From 47814e50a476ecc0ed42da412fd1a67fbdc69277 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Thu, 8 May 2008 12:55:01 +0000
Subject: [PATCH] From Philip Lowman, "Attached is a patch to the toplevel
 CMakeLists.txt which adds an automated test for
 OSG_GLU_TESS_CALLBACK_TRIPLEDOT.  This should help ease initial configuration
 on OS X systems."

---
 CMakeLists.txt | 44 ++++++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a570e6b76..141258746 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -98,26 +98,6 @@ INCLUDE_DIRECTORIES(
 #ADD_DEFINITIONS(-D)
 # Platform specific definitions
 
-IF(NOT DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT)
-
-    SET(DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT OFF)
-
-    IF   (CMAKE_SYSTEM MATCHES "AIX.*")
-        SET(DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT ON)
-    ENDIF(CMAKE_SYSTEM MATCHES "AIX.*")
-
-    IF   (APPLE)
-        SET(DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT ON)
-    ENDIF(APPLE)
-    
-ENDIF(NOT DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT)
-
-OPTION(OSG_GLU_TESS_CALLBACK_TRIPLEDOT "Set to ON to build build with (...) version of GLU tesselator callback" ${DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT})
-
-IF   (OSG_GLU_TESS_CALLBACK_TRIPLEDOT)
-    ADD_DEFINITIONS(-DGLU_TESS_CALLBACK_TRIPLEDOT)
-ENDIF(OSG_GLU_TESS_CALLBACK_TRIPLEDOT)
-
 
 IF(WIN32)
 
@@ -254,7 +234,31 @@ ELSE(DESIRED_QT_VERSION)
     
 ENDIF(DESIRED_QT_VERSION)
 
+#
+# Test to determine if we want the "tripledot" form of the GLU tesselator callback.
+#
+IF(NOT DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT)
+    INCLUDE(CheckCXXSourceCompiles)
+    SET(CMAKE_REQUIRED_DEFINITIONS -DGLU_TESS_CALLBACK_TRIPLEDOT)
+    SET(CMAKE_REQUIRED_INCLUDES ${CMAKE_CURRENT_SOURCE_DIR}/include ${GLUT_INCLUDE_DIR} ${GL_INCLUDE_DIR})
+    SET(CMAKE_REQUIRED_LIBRARIES ${GLUT_LIBRARY} ${GL_LIBRARY})
+    CHECK_CXX_SOURCE_COMPILES(
+    "#include <osg/GL>
+     #include <osg/GLU>
+     static void testcb(GLvoid *, void*) { }
+     int main()
+     {
+        GLUtesselator *t = gluNewTess();
+        gluTessCallback(t, GLU_TESS_VERTEX_DATA, (GLU_TESS_CALLBACK) testcb);
+        return 0;
+     }"
+    DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT)
+ENDIF(NOT DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT)
 
+OPTION(OSG_GLU_TESS_CALLBACK_TRIPLEDOT "Set to ON to build build with (...) version of GLU tesselator callback" ${DEFAULT_GLU_TESS_CALLBACK_TRIPLEDOT})
+IF(OSG_GLU_TESS_CALLBACK_TRIPLEDOT)
+    ADD_DEFINITIONS(-DGLU_TESS_CALLBACK_TRIPLEDOT)
+ENDIF(OSG_GLU_TESS_CALLBACK_TRIPLEDOT)
 
 # Platform specific:
 # (We can approach this one of two ways. We can try to FIND everything