Question

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;
}

Answer 1

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.