feat: install osmesa off-screen renderer on Windows runners

[RobPasMue]

Although we were using the installer on Windows, we were not providing the osmesa.dll to the systemwide installation. This new implementation fixes it by adding it to the install_opengl.sh script as an optional feature (in case users want to benefit from it). By default, it is not enabled to avoid breaking changes.

It also defines VTK_DEFAULT_OPENGL_WINDOW=vtkOSOpenGLRenderWindow which is needed to force the usage of osmesa.dll based on https://docs.vtk.org/en/latest/advanced/runtime_settings.html

README has been adapted and new action inputs are created.

[RobPasMue]

Ubuntu 20.04 runners are no longer generally available AFAIK.

[RobPasMue]

Pinging @banesullivan @larsoner @akaszynski for review (sorry for the ping, I don't know if you would get the PR notification otherwise).

Here is a PR were we are making use of this new approach (temporarily, until the fix is in)
ansys/pyansys-geometry#1927

[SMoraisAnsys]

Thanks for adding this changes Roberto

[akaszynski]

Looks like ubuntu 20.04 is set for deprecation. Let's disable that.

[RobPasMue]

Looks like ubuntu 20.04 is set for deprecation. Let's disable that.

Just opened #30

[larsoner]

I think maybe we should have it default to true and cut a v4. Seems like almost all Windows user would want this, no?

[RobPasMue]

I think maybe we should have it default to true and cut a v4. Seems like almost all Windows user would want this, no?

If I was using a Windows self-hosted runner or even a Windows GitHub runner, I would be interested indeed -- but I wanted to avoid changing critical behavior without y'all confirming that it is the right way to go =) that's why I went with the false default at first :)

[SMoraisAnsys]

I think maybe we should have it default to true and cut a v4. Seems like almost all Windows user would want this, no?

If I was using a Windows self-hosted runner or even a Windows GitHub runner, I would be interested indeed -- but I wanted to avoid changing critical behavior without y'all confirming that it is the right way to go =) that's why I went with the false default at first :)

I expect multiple maintainer to leverage pyvista/setup-headless-display-action soon since the other alternative of using vtk-osmesa is no longer available. There are no more wheels provided starting from VTK 9.4 and while

OSMesa and EGL support are included by default in the vtk wheels and can be selected at runtime.
we need to have OSMesa installed now, see https://docs.vtk.org/en/latest/release_details/9.4/support-runtime-opengl-window-selection.html

[akaszynski]

I think maybe we should have it default to true and cut a v4. Seems like almost all Windows user would want this, no?

Let's plan to bump to v4 once merged. Thanks all!

[RobPasMue]

This will need a follow up release. As it is, a minor (v3.3 and v3) should be fine.

[larsoner]

As it is, a minor (v3.3 and v3) should be fine.

The motivation for major is that we added a behavior change that might break stuff for people. But if we can consider it safely enough as a bugfix then minor is okay

[RobPasMue]

As it is, a minor (v3.3 and v3) should be fine.

The motivation for major is that we added a behavior change that might break stuff for people. But if we can consider it safely enough as a bugfix then minor is okay

Oh, yeah, I agree! If we set the default value to true we should put it as a major bump IMO (i.e. v4). However, the PR was merged as is, with the default set to false. I'll let you both decide on the versioning strategy though (@akaszynski @larsoner)

[larsoner]

My vote is to set to true and bump to v4, @akaszynski WDYT?

[akaszynski]

My vote is to set to true and bump to v4, @akaszynski WDYT?

Recommending the same. Set to true and bump.

[RobPasMue]

Sounds good, I'll do a follow up PR tomorrow - and adapt the README

[larsoner]

Already opened a PR and cut a release but maybe the README still needs to be updated