In my game I would like to change the speed of the time so that all animations and gameplay is slowed down or speed up. Ideally this speed also goes below zero so that everything goes backwards.

Basically I have everything dependent to a time variable which I update every frame using the time from the OS.

void calledEveryFrame()
{
    time = System.accurateTime();
}

Now I tried the following but it didn't work:

    lastTime = time;
    long now = System.accurateTime();
    double diff = now - lastTime;       
    time = (lastTime + diff * speed);

That obviously doesn't work because you can't just multiply the speed times the difference because it is not called exactly regularly.

I want to be able to change the game speed, to speed up or slow down all animations and gameplay. Ideally, this could also be set to a negative number to make everything go backwards.

I tried this:

I made everything dependent on a time variable, updated every frame from the OS time:

void calledEveryFrame()
{
    time = System.accurateTime();
}

Then I tried just scaling that time.

lastTime = time;
long now = System.accurateTime();
double diff = now - lastTime;       
time = (lastTime + diff * speed);

That obviously doesn't work, because you can't just multiply the speed times the difference because it is not called exactly regularly.

How do I do this correctly?

in my game i would like to change the speed of the time so that all animations and gameplay is slowed down or speed up. ideally this speed also goes below zero so that everything goes backwards.

basically i have everything dependant to a time variable which i update every frame using the time from the OS.

void calledEveryFrame()
{
    time = System.accurateTime();
}

now i tried the following but it didnt work:

    lastTime = time;
    long now = System.accurateTime();
    double diff = now - lastTime;       
    time = (lastTime + diff * speed);

that obviously doesnt work because you cant just multiply the speed to the difference because it is not called exactly regularly.

In my game I would like to change the speed of the time so that all animations and gameplay is slowed down or speed up. Ideally this speed also goes below zero so that everything goes backwards.

Basically I have everything dependent to a time variable which I update every frame using the time from the OS.

void calledEveryFrame()
{
    time = System.accurateTime();
}

Now I tried the following but it didn't work:

    lastTime = time;
    long now = System.accurateTime();
    double diff = now - lastTime;       
    time = (lastTime + diff * speed);

That obviously doesn't work because you can't just multiply the speed times the difference because it is not called exactly regularly.