Re: [Flightgear-devel] Moonlight

[Edward d'A. <tru...@gm...>]

On 24 May 2017 at 15:04, Florent Rougon <f.r...@fr...> wrote:
> Hi,
>
> "Edward d'Auvergne" <tru...@gm...> wrote:
>
>> The reason for having a perfect set of --start-date-lat, --lat, --lon,
>> --altitude, and --heading values corresponding to basic 3-body
>> orientation parameters (sun, moon, and earth) would be for easy
>> debugging, now and far into the future.
>
> Can someone explain how latitude has any influence on how the starting
> date is to be interpreted? Longitude, I could understand, but latitude?
>
> Besides:
>
> static int
> fgOptStartDateLat( const char *arg )
> {
>     long int theTime = parse_date( arg, "latitude" );
>     if (theTime>=0)
>     {
>         fgSetLong("/sim/startup/time-offset", theTime);
>         fgSetString("/sim/startup/time-offset-type", "latitude");
>     }
>     return FG_OPTIONS_OK;
> }
>
> and:
>
> static long int
> parse_date( const string& date, const char* timeType)
> {
>     struct tm gmt,*pCurrentTime;
>     int year,month,day,hour,minute,second;
>     char *argument, *date_str;
>
>     SGTime CurrentTime;
>     CurrentTime.update(SGGeod(),0,0);
>
>     // FIXME This should obtain system/aircraft/GMT time depending on timeType
>     pCurrentTime = CurrentTime.getGmt();
>
>     ...
>
> }
>
> The function doesn't use its 'timeType' argument at all. Understandably,
> the help text obtained with 'fgfs --help -v' isn't much more helpful...
>
>    --start-date-sys=yyyy:mm:dd:hh:mm:ss
>                                 Specify a starting date/time with respect to
>
>    --start-date-gmt=yyyy:mm:dd:hh:mm:ss
>                                 Specify a starting date/time with respect to
>
>    --start-date-lat=yyyy:mm:dd:hh:mm:ss
>                                 Specify a starting date/time with respect to
>

I always interpreted --start-date-lat to be the local time, from
$FG_DATA/options.xml:

   <option>
    <name>start-date-lat</name>
    <arg>yyyy:mm:dd:hh:mm:ss</arg>
    <description>start-date-desc</description>
    <description>locale-aircraft-time</description>
   </option>

I have no idea why this is called state-date-lat, or why the
<start-date-desc> translation values are left truncated and the second
<description> tag not taken into account!

Regards,

Edward