ReleaseNotes.md

# v01-01

* 2017-07-06 Markus Frank ([PR#201](https://github.com/AIDASoft/DD4hep/pull/201))
  ## DDCore: Changes to the VolumeManager interface
  
    Recent descrepancies showed that the call to lookup a placement
    from the volume manager may have an ambiguous meaning:
    It may (as used until now) be the placement of thge closest
    detector element - a functionality used by various tests
    or be the placement of the sensitive volume itself.
    So far, since each sensitive volume in the DD4hep tests
    is represented by a DetElement structure, both
    approaches returned the same placed volume.
  
    Since there is the possibility to have sensitive volumes, which are not
    directly connected to a single DetElement structure, this call was
    split to resolve this ambiguity:
  
    /// Lookup a physical (placed) volume identified by its 64 bit hit ID
    PlacedVolume lookupVolumePlacement(VolumeID volume_id) const;
    /// Lookup a physical (placed) volume of the detector element
    /// containing a volume identified by its 64 bit hit ID
    PlacedVolume lookupDetElementPlacement(VolumeID volume_id) const;

* 2017-07-06 Andre Sailer ([PR#200](https://github.com/AIDASoft/DD4hep/pull/200))
  - Now will give a warning if multiple entities (e.g., constants) of the same name are defined in the XML

# v01-00-01

* 2017-07-04 Frank Gaede ([PR#199](https://github.com/AIDASoft/DD4hep/pull/199))
  - bug fix for VolumeManagerContext::toElement() and VolumeManagerContext::placement() 
        - set flag=true in VolumeManager_Populator::add_entry when 
           a ContextExtension is needed, i.e. sensitive volume is not DetElement's volume
  - fixes problems in CellIDPositionConverter

# v01-00

* 2017-06-22 Marko Petric ([PR#192](https://github.com/AIDASoft/DD4hep/pull/192))
  - Move `AlignDet_Telescope_readback_xml` to later in the pipeline since it depends on the output of `AlignDet_Telescope_write_xml`

* 2017-06-22 Andre Sailer ([PR#191](https://github.com/AIDASoft/DD4hep/pull/191))
  - Surface: fix memory leak of transformation matrix
  - XML::Layering: fix memory leak of contained layers in the object

* 2017-06-23 Andre Sailer ([PR#197](https://github.com/AIDASoft/DD4hep/pull/197))
  - Fix memory leaks for Tube, EllipticalTube and Polyhedron

* 2017-06-23 Andre Sailer ([PR#196](https://github.com/AIDASoft/DD4hep/pull/196))
  - CMake: add `Project( DD4hep )`, needed to get the correct CMAKE_CXX_COMPILER_ID on macs due to CMP0025 (cmake policy)
  - CMake: fix treatment of linker flags, they are now properly set for Linux and Macs to error when undefined functions are encountered at link time
  - CMake: fix elif --> elseif when checking threading libraries

* 2017-06-23 Frank Gaede ([PR#195](https://github.com/AIDASoft/DD4hep/pull/195))
  - fix crash in `dd4hep::rec::Surface` after changes in Handle assignment (PR #193)
  - fix use of deprecated `dd4hep::rec::MaterialManager` c'tor in Surface

* 2017-06-20 Frank Gaede ([PR#185](https://github.com/AIDASoft/DD4hep/pull/185))
  - bug fix in material utilities
       - call `MaterialManager( Volume v)` with `Detector.world().volume()`

* 2017-06-20 Marko Petric ([PR#184](https://github.com/AIDASoft/DD4hep/pull/184))
  - Reinstate the full test-suite on Travis

* 2017-06-20 Markus Frank ([PR#183](https://github.com/AIDASoft/DD4hep/pull/183))
  - Unify header guards in DDCore
  - Add header to steer ignoring warnings of rootcling generated dictionaries.

* 2017-06-20 Frank Gaede ([PR#182](https://github.com/AIDASoft/DD4hep/pull/182))
  - cleanup of namespace `dd4hep::rec`
    - remove obsolete bwd compatibility for `DD4hep::DDRec`
    - re-introduce `[deprecated]` warnings for unmaintained classes in DDRec/API 
    - re-fix deprecated c'tor for `MaterialManager` in material utilities

* 2017-06-20 Markus Frank ([PR#181](https://github.com/AIDASoft/DD4hep/pull/181))
  - Attack many warnings from:
    - `-Wshadow`
    - `-Winclude-hygiene`
    - `-Woverlength-strings` (int cling dictionaries)

* 2017-06-20 Markus Frank ([PR#179](https://github.com/AIDASoft/DD4hep/pull/179))
  - Remove a bunch of shadow warnings and include-hygiene warnings.

* 2017-06-21 Marko Petric ([PR#169](https://github.com/AIDASoft/DD4hep/pull/169))
  - Make boost explicit requirement for DD4hep and drop DD4HEP_USE_BOOST

* 2017-06-21 David Blyth ([PR#168](https://github.com/AIDASoft/DD4hep/pull/168))
  - Added environment helper scripts `thisdd4hep_only.(c)sh` that only set up variables for DD4hep and not for dependencies.

* 2017-06-19 Markus Frank ([PR#178](https://github.com/AIDASoft/DD4hep/pull/178))
  - Update documentation after reorganization of namespaces (put back previous docs).

