[ptx] where are PTStitcher layer masks computed?

[Littlefields - Rik, Janis, Kyle & Peter]

Hi all -- I am trying to find the code that PTStitcher uses
to compute the layer masks that appear in a type
"PSD_mask" output file.

 From reading the code, I thought it would be the stuff
in seamer_.c .  But I have set traps all through that code,
and it's not getting called.  Likewise for everyplace else
I can find that looks promising.

I have just about convinced myself that the masks must
be computed inside PTStitcher.exe, and not in pano12.dll .

Does anyone else know?

Thanks much,
--Rik