[gtk+/wip/window-scales: 7/11] configure: Add buildtime check for cairo_surface_set_device_scale

[Alexander Larsson <alexl src gnome org>]

commit 2b07f7c528452f0adb08b56cb8b9b3ba309c264a
Author: Alexander Larsson <alexl redhat com>
Date:   Tue Jun 4 10:39:32 2013 +0200

    configure: Add buildtime check for cairo_surface_set_device_scale
    
    We will need this for the window scale support, but its not yet
    in a stable cairo release (or even on a master yet), so we make
    this optional.

 configure.ac |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 997fbb2..b835b03 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1258,6 +1258,17 @@ else
         LIBS="$gtk_save_LIBS"
 fi
 
+# Check for cairo_set_device_scale, as we don't want to depend hard on
+# this until there is a stable release with it
+CAIRO_CFLAGS=`$PKG_CONFIG --cflags cairo`
+CAIRO_LIBS=`$PKG_CONFIG --libs cairo`
+CFLAGS="$CFLAGS $CAIRO_CFLAGS"
+gtk_save_LIBS="$LIBS"
+LIBS="$CAIRO_LIBS $LIBS"
+AC_CHECK_FUNCS(cairo_surface_set_device_scale)
+LIBS="$gtk_save_LIBS"
+
+
 CFLAGS="$saved_cflags"
 LDFLAGS="$saved_ldflags"