* 2017-06-19 Markus Frank ([PR#175](https://github.com/AIDASoft/DD4hep/pull/175))
  ## DD4hep namespace reorganization
  
  Re-organize namespaces according to the decisions of the DD4hep developers meeting from 16th June we have decided:
  
  1. all namespaces will be lower case and shorter
      * rename namespace `DD4hep` -> `dd4hep`
      * rename namespace `DD4hep::DDRec` -> `dd4hep::rec`
      * rename namespace `DD4hep::Simulation` -> `dd4hep::sim`
      * rename namespace `XML` -> `xml` and `JSON` -> `json`
      * rename all other namespaces according to this pattern
  2. The namespace `DD4hep::Geometry::` will be incorporated into `dd4hep::`
  3. All utilities will be moved `dd4hep::detail`
  4. `LCDD` will be renamed to `Detector` and current `Detector.h` will be renamed to `DetElement.h`
  8. Examine if `DDSegmentation` can be incorporated into `DDCore` and make it volume aware
      * If this this cannot be achieved in whole place `DDSegmentation` into the right namespace
  
    ## DDParsers
  
    DDParsers are now a separate package. This does not make it yet standalone,
    but it is at the same level as e.g. DDSeqmentation. Any librarian is
    encouraged to externialize it fully.

# v00-24

* 2017-06-08 Markus Frank ([PR#160](https://github.com/AIDASoft/DD4hep/pull/160))
  * Add a new class `AlignmentsNominalMap`, which behaves like a `ConditionsMap` and handles alignment entries. 
  * The `AlignmentsNominalMap` is not a conditions cache per-se. This implementation  behaves like a `conditionsmap`, but it shall not return real conditions to the user, but rather return the default alignment objects (which at the basis are conditions as well) to the user. These alignments are taken from the `DetElement` in question `Alignment DetElement::nominal()`.
  
  * The basic idea is to enable users to write code "as if" there would be conditions present. This is important to ease in the lifetime of the experiment the step from the design phase (where obviously no conditions are taken into account) to a more mature phase, where alignment studies etc. actually are part of the "bread and butter work".
  
  * Added a corresponding example in examples/AlignDet:
  ```
  $>   geoPluginRun -volmgr -destroy -plugin DD4hep_AlignmentExample_nominal \
           -input file:${DD4hep_DIR}/examples/AlignDet/compact/Telescope.xml
  ```
     * Access the DetElement nominal conditions using the `AlignmentNominalMap`.
     Any use of DDCond is inhibited.
       1) We use the generic printer, which during the detector element scan accesses the conditions map.
       2) We use a delta scanner to extract the nominal deltas from the `DetElement`'s nominal alignments
       3) We use a `ConditionsTreeMap` to perform the alignments re-computation.

* 2017-06-08 Markus Frank ([PR#159](https://github.com/AIDASoft/DD4hep/pull/159))
  # Implementation of the decisions made at the Conditions mini-workshop
  
  ## Access mechanisms of DD4hep conditions for utilities
  
  Access to conditions is solely supported using the interface class DDCore/ConditionsMap.
  * All utilities must use this interface.
  * Any concrete implementation using conditions/alignment utilities must implement this interface
  * Basic implementation using STL `map`, `multimap` and `unordered_map` are provided.
  * A special no-op implementation of this interface shall be provided to access "default" alignment conditions. This implementation shall fall-back internally to the `DetElement::nominal()` alignment. 
  Known clients: `VolumeManager` (hence: DDG4, DDRec, etc.)
  
  Though this sounds like a trivial change, the consequences concern the entire conditions
  and alignment handling. This interface decouples entirely the core part of DD4hep
  from the conditions cache handling and the alignment handling.
  
  Based on this interface most utilities used to handle conditions, detectors scans
  to visit `DetElement` related condition sets, alignment and conditions printers etc.
  
  For details, please see:
  ```
  DDCore/include/DD4hep/AlignmentsPrinter.h
  DDCore/include/DD4hep/AlignmentsProcessor.h
  DDCore/include/DD4hep/ConditionsPrinter.h
  DDCore/include/DD4hep/ConditionsProcessor.h
  DDCore/include/DD4hep/DetectorProcessor.h
  ```
  
  ## Naming conventions for detector conditions
  
  * Condition are logically attached to DetElements
     * Condition names are: `DetElement.path()+"#"+condition-name`
         Example: `/world/LHCb/DownstreamRegion/Muon/M5/M5ASide/R3ASide/Cham046#alignment`
  
  * Condition keys are a `int64` compound of two `int32`:
  ```cpp
     union {
       int64 key;
       struct {
         int32 item_key;
         int32 det_key;     // Needs to be the high word to have a properly ordered map
       } values;
     };
     det_key  = hash32(DetElement.path())
     item_key = hash32(condition-name)
  ```
     **Condition keys must be unique throughout the detector description.**
  
  * Alignment conditions naming conventions:
    * Alignment-delta conditions are called `alignment_delta`.
    * Fully qualified alignment conditions are called `alignment`.
     DD4hep provided alignment utilities rely on this convention.
  
  * Other conditions can be named freely.
  
  ## Important Notice
  The **Alignment conditions naming conventions** are already used by several utilities involving alignments. If you plan to use these, do not freely ignore these recommendations. When the naming conventions are ignored, these utilities shall not work.
  
  ## Updates to DDCond
  DDCond implements a working conditions cache following the design criteria sketched above. The `conditionsSlice` object implements (though by forwarding to the `ConditionsUserPool`) a `ConditionsMap` interface.
  
  The `DD4hep_ConditionsMapUserPool` plugin implements in a very efficient way this interface using an ordered map. Using the above described key definition, this implementation allows very efficient scans of conditions/alignments etc. of individual detector elements, since conditions which belong to the same detector element are contiguous.
  
  ## Alignment handling/computations
  Using the conditions maps, the computation of (mis-)alignment data from deltas
  is no longer bound to the conditions mechanisms.
  
  A special utility called `AlignmentsCalculator` is put in place (see `DDCore/include/DD4hep/AlignmentsCalculator.h`) to facilitate the computation of a coherent set of alignments given a set of delta-parameters. This mechanism is much simpler, easier to understand and far less code intensive than the previously designed callback mechanism where alignments are obtained using conditions derivation.
  
  ## Update of the existing examples
  
  The example sets in DDDB, `examples/Conditions, examples/AlignDet`, `examples/DDDB` were updated according to the changed mechanism of accessing conditions. Here we can see the real benefits of the new approach: keeping same functionality, the examples became way off simpler. Simply count the number of lines of code.

