$Id: History,v 1.132 2009/05/20 08:27:26 gcosmo Exp $
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     =========================================================
     Geant4 - an Object-Oriented Toolkit for Simulation in HEP
     =========================================================

                      Category History file
                      ---------------------
This file should be used by G4 developers and category coordinators
to briefly summarize all major modifications introduced in the code
and keep track of all category-tags.
It DOES NOT substitute the  CVS log-message one should put at every
committal in the CVS repository !

     ----------------------------------------------------------
     * Reverse chronological order (last date on top), please *
     ----------------------------------------------------------

May 20th, 2009 - P.Arce (geomnav-V09-02-05)
-----------------------
- Added method BuildContainerSolid() taking a solid as argument to
  G4PhantomParameterisation. Added protection to GetMaterialIndex()
  for zero index.

May 18th, 2009 - T.Nikitina (geomnav-V09-02-04)
---------------------------
- Enhanced algorithm for 'FB_intersects' in order to speedup BrentLocator.
- Fix in the usage of the geometrical tolerance in G4VIntersectionLocator
  in method AdjustementOfFoundIntersection().

May 13th, 2009 - J.Apostolakis (geomnav-V09-02-03)
------------------------------
- Fix in G4PathFinder: A geometry is at a boundary if its step is within 
   tolerance of the minimum step for any geometry.

May 5th, 2009 - T.Nikitina (geomnav-V09-02-02)
--------------------------
- Fix in G4Navigator::ComputeStep() for the computation of rotation of the
  'LocalExitNormal' in cases when DistanceToOut() returns non-valid normal
  for optical photons in rotated solids. Addresses problem report #1059.

February 26th, 2009 - T.Nikitina (geomnav-V09-02-01)
--------------------------------
- Fixed problem in G4BrentLocator::EstimateIntersectionPoint() responsible
  for rare cases of negative steps.

January 27th, 2009 - G.Cosmo (geomnav-V09-02-00)
----------------------------
- Added G4RegularNavigationHelper class, used by G4RegularNavigation for
  counting the number of step lengths in each voxel of the regular structure
  (by P.Arce).
- Some code cleanup...

December 11th, 2008 - T.Nikitina (geomnav-V09-01-10)
--------------------------------
- Reinstated G4MultiLevelLocator as the default locator to allow for proper
  tuning of parameters in propagation in field and avoid CPU penalty currently
  induced by default parameters.
- Corrected text in exceptions in locators classes.

November 14th, 2008 - T.Nikitina, J.Apostolakis (geomnav-V09-01-09)
-----------------------------------------------
- Introduced first implementation of new optional method in locator classes
  AdjustementOfFoundIntersection() using surface-normal of the intersecting
  solid to boost accuracy. Added the optional call to the new method in each
  concrete locator.
- Removed unnecessary accessors for Brent locator in G4PropagatorInField.
- G4VoxelNavigation: implemented additional check when running in "check"
  mode; if it is on the surface, ensure that it can move on next step;
  either DistanceToIn(p,v) or DistanceToOut(p,v) should return a finite
  value greater than the tolerance.

November 10th, 2008 - G.Cosmo (geomnav-V09-01-08)
-----------------------------
- G4PathFinder: cleared unecessary calls to ComputeSafety() in ReLocate().

October 28th, 2008 - T.Nikitina (geomnav-V09-01-07)
-------------------------------
- Moved method LocateIntersectionPoint() in G4PropagatorInField to a separate
  class G4VIntersectionLocator, now allowing to use different location
  algorithms: Brent, MultiLevel, Simple.
- New classes: G4VIntersectionLocator, G4SimpleLocator, G4BrentLocator and
  G4MultiLevelLocator.  
- Coworks with tag "field-V09-01-03".

October 10th, 2008 - G.Cosmo (geomnav-V09-01-06)
----------------------------
- Introduced optional Boolean argument in G4Navigator::ComputeSafety() to
  allow for computation of safety without modifying the state restoring of
  the navigator.
- Modified accordingly the following classes, for calls to ComputeSafety():
  G4SafetyHelper, G4PathFinder (now calling ComputeSafety() with TRUE
  argument to preserve navigator's state), G4MultiNavigator and
  G4ErrorPropagationNavigator.

May 5th, 2008 - T.Nikitina (geomnav-V09-01-05)
--------------------------
- Added Brent method for LocateIntersectionPoint() in G4PropagatorInField.
  The Brent method is now used as default and can be switched off through
  call to the proper accessor function SetBrentMethod().
- Requires related update to G4ChordFinder in geometry/magneticfield module
  included in tag "field-V09-01-02".

April 29th, 2008 - M.Asai (geomnav-V09-01-04)
-------------------------
- G4PathFinder: commented out warning and exception in ComputeStep()
  for step smaller than minimum threshold.

April 28th, 2008 - G.Cosmo (geomnav-V09-01-03)
--------------------------
- Corrected condition for wrong evaluation order introduced in the
  previous tag.

