[cogl] configure: Add a minimum required version for the wayland package

[Neil Roberts <nroberts src gnome org>]

commit d899955b714e5ed50c6c89b9fde4b341bcf80558
Author: Neil Roberts <neil linux intel com>
Date:   Wed Mar 20 16:36:58 2013 +0000

    configure: Add a minimum required version for the wayland package
    
    Previously Cogl would accept any version of Wayland when building the
    Wayland backend. Seeing as there is now a stable API we might as well
    specify that we require at least version 1.0.0. This is now also
    mentioned in the README. This patch also changes it to use
    PKG_CHECK_MODULES instead of PKG_CHECK_EXISTS because it does need to
    abort if it fails and it shouldn't be checking it silently.
    
    Reviewed-by: Robert Bragg <robert linux intel com>

 README.in    |    3 +++
 configure.ac |   20 +++++++++-----------
 2 files changed, 12 insertions(+), 11 deletions(-)
---
diff --git a/README.in b/README.in
index 4fbf8e3..935ab84 100644
--- a/README.in
+++ b/README.in
@@ -52,6 +52,9 @@ On X11, Cogl depends on the following extensions
   • XExt
   • XFixes ≥ @XFIXES_REQ_VERSION@
 
+For the Wayland backend, Cogl requires:
+  • Wayland ≥ @WAYLAND_REQ_VERSION@
+
 When running with OpenGL, Cogl requires at least version 1.3
 or 1.2 with the multitexturing extension. However to build Cogl
 you will need the latest GL headers which can be obtained from:
diff --git a/configure.ac b/configure.ac
index ee49c94..e7bf1f2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -86,6 +86,7 @@ m4_define([xfixes_req_version],         [3])
 m4_define([xcomposite_req_version],     [0.4])
 m4_define([xrandr_req_version],         [1.2])
 m4_define([cairo_req_version],          [1.10])
+m4_define([wayland_req_version],        [1.0.0])
 
 dnl These variables get copied into the generated README
 AC_SUBST([GLIB_REQ_VERSION], [glib_req_version])
@@ -97,6 +98,7 @@ AC_SUBST([XFIXES_REQ_VERSION], [xfixes_req_version])
 AC_SUBST([GTK_DOC_REQ_VERSION], [gtk_doc_req_version])
 AC_SUBST([GI_REQ_VERSION], [gi_req_version])
 AC_SUBST([UPROF_REQ_VERSION], [uprof_req_version])
+AC_SUBST([WAYLAND_REQ_VERSION], [wayland_req_version])
 
 # Save this value here, since automake will set cflags later and we
 # want to know if the user specified custom cflags or not.
@@ -939,12 +941,10 @@ AS_IF([test "x$enable_wayland_egl_platform" = "xyes"],
         NEED_EGL=yes
         EGL_PLATFORMS="$EGL_PLATFORMS wayland"
 
-        PKG_CHECK_EXISTS([wayland-egl],
-                         [
-                           COGL_PKG_REQUIRES="$COGL_PKG_REQUIRES wayland-egl"
-                           COGL_PKG_REQUIRES="$COGL_PKG_REQUIRES wayland-client"
-                         ],
-                         [AC_MSG_ERROR([Unable to locate required wayland libraries])])
+        PKG_CHECK_MODULES(WAYLAND_CLIENT,
+                          [wayland-egl >= wayland_req_version wayland-client >= wayland_req_version])
+        COGL_PKG_REQUIRES="$COGL_PKG_REQUIRES wayland-egl >= wayland_req_version"
+        COGL_PKG_REQUIRES="$COGL_PKG_REQUIRES wayland-client >= wayland_req_version"
 
         COGL_DEFINES_SYMBOLS="$COGL_DEFINES_SYMBOLS COGL_HAS_EGL_PLATFORM_WAYLAND_SUPPORT"
       ])
@@ -995,11 +995,9 @@ AS_IF([test "x$enable_wayland_egl_server" = "xyes"],
       [
         NEED_EGL=yes
 
-        PKG_CHECK_EXISTS([wayland-server],
-                         [
-                           COGL_PKG_REQUIRES="$COGL_PKG_REQUIRES wayland-server"
-                         ],
-                         [AC_MSG_ERROR([Unable to locate required wayland-server library])])
+        PKG_CHECK_MODULES(WAYLAND_SERVER,
+                          [wayland-server >= wayland_req_version])
+        COGL_PKG_REQUIRES="$COGL_PKG_REQUIRES wayland-server >= wayland_req_version"
 
         COGL_DEFINES_SYMBOLS="$COGL_DEFINES_SYMBOLS COGL_HAS_WAYLAND_EGL_SERVER_SUPPORT"
       ])