* 2017-06-17 Marko Petric ([PR#170](https://github.com/AIDASoft/DD4hep/pull/170))
  - Add clang flag to warn about using namespace directive in global context in header

* 2017-06-17 Frank Gaede ([PR#167](https://github.com/AIDASoft/DD4hep/pull/167))
  - renamed the namespace DD4hep::DDRec to dd4hep::rec (see #166)
         - provide backward compatibility to outside world for now
  - moved the interfaces in namespace DDSurfaces to dd4hep::rec
         - provide backward compatibility to outside world for now

* 2017-06-15 Frank Gaede ([PR#165](https://github.com/AIDASoft/DD4hep/pull/165))
  - started to cleanup DDRec
        - don't use  LCDD::getInstance() in SurfaceManager and SurfaceHelper
        -  deprecate unused(?) classes in DDRec/API and DDRec/Extensions
        -  deprecate MaterialManager() using LCDD::getInstance()

# v00-23

* 2017-05-12 Marko Petric ([PR#152](https://github.com/aidasoft/DD4hep/pull/152))
  - Update CI to GCC 7.1 and LLVM 4.0 and include Geant4 10.3

* 2017-05-22 Frank Gaede ([PR#154](https://github.com/aidasoft/DD4hep/pull/154))
  - protect against NANs in Guineapig pairs files in Geant4EventReaderGuineaPig
  - make INFO printout more consistent  with dd4hep style

* 2017-06-07 Frank Gaede ([PR#157](https://github.com/aidasoft/DD4hep/pull/157))
  -  bug fix in test_cellid_position_converter
       - with this no tests for position from cellID lookup should fail
  - re-implement ```CellIDPositionConverter::cellID(pos)```

* 2017-06-08 Marko Petric ([PR#156](https://github.com/aidasoft/DD4hep/pull/156))
  - Mark all fallthroughs in case statements with attributes to suppress warning

* 2017-06-01 Frank Gaede ([PR#155](https://github.com/aidasoft/DD4hep/pull/155))
  - add new class rec::CellIDPositionConverter
        - replaces rec::IDDecoder
        - implement positionNominal(CellID id) and cellID(position)
       - prepare for using alignment map by separating transforms to DetElement and daughter volume
       - do not use deprecated methods/members in VolumeManager
  - add test_cellid_position_converter.cpp
  - add VolumeManagerContext::toElement
       - transform from sensitive volume to next DetElement

# v00-22

* 2017-04-28 Markus Frank ([PR#148](https://github.com/aidasoft/DD4hep/pull/148))
  Improvements to the compact xml processing
  ===========================================
  
  Elements may now be specified within compact in 2 ways:
  1) old way: create an effective element:
  `    <element Z="4" formula="Be" name="Be" >`
  `      <atom type="A" unit="g/mol" value="9.01218" />`
  `    </element>`
  
  2) create element by defining an isotope mixture:
  `    <isotope name="C12" Z="6" N="12"/>`
  `      <atom unit="g/mole" value="xxxx"/>`
  `    </isotope>`
  `.....`
  `   <element name="C">`
  `     <fraction n="0.9893" ref="C12"/>`
  `     <fraction n="0.0107" ref="C13"/>`
  `   </element>`
  
  Improved debugging of compact xml conversions
  The following tags allow to enable increased prinout depending on additional tags in the compact file:
  `    <debug>`
  `      <type name="isotopes"     value="1"/>`
  `      <type name="elements"     value="1"/>`
  `      <type name="materials"    value="0"/>`
  `      <type name="visattr"      value="0"/>`
  `      <type name="regions"      value="0"/>`
  `      <type name="readout"      value="0"/>`
  `      <type name="limits"       value="0"/>`
  `      <type name="segmentation" value="0"/>`
  `    </debug>`
  
  Disable the ROOT TGeo element table from the compact xml. 
  Note: ALL elements must then be specified in the XML material database.
  `    <geometry>`
  `      <clear name="elements"/>`
  `    </geometry>`
  
  By default compact accepts exactly one input file (others may be included therein).
  In order to process iteratively multiple input files, the opening and the closing of the
  geometry steering tags may be added to the compact description. This example 
  gives the default behaviour:
  `    <geometry open="true" close="true"/>`
  
  Please note: per compact file exactly ONE geometry tag is allowed.
  
  
  Debugging the DDG4 geometry conversion mechanism
  =============================================
  New boolean properties of the Geant4DetectorGeometryConstruction object,
  which result in debugging printouts (defaults are OFF):
    DebugMaterials
    DebugElements
    DebugShapes
    DebugVolumes
    DebugPlacements
    DebugRegions
    PrintPlacements
    PrintSensitives

* 2017-04-28 Ben Couturier ([PR#146](https://github.com/aidasoft/DD4hep/pull/146))
  * Trivial fix for the DDDB converter to create paramphysvol3D volumes, which are otherwise ignored.

* 2017-04-20 Andre Sailer ([PR#145](https://github.com/aidasoft/DD4hep/pull/145))
  - LCIOOutput: Add setting of ProducedBySecondary bit for SimTrackerHits if the hit is produced by a particle that is not stored in the MCParticle collection, needs lcio 2.8

* 2017-05-05 Andre Sailer ([PR#150](https://github.com/aidasoft/DD4hep/pull/150))
  - Always create dd4hepConfigVersion.cmake in CMAKE_INSTALL_PREFIX and cmake folder
  - Create DD4hepConfig.cmake also in cmake folder
  - renamed Cmake Macro GENERATE_PACKAGE_CONFIGURATION_FILES to DD4HEP_GENERATE_PACKAGE_CONFIGURATION_FILES so it does not clash with the macro of the same name in ilcutil/cmakemodules

* 2017-05-07 Andre Sailer ([PR#151](https://github.com/aidasoft/DD4hep/pull/151))
  - Use cmake to create Version.h file to contain dd4hep version information and macros
  - Change the way dd4hep package version is defined and set standard cmake variables for this purpose

# v00-21

* 2017-04-03 Marko Petric ([PR#142](https://github.com/AIDASoft/DD4hep/pull/142))
  - Update to the CI system:
    - Install directly cvmfs on base system, which removes the need for the parrot connector 
    - Replace CernVM docker with plain docker
    - This reduces the build run time from 50 min to 25 min

* 2017-03-27 Shaojun Lu ([PR#134](https://github.com/AIDASoft/DD4hep/pull/134))
  - Set verbose true for G4EmSaturation to printout Birks coefficient.

