Better detection of OpenGL.

configure.in

@@ -135,8 +135,8 @@ then
     fi
 
     dnl Check for the presence of Mesa
-    AC_CHECK_HEADERS(GL/gl.h GL/osmesa.h)
-    if test "$ac_cv_header_GL_gl_h" = "yes" -a "$ac_cv_header_GL_osmesa_h" = "yes"
+    AC_CHECK_HEADERS(GL/gl.h GL/glx.h GL/osmesa.h)
+    if test "$ac_cv_header_GL_gl_h" = "yes" -a "$ac_cv_header_GL_glx_h" = "yes"
     then
         dnl Check for some problems due to old Mesa versions
         AC_CACHE_CHECK("for up-to-date Mesa version", wine_cv_mesa_version_OK,
@@ -151,7 +151,11 @@ then
         if test "$wine_cv_mesa_version_OK" = "yes"
         then
 	    dnl Check for the presense of the library
-            AC_CHECK_LIB(MesaGL,OSMesaCreateContext,AC_DEFINE(HAVE_LIBMESAGL) X_PRE_LIBS="$X_PRE_LIBS -lMesaGL",,$X_LIBS -lXext -lX11 -lm)
+            AC_CHECK_LIB(GL,glXCreateContext,AC_DEFINE(HAVE_LIBMESAGL) X_PRE_LIBS="$X_PRE_LIBS -lGL",,$X_LIBS -lXext -lX11 -lm)
+	    if test "$ac_cv_lib_GL_glXCreateContext" = "no"
+	    then
+		AC_CHECK_LIB(MesaGL,glXCreateContext,AC_DEFINE(HAVE_LIBMESAGL) X_PRE_LIBS="$X_PRE_LIBS -lGL",,$X_LIBS -lXext -lX11 -lm)
+	    fi
         fi
     fi
 

include/config.h.in

@@ -184,6 +184,9 @@
 /* Define if you have the <GL/gl.h> header file.  */
 #undef HAVE_GL_GL_H
 
+/* Define if you have the <GL/glx.h> header file.  */
+#undef HAVE_GL_GLX_H
+
 /* Define if you have the <GL/osmesa.h> header file.  */
 #undef HAVE_GL_OSMESA_H
 

include/wine_gl.h

@@ -9,7 +9,7 @@
 
 #include "config.h"
 
-#if defined(HAVE_LIBMESAGL) && defined(HAVE_GL_OSMESA_H)
+#if defined(HAVE_LIBMESAGL) && defined(HAVE_GL_GLX_H)
 
 #define HAVE_MESAGL
 
@@ -18,9 +18,6 @@
 #undef WINAPI
 
 #include <GL/gl.h>
-/* These will need to have some #ifdef / #endif added to support
-   more than the X11 using OSMesa target */
-#include <GL/osmesa.h>
 #include <GL/glx.h>
 
 #undef APIENTRY