Create functions that will work with C/C++

[stubrittain]

VolumeLibrary is used by the FuelCalc program produced by the Missoula Fire Sciences Lab

FuelCalc is written in C++

FuelCalc experiences exceptions using the current VolumeLibrary functions.

I have written a wrapper that allows FuelCalc to call it's necessary VolumeLibrary functions, which entail adding explicit sizes to string lengths as parameters.

I would like to create a Pull Request and add these functions, as well as a simple command line test program.

I have only tested on MS Windows 64 bit, using the Intel Fortran compiler. However, there are plans to migrate FuelCalc to Linux in the near future, and I would most likely want to be able to build and test these changes with gnu Fortran.

[BenCamps]

Hi @stubrittain
It looks like in the past there have been other efforts to inter-op with the Volume Library using C++, but the inter-op code hasn't been maintain after the projects using them have been discontinued. See vollib09.f, charmod.f. Also the volMT directories appear to contain a project that was used to experiment with multi-threaded use of the Volume Library from C++. Its quite old code and there have been many changes to the Volume Library interfaces since then but it might be useful as example code.

[stubrittain]

Hi Ben,
Yes, I used some of that older code that was in the repo to get things working.
FuelCalc is still alive and well and uses VolumeLibrary. There is some talk of adding FuelCalc to the Fire Modeling Services Framework as well.

What I have done is created vollibcpp.f and added it to the vollib project, which is simply a wrapper call to VOLINIT()
I also created a command line C++ project that has slightly modified DLLVolume.cpp & .h, as well as uses f77char and f90char, and just does a simple to to volumelibrary to ensure parameters work, especially the string parameters which were causing a lot of problems.

The Fire Modelling Services Framework is a cloud based service that runs on AWS, and they would need to be able to build volume library for every instance they create, as they build FuelCalc library.

[FMSC-YingfangW]

Hi @stubrittain ,
Could you create the pull request?