Introduction
------------

This is some experiments with the panama-foreign abi JEP for invoking
native C functions from Java directly and without JNI.

The main goal is to experiment with creating a "java friendly" and
mostly type-safe api directly in one step, without requiring
additional wrapping or inconvenient use.

It's roughly tracking the openjdk repository of the same date.

It uses a gcc plugin to compile the headers to obtain most of the api
information, but requires cpp and perl to extract the values of
#define constants.

This api information is then converted to Java wrappers using a
config-directed perl script `generate-native'.  The config is flexible
enough to either generate c-like libraries of static functions or
object-oriented layouts with data, static and object functions grouped
by class.

test-vulkan uses a different approach as the vulkan api is officially
defined by an xml registry and not the generated C headers.  This is
directly converted to about-as-java-friendly a vulkan api as one can
hope for (all those structs you need to initialise get messy in any
language).  Most of the script is converting the registry vk.xml file
into a usable structure as it's really only designed for outputting c
headers.

Compile
-------

Requirements are gcc and cpp, perl, GNU make.

First run make in src.

See test-*/* for examples.  JAVA_HOME must point to a compatible
panama-enabled jdk.

Status
------

It's all work in progress of course.

* bitfields not implemented yet.
* varargs is not implemented.
* the support library in Memory.java is copied to each output api, but should
  be global.
* the scope and object lifecycle stuff is not really sorted out yet.

License
-------

GNU General Public License, version 3 or later, but see individual
file headers for specifics.

Links
-----

 * https://www.zedzone/software/panamaz.html - project page.
 * https://openjdk.java.net/projects/panama - openjdk panama page.
 * https://github.com/openjdk/panama-foreign - openjdk panama source.