* 2017-03-29 Frank Gaede ([PR#139](https://github.com/AIDASoft/DD4hep/pull/139))
  - add a utility to dump the B-field for a given Volume
          - usage: dumpBfield compact.xml x y z dx dy dz [in cm]  
          - will dump the B-field in volume [-x:x,-y:y,-z,z] with steps [dx,dy,dz]

* 2017-03-29 Joschka Lingemann ([PR#138](https://github.com/AIDASoft/DD4hep/pull/138))
  - Direct implementation that calculates eta from cartesian coordinates
  - Fix: Add registration of Phi-Eta segmentation

* 2017-03-29 Joschka Lingemann ([PR#137](https://github.com/AIDASoft/DD4hep/pull/137))
  - Adding GridRPhiEta a segmentation of equidistant size in R, Phi and Pseudorapidity
  - Adding GridPhiEta a segmentation of equidistant size in Phi and Pseudorapidity

* 2017-03-28 Markus Frank ([PR#135](https://github.com/AIDASoft/DD4hep/pull/135))
  - Accidentally the Segmentations of Joschka were added in the wrong place of the hierarchy.
     I removed them. He will later add them to the proper location.
  - Some C++ warnings concerning the C++11 standard were also fixed.

* 2017-03-24 Yorgos Voutsinas ([PR#132](https://github.com/AIDASoft/DD4hep/pull/132))
  - modifying the LayeredCalorimeterData struct in order to cope with conical shaped calorimeters

* 2017-03-31 Markus Frank ([PR#143](https://github.com/AIDASoft/DD4hep/pull/143))
  - Add new test for multi segment multi collections segmentations using a calorimeter endcap.
     See also: https://github.com/AIDASoft/DD4hep/issues/141, which is still unresolved,
     but seems not to be directly related to the Monte-Carlo truth handling.
  - Side effect: add Geant4EventActions to dump hits and particles
  - Fix a linker problem for unicode tags.

* 2017-03-31 Frank Gaede ([PR#140](https://github.com/AIDASoft/DD4hep/pull/140))
  - clarify documentation for CartesianField and implementations
  - make clear that  void fieldComponents() has to add
     the new field to the given field vector

Marko Petric 2017-03-23 
  - Convert Release notes to markdown
  - Add some text about WIP and issue tracking
  - Add CONTRIBUTING.md and PULL_REQUEST_TEMPLATE

Markus Frank 2017-03-17
 
 - Add a new input type by parsing JSON files. The basic json interpreter
    is present and offers essentially the same interface as the XML persers.
    The integration to the compact dialect however is not yet done.
    It should become however a valid alternative to parsing XML files
    with a small maintenance overhead, since the enhancement implementation
    present in XMLDimesion.h, XMLDetector.h and XMLChildValue.h is shared
    and instantiated for both.

Markus Frank 2017-03-10
 
 - New round to kill coverity deficiencies.
 - Add exception try-catch clauses around various main programs in UtilityApps
    See UtilityApps/src/main.h for details.

Markus Frank 2017-03-09
 
 - Fix issue with long volume ids exceeding 32 bits.
    Test added in examples/ClientTests
 - Fix volume manager id identical placed volumes are used in different places of the hierarchy.
    Test added in examples/ClientTests
 - Remove various svn left-overs (ID$ strings etc.)


Frank Gaede 2017-02-10
 
- allow event readers to create more than one vertex per event
     this should be possible as most generator formats allow to specify
     more than one event vertex 
  - changed signature of Geant4EventReader::readParticles(int,Vertex*, Particles&)
        to Geant4EventReader::readParticles(int,Vertices&, Particles& )
  - implement in LCIOEventReader, Geant4EventReaderHepEvt and Geant4EventReaderHepMC
  - for now still one vertex only is created using the first final state particle
        for HepEvt and LCIO

# v00-20

Frank Gaede 2017-01-13 
- fix computation of radiation and interaction lengths
- require the density to be specified in the materials xml file
 
Frank Gaede 2017-01-04 
- adopt numbers in test_surface.cc to elements.xml
- use elements.xml generated with plugin in DDTest
-  add ROOT version to dumped element table

Frank Gaede 2016-12-22 
- fix test_surfaces by adapting to elements.xml
- fix test_units by including elements.xml
 
Markus Frank 2016-12-21 
- Add plugin to dump the default ROOT element table
 
Markus Frank 2016-12-20 
- Remove obsolete build flags
 
Markus Frank 2016-12-19 
- Add Multi-threading conditions example
 
Andre Sailer 2016-12-16 
- Add drivers for Beampipe, Mask and Solenoid from lcgeo, changed name to dd4hep_*
 
Rosa Simonielo, Frank Gaede 2016-12-15 
- add new struct rec::NeighbourSurfacesStruct defined for neighbouring surfaces
 
Frank Gaede 2016-12-14 
- fix library pathes in env scripts for macos
- use DD4HEP_LIBRARY_PATH and full lib path on mac
- apply rpath compiler settings to GaudiPluginService
- make compatible w/ Geant4 10.3
 
