build: Require libepoxy

If we want to use OpenGL in GDK then we have two choices; either:

  - find the GL headers on each platform
  - do extension discovery
  - implement all the crazy dlopen()/dlsym() dispatch tables

*or* use libepoxy, which shields us from all this madness and provides a
decent layer for GL clients to use, without creating its own namespace.

Epoxy is also used by other projects, like Xorg and piglit, and it's
portable to all the platforms GDK cares about.

https://bugzilla.gnome.org/show_bug.cgi?id=119189

diff --git a/configure.ac b/configure.ac
index 65de7fc2ed5587c07378b74c2989f70382596159..7927b39760dbfbc924b97dafb37d8189bfe61546 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -48,6 +48,7 @@ m4_define([cairo_required_version], [1.12.0])
 m4_define([gdk_pixbuf_required_version], [2.30.0])
 m4_define([introspection_required_version], [1.39.0])
 m4_define([wayland_required_version], [1.5.91])
+m4_define([epoxy_required_version], [1.0])
 GLIB_REQUIRED_VERSION=glib_required_version
 PANGO_REQUIRED_VERSION=pango_required_version
 ATK_REQUIRED_VERSION=atk_required_version
@@ -1326,7 +1327,7 @@ CFLAGS="$saved_cflags"
 LDFLAGS="$saved_ldflags"
 
 GDK_PACKAGES="$PANGO_PACKAGES gdk-pixbuf-2.0 >= gdk_pixbuf_required_version cairo >= cairo_required_version cairo-gobject >= cairo_required_version"
-GDK_PRIVATE_PACKAGES="$GDK_GIO_PACKAGE $X_PACKAGES $WAYLAND_PACKAGES $cairo_backends"
+GDK_PRIVATE_PACKAGES="$GDK_GIO_PACKAGE $X_PACKAGES $WAYLAND_PACKAGES $cairo_backends epoxy >= epoxy_required_version"
 if test "x$enable_x11_backend" = xyes; then
   GDK_PRIVATE_PACKAGES="$GDK_PRIVATE_PACKAGES pangoft2"
 fi