Infrastructure

Celeritas is built using modern CMake. It has multiple dependencies to operate as a full-featured code, but each dependency can be individually disabled as needed.

Installation

This project requires external dependencies to build with full functionality. However, any combination of these requirements can be omitted to enable limited development on personal machines with fewer available components.

Component	Category	Description
CUDA	Runtime	GPU computation
Geant4	Runtime	Preprocessing physics data for a problem input
G4EMLOW	Runtime	EM physics model data
HepMC3	Runtime	Event input
HIP	Runtime	GPU computation
nljson	Runtime	Simple text-based I/O for diagnostics and program setup
Open MPI	Runtime	Shared-memory parallelism
ROOT	Runtime	Input and output
SWIG	Runtime	Low-level Python wrappers
VecGeom	Runtime	On-device navigation of GDML-defined detector geometry
Breathe	Docs	Generating code documentation inside user docs
Doxygen	Docs	Code documentation
Sphinx	Docs	User documentation
sphinxbib	Docs	Reference generation for user documentation
clang-format	Development	Code formatting enforcement
CMake	Development	Build system
Git	Development	Repository management
GoogleTest	Development	Test harness

Downstream usage as a library

The Celeritas library is most easily used when your downstream app is built with CMake. It should require a single line to initialize:

find_package(Celeritas REQUIRED CONFIG)

and if VecGeom or CUDA are disabled a single line to link:

target_link_libraries(mycode PUBLIC Celeritas::Core)

Because of complexities involving CUDA Relocatable Device Code, linking when using both CUDA and VecGeom requires an additional include and the replacement of target_link_libraries with a customized version:

include(CeleritasLibrary)
celeritas_target_link_libraries(mycode PUBLIC Celeritas::Core)

Developing

See the Development Guide section for additional development guidelines.