March 13th, 2008 - G.Cosmo (geomnav-V09-01-02)
--------------------------
- Cleared compilation warnings in G4ReplicaNavigation on gcc-4.3.0 for
  ambiguous use of parentheses in condition statements.

January 24th, 2008 - T.Nikitina (geomnav-V09-01-01)
-------------------------------
- G4PropagatorInField: changed condition for 'ReEstimationEndPoint'
  in order to better handle very strict parameters of propagation.
  Also added more verbosity in case of error for negative step.
  Fixes rare problem observed in production by ATLAS.

January 22nd, 2008 - P.Arce (geomnav-V09-01-00)
---------------------------
- G4PhantomParameterisation:
  o Bug fix in GetReplicaNo() to catch overflows in X and Y.
    (on suggestion by S.Stute)
  o Made CheckVoxelsFillContainer() visible in public interface.

November 16th, 2007 - G.Cosmo (geomnav-V09-00-12)
-----------------------------
- Cleared compilation warnings for shadowing of variables in classes
  within the module.

November 14th, 2007 - G.Cosmo (geomnav-V09-00-11)
-----------------------------
- Reintroduced artificial push in G4ReplicaNavigation::ComputeStep().
  Further investigation and eventually reimplementation of LevelLocate()
  required to take into account point and direction ...

November 14th, 2007 - G.Cosmo (geomnav-V09-00-10)
-----------------------------
- Trial to remove artificial push in G4ReplicaNavigation::ComputeStep().
- Some minor cleanup.

November 9th, 2007 - J.Apostolakis (geomnav-V09-00-09)
----------------------------------
- G4SafetyHelper: Improved ComputeSafety() not to call G4Navigator
  if exactly on safety 'center'.  
- G4PathFinder: correction to debug code under #ifdef G4DEBUG_NAVIGATION.

November 9th, 2007 - G.Cosmo (geomnav-V09-00-08)
----------------------------
- Fix in G4ReplicaNavigation::DistanceToOut() for exact classification of
  the linear step for Cartesian case.
- Made IdentifyAndPlaceSolid() method inlined in G4ParameterisedNavigation.
- Minor cosmetics and cleanup.

November 6th, 2007 - P.Arce (geomnav-V09-00-07)
---------------------------
- Optimisation in G4RegularNavigation: use voxelBox->DistanceToOut() instead
  of ComputeStep() in ComputeStepSkippingEqualMaterials().
- Some cleanup and proper formatting of error/warning messages.

November 2nd, 2007 - J.Apostolakis (geomnav-V09-00-06)
----------------------------------
- Merging fixes in "geomnav-V09-00-03b" and "geomnav-V09-00-03c" on top
  of tag "geomnav-V09-00-05".

November 2nd, 2007 - J.Apostolakis (geomnav-V09-00-03c)
----------------------------------
- G4PathFinder: 
  o Added setting of 'fNoGeometriesLimiting' in DoNextCurvedStep().
  o Check to verify that 'fNoGeometriesLimiting' is set by DoNext*Step methods.
  o Revised data type of 'fNoGeometriesLimiting' to be a int, so that < 0
    shows 'unset'.
- G4PropagatorInField: 
  o Fixes for compilation of code under G4DEBUG_FIELD (problem report #982).
  o Added extra check of method LocateIntersectionPoint() arguments.
- Tag based on "geomnav-V09-00-03b".

October 29th, 2007 - J.Apostolakis (geomnav-V09-00-03b)
----------------------------------
- G4PathFinder: first fix for problem of another process shortening steps
  (between calls to ComputeStep by different processes in same step.)
  I.e.  First call to ComputeStep (geom 1) has proposed Step = 3.0 cm
        Next  call to ComputeStep (geom 2) has proposed Step = 1.0 cm
        (e.g. Multiple Scattering)
- Tag based on "geomnav-V09-00-03a".

October 24th, 2007 - J.Apostolakis (geomnav-V09-00-05)
----------------------------------
- Merging fixes introduced in "geomnav-V09-00-03a" on top of
  "geomnav-V09-00-04".

October 24th, 2007 - J.Apostolakis (geomnav-V09-00-03a)
----------------------------------
- G4PathFinder: fix to now set 'fNoGeometriesLimiting' in DoNextLinearStep()
  when WhichLimited() is not called, i.e. in case of one navigator
  optimisation.
- Tag based on "geomnav-V09-00-03".

October 18th, 2007 - G.Cosmo (geomnav-V09-00-04)
----------------------------
- Added new specific navigation for regular structures and phantoms.
  New classes: G4RegularNavigation, G4PhantomParameterisation (by P.Arce).
  Added cases to G4Navigator. Added dependency on "materials" module.

October 12th, 2007 - J.Apostolakis (geomnav-V09-00-03)
----------------------------------
- G4PathFinder: added new methods GetNumberGeometriesLimitingStep()
  and GetMinimumStep() needed by G4CoupledTransportation to see whether
  to relocate.

September 25th, 2007 - G.Cosmo (geomnav-V09-00-02)
------------------------------
- Some code cleanup in G4PathFinder. Switch off additional optimisation
  for safety in method DoNextLinearStep().
- Set 'fRecomputeFactor' in G4SafetyHelper to 0.0, to switch off internal
  optimisation and allow for reproducibility of steps (A.Howard).

