This issue occurred only on Mac which has to circumvent
geometry shaders lacking support for them.
This patch reverts the vertex shader for Mac devices to
how it was before f9ea64b0ba. (and uses the frag shader from before that commit)
In order to communicate that to the user I added a label
in the GUI when the platform is Mac.
Co-authored-by: Clément Foucault <foucault.clem@gmail.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/125967