kicad-developers team mailing list archive

[Ian McInerney <Ian.S.McInerney@xxxxxxxx>]

The upcoming wxWidgets 3.1.5 release has added a new backend supporting
Wayland/EGL to the wxGLCanvas that we use for displaying the OpenGL drawing
canvas. This backend appears to be the new default backend for wxGTK unless
it is explicitly disabled on the wxWidgets configure step (you
pass --disable-glcanvasegl to the configure script). It is also not
currently possible to change this backend at runtime. This means that we
will be forced to use whatever the distro-defaults are for the canvas
backend once wx 3.1/3.2 is being used in the wild.

I was just working with it some, and our main bottleneck for supporting it
natively is currently the GLEW dependency we have in our rendering code.
GLEW requires a compile-time selection of either X11 or EGL backends, and
all distributions seem to only ship a library built for the X11 backend.

I have done some experimenting, and building a version of GLEW that is
meant for EGL is fairly simple and uses a single C file and the public
headers. It can be compiled into a static library that we then link into
our code, so we don't actually need to bundle a shared library. My thinking
currently is that we provide these GLEW files in the thirdparty directory,
and only use them if a specific compile-time option to use EGL is provided.
That will mean that linux packaging will still use distro-provided GLEW
libraries when using the X11 backend, and if the distro can supply an
EGL-capable GLEW version we can try to use that (I am not sure how the
distros will manage this though).

-Ian