July 12th, 2007 - J.Apostolakis (geomnav-V09-00-01)
-------------------------------
- Restores fixes/improvements of geomnav-V08-03-07
- G4PathFinder: includes fix for result of ObtainSafety(), used in
  CoupledTransportation.

July 12th, 2007 - J.Apostolakis (geomnav-V09-00-00)
-------------------------------
- G4PathFinder: 
  o Include correction to signature of method PrepareNewTrack(). 
    (This was done on a branch for this class in order to keep only
     development of geomnav-V08-03-06) 
- G4PropagatorInField:
  o Included revisions and fixes for G4PropagatorInField of June 8th.
- This tag is based on "geomnav-V08-03-06" and does NOT include the
  revisions of "geomnav-V08-03-07".

July 5th, 2007 - G.Cosmo
------------------------
- G4PathFinder: 
  o Corrected signature to method PrepareNewTrack().
    Resolves linking problems detected on SUN-CC platform.
- Changes included in tag  "geomnav-V08-03-02c", included in relase 9.0.p01.

June 8th, 2007 - T.Nikitina
---------------------------
- G4PropagatorInField:
  o Put in the constructor creation of array of FieldTracks used in
    LocateInterSectionPoint().
  o Change in ReEstimateNewPoint() in order to handle cases with zero step
    caused by diffCurve=0.
  o In case of proposed step less than tolerance, now return 'kInfinity'
    as per convention of geometry instead of 'DBL_MAX'.
    (by J.Apostolakis, May 18th 2007)
- Changes included in tag "geomnav-V08-03-02b", included in release 9.0.

June 5th, 2007 - J.Apostolakis (geomnav-V08-03-07)
------------------------------
- G4PathFinder: 
  o New method to return the safety sphere last calculated for
    a PreStep point (it could be a previous one - due to optimasation).
    >> If last step(s) were smaller than safety, then for a linear
    track (no field or no charge) Navigator's ComputeSafety is not
    called.  The older PreStep (previous step or some steps back 
    in case of many small steps) is stored for this - and provided.
  o ComputeStep() still returns current PreStep point's safety (must).
  o Revisions are to make this (used by CoupledTransportation) more
    compatible with the old direct use of G4Navigator by G4Transportation.

May 29th, 2007 - J.Apostolakis (geomnav-V08-03-06)   
------------------------------
- G4Navigator
  o Fixed **ComputeSafety**: wrong coordinates used (last tag only). 
    For certainty reinstated LocateGlobalPointWithinVolume (for now).
  o Corrected calculation of fStepEndPoint (in ComputeStep)
    for case of step not limited by geometry
- G4PathFinder
  o PrepareNewTrack: calls to re-initialise SafetyHelper (reset safety)
  o ReLocate: Corrected check of move (avoid one side effect on stored safety)
              --> ComputeSafety still results individual navigators' values.

May 24th, 2007 - J.Apostolakis (geomnav-V08-03-05)
------------------------------
- G4PathFinder: 1 correction and 2 optimisations:
  o PrepareNewTrack() clear safety - to avoid potential problems in overlaps.
  o DoNextLinearStep() only calls ComputeStep() for a navigator whose safety
    greater than the step.
  o DoNextCurvedStep(), if there's one geometry, no longer calls
    ComputeSafety() at start.
- G4Navigator ComputeSafety: 
  o Corrected it to address use at non-endpoint
  o Replaced call to LocateGlobalPointWithinVolume() with calls to
    sub-navigators.

May 21st, 2007 - G.Cosmo
------------------------
- Made 'fVerbose' protected in G4Navigator, reused in G4MultipleNavigator.
- Some cleanup in G4MultipleNavigator implementation.
- Make G4PathFinder singleton definition canonical.
- Added method CheckPointExiting() in G4AuxiliaryNavServices utility
  class (by P.Arce).

May 19th, 2007 - J.Apostolakis (geomnav-V08-03-04)
------------------------------
- Corrections and additions in G4PathFinder: 
    1) Added calculation of start-point safety in DoNextCurvedStep
    2) Corrected GetCurrentSafety() - uses mininum of 1)
    3) Added method to obtain safety of one navigator (after call to all).
    4) Deleted obsolete data member 'fMinSafety'.
    5) If only one geometry, do not call WhichLimited in DoNextLinearStep (optimisation)
    6) ComputeSafety: save the values of isotropic safety for each navigator

May 18th, 2007 - A.Howard (geomnav-V08-03-03)
------------------------
- Fixed return value for G4PathFinder::ComputeStep in case of
   step smaller than tolerance (now kInfinity): fixes one PathFinder issue (JA).
- Added compiler flags for verbosity in G4PathFinder.cc
- Added compiler flags for verbosity in G4MultiNavigator.cc

May 18th, 2007 - G.Cosmo (geomnav-V08-03-02)
------------------------
- Use kAngTolerance and kRadTolerance from G4GeometryTolerance class.
- Coworks with tag "global-V08-03-03".

