From dca6e5e039f5acea6a1e33718b81b32ee46a6b4a Mon Sep 17 00:00:00 2001
From: Matthew Waters <ystreet00@gmail.com>
Date: Mon, 5 May 2014 20:06:29 +1000
Subject: [PATCH] gl: check if we can include both GL and GLES2 headers at the
 same time

If we cannot, then default to GL over GLES2 unless GLES2 is required.
---
 configure.ac | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/configure.ac b/configure.ac
index 6259b31154..6f2c230a04 100644
--- a/configure.ac
+++ b/configure.ac
@@ -812,6 +812,42 @@ else
   fi
 fi
 
+dnl check if we can include both GL and GLES2 at the same time
+if test "x$HAVE_GL" = "xyes" -a "x$HAVE_GLES2" = "xyes"; then
+  GL_INCLUDES="
+# include <GLES2/gl2.h>
+# include <GLES2/gl2ext.h>
+# if __APPLE__
+#  include <OpenGL/OpenGL.h>
+#  include <OpenGL/gl.h>
+# else
+#  include <GL/glu.h>
+#  include <GL/gl.h>
+#  if __WIN32__ || _WIN32
+#   include <GL/glext.h>
+#  endif
+# endif
+"
+  AC_MSG_CHECKING([whether it is possible to include both GL and GLES2 headers])
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[$GL_INCLUDES]], [[
+    #if !defined(GL_FALSE)
+    #error Failed to include GL headers
+    #endif
+    ]])],[ AC_MSG_RESULT(yes)
+    ],[AC_MSG_RESULT(no)
+    if test "x$NEED_GLES2" = "xyes"; then
+      if test "x$NEED_OPENGL" = "xyes"; then
+        AC_MSG_ERROR([Cannot seem to include both GL and GLES2 headers. Try disabling one API])
+      fi
+      AC_MSG_WARN([Disabling Desktop GL support])
+      HAVE_OPENGL=no
+    else
+      AC_MSG_WARN([Disabling GL|ES 2.0 support])
+      HAVE_GLES2=no
+    fi
+  ])
+fi
+
 #dnl Check for OpenGL, GLU
 echo host is $host
 case $host in