Marko Petric 2016-12-13 
- Fix compiler flag handling
 
Daniel Jeans 2016-12-08 
- add utility graphicalMaterialScan
 
Markus Frank 2016-12-07 
- Fix compiler error on MacOSX gcc 4.9
 
Marko Petric 2016-12-07 
- Remove few tests from Travis
- move flag to CMAKE_SHARED_LINKER_FLAGS
- Remove the dynamic lookup on runtime for libs on mac
 
Markus Frank 2016-12-05 
- First version of conditions and alignments
 
Andre Sailer 2016-12-06 
- DDTest: fix location to install DDtest header files
- Remove minimum required cmake version from DD4hepBuild, this interferes with other packages depending on dd4hep
 
Marko Petric 2016-12-02 
- Fix missing CLHEP in thisdd4hep.sh
- Clean up FindPYTHON.cmake file
- Change gaudi auto_ptr to unique_ptr since the auto is deprecated
- Fix initAClick
 
Marko Petric 2016-11-29 
- Fix rpath issues on mac with python
- Add custom DynamicPath on mac when loading python libs
- Add function to set the DD4HEP_LIBRARY_PATH
 
Marko Petric 2016-11-28 
- Update all minimum CMake versions
- Fix gitlab builds
- Rename MakeRootMap to MakeGaudiMap for consistency
- Remove ROOT5 things and make approprite fixed to the usage of ROOTConfig.cmake
 Remove FindROOT.cmake and use from now on ROOTConfig.cmake
 
 
Markus Frank 2016-11-30 
- New version of conditions handling
 
Andre Sailer 2016-11-25 
- Fix ProductionCut conversion in Geant4Converter.cpp: cut is a range
 
Markus Frank 2016-11-24 
- Fix linker errors on MAC
- Remove compiler warnings on MACOSX
- First fixes to version of alignment constant processing also remove where visited the $ statements in the files.
They are useless, since git does not support them. Fixed some tests, which no longer properly worked in
the conditions area.
- First usable version of alignment constant processing
 
 
Markus Frank 2016-11-16 
- Try to improve efficiency using C++11 default operations
 
Markus Frank 2016-11-10 
- Simplify opaque data mappings for conditions
 
# v00-19
2016-11-17 D.Jeans
- rewritten MegatileLayerGrid class 
  - not backward compatible 

M.Petric:
- improved Travis CI configuration 
- remove some tests from CI

# v00-18

2016-11-09 F.Gaede
- updated rec::LayeredCalorimeterData::Layer:
  - remove deprecated thickness 
  - add phi0  
- add copy assignement to rec::MaterialData

2016-11-08 M.Frank
- Improve conditions handling. Started to implement using simple telescope
  detector from C.Burr.
- Add variable DD4HEP_LIBRARY_PATH to be used on MacOSX El Capitane
  to overcome DYLD_LIBRARY_PATH protection issues.
- Fix to copy with negative(rebased) IDDDescriptor fields
  (affects IDDDescriptor and VolumeManager).
  2 New tests:
  - ClientTests/Bitfield_SidesTest.xml to test readout string:
    system:8,barrel:-2
  - ClientTests/Bitfield_SidesTest2.xml to test readout string:
    system:16,barrel:16:-5
    
2016-10-18 M.Frank
-  Due to pressure of the FCC folks, I tried to implement a more dd4hep like implementation of the
  the segmentation objects. For testing only CartesianGridXY. If this mechanism works,
  it could be a starting recipe for the rest of the segmentations. The draw-back of this approach is,
  that assignments are not reversible:
  dd4hep::CartesianGridXY xy = readout.segmentation();  // Works
  dd4hep::Segmentation seg = xy;                    // Should not work

-  Reason: the managed objects are different....at some point in time I will have to find a
  clean solution for this, but the required changes for such a solution shall be manageable.

# v00-17

2016-09-29 V.Volkl
- Small fixes and extensions of DDEve. Show "Views" menu even if specifying xml on the command line.
  Add possibility to specify event data in EveDisplay method, rather than having to select it in the gui dialogue.
  Selects FCC EventHandler if specified in the config xml (as an "eventHandler"-attribute to the "display" node),
  but keeps default behavior if not.


2016-08-24 M.Frank
- Adding first somehow useful implementation to use conditions and the consequent loading thereof.
	Used by the DDDB implementation/example. DDDB is an alternative way to populate the dd4hep
	detector description using LHCb's detector description database.
	The reason is, that only a running experiment has a reasonable base to conditions data
	to excercise the dd4hep conditions.
	If interested, please have a look in the DDDB examples.

- Still TODO:
  - A formal way to bootstrap the conditions loading still has to be found.
  - Conditions loading from XML files and a small comprehensive example.

# v00-16
2016-07-26 Shaojun Lu  
- Added new MegatileLayerGridXY segmentation for Scintillator strip Ecal, which is implemented by K.Kotera, 
 and used by SEcal04Hybrid geometry driver.

 - many ( minor fixes ) by F. Gaede, M. Petric, A Sailer, ...

2016-06-24 M.Frank
- Implement multiple segmentations.
  Though one readout objects (associated to one DetElement) may only have on segmentation,
  The MultiSegmentation type allows to have several sub-segmentations, which can be chosen
  from.
  Please see examples/ClientTests/*/MultiSegmentations

- At the same time allow the readout object to defined multiple collections through
  the IDDescriptor.
  Please see examples/ClientTests/*/MultiCollections

- The combined example can be found in
  Please see examples/ClientTests/*/NestedSegmentations



2016-05-03 M.Frank
- Green light is ON. You may use revision 2237 and above.

2016-05-03 M.Frank
- **Mega commit. Do not use until green signal arrives with seperate release notice.**
- Package DDDB: Prove of concept, that we can populate the geometry also from other
  sources than xml files obeying the lccdd notation.
- DDCore/XML: Implement the possibility to use external entity resolution for Xerces.
  There is not equivalent in TinyXML (AFAIK).
- Remove some of the Spirit parsers, since the libraries are getting way too big.
  This implicitly assumes, that object properties of 'exotic' types such as
  deque<long double> etc. are not really used. If you need properties stay to the obvious:
  string, int float, double and vectors, maps and sets thereof!
- DDG4 needed to public the DDG4Python include directory (Now in DDG4/Python).
  Reason: try to create ROOT 6 dictionaries, which can be relocated for release purposes.
- ROOT 6 dictionary generation: Create dictionaries with the additional flag:
  "-inlineInputHeader" which physically includes the header files used to generate the 
  dictionaries --> relocatability.

