How to use existing (non-arduino-specific) library with subfolders in Arduino IDE?

Question

I have a generic c++ library that i'd like to use in an arduino project without making changes to the library code. The library contains subfolders and files in the library include other files of the same library with includes of the form

#include "libraryroot/subfoldername/header.h"

I tried putting 'libaryroot' into C:/Users/Username/Documents/Arduino/libraries but while I can include headers that lie directly inside 'libraryroot' using #include <filename.h> (not #include <libraryroot/filename.h>), Arduino fails to find the headers these files include

How can I make use of such a library in Arduino without having to change the library?

• geometrikal: Check out Platform IO for visual studio code. It is a much better IDE and will let you this type of thing more easily.
• matthias_buehlmann: @Juraj I already read this but I still didn't figure out how it can be done

Answer 1

To utilize subfolders with any name in an Arduino library, you must use the 1.5 library specification.

In libraries folder in your sketch folder, create a folder for the library. In this folder create a src subfolder and put the library source code into that subfolder. Then create a library.properties file in the root folder of the library with some dummy information. Fill the includes key with the main .h file of the library.

Documents/
 Arduino/
 libraries/
 FooLib/
 src/
 subfoldername/
 header.h
 some.h
 some.cpp 
 foolib.h 
 foolib.cpp
 library.properties

In code then use in #include the path with src folder as starting location.

#include <subfoldername/header.h>