From: Julian Ospald <hasufell@gentoo.org>
Date: Tue May  1 20:00:44 UTC 2012
Subject: build system

remove automagic handling of glut and add configure option
fix "header present but cannot be compiled" warning for nvtt

--- m4/ax_check_glut.m4
+++ m4/ax_check_glut.m4
@@ -114,4 +114,11 @@
 
 AC_SUBST([GLUT_CFLAGS])
 AC_SUBST([GLUT_LIBS])
+
+AC_ARG_ENABLE([glut],
+	       [AS_HELP_STRING([--enable-glut],
+			       [Enable support for glut (default=yes)]) ],
+	       [enable_glut=$enableval],
+	       [enable_glut="yes"])
+
 ])dnl
--- m4/devil-api_checks.m4
+++ m4/devil-api_checks.m4
@@ -31,8 +31,8 @@
                  AS_IF([test "x$no_gl" != "xyes" -a "x$no_glu" != "xyes"],
                        [use_ogl="yes"
 		        ILUT_LIBS="$GLU_LIBS $GL_LIBS $ILUT_LIBS" 
-                        AS_IF([test "x$no_glut" != "xyes"],
-                              [have_glut="yes"
+                        AS_IF([test "x$no_glut" != "xyes" -a "x$enable_glut" = "xyes"],
+                              [use_glut="yes"
                                ILUT_LIBS="$GLUT_LIBS  $ILUT_LIBS"])
                         AC_DEFINE([ILUT_USE_OPENGL],
 	                          [1],
--- configure.ac
+++ configure.ac
@@ -343,8 +343,10 @@
 			    [Do you want to use the Nvidia texture tools if possible? (enables GPU accelerated image manipulation, default="yes")]) ],
 	    [],
 	    [with_nvtt="yes"])
+AC_LANG_PUSH([C++])
 AS_IF([test "x$with_nvtt" = "xyes"],
       [DEVIL_CHECK_NVIDIA_TEXTOOLS])
+AC_LANG_POP
 
 dnl
 dnl ILUT APIs library checking
@@ -392,8 +394,8 @@
 AM_CONDITIONAL([USE_OPENGL],
                [test "x$use_ogl" = "xyes"])
 
-AM_CONDITIONAL([HAVE_GLUT],
-	       [test "x$have_glut" = "xyes"])
+AM_CONDITIONAL([USE_GLUT],
+	       [test "x$use_glut" = "xyes"])
 
 AM_CONDITIONAL([USE_SDL],
                [test "x$use_sdl" = "xyes"])
@@ -410,7 +412,7 @@
 AM_CONDITIONAL([USE_X11],
                [test "x$use_x11" = "xyes"])
 #this is instedad AM_COND_IF([USE_OPENGL && USE_X11])
-AS_IF([test "x$have_glut" = "xyes" -a "x$use_x11" = "xyes"],
+AS_IF([test "x$use_glut" = "xyes" -a "x$use_x11" = "xyes"],
       [EXAMPLES_TO_BUILD="$EXAMPLES_TO_BUILD ILUT_gl ILUT_volume"])
 
 dnl Win32
--- bin/Makefile.am
+++ bin/Makefile.am
@@ -45,11 +45,11 @@
 examples_PROGRAMS += ILUT_animation
 endif #USE_W32
 
-if HAVE_GLUT
+if USE_GLUT
 if USE_X11
 examples_PROGRAMS += ILUT_gl ILUT_volume
 endif #USE_X11
-endif #HAVE_GLUT
+endif #USE_GLUT
 
 endif #BUILD_ILUT