meson's configure_file emits only a comment like /* #undef ... */
for values which are unset in the configuration_data. For
gstglconfig.h, this differs from the autotools build where the
preprocessor definitions are always either 0 or 1. So loop over a
list of variables to set to zero as default.
Also sync up the gstglconfig.h.meson file with the additional
macros defined by the autotools build.
https://bugzilla.gnome.org/show_bug.cgi?id=781043
e.g. passing with_gl_api=gles2 would still build the glx code but not be
linking against the libGL library which is where the glX* functions are
located and would result in a linker error.
Solved by checking for the libGL library if either opengl or glx may be
needed and then disabling the corresponding deps as requested.
https://github.com/mesonbuild/meson
With contributions from:
Tim-Philipp Müller <tim@centricular.com>
Matej Knopp <matej.knopp@gmail.com>
Jussi Pakkanen <jpakkane@gmail.com> (original port)
Highlights of the features provided are:
* Faster builds on Linux (~40-50% faster)
* The ability to build with MSVC on Windows
* Generate Visual Studio project files
* Generate XCode project files
* Much faster builds on Windows (on-par with Linux)
* Seriously fast configure and building on embedded
... and many more. For more details see:
http://blog.nirbheek.in/2016/05/gstreamer-and-meson-new-hope.htmlhttp://blog.nirbheek.in/2016/07/building-and-developing-gstreamer-using.html
Building with Meson should work on both Linux and Windows, but may
need a few more tweaks on other operating systems.
