Simverge developed an application programming interface (API) in the C programming language for the Point Data Abstraction Library (PDAL) and published it under the BSD 3-Clause license at GitHub. PDAL is a library for point cloud data processing and analysis written in C++. The API exposes PDAL’s JSON pipeline functionality just like the Python and Java bindings. Take a look at the unit tests for examples on how to use the API.
A pdal-c package is also available for vcpkg and a conda-forge package is on its way. I hope that this library serves as a useful interface for other language bindings. Please submit an issue or pull request at GitHub if you have any suggestions!