2016-03-21 M.Frank
- Add additional vertex argument to EventReader::readParticles, which supposedly should

2016-03-03 M.Frank
- Improve/complete job options type palette. 
- Allow modify the Geant4IsotropGenerator to shoot particle distributions according
  to several distributions:
  flat in : uniform, cos(theta), eta/pseudorapidity, ffbar (1+cos^2 theta)
  Option: generator.Distribution = 'cos(theta)'
  Default is uniform.

# v00-15     
2016-02-15 A.Sailer
-  LCIOStdHepReader.cpp
   - fixed memory leak, compiled and valgrinded

2016-02-10 F.Gaede
- added utility  dd4hep::xml::setDetectorTypeFlag()
  to set the TypeFlag from xml element <type_flag type="0x42"/>
- select detectors with 
  dd4hep::DetectorSelector(description).detectors(  ( dd4hep::DetType::TRACKER | dd4hep::DetType::ENDCAP )) ;
- used in UtilityApps/dumpdetector.cc
- added detector_types.xml with int constants defined in DetType.h, include with :
  `<include ref="${DD4hepINSTALL}/DDDetectors/compact/detector_types.xml"/>`
  - add elements to xml, e.g.
    <type_flags type="DetType_TRACKER +  DetType_ENDCAP  + DetType_PIXEL + DetType_STRIP "/>

2016-02-10 M.Frank
- DDCond:
    First implementation of conditions access. Required some movements of files
    from DDG4 (Properties) and some changes in the core conditions implementation.
    The basic infrastructure is now present. Don't know yet however how buggy it is...

2016-02-05 F.Gaede
-  added DetElement::typeFlag() and DetElement::setTypeFlag(unsigned int types)
- added utility class DetType for setting detector type properties in type flag

2016-02-03 N.Nikiforou
- DDDetectors
  - Added plugin dd4hep_GenericSurfaceInstallerPlugin, copied from lcgeo
    to allow installation of surfaces to any sliced detector
  cmake/Doxyfile.in
  - Added DDDetectors to the sources directory so Doxygen picks up the
    plugin documentation

2016-02-02 F.Gaede
- set momentum at endpoint (if lcio version > 2.6 ) for MCParticles in Geant4Output2LCIO.cpp 
- fixed printlevel in Geant4Action::print()
- removed random lines drawn in teveDisplay
- dont't print DetectorData by default in dumpdetector

2016-02-02 A.Sailer
- DDG4
  - Implemented SimulatorFlags (DDFORHEP-17)
    * In ParticleHandler: vertexIsNotEndpointOfParent, Stopped, leftDetector
    * Steerable distance for vertexIsNotEndpointOfParent
    * TCUserParticleHanlder Simulator flags: DecayedInTracker, DecayedInCalorimeter

2016-01-21 A.Sailer/M.Frank
- DDG4
  - Improved user defined physics constructors
    * Allows user defined global rangecut
    * Allows extending particle table (e.g. B-Hadrons unknown to geant4)

2016-01-18 F.Gaede
- fixed default c'tors in DDRec/DetectorData.h  to zero initialize sub-structures (LayerLayout etc)

2016-01-13 F.Gaede
- allow the default sensitive action to be a tuple with parameter dictionary in DDG4.py/ddsim.steer e.g.:
  SIM.action.tracker = ("Geant4TrackerWeightedAction", {"HitPositionCombination" : 1 , "CollectSingleDeposits" :  False } )
- fixed endpoint in MC-truth particles
 
2016-01-11 F.Gaede
- fix hit momentum in Geant4TrackerAction (Geant4SDActions.cpp)

2016-01-11 A.Sailer
- DDG4
  - Add LargestAcceptableStep to field setup

2016-01-07 A.Sailer
- DDG4
  - Fix the logic for skipping of events at the start of input files: LCIO, HepMC, stdhep and HepEvt
  - Event number in lcio outputfile takes skipped events into account now

2016-01-06 F.Gaede
- bug fix in DDSurfaces::ISurface for surface properties (orthogonal/parallel to z)
  (affected ILD VXD)

2016-01-05 F.Gaede
- added print functions for rec::DetectorData objects
- used in dumpdetector:
  dumpdetector compact.xml -d 


2015-12-09 N.Nikiforou
- UtilityApps/teveDisplay
  - Modified teveDisplay to have three separate collections of surface vectors (u,v,n) 
    instead of one collection. Now the vectors are colored differently.
  - Changed signature of getSurfaceVectors() to allow selection of o,u,v,n vectors to 
    add to the collection, added option for name and color of collection.
  - Renamed surface list collections to "HelperSurfaces" and "SensitiveSurfaces".
  - Changed signature of getSurfaces() to allow setting of name and color of collection.
  

2015-12-01 M.Frank
- DDG4
  - Remove some of the compilation warnings
  - Remove energy cut in sensitive detectors
    If you though need, use a Geant4Filter to mask the action processing
  examples/CLICSiD
  - Add a few tests for materialscan and simulation setups using XML or CINT.
  examples/ClientTests
  - Add a few tests for materialscan and simulation

2015-11-24 M.Frank
- DDG4
  - Implementation of multi-threading mode.
    To use and understand, please consult the DDG4 manual from the doc area.
  - "Old" Single threaded mode and functionality is preserved.
  - Numerous new classes supporting thread and master specific setup
    functionality.
  - Support for python configuration (see manual for details)
  - Support for global Geant4Actions executing in thread reentrant shared mode.
    (see manual for details)
  - DDG4 examples: DDG4/examples/CLICSidSimu.py deleted and replaced with:
    1) DDG4/examples/SiDSim.py  (single threaded, old example)
    2) DDG4/examples/SiDSim_MT.py (multi threaded version of SiDSim.py)
  DDCore:
  - Support user formats for the default printout statements for nicer printouts.
  - Removal of compiler warnings

2015-11-23 F.Gaede
- added glbal method dd4hep::versionString() 

2015-11-13 S.Lu
-  Added a new AHcal Barrel segementation: TiledLayerGridXY, to be used e.g.  
   for the ILD AHcal Barrel Sensitive layer segmentation design.

