Changes to HDGeant

[David Lawrence <davidl@jlab.org>]

Hi All,

    I just committed several changes to HDGeant, hdds, and HDGEOMETRY. 
The short reason is that
now the magnetic field map and FDC Lorentz deflections field are 
obtained through the calibration database API rather than from local 
files. With these changes, I have finally made the 1500A field the 
default (and only about 3 years after we got it!). This bridges a part 
of the connection between the simulation and reconstruction so that 
parameters such as attenuation lengths, drift velocities etc, can be 
specified in a single place. )The other part is the geometry information 
that originates in the XML which is still not done.)

    This required some significant changes since now hdgeant had to link 
in with C++ code. I have checked it out on Mac OS X, Ubuntu6 and RHEL4 
and it seems to compile and link just fine. However, I anticipate some 
folks may run into issues. Please let me know if you are unable to get 
it to link properly.

    Since information is now being pulled from the calibration database, 
you will need to make sure your JANA_CALIB_URL environment variable is 
set appropriately to point to where you have checked out the calibration 
constants (svn co https://halldsvn.jlab.org/repos/trunk/calib).  I have 
updated the documentation on the wiki to help with this (albeit sparse):

http://www.jlab.org/Hall-D/software/wiki/index.php/Getting_started_with_GlueX_Software

Please let me know if you have any issues.

Regards,
-David

-- 

------------------------------------------------------------------------
  David Lawrence Ph.D.
  Staff Scientist                 Office: (757)269-5567   [[[  [   [ [       
  Jefferson Lab                   Pager:  (757)584-5567   [  [ [ [ [ [   
  http://www.jlab.org/~davidl     davidl@jlab.org         [[[  [[ [[ [[[
------------------------------------------------------------------------