Re: [Flightgear-devel] ISA conditions

[James T. <ja...@fl...>]

> On 25 Jul 2023, at 13:23, PlayeRom Roman Ludwicki <rom...@pl...> wrote:
> 
> If we want to get rid of `fgGetBool` when creating `FGEnvironment dummy;`, I see the following solution:
> 
> 1. set the `is-isa` flag in the `/environament/climate/is-isa` property.
> 2. In the function `FGClimate::bind()` bind the flag `_tiedProperties.Tie( "is-isa", &_is_isa);`.
> 3. In the `FGClimate::update` function, call `set_is_isa`:
> 
> FGEnvironment dummy;
> dummy.set_is_isa(_is_isa);
> ...
> 
> 
> This means that `_tiedProperties.Tie` for `is_isa` in `FGEnvironment::Tie` is redundant and should be removed.
> 
> If this is a more appropriate solution, I can implement it.
> 

Yes, that’s better, if you don’t mind.

Thank you for digging into this, I knew there was some copying / re-creating of FGEnvironment but did not realise it had gotten this complicated … not very easy to hack on :(

> There is another call of `FGEnvironment dummy;` in `MetarProperties::setMetar`, but I wouldn't change anything there, because as far as I can see it is only run for the `Live data` weather scenario, where `is_isa` must be `false` anyway.
> 

Sure, no problem.

Kind regards,
James