CODEWITHSUNDEEP
c++timersdl
Xirdus
Xirdus

Reputation: 3087

Timer working improperly

I have a problem with a timer class based on a SDL timer.

class CTimer
{
    public:
    CTimer(): startTick(0), endTick(0), curTime(0), running(false) {};
    void Start() { startTick += SDL_GetTicks() - endTick; running = true; };
    void Stop() { endTick = SDL_GetTicks(); running = false; };
    void Reset() { startTick = 0; endTick = 0; curTime = 0; };
    inline int operator()() { return running ? curTime = ((int) SDL_GetTicks - startTick) / 1000 + 1 : curTime; };
    private:
    int startTick;
    int endTick;
    int curTime;
    bool running;
};

The () operator should return time in seconds (stored in curTime). But it always returns 4202 (curTime is always equal to that). What am I doing wrong?

Test code:

int main()
{
    SDL_Init (SDL_INIT_TIMER);
    CApp::CTimer timer;
    timer.Start();
    for (int i = 0; i < 15; ++i)
    {
        SDL_Delay (1000);
        std::cout << timer() << '\n';
    }
    return 0;
}

Upvotes: 0

Views: 364

Answers (4)

Mark B
Mark B

Reputation: 96271

In addition to the attempted call to SDL_GetTicks instead of SDL_GetTicks() causing it to take the address of that function (and always returning the constant as you observed), it looks like if you call Start and then Stop before calling operator() you won't get a meaningful result.

Upvotes: 0

Mark Ransom
Mark Ransom

Reputation: 308256

This is a perfect example of why you don't want to use old-style C casts in C++.

(int) SDL_GetTicks

The missing parentheses on the function call mean you're casting a pointer to the function to an int, not the return value. Surprisingly enough the pointer to the function never changes.

Upvotes: 3

Steve Townsend
Steve Townsend

Reputation: 54168

For starters,

inline int operator()() { return running ? curTime = 
    ((int) SDL_GetTicks - startTick) / 1000 + 1 : curTime; };

should be 

inline int operator()() { return running ? curTime = 
    ((int) SDL_GetTicks() - startTick) / 1000 + 1 : curTime; };

I would think.

Did you get a warning error about this?

Upvotes: 1

Jeff
Jeff

Reputation: 2009

Are you missing parentheses for SDL_GetTicks?

inline int operator()() { return running ? curTime = ((int) SDL_GetTicks - startTick) / 1000 + 1 : curTime; };

Upvotes: 1

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