Question about timers

[James]

I'm trying to put in a timer into my pong application. It will be a count down timer that will be displayed above the scores at the top of the screen. When the timer reaches 0:00 the game advances to the next level and the timer is reset.

The problem I am running in to is that I have tried a dozen different timers and I can't seem to figure out how to make a timer run in its own thread without effecting the parent window "hWnd". I have created a new static control that will have the time printed on there, but when I put a timer on there it effects the game play (slowing everything down significantly almost to a unplayable state).

I have tried do while loops, while loops, for loops, settimer() queryprocess timers, the time_t structure and maybe a few other methods I'm forgetting, but they all effect the game for some reason.

Heres some code:

The function is being called from WinMain(). Should I be calling it from somewhere else possibly?

void CALLBACK TimerProc(HWND hwnd, UINT uMsg, UINT idEvent, DWORD dwTime) 
{
    RECT rc;
    GetClientRect(hWnd, &rc);
    int width = 100;
    int height = 50;
    char szBuffer[50];
    int counter = 0;

    j--;
    //printf("Cool!\n");
    _stprintf_s(szBuffer,"Test: %i", counter);
    myTimer = CreateWindowEx(0, "STATIC", szBuffer, WS_CHILD | WS_VISIBLE, ((rc.right - rc.left - 50) / 2), 0, width, height, hWnd, (HMENU)IDS_MYTIMER, hInst, NULL);
    
    ShowWindow(myTimer, SW_SHOW);
    UpdateWindow(myTimer);
    counter ++;
}


void drawTimer()
{
    RECT rc;
    GetClientRect(hWnd, &rc);
    int width = 100;
    int height = 50;
    char szBuffer[50];
    UINT id;
    int counter = 0;
    MSG msg;
    
    id = SetTimer(myTimer, 0, 3000, (TIMERPROC) TimerProc);

    while(j) 
    {
        GetMessage(&msg, NULL, 0, 0);
        DispatchMessage(&msg);
    }
    KillTimer(NULL, id);

    /*
    do
    {
        _stprintf_s(szBuffer,"Test: %i", i);
        myTimer = CreateWindowEx(0, "STATIC", szBuffer, WS_CHILD | WS_VISIBLE, ((rc.right - rc.left - 50) / 2), 0, width, height, hWnd, (HMENU)IDS_MYTIMER, hInst, NULL);
    
        ShowWindow(myTimer, SW_SHOW);
        UpdateWindow(myTimer);
        counter ++;

    }while(counter <= (5));
    */

/*
    time_t today;
    struct tm *tm;
    today = time(0);
    tm = localtime(&today);
    tm->tm_sec = 5;
    tm->tm_hour = 0;
    tm->tm_min = 0;
    int total = 5;
    mktime(tm);


        _stprintf_s(szBuffer,"Time: %02d:%02d %i", tm->tm_min, tm->tm_sec, total);
        myTimer = CreateWindowEx(0, "STATIC", szBuffer, WS_CHILD | WS_VISIBLE, ((rc.right - rc.left - 50) / 2), 0, width, height, hWnd, (HMENU)IDS_MYTIMER, hInst, NULL);
    
        ShowWindow(myTimer, SW_SHOW);
        UpdateWindow(myTimer);
        total = (tm->tm_sec) - 1;
*/
} 

[Elgan]

first you need to set a specific timer loop for your FPS count, so google QueryPerformanceCounter




use peekmessage instead of getmessage , to speed your game up a lot.

[James]

Hmm, maybe I'm not clear sorry.
The only reason the game is running slow is because of this 2nd timer. The only reason I have a 2nd timer is for a countdown, I'm not sure of any other accurate way of doing a timer without affecting the gameplay. I don't want to speed up or slow down the game. I want 1 timer to control the game, and the only other timer I want is a visual timer that tells the player how many more minutes\seconds are left in the game. I just can't seem to figure out a way of doing that without effecting the game speed.

I tried your suggestions, and still no dice.

void StartCounter()
{
    char szBuffer[1024];

    LARGE_INTEGER li;
    if(!QueryPerformanceFrequency(&li))
    {
        _stprintf_s(szBuffer,"QueryPerformanceFrequency failed!", NULL);
        SetWindowText(myTimer, szBuffer);
    }

    PCFreq = double(li.QuadPart)/1000.0;

    QueryPerformanceCounter(&li);
    CounterStart = li.QuadPart;
}
double GetCounter()
{
    LARGE_INTEGER li;
    QueryPerformanceCounter(&li);
    return double(li.QuadPart-CounterStart)/PCFreq;
}

void drawTimer()
{
    RECT rc;
    GetClientRect(hWnd, &rc);
    int width = 100;
    int height = 50;
    char szBuffer[1024];
    MSG msg;

    StartCounter();
    _stprintf_s(szBuffer,"Counter: %Lg", GetCounter());

    myTimer = CreateWindowEx(0, "STATIC", szBuffer, WS_CHILD | WS_VISIBLE, ((rc.right - rc.left - 50) / 2), 0, width, height, hWnd, (HMENU)IDS_MYTIMER, hInst, NULL);
    
    ShowWindow(myTimer, SW_SHOW);
    UpdateWindow(myTimer);
} 

[Elgan]

I think you miss understand

QueryPerformanceCounter is for an accurate game loop, i dont even see a game loop now, and peekmessage to not slow it down.


then you should be safe making a timer, if u have a non accurate game loop, it will run at different speeds on different computers, which is why it runs different for people on modtheater

and then with an accurate timed game loop, u dont even need a mutex or second process running a timer loop with a call back, which just fires windows events.


u can just use the clock and get the time ur app started, and test it ever second or so....?

clock_t initial = clock();
//do stuff here
clock_t current = clock();
float difference = (current - initial) / 1000.0f;//1000 millis = 1 second

[Razo[R]apiD]

Create a thread and do your timer there, it won't affect the game or it shouldn't.