May 16th, 2007 - G.Cosmo (geomnav-V08-03-01)
------------------------
- Introduced new class G4ErrorPropagationNavigator, a specialised navigator
  for performing double navigation in the detector geometry and on the
  target surface for error propagation (by P.Arce).
- Fixed bug in G4GeomTestSegment in case of TestPoint on the surface,
  reducing cases of reported spurious overlaps.
- Coworks with tag "global-V08-03-02".

May 16th, 2007 - J.Apostolakis (geomnav-V08-03-00a)
------------------------------
- Moved to G4PathFinder version without extra prints

April 26th, 2007 - G.Cosmo (geomnav-V08-03-00)
--------------------------
- Use call to G4GeometryTolerance instead of kCarTolerance where needed.
- Revised data members in G4SafetyHelper to conform to convention.
- Requires tag "global-V08-03-00" and related tag set.

April 26th, 2007 - T.Nikitina (geomnav-V08-02-03)
-----------------------------
- Fixed case of out of range access in G4GeomTestSegment responsible for
  crashes observed when recursive-grid test for overlaps was run.
  Addressing problem report #784.

April 20th, 2007 - G.Cosmo (geomnav-V08-02-02)
--------------------------
- Some cleanup and minor cosmetics ...

April 12st, 2007 - V.Ivanchenko
-------------------------------
- G4SafetyHelper become a unique class, which can be accessed via
  G4TransporationManager. Depending on type of navigation (single
  world or multiple navigation) it uses mass navigator or G4PathFinder.
  All calls from EM processes to geometry are provided by G4SafetyHelper.
- G4TransportationManager: added G4SafetyHelper.
- G4PathFinder: initialisation of G4SafetyHelper.
- Tagged "geomnav-V08-02-02-beta2".

March 31st, 2007 - J. Apostolakis
---------------------------------
- G4Navigator:
  o New method CheckNextStep() makes a trial step, without
    changing the state of the Navigator (to be verified). 
    It is a variant of ComputeStep, whose signature it shares.
- Tagged "geomnav-V08-02-02-beta1".

February 13th, 2007 - J.Apostolakis
-----------------------------------
- G4Navigator:
  o Improvement for creating touchable history when located outside world.
    Retain whether last point was located outside, and if so call default
    TouchableHistory constructor (that initialised world to null).
    NOTE: testing found problems with SteppingManager::SetInitialStep()
          as the Vertex physical volume was not set. Protection is potentially
          required, or bigger issue to be resolved.
    Currently, changes in G4Navigator.hh,cc are safe, but the fix in .icc is
    temporarly suspended and NOT included.
- Attempted fix created Dec 7th, 2006

February 13th, 2007 - J.Apostolakis (geomnav-V08-02-01)
-----------------------------------
- G4PropagatorInField:
  o Implemented ClearPropagatorState() to clear all the track-dependent
    state (incl. safety, zero-steps, loop flag ...).
    ** Calling this is mandatory for each new track because in the case of
       geometry overlaps, the safety can be easily inconsistent (and/or
       incorrect) otherwise
    ** Must be called from G4Transportation (or alternatives) !!
- Fix created Jan 25th, 2007

January 31st, 2007 - G.Cosmo (geomnav-V08-02-00)
----------------------------
- G4Navigator: forcing call to CheckOverlaps() on the current volume
  before event abortion for cases of stuck tracks.
- Requires tag "geommng-V08-02-00".

November 23rd, 2006 - J.Apostolakis (geomnav-V08-01-08)
-----------------------------------
- G4PathFinder: 
  o Fix when report a problem only if move > safety (additional check).
  o Revised condition for extra checking against safety.
  o Many small and cosmetic changes in debug printing.

November 18th, 2006 - J.Apostolakis (geomnav-V08-01-07)
-----------------------------------
- G4PathFinder: 
  o Fix for problem when step is fully taken. 
    Note: this occurs due to optimisation in PiF that avoids calling
    G4(Multi)Navigator!!
  o Function LimitedString( ELimited lim ) enables printing this enum
  o Improved printing in IntersectChord. Deleted/simplified few prints in
    ComputeStep().
- G4MultiNavigator: cleanup, cosmetics

November 13th, 2006 - G.Cosmo (geomnav-V08-01-06)
-----------------------------
- Fixed compilation warnings and some cleanup ...

November 11th, 2006 - J.Apostolakis (geomnav-V08-01-05)
-----------------------------------
- G4PathFinder improvements for parallel Navigation
  o ComputeStep method signature extended to add volume
  o Use G4MultiNavigator for tracking in field.
- G4MultiNavigator:
  o Several fixes, primarily for taking care of condition of
    geometry limited step.

November 11th, 2006 - J.Apostolakis (geomnav-V08-01-04)
-----------------------------------
- G4PropagatorInField:
  o Refined fix in LocateIntersectionPoint(), to subdivide
    in case it cannot find intersection point quickly (T.Nikitina).
    Second version, with several levels of cutting.
  o NOTE: Special tags made (later) not including the Developments in
    G4TransportationManager, G4PathFinder, G4SafetyHelper for parallel
    navigation. i.e. - based on tag "geomnav-V08-01-03".

