COGL should ship its own pkg-config file, obviously still pointing
to Clutter's compiler flags and linking options, for COGL-specific
variables that might be queried at configure time.
For instance, it's easier (and less verbose) to do:
PKG_CHECK_EXISTS([cogl-gl-1.0],
[has_gl_backend=yes],
[has_gl_backend=no])
Than doing:
AC_MSG_CHECKING([for GL support in COGL])
cogl_backend=`$PKG_CONFIG --variable=cogl clutter-0.9`
if test x$cogl_backend = xgl; then
has_gl_backend=yes
AC_MSG_RESULT([found])
else
has_gl_backend=no
AC_MSG_RESULT([not found])
fi
