From 36829a8d7ad2888515fbee95c2a70b3d636d7538 Mon Sep 17 00:00:00 2001
From: Ross Burton <ross.burton@intel.com>
Date: Wed, 9 Jul 2014 14:30:33 +0200
Subject: [PATCH 2/9] Correctly implement with AC_WITH(glut) so that
 --without-glut works.

---
 configure.ac | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/configure.ac b/configure.ac
index c4ee12b..9445424 100644
--- a/configure.ac
+++ b/configure.ac
@@ -67,21 +67,25 @@ DEMO_CFLAGS="$DEMO_CFLAGS $GL_CFLAGS"
 DEMO_LIBS="$DEMO_LIBS $GL_LIBS"
 
 dnl Check for GLUT
-GLUT_CFLAGS=""
-GLUT_LIBS=-lglut
-glut_enabled=yes
+glut_enabled=no
 AC_ARG_WITH([glut],
 	[AS_HELP_STRING([--with-glut=DIR],
 			[glut install directory])],
 	[GLUT_CFLAGS="-I$withval/include"
-	 GLUT_LIBS="-L$withval/lib -lglut"])
-AC_CHECK_HEADER([GL/glut.h],
-		[],
-		[glut_enabled=no])
-AC_CHECK_LIB([glut],
-		[glutInit],
-		[],
-		[glut_enabled=no])
+	 GLUT_LIBS="-L$withval/lib -lglut"],
+	[GLUT_CFLAGS=""
+	 GLUT_LIBS="-lglut"]
+        )
+AS_IF([test "x$with_glut" != xno],
+      [AC_CHECK_HEADER([GL/glut.h],
+                       [],
+                       [glut_enabled=no])
+       AC_CHECK_LIB([glut],
+                    [glutInit],
+                    [],
+                    [glut_enabled=no])
+       glut_enabled=yes
+])
 
 dnl Check for FreeGLUT 2.6 or later
 AC_EGREP_HEADER([glutInitContextProfile],
-- 
2.0.0