[twg-tds] Question: how to include an image file in a document class?

[Karl Berry]

    Are there generic, platform-independent TEX variables like @TEXMF and
    @TEXMFLOCAL to resolve the directory tree defined in TDS for both Tex
    Live and MikTeX?

No.  There is no platform-independent way to access environment or
other configuration variable values at the TeX level in the first place.

    I post a generic question for a hypothetical package in an attempt to
    find a general answer.

The general answer is, files to be accessed by TeX at runtime need to be
placed by the TeX distributor in a place where TeX can read them.  Those
places (texmf/tex/...) are described in the TDS, but obviously the TDS
cannot address bugs by the distributors.  An individual package author
cannot plausibly solve this within his or her own TeX code.

Files being misplaced by distributors (both TL and MiKTeX) happens all
the time.  The answer is, file a bug report, and we fix it.  That's it.

    e.g. To allow any of the following to work:

Those constructs would be far more fragile and cause far more problems
than anything we have today.

I believe that the best approach for package authors is to completely
avoid using directory names at the TeX level.

Best,
Karl