# Contributing to libfprint

## GLib

Although the library uses GLib internally, libfprint is designed to provide
a completely neutral interface to it's application users. So, the public
APIs should never return GLib data types or anything like that.

## Two-faced-ness

Like any decent library, this one is designed to provide a stable and
documented API to its users: applications. Clear distinction is made between
data available internally in the library, and data/functions available to
the applications.

This library is confused a little by the fact that there is another 'interface'
at hand: the internal interface provided to drivers. So, we effectively end
up with 2 APIs:

 1. The [external-facing API for applications](libfprint/fprint.h)
 2. The [internal API for fingerprint drivers](libfprint/drivers_api.h)

Non-static functions which are intended for internal use only are prepended
with the "fpi_" prefix.

## Documentation

All additions of public API functions must be accompanied with gtk-doc
comments.

All changes which potentially change the behaviour of the public API must
be reflected by updating the appropriate gtk-doc comments.


## Contributing

Patches should be sent as merge requests to the gitlab page:
https://gitlab.freedesktop.org/libfprint/libfprint/merge_requests

Drivers are not usually written by libfprint developers, but when they
are, we require:
- 3 stand-alone devices. Not in a laptop or another embedded device, as
  space is scarce, unless the device has special integration with that
  hardware.
- specifications of the protocol.

If you are an end-user, you can file a feature request with the "Driver Request"
tag on [libfprint's issue page](https://gitlab.freedesktop.org/libfprint/libfprint/issues?scope=all&utf8=%E2%9C%93&state=opened&label_name[]=Driver%20Request),
or subscribe to an existing feature request there.

If you are an enterprising hacker, please file a new merge request with
the driver patches integrated.