[Therion] Custom headers to distinguish between projections - plan, extended, elevation xxx deg

19 May 2015

      I'm working on some custom headers, specific to the projection that is being
produced, however it would be more efficient to have a single custom header
that could automatically detect the projection and include or exclude text
appropriately.

Unfortunately my tex coding is not up to it, and so I would like some tips
as to how to test for the projection so I can selectively use the snippets
below.  What I am missing is the existing variable names and a little bit of
skill in conditional tests in tex.

For example, I would like to include, below the scale bar and above the
map-comment;

-"Extended Elevation" for maps where the projection is extended, 

            {\the\legendtextsize\ss {Developed elevation looking generally
North} \par}

-"\outcsname Plan View<br>Arrow points to \northdir north" for maps where
the projection is plan

                 \edef\tmp{\the\outcsname} \ifx\tmp\empty \else

                 {\the\legendtextsize\ss\the\outcsname { plan
projection}\par}

                 \fi

                \edef\tmp{\the\northdir} \ifx\tmp\empty \else

                {\the\legendtextsize\ss Arrow points to \the\northdir {
north }\par\par} 

                \fi            

I need to sort this out so it gives a sensible result if the coordinate
system is arbitrary, and hopefully figure out a way to detect if the
bearings are magnetic or adjusted by a declination (and hence grid or true
north), but first things first...

and  -"\outcsname Elevation looking XXX deg" for maps where the projection
is [elevation XXX deg]

            \edef\tmp{\the\outcsname} \ifx\tmp\empty \else

                {\the\legendtextsize\ss\the\outcsname { elevation looking
020 deg}\par}

                \fi

As well as detecting that the projection is 'elevation', I need a way of
detecting what the elevation bearing is, rather than hard coding it as I
have done here

Ideas anyone?

Bruce