November 11th, 2006 - J.Apostolakis
-----------------------------------
- Created G4MultiNavigator class and utilised it from G4PathFinder
  to implement curved trajectory parallel navigation.

November 10th, 2006 - J.Apostolakis (geomnav-V08-01-03)
-----------------------------------
- G4PropagatorInField:
  o Fix in LocateIntersectionPoint(), to subdivide in case it cannot find
    intersection point quickly (T.Nikitina).
    First version, only one level of cutting
  o NOTE: Special tags made (later) not including the Developments in
    G4TransportationManager, G4PathFinder, G4SafetyHelper for parallel
    navigation. i.e. - based on tag "geomnav-V08-01-02".

November  9th, 2006 - J.Apostolakis
-----------------------------------
- G4SafetyHelper:
  o Changed default value of 'fUseParallelGeometries' to 'false'.
    This is the default, except when using parallel geometries.
    Value 'true' will become the default.

November 4th, 2006 - M.Asai
---------------------------
- G4TransportationManager:
  o added new method SetWorldForTracking() to enable change of world from
    the RunManager.

October 31st, 2006 - J.Apostolakis
----------------------------------
- G4SafetyHelper
  o Added new class variable 'fUseParallelGeometries', to enable
    it to work call G4Navigator of Mass geometry directly, in
    the case of single geometry (when G4PathFinder is disabled).
  o Default value is currently 'true' --> for parallel navigation development.
- G4PathFinder
  o Improved the code that checks within relocation whether position
    is proposed to be moved outside safety sphere from endpoint. 

October 26th, 2006 - G.Cosmo (geomnav-V08-01-02)
----------------------------
- G4Navigator:
  o Added inline methods EnteredDaughterVolume() and ExitedMotherVolume() to
    allow for verification of a point entering a daughter volume or exiting
    the mother volume.
  o Made LocateGlobalPointAndSetup() method virtual. Moved to non virtual
    and inline LocateGlobalPointAndUpdateTouchableHandle() method.
  o Moved 'fHistory' data member to protected to aloow for more complete
    subclassing.
  o Minor cosmetics to recently introduced printout diagnostics in
    ComputeSafety() method.
- G4TransportationManager:
  o Added methods to access the list of the registered worlds.
- NOTE: this tag does NOT include the recent developments introduced for
  G4PathFinder. It resumes from tag "geomnav-V08-00-01"; anything else
  introduced after it, except for changes in G4Navigator, is NOT included !

October 25th, 2006 - J.Apostolakis
----------------------------------
- G4PathFinder: fixed initialisation of cached value for the
  G4TransportationManager to cope with singletons.

October 16th, 2006 - J.Apostolakis    (geomnav-V08-01-01)
----------------------------------
- G4Navigator: moved debug printing behind fVerbose conditions

October 12th, 2006 - J.Apostolakis (geomnav-V08-01-00)
----------------------------------
- New class G4SafetyHelper to aid multiple scattering inn 
  determining the correct Mass geometry step (via PathFinder)
  and all-geometry safety.
- Several revisions, fixes to G4PathFinder.

June 8th, 2006 - J.Apostolakis (geomnav-V08-00-06)
------------------------------
- G4PathFinder:
  o New method 'ComputeSafety' to compute safety at endpoint of last step.

June 2nd, 2006 - J.Apostolakis (geomnav-V08-00-05)
------------------------------
- G4PathFinder:
  o New method ReLocate() for non-Transportation classes to call when moving
    the endpoint of a particle. Uses LocateGlobalPointWithinVolume() method
    of the navigators.
  o Small fixes and protection of debug printing with Verbose flag.
  o Default verbose level is now 0.

May 28th, 2006 - J.Apostolakis (geomnav-V08-00-04)
------------------------------
- G4PathFinder:
  o Check whether a process shifted the position since the last step.
  o Corrected checking for 'Unique', i.e. one process limiting step.
  o Revised printing (more information, some protected by verbose flag).

May 27th, 2006 - J.Apostolakis (geomnav-V08-00-03)
------------------------------
- G4PathFinder revised significantly:
  o Workaround for problem of CreateHistory() when outside world.
  o Revised for new counting of Navigator IDs (M.Asai).
  o Added MovePoint() method that signals if it moved.
  o Added state to cope with cases where a full step is taken,
    i.e. to cope with steps that return kInfinity:
    New state:
      RelocatedPoint - to show if it is moved;
      TrueMinStep    - finite whereas reported can be kInfinity.
    and to aid in clarifying the state of the (singleton) object:
      LastStepNo     - already kept in one method (static), now exposed;
      CurrentStepNo  - mostly for debugging and printing out.
  o Small improvements in tests.

May 23rd, 2006 - J.Apostolakis (geomnav-V08-00-02)
------------------------------
- Added new prototype class G4PathFinder to coupled navigation
  in parallel geometries.

