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<p>Hi Martin,<br>
at the time of writing, jextract does not have a solution for
this.</p>
<p>I also believe that a general solution might not even exist -
sometimes the bindings can vary quite wildly across different
platforms, and there could be significant layout mismatches which
would be hard to reconcile. For instance on Windows, C_LONG is a
layout with type ValueLayout.OfInt, whereas on Linux x64 the type
is ValueLayout.OfLong. On top of that, some subset of native
functions might only be available on some platforms but not in
others, etc.</p>
<p>Considering all this, while some automated solution might be
possible for the use case you have in mind, most surely it would
fail to scale to the general case - so the general recommendation
is to generate different bindings (one per platform) and then come
up with some abstraction layer on top (which is sort of what you
are trying to do). Another approach that might work would be to
work at a lower level - and generate ad-hoc downcall method
handles which automagically fix up mismatches that can arise
across platforms (e.g. if a function is available in two platforms
with a parameter mismatch int vs. long, adapt the int-accepting
method handle to take a long, so that a uniform signature can be
used). Note that jextract should expose the method handles it
generates, so perhaps this adaptation can be done
semi-automatically based on what comes out of jextract (and based
on what the mismatches really are in your use case). <br>
</p>
<p>I know that e.g. the JavaDoesUSB [1] project has faced similar
issues, so perhaps their authors might want to share some insights
here.</p>
<p>Cheers<br>
Maurizio<br>
<br>
[1] - <a class="moz-txt-link-freetext" href="https://github.com/manuelbl/JavaDoesUSB">https://github.com/manuelbl/JavaDoesUSB</a><br>
</p>
<div class="moz-cite-prefix">On 20/12/2022 15:04, Martin Pernollet
wrote:<br>
</div>
<blockquote type="cite" cite="mid:74cJVGa9pM5ITkWNNcQWqDEttFfBMlhbKsdBGH25SduiUtoPEsY2Parc7F9Ei4EEzNVd6LSIYgu_vUyjGKY_H8LxU7m4OhgQVZ7AW_VNjPg=@protonmail.com">
<div style="font-family: Arial; font-size: 14px;">Hi everyone,</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;">I am back on
track with OpenGL binding with Panama!</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;">I have one code
design / tooling question related to JExtract : is it possible
to <b>generate a common interface that would be implemented by
all platform specific binding</b> generated by JExtract since
JDK 19 or 20?</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;">Here's my use
case in more detail : I've been advised to generate <b>different
binding for different OS</b> (and maybe version). For OpenGL,
this lead me to a glut_h binding for macOS, one for Windows and
one for Linux.</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;">To let <b>the
user/developer face a single entry point</b>, I manually write
a <a href="https://github.com/jzy3d/panama-gl/blob/feature/fbo/src/main/java/opengl/GL.java" title="GL interface" moz-do-not-send="true">GL interface</a>.
I then define a <a href="https://github.com/jzy3d/panama-gl/blob/feature/fbo/src/main/java/opengl/macos/GL_macOS_10_15_3.java" title="GL_macOS_10_15_3" moz-do-not-send="true">GL_macOS_10_15_3</a>
class that wraps the binding (!). When I expand the prototype to
Windows, I should copy paste this to GL_Windows_10 and modify
the imports to reference the appropriate bindings. The goal is
to write code like this</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;">GL gl =
Platform.selectAmong(GL_macOS_10_15_3.class,
GL_windows_10.class, ...)</div>
<div style="font-family: Arial; font-size: 14px;">gl.glDoSomething()</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;">I don't think
there would be another way to have java developer write <b>applications
that ignore the target hardware</b>. However my approach is
stupid : time consuming and error prone because manual. A real
life case may have 10 implementations and 1000 functions.</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;"><b>Does JExtract
provide a solution to this</b>? Should I create this tool by
myself based on all generated bindings ? Would anyone <b>recommend
something smarter</b>?</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;">Regards,</div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div style="font-family: Arial; font-size: 14px;">Martin </div>
<div style="font-family: Arial; font-size: 14px;"><br>
</div>
<div class="protonmail_signature_block" style="font-family: Arial;
font-size: 14px;">
</div>
</blockquote>
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