Assert triggered by negative io.DeltaTime

I realized that if I let the iOS app I'm building run for 10 or 20 minutes, it triggers an assert error on line imgui.cpp:2044 on this line:

IM_ASSERT(g.IO.DeltaTime >= 0.0f);    
// Need a positive DeltaTime (zero is tolerated but will cause some timing issues)

During this time I do not interact with the app. I just let it run. I see the used values are all floats, so they should not overflow in such a short time. What could be the reason?

Maybe a simple solution would be to replace this

    float currentTime = ofGetElapsedTimef();
    if (lastTime > 0.f)
    {
        io.DeltaTime = currentTime - lastTime;
    }
    else
    {
        io.DeltaTime = 1.0f / 60.f;
    }

with this

    float currentTime = ofGetElapsedTimef();
    if (currentTime > lastTime)
    {
        io.DeltaTime = currentTime - lastTime;
    }
    else
    {
        io.DeltaTime = 1.0f / 60.f;
    }

This would avoid negative values, but it does not explain how they happen in the first place.

I'm running my app at 30 fps. Could that be an issue?

jvcleave / ofxImGui

Assert triggered by negative io.DeltaTime #51