May 22nd, 2006 - G.Cosmo (geomnav-V08-00-01)
------------------------
- Extended G4TransportationManager to handle multiple navigators.
  Preserved interface for navigation in mass/tracking geometry.
- Added activation flag to G4Navigator and related accessor methods.

Feb 8th, 2006 - J.Apostolakis (geomnav-V08-00-00)
-----------------------------
- Addressing problem with convergence in LocateIntersectionPoint()
  of G4PropagatorInField (problem identified by Atlas, observed when
  requesting high precision, i.e. small values of eps_min/max, delta_one_step, 
  due e.g. to need for small delta_intersection):
  o First solution by increasing maximum iterations (from 100 to 10,000).
  o Until correct information can be returned, an Exception is thrown
    in case of too many iterations.
  o Warn in case over 1000 iterations, to let user see difficulty.
- This fix is an interim solution, in lieu of improving the algorithm 
  for location (or returning correct incomplete progress).

Nov 24th, 2005 - J.Apostolakis (geomnav-V07-01-02)
------------------------------
- Revised G4ParameterisedNavigation, to use new interface for 
  ComputeMaterial(). Now no longer needing 'Physical Touchable'.

Sep 19th, 2005 - G.Cosmo  (geomnav-V07-01-01)
------------------------
- G4DrawVoxels: removed unnecessary 'panic' message in ComputeVoxelPolyhedra()
  and some code cleanup.

Jul 25th, 2005 - G.Cosmo  (geomnav-V07-01-00)
------------------------
- Some cleanup and cosmetic changes for Software Reference Manual.

Jun 14th, 2005 - J.Apostolakis  (geomnav-V07-00-00)
------------------------------
- Added ability to use Nested Parameterisations to Parameterised Navigation
  Coworks with tag "geomvol-V07-00-01".

Dec 2nd, 2004 - G.Cosmo  (geomnav-V06-02-08)
-----------------------
- Implemented migration to <cmath> for standard mathematical functions.

Nov 24th, 2004 - G.Cosmo  (geomnav-V06-02-07)
------------------------
- Fix in G4ReplicaNavigation::DistanceToOutPhi() for the case of phi
  sections on convex surfaces. Fixes problem report #651.

Nov 19th, 2004 - J.Apostolakis  (geomnav-V06-02-06)
------------------------------
- New access method in G4Navigator for SeverityOfZeroStepping().

Nov 17th, 2004 - G.Cosmo  (geomnav-V06-02-05)
------------------------
- Allow consecutive corrections for stuck tracks in G4Navigator::ComputeStep()
  up to 10 times before aborting the event.

Sep 28th, 2004 - G.Cosmo  (geomnav-V06-02-04)
------------------------
- Invoke G4LogicalVolume::UpdateMaterial() instead of SetMaterial() for
  parameterised navigation in G4Navigator and G4ParameterisedNavigation
  (M.Asai).
- Coworks with tag "geommng-V06-02-02".

Sep 13th, 2004 - G.Cosmo  (geomnav-V06-02-03)
------------------------
- G4Navigator: corrected computation of fGrandMotherExitNormal in ComputeStep()
  in the case where a not valid exit-normal exists.

Sep 11th, 2004 - G.Cosmo  (geomnav-V06-02-02)
------------------------
- Dump out contents from the solid when a fatal G4Exception is thrown from
  the navigators in ComputeStep().
  Modified files G4NormalNavigation.cc, G4ParameterisedNavigation.cc,
                 G4ReplicaNavigation.cc, G4VoxelNavigation.cc.

Aug 31st, 2004 - D.C.Williams  (geomnav-V06-02-01)
-----------------------------
- G4GeomTestSegment: fix to correctly determine whether starting trajectory
  is entering or exiting the solid when the starting point is on a surface.
  Added additional tests on solid consistencies (from roundoff sometimes) to
  avoid incorrect overlap warnings. Addresses problem reports #610 and #652.

Jun 29th, 2004 - G.Cosmo  (geomnav-V06-02-00)
------------------------
- Fixed zero step-length problem in G4ReplicaNavigation::ComputeStep()
  for cases where different replica types are coincident. Resolves
  problem report #633.
- G4NormalNavigation: added extra verbosity to print out information
  for each solid which returns a 'lowest-yet' step, including the
  mother volume. It is activated by setting verbose level to 2 or
  more (J.Apostolakis).

Jun 18th, 2004 - G.Cosmo  (geomnav-V06-01-03)
------------------------
- Enhanced check for null step in G4Navigator::ComputeStep().
  Now attempting a corrective action after 10 consecutive zero steps.
  Event gets aborted after 25 zero steps.

Jun 15th, 2004 - G.Cosmo  (geomnav-V06-01-02)
------------------------
- Relax exception in G4Navigator::ComputeStep() for stuck tracks.
  Event gets aborted after 25 zero steps.

Jun 11th, 2004 - G.Cosmo  (geomnav-V06-01-01)
------------------------
- Added check to G4Navigator to count the number of steps with zero length
  and issue an exception for tracks that get stuck in a loop (J.Apostolakis).
- Modified GNUmakefile to define G4GEOMETRY_ALLOC_EXPORT flag for DLLs
  build on Windows.