2015-10-30 F.Gaede
- fixed LCIOFileReader to use sequential reading mode
  as using direct access always required runNum==0 and sequential evt nums ...
   

2015-10-15 F.Gaede
- DDSurfaces::ISurface/Surface
  - added implemation of conical surfaces 
    - ICone, VolConeImpl, VolCone, ConeSurface

2015-10-13 M.Frank
- DDG4
  - Remove explicit constructors for modular physics lists.
    Use the native Geant4 provided G4PhysListFactory instead.
    The physics list is instantiated as before with the "Extends" property.
  - Implement angular ranges in the Geant4IsotropeGenerator for phi [0,2pi] and theta[0,pi]
  - New sensitive detector Geant4TrackerWeightedAction
    Attempt to properly process combined deposits in tracking detectors.
  - Debug component Geant4SurfaceTest similar to the standalone program
    test_surfaces, but to be appended as a DDG4 event action for event by event
    tests of hits.

2015-10-09 M.Frank
- DDG4
  - Extend the functionality of the DDG4 plugins
    Geant4InteractionVertexBoost and Geant4InteractionVertexSmear.
    If the Mask property is set to -1, all interactions present
    at call time are smeared/boosted according to the parameters.
    Note, that the position of the plugins within the generation 
    sequence is important.
  - Add a new generator Geant4GeneratorWrapper to allow the use
    of native G4 generator classes such as the G4ParticleGun or
    the G4GeneralParticleSource. Still to be tested.
  - Extend the Geant4Random functionality: May now be instantiated
    like any other Geant4Action. Users may set the seed or the 
    luxury level.
    All calls to HepRandom (CLHEP) or gRandom (ROOT) will re-use 
    this instance. See DDG4/examples/CLICRandom.py for illustration.
  - Updated DDG4 manual.

2015-09-30 F.Gaede
- updated createGearForILD.cpp to use new parameters in LayeredCalorimeterData
  ( innerThickness, innerRadLength, etc)


2015-09-15 F.Gaede
- refactoring of Surface classes:
    - made VolSurface a reference counting handle to 
      a polymorphic pointer of type VolSurfaceBase
      - this should facilitate the creation
        of dedicated surface classes for special cases
        such as inside the beampipe or the face of the calorimeter

2015-08-27 F.Gaede
- added macros DD4HEP_VERSION_GE(MAJV,MINV) and DD4HEP_VERSION_GT(MAJV,MINV)
  to Detector.h

- increased version number to v00-15


2015-08-20 M.Frank
- DDCore: Modularize/abstract plugin manager 
- VolumeManager: Fix bug propagating sensitive detectors
  Showed up in the examples of nested detectors


2015-08-12 N.Nikiforou
- DDCore/XML: Added new helper functions to Layering engine:
   - double absorberThicknessInLayer(xml::Element e) : 
     returns total absorber thickness in given layer
   - void sensitivePositionsInLayer(xml::Element e, std::vector<double>& sens_pos) :
     provides positions of sensitive slices within a layer with respect to the 
     center of the layer


2015-07-25 M.Frank
- DDSegmentation: Remove several 'shadow' warnings.

- New build system for the dd4hep core, which greatly simplyfies the cmake files
  for the various sub-packages. 
  Tested with Andre's build script doc/CompileAllOptionPermutations.sh.
  (GEAR usage not tested though)

# v00-14     
F.Gaede
- fixed writing of generator status for lcio::MCParticle
  in Geant4Output2LCIO.cpp

A.Sailer 
- Add missing scope to /DD4hep/Factories.h, to not force everyone to use using namespace

F.Gaede: 2015-07-15
- changed type in SurfaceList and SurfaceMap from Surface to ISurface
- added methods length_along_u/v() to ISurface
- moved setting of CMAKE_CXX_FLAGS (if DD4HEP_USE_CXX11) from DD4hep.cmake to CMakeLists.txt

2015-07-11 M.Frank
-  added starter docs dd4hepStartersGuide.pdf

*** **Important** ***
  **Before updating, backup your existing and working checkout. Though I was running 
  the basic tests, there may be unchecked corners of the software.**

Notes:
- Backwards compatibility mode for the usage of ROOT 5 and ROOT 6 alternatively.
- For ROOT 6 the Gaudi PluginService is used and added to the distribution.
- dd4hep is distributed with a licence. See $DD4hepINSTALL/LICENSE for details.
- In the doc area the $DD4hepINSTALL/doc/CREDITS file everybode should add her/his 
  name, if contributed significantly.
- Unfortunately this meant to add/change the headers of all files and give a 
  pointer to the licence file. If I accidentally changed the author name, please
  chagne it back.
- The plugin factory declaration statements were changed to accomodate both
  ROOT 5 and ROOT 6 and to keep the number of 'ifdef' statements at a minimum.
- TODO: Properly change the cmake scripts to accomodate for ROOT 6 and the 
  automatic switch when building dd4hep. 
- For reference reasons: this commits is revision 1812 + 1813 (DDDetectors)

# v00-13  
2015-07-03 F.Gaede
- updated doxygen for detector rec::DetectorData structs and usage in convertToGear

2015/07/02 Nikiforos Nikiforou
- Added isRadiator() helper function in DDCore/XML/XMLDetector.h/cpp 
  Mirroring functionality of isSensitive() and used in geometry drivers
  e.g. to calculate total absorber thickness
  
