Discussion Any advice on how to deal with timers, delays and such events?

[Moach]

i've come to a point in eveloping the G42 that i'm ready to begin coding the simulation logic behind the workings of the ship

first thing i thought i'd do, is add a "mode switch" delay between engine configurations....

while this could be achieved easily by using "in-transition" states, this isn't much of a reusable approach, and will increase the spaghettiness of my module a bit


so i was wondering how i could proceed with this and similar situations... in Flash and JavaScript, which i'm largely accustomed to, i'd just use setTimeout() and have it call a function after a set amount of milliseconds....

but c++ has no such function :shifty:


would it be worthy, or even advisable at all, to create my own implementation of setInterval? - and in doing so, should i go with using a separate thread, or do i have a loop checking live intervals?

i assume the latter would be more suitable, and safe to use... since Orbiter itself appears to run single-threaded (does it?) :uhh:

but with the advent of whole-bunch-of-cores-CPU's, i can't help but to feel like threading is the "proper way" of doing things :huh:


any thoughts?

 

[Urwumpe]

Define a double precision counter variable in the vessel class, and subtract the Delta-SimT every time step from it... or use the variable to store the simulation time when the timer was started and compare it to the current simulation time.

 

[Urwumpe]

As tiny addition... I usually define 2-3 general purpose timer variables in my add-on code (dfTimerA, dfTimerB, dfTimerC) which can be used in the sequence state automate. I never needed more than three so far.

Usually I initialize the variables with 0.0 and in PreStep decrement them by the length of the time step, if they are bigger than 0.0. A typical application would look like that:

1. In the transition code from State q to State r, I set the available timer variable to the delay.
2. In State r, I wait until the timer is zero again, and then transition to State s. This could for example include a staging event during the transition.
3. In State s, I do what ever was needed to be delayed...for example a different autopilot