May 17th, 2004 - G.Cosmo  (geomnav-V06-01-00)
------------------------
- Added more verbosity on solids response for navigators (optimised/not
  optimised) if "check_mode" state is combined with verbose level-1.

Mar 11th, 2004 - G.Cosmo  (geomnav-V06-00-02)
------------------------
- Added "check_mode" state for navigators. The state can be activated by
  a new UI command (geometry/navigator/check_mode [true/false]) and will
  force more strict and less tolerant checks in step/safety computation to
  verify the correctness of solids' response in the geometry.
- Reorganised verbosity levels. Added more useful information activated
  when in G4VERBOSE mode and verbosity level selected.
  Fixed output formatting when entering/exiting verbose blocks.

Feb 27th, 2004 - G.Cosmo  (geomnav-V06-00-01)
------------------------
- G4Navigator.cc:
  o Fixed old outstanding bug in ComputeStep() for the location of the
    the local point in the calculation of a valid exit normal. (V.Grichine)

Feb  9th, 2004 - J.Apostolakis  (geomnav-V06-00-00)
------------------------------
- G4PropagatorInField.cc:
  o ReEstimateEndpoint:  Changed to cope with a failure of AccurateAdvance,
                         by calling it iteratively up maximum 20 times.
  o SetVerboseLevel, now forwards the verbosity (minus 3) to integration driver

Dec 11th, 2003 - J.Apostolakis  (geomnav-V05-02-15)
------------------------------
- G4PropagatorInField.cc:
  o LocateIntersectionPoint: Refined re-setting of finalSection.
    --> Endpoint recalculation is returned only for final section.
    (trial fix in -14 is replaced by above code)
  o Fixed ReEstimateEndPoint which ignored return code of AccurateAdvance
    and moved to short end-point for long requests
    It now leaves the endpoint unchanged, when it cannot improve it.
  o Few format changes for PrintStatus

Dec 10th, 2003 - J.Apostolakis  (geomnav-V05-02-14)
------------------------------
- G4PropagatorInField.cc on top of latest (not 1.7):
  o Fix for the case where two previous corrections are 'operational'
     Problem if the current endpoint is not the final one, and it has been
     recalculated, and we need to go beyond the current section to the
     final one -- the recalcuted endpoint no longer valid!

Dec 10th, 2003 - J.Apostolakis  (geomnav-V05-02-13)
------------------------------
- G4PropagatorInField.cc:
  o Gone back to version 1.7, without the fix in LocateIntersectionPoint 
      for the "long-standing error".

Dec  5th, 2003 - G.Cosmo - (geomnav-V05-02-12)
------------------------
- G4TransportationManager.cc:
  o removed initialisation of allocators for navigation levels, where they
    were introduced as workaround for solving static initialisation a long
    time ago. Now moved to "volumes" module, where they should belong, in
    G4TouchableHistory.cc.
- Restored original unit-tests, using inherited navigator.
  --> Requires geomvol-V05-02-08
 
Dec  4th, 2003 - J.Apostolakis  (geomnav-V05-02-11)
------------------------------
- G4PropagatorInField.cc 
  o Corrected placement of #endif for two #ifdef VERBOSE

Dec  2nd, 2003 - J.Apostolakis  (geomnav-V05-02-10)
------------------------------
- G4PropagatorInField[.hh.cc]:
   o Fixed LocateIntersectionPoint for long-standing error.
     A section of the chord was not considered in use case where
     a previous chord at first appeared to have an intersection, but did not.

Nov 26th, 2003 - J.Apostolakis  (geomnav-V05-02-09)
------------------------------
- G4PropagatorInField[.hh.cc]:
  o Added argument Method LocateIntersectionPoint G4bool& recalculatedEndPt
    to return 'true' if the endpoint has been recalculated.
    This fixes a problem that can occasionally cause the skipping of a volume 
    boundary - in the case when a re-integration was done near a boundary,
    because the new endpoint was previously not passed back.
  o ComputeStep also changed to accept above recalculation.
  o New method GetVerboseLevel(),  closer to std naming than Verbose()

Nov 14th, 2003 - J.Apostolakis  (geomnav-V05-02-08)
------------------------------
- Retagged the files of tag "geomnav-V05-02-07", due to tagging with same
  name incorrectly files in another directory and, as such confusing Bonsai.

Nov 13th, 2003 - J.Apostolakis  (geomnav-V05-02-07)
------------------------------
- G4PropagatorInField[.hh.icc.cc]:
  o Pass safety sphere information to G4ChordFinder for optimisation
  o Including G4ChordFinder.hh only in .cc file
- Requires and coworks with "field-V05-02-08" tag. 


Nov 10th, 2003 - G.Cosmo  (geomnav-V05-02-06)
------------------------
- G4Navigator[.hh.icc.cc] - methods review:
  o Removed obsolete methods: IsExitNormalValid(), GetLocalExitNormal().
  o Renamed method LocateGlobalPointAndSetup(p,v,history) to
    ResetHistoryAndLocate(p,v,history).
  o Moved to protected the following methods: GetCurrentLocalCoordinate(),
    ComputeLocalPoint(), ComputeLocalAxis(), NetTranslation(),
    NetRotation(), EnteredDaughterVolume().
  o Fixed consistency of inline/not-inline implementations of methods.
- Coworks with tag "tracking-V05-02-03".