[Elgan]

yes you can do that but btw you should also still setup a proper game loop

[James]

I don't understand what you mean by game loop elg?

Not sure if you saw my source, but I have the main window created in WinMain() then the looping is done in wndProc() via message handling.
SO events like wm_Create, wm_Paint, wm_timers etc etc all do what they need. As far as I know this is the correct way of doing the looping. Could you show me an example of what you're referring to?

[Elgan]

not looked at your source but above it looks awkward.


game loop is like the winapi one ebut somtimes u may want to use peekmessage, depends how ur loop is, and if u want ur game to have a set fps or tick count or such so that its speed is constant

[James]

I have a bunch of custom functions that are running simultaneously and are executed based on the msg being sent. Everything works fine but the timer.
@ RR, I did what you said, I'll give this a go and see what happens. Thanks!

EDIT:
Alright I think I did what RR suggested, and now I'm trying a simple function called test(), and it's not working... WTF... This shouldn't be so hard. haha.

Here is what I did:

void test(HWND hWndT)
{
    char szBuffer[1024];
    int counter = 0;

    for(int i = 0; i < 6; i ++)
    {
        wait(1);
        _stprintf_s(szBuffer, "Counter:", NULL);
        SetWindowText(myTimer, szBuffer);
        UpdateWindow(myTimer);
        counter++;
    }
}
LRESULT CALLBACK WndProcTimer(HWND hWndTimer, UINT message, WPARAM wParam, LPARAM lParam)
{
    PAINTSTRUCT ps;
    HDC hdc;
    RECT rc = {0};

    switch (message)
    {
        case WM_ERASEBKGND:
        {
            return TRUE;
        }
        break;

        case WM_PAINT:
        {
            hdc = BeginPaint(myTimer, &ps);            

            // TODO: Add any drawing code here...
            GetClientRect(myTimer, &rc); 
            AdjustWindowRectEx(&rc, WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU, FALSE, NULL); 
            test(hWndTimer);
            ReleaseDC(myTimer, hdc);

            EndPaint(myTimer, &ps);
        }
        break;

        case WM_CREATE:
        {
            test(hWndTimer);
            SetTimer( myTimer, NULL, USER_TIMER_MINIMUM, NULL );
        }
        break;

        case WM_TIMER:
        {
            test(hWndTimer);
            GetClientRect( myTimer, &rc );
            InvalidateRect( myTimer, &rc, TRUE );
        }
        break;

        default:
            return DefWindowProc(myTimer, message, wParam, lParam);
    }
    return 0;
}
int APIENTRY drawTimer( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow )
{
    char szWindowClass[] = "myTimer";
    MSG msg;
    RECT rc;
    GetClientRect(hWnd, &rc);
    int width = 100;
    int height = 50;

    WNDCLASSEX wcex        = {0};
    wcex.cbSize            = sizeof(WNDCLASSEX);
    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProcTimer;
    wcex.hInstance      = hInstance;
    wcex.hCursor        = LoadCursor( NULL, IDC_ARROW );
    wcex.hbrBackground    = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wcex.lpszClassName  = szWindowClass;
    wcex.hIcon            = LoadIcon(NULL, IDI_APPLICATION);
    wcex.hIconSm        = LoadIcon(NULL, IDI_APPLICATION);
    RegisterClassEx( &wcex );

            
    //Main Application Window
    myTimer = CreateWindowEx(0, "STATIC", "", WS_CHILD | WS_VISIBLE, ((rc.right - rc.left - width) / 2), 0, width, height, hWnd, (HMENU)IDS_MYTIMER, hInst, NULL);
    
    // Do stuff here


    //End

    if(!myTimer)
    {
        return FALSE;
    }

    //Activate our Main Window
    ShowWindow(myTimer, nCmdShow);
    UpdateWindow(myTimer);

    //while(GetMessage(&msg, NULL, 0, 0))
    while(PeekMessage( &msg, myTimer, 0, 0, PM_REMOVE ))
    {
        TranslateMessage( &msg );
        DispatchMessage( &msg );
    }

    return (int) msg.wParam;
} 

And I'm calling drawTimer() from the WinMain function like this:

drawTimer(hInstance, hPrevInstance, lpCmdLine, nCmdShow); 

I know it's calling it correctly, because if I don't apply a transparent brush then I can see the static box that I created, but I can't seem to print text to it and I should be able to.
I'm calling test() from WM_Create and WM_TIMER and neither work...

[Razo[R]apiD]

I was talking about using:

http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx
http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx

and SetTimer in that thread, but I don't if this will be any good for you.