- Extended LayeredCalorimeterStruct in DDRec/DetectorData.h to include 
  additional parameters required by Pandora:
  - inner_phi0 (e.g. alignment for inner symmetry)
  - outer_phi0 (e.g  aligment for outer symmetry)
  - NOTE: phi0 still remains but is deprecated
  - gap0 (e.g stave gap along r-phi)  
  - gap1 (e.g middle stave gap along z)
  - gap2 (reserved for future use)

 2015-06-29 A.Sailer
 - always store lcio collections, even if they are empty in Geant4Output2LCIO (DDG4/ddsim)


2015-06-29 F.Gaede
- changed env scripts to prepend to library pathes (dd4hep and dependant packages)
   - using a newer lcgeo version than the one provided in ilcsoft can simply
        be done w/ source ./bin/thislcgeo.sh 
	      
# v00-12  
2015/06/17 Markus Frank
- Add possibility to block access to constants by name from Detector.
  Functionality enabled by a constant named "Detector_InhibitConstants" with value "1", "True", "Yes".
  Test: geoDisplay -compact file:../DD4hep.trunk/examples/ClientTests/compact/InhibitConstants.xml 

- Add DetectorHelper handle object to easily access the sensitive detector object of a detector
  using either the subdetector name or the detector element (or one of its children).
  See: dd4hep/DetectorHelper.h
  Test: ``` 
  geoPluginRun -input file:../DD4hep.trunk/examples/CLICSiD/compact/compact.xml \
                     -plugin CLICSiD_DetectorHelperTest  \
         optional:  -<detector-name (default:SiVertexEndcap)>  [Note the '-'!!!] 
         ```

- Check when adding new sub-detector detector elements if a given one already exists.
  if yes: exception.
  Test: `geoDisplay -compact file:../DD4hep.trunk/examples/ClientTests/compact/DuplicateSysID.xml`


A. Sailer
- DDSegmentation: Added function cellDimension which returns the dimension of any given cell

S.Lu:
- Added a switch for BirksLaw to Geant4StepHandler. 
  For backward compatable, by default, do not apply BirksLaw, and apply BirksLaw with call 'doApplyBirksLaw()'.
  added optional Geant4ScintillatorCalorimeterAction
- Added one 'Geant4ScintillatorCalorimeterAction' into DDG4 plugins Geant4SDActions for  scintillator to take 
  Geant4 BirksLaw effect as sensitive detector active layer.

F.Gaede
- added SurfaceManager class that holds maps of surfaces for 
  "world","tracker","calorimeter","passive" and all individual subdetectors
    - to be used in reconstruction code where a lookup from cellID
      to corresponding surface is needed
    - needs plugin "InstallSurfaceManager" to be in the compact file
    - access via:  
      SurfaceManager surfMan = *description.extension< SurfaceManager >() ;
      const SurfaceMap& surfMap = *surfMan.map( "world" ) ;
- renamed old SurfaceManager to SurfaceHelper

- added method: Volume createPlacedEnvelope()
  - to be used in all LC detector drivers to create a placed envelope volume
    rest of the detector is then instantiate in this volume

- added BooleanShape plugin for creating generic boolean
  shapes (subtraction, union or intersection )
   - to be used for envelope definition in xml

   - added new build_type: BUILD_ENVELOPE 
      - can be used to visulize envelopes only (geoDisplay, teveDisplay,...)

2015/05/22 Nikiforos Nikiforou
- Fixed bug in DDG4/lcio/LCIOConversions.cpp, which stored only the PDG of the primary particle 
  in multiple particle contributions in SimCalorimeterHits instead of both the primary and secondary PDGs.


2015/05/13 Markus Frank
- Fix bug in DDG4, which forced DDG4 to exit if a property from the Geant4 prompt could
  not be set. No an error message is printed and the prompt is returned to the user.
  (Bug submitted by A. Sailer)

2015/05/11 Andre Sailer
- CMake updates:
  - Split libraries into components: use find_package(dd4hep COMPONENTS <component> [...] )
    to find the components you need.
  - At the moment there are these components are sensible to link against: DDRec, DDG4, DDEve, DDSegmentation
  - To link against the librarie use either dd4hep_COMPONENT_LIBRARIES or dd4hep_<COMPONENT>_LIBRARY,
    where <COMPONENT> needs to be replaced by the UPPER case name of the component

2015/05/09 Markus Frank
- Allow to access detectors by type from description.
  - The sensitive type of a detector is set in the 'detector constructor'.
  - Not sensitive detector structures have the name 'passive'
  - Compounds (ie. nested detectors) are of type 'compound'
- Dump detector types using plugin:

         geoPluginRun -plugin DD4hepDetectorTypes -input <compact-file>

2015/03/12 Markus Frank
- Add support for ellipsoids in gdml/description and geant4 conversion.
- Allow to include files with environment variables from compact notation.

2015/03/09 Markus Frank
- Finalize move to geant4 version 10, started by A.Sailer
- Add non-isotrop particle generator in DDG4 (request P.Kostka)
- Isolate ROOT plugin manager as start to move to ROOT 6

# v00-11     
- DDDetectors
  - new Package containing generic dd4hep detector palette (MF)
  - added 'dimension' argument to dd4hep_SiTrackerBarrelSurfacePlugin (FG)
    to handle pixel and strip detectors 

- DDRec (Frank Gaede)
  - added simple data structs in DDRec/DetectorData.h
    providing interface needed for GEAR:
  - added plugin for creating GEAR file for ILD
  - Extended IDDecoder to give access to layer, system and barrel/endcap information. (CG)
    IDDecoder is now independent of Readout object, instead it finds the correct
    readout based on the cellID / position
  - fixed surface implementations: removed inline virtual functions
  - added methods:
    VolSurface::length_along_u()
    VolSurface::length_along_v()