Nov 6th, 2003 - J.Apostolakis  (geomnav-V05-02-05)
-----------------------------
- G4PropagatorInField[.hh.icc.cc]:
  o Implements move of EpsilonMin / Max to G4FieldManager.
- Requires and coworks with "field-V05-02-04" or later tag.

Nov 6th, 2003 - G.Cosmo  (geomnav-V05-02-04)
-----------------------
- G4Navigator[.hh.icc.cc]:
  o Made relevant methods virtual to verify performance impact.
    If tests will behave reasonably, a further refinement in the
    design of the class will be applied, in view of a more consistent
    design review next year.

Nov 3rd, 2003 - G.Cosmo  (geomnav-V05-02-03)
-----------------------
- Code cleanup and headers inclusion review
  (replaced by forward declarations where necessary).
- Added build system to tests. Cleared compilation warnings.

Oct 29th, 2003 - J.Apostolakis  (geomnav-V05-02-02)
------------------------------
- G4PropagatorInField: 
  Added option to turn On/Off the optimisation of using the safety 
  in calling G4Navigator. 
- Unit tests: moved test testG4NavigatorX, X=1,2,3,4,5,6 here from
  "volumes" module.

Oct 24th, 2003 - G.Cosmo  (geomnav-V05-02-01)
------------------------
- Migrated calls to G4Exception to new scheme.
- Fixed compilation warning in G4PropagationInField.

Sep 29th, 2003 - G.Cosmo  (geomnav-V05-02-00)
------------------------
- Created.
  Imported classes from "volumes", "management" and "verification" modules:
    G4AuxiliaryNavServices[.hh.icc]		- from geometry/volumes
    G4GeometryMessenger[.hh.cc]			-	"	"
    G4Navigator[.hh.icc.cc]			-	"	"
    G4NormalNavigation[.hh.icc.cc]		-	"	"
    G4ParameterisedNavigation[.hh.icc.cc]	-	"	"
    G4PropagatorInField[.hh.icc.cc]		-	"	"
    G4ReplicaNavigation[.hh.icc.cc]		-	"	"
    G4TransportationManager[.hh.icc.cc]		-	"	"
    G4VoxelNavigation[.hh.icc.cc]		-	"	"
    G4DrawVoxels[.hh.cc]			- from geometry/management
    G4GeomTest*[.hh.cc]				- from geometry/verification
- Cleared call to PV->Setup() according to changes in G4VPhysicalVolume.
  Affected files: G4Navigator[.icc.cc], G4ParameterisedNavigation[.icc.cc],
                  G4VoxelNavigation[.icc.cc], G4ReplicaNavigation[.icc.cc],
                  G4NormalNavigation[.icc.cc].
- G4DrawVoxels: retrieve top transformation through touchable history in
  method DrawVoxels(). Removed old method GetAbsoluteTransformation().
- G4GeomTestErrorList.cc: retrieve top transformation through touchable
  history in method FindGlobalCoordinateSystem().

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Imported History file from old geometry/verification module
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

May 20th, 2003          G.Cosmo  (geomver-V05-01-00)
- G4GeomTestVolume[.hh.cc]:
  o Added methods TestRecursiveLine() and TestRecursiveCylinder() for
    allowing recursion on line_test and cylinder_test respectively.
  o Introduced ability to control depth and starting level of recursion.

Jul 30th, 2002          G.Cosmo  (geomver-V04-01-00)
- G4GeomTestVolume.cc: fixed recursive call to G4GeomTestVolume passing also
  'tolerance' as argument in the recursive test algorithm.

Apr 19th, 2002          G.Cosmo  (geomver-V04-00-00)
- Moved inline constructors and destructors to no inline.
  Affected files: G4GeomTestStreamLogger[.hh.cc].

Oct 24th, 2001          G.Cosmo  (geomver-V03-02-02)
- Fixed compilation error and warnings on HP-aCC. Modified files:
  G4GeomTestVolume.cc, G4GeomTestStreamLogger.cc.

Oct 24th, 2001          G.Cosmo  (geomver-V03-02-01)
- Moved messenger to geometry/volumes and renamed G4GeometryMessenger.
- Removed dependencies from intercoms and geometry/volumes.

Oct 22nd, 2001		G.Cosmo  (geomver-V03-02-00)
- Added "/geomtest/tolerance" command to set custom error tolerance.
  Added Set/GetTolerance() methods to G4GeomTestVolume class.
- Introduced additional diagnostics in G4GeomTestStreamLogger to report
  in case no intersections/overlaps are detected.

Oct 16th, 2001		G.Cosmo
- Added messenger for geometry overlaps testing.
- General source code formatting.
- G4TestGeom* classes implementation by D.C.Williams (UCSC, BaBar).
