==VK_ESCAPE)
		    {
				ChangeDisplaySettings(NULL,0);	//switch back to the window mode
				PostQuitMessage(0);
			}
		}
		
		case WM_PAINT:
			BeginPaint(hwnd, &ps);
			EndPaint(hwnd, &ps);
				return 0;
				

		case WM_CLOSE:
		case WM_DESTROY:
		{
			ChangeDisplaySettings(NULL,0);	//switch back to the window mode
			
			PostQuitMessage(0);
				return 0;
		}
		break;
    
	}

    return(DefWindowProc(hwnd, message, wparam, lparam));
}

hwnd = CreateWindowExA(WS_EX_APPWINDOW, class_name, "fps test", WS_POPUP | WS_CLIPSIBLINGS | WS_CLIPCHILDREN, CW_USEDEFAULT, CW_USEDEFAULT, SCREENWIDTH, SCREENHEIGHT, NULL, NULL, hinstance, NULL);

int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprev, PSTR cmdline, int ishow){	    HWND hwnd;    MSG msg;    WNDCLASSEX wndclassex = {0};	    char class_name[] = "fps";    wndclassex.cbSize = sizeof(WNDCLASSEX);    wndclassex.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;    wndclassex.lpfnWndProc = WinProc;    wndclassex.hInstance = hinstance;    wndclassex.hIcon = LoadIcon(hinstance,IDI_APPLICATION);    wndclassex.hbrBackground = NULL;    wndclassex.lpszClassName = class_name;    wndclassex.hCursor = LoadCursor(NULL, IDC_ARROW);    RegisterClassEx(&wndclassex);	// F451 - start 11/25/05 - moved from WM_CREATE in WinProc section	if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDYES)	{		//switching to the full screen display mode		DEVMODE dmScreenSettings;								// device mode		memset(&dmScreenSettings, 0, sizeof(dmScreenSettings));	// clear memory		dmScreenSettings.dmSize=sizeof(dmScreenSettings);		// size of devmode structure		dmScreenSettings.dmPelsWidth = 800;						// selected screen width		dmScreenSettings.dmPelsHeight = 600;					// selected screen height		dmScreenSettings.dmBitsPerPel = 32;						// selected bits per pixel		dmScreenSettings.dmFields = DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;			ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN);	    	}	// F451 - end 11/25/05    hwnd = CreateWindowEx(WS_EX_APPWINDOW, class_name, "fps test", WS_POPUP | WS_CLIPSIBLINGS | WS_CLIPCHILDREN, CW_USEDEFAULT, CW_USEDEFAULT, 800, 600, NULL, NULL, hinstance, NULL);		if(!hwnd)		{			UnregisterClass(class_name,hinstance);				return EXIT_FAILURE;		}