[mutter] x11: Use EGL instead of GLX when drawing using GLES

[Jonas Ådahl <jadahl src gnome org>]

commit ac813d528558068de8efd04d0f30721dd10d6632
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Sep 23 11:49:10 2016 +0800

    x11: Use EGL instead of GLX when drawing using GLES
    
    When running as a X11 CM we shouldn't use the GLX winsys when the
    driver doesn't support it, i.e. OpenGL ES drivers.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=771636

 cogl/cogl/cogl-mutter.h                    |    4 ++--
 cogl/cogl/cogl-renderer-private.h          |    5 +++--
 cogl/cogl/cogl-renderer.c                  |    7 ++++---
 src/backends/native/meta-renderer-native.c |    2 +-
 src/backends/x11/meta-renderer-x11.c       |   19 ++++++++++++++++---
 5 files changed, 26 insertions(+), 11 deletions(-)
---
diff --git a/cogl/cogl/cogl-mutter.h b/cogl/cogl/cogl-mutter.h
index 4bfac07..a1cd7e3 100644
--- a/cogl/cogl/cogl-mutter.h
+++ b/cogl/cogl/cogl-mutter.h
@@ -42,7 +42,7 @@
 #include <cogl/winsys/cogl-winsys-egl-private.h>
 #include <cogl/winsys/cogl-winsys-private.h>
 
-void cogl_renderer_set_custom_winsys (CoglRenderer          *renderer,
-                                      CoglWinsysVtableGetter winsys_vtable_getter);
+void cogl_renderer_set_custom_winsys (CoglRenderer                *renderer,
+                                      CoglCustomWinsysVtableGetter winsys_vtable_getter);
 
 #endif /* __COGL_MUTTER_H___ */
diff --git a/cogl/cogl/cogl-renderer-private.h b/cogl/cogl/cogl-renderer-private.h
index 33ed0ce..a833a68 100644
--- a/cogl/cogl/cogl-renderer-private.h
+++ b/cogl/cogl/cogl-renderer-private.h
@@ -39,12 +39,13 @@
 #include "cogl-texture-driver.h"
 #include "cogl-context.h"
 #include "cogl-closure-list-private.h"
-#include "cogl-mutter.h"
 
 #ifdef COGL_HAS_XLIB_SUPPORT
 #include <X11/Xlib.h>
 #endif
 
+typedef const CoglWinsysVtable *(*CoglCustomWinsysVtableGetter) (CoglRenderer *renderer);
+
 struct _CoglRenderer
 {
   CoglObject _parent;
@@ -53,7 +54,7 @@ struct _CoglRenderer
   const CoglDriverVtable *driver_vtable;
   const CoglTextureDriver *texture_driver;
   const CoglWinsysVtable *winsys_vtable;
-  CoglWinsysVtableGetter custom_winsys_vtable_getter;
+  CoglCustomWinsysVtableGetter custom_winsys_vtable_getter;
   CoglWinsysID winsys_id_override;
   GList *constraints;
 
diff --git a/cogl/cogl/cogl-renderer.c b/cogl/cogl/cogl-renderer.c
index e6575d8..23cd3f8 100644
--- a/cogl/cogl/cogl-renderer.c
+++ b/cogl/cogl/cogl-renderer.c
@@ -565,8 +565,8 @@ _cogl_renderer_choose_driver (CoglRenderer *renderer,
 /* Final connection API */
 
 void
-cogl_renderer_set_custom_winsys (CoglRenderer          *renderer,
-                                 CoglWinsysVtableGetter winsys_vtable_getter)
+cogl_renderer_set_custom_winsys (CoglRenderer                *renderer,
+                                 CoglCustomWinsysVtableGetter winsys_vtable_getter)
 {
   renderer->custom_winsys_vtable_getter = winsys_vtable_getter;
 }
@@ -575,10 +575,11 @@ static CoglBool
 connect_custom_winsys (CoglRenderer *renderer,
                        CoglError   **error)
 {
-  const CoglWinsysVtable *winsys = renderer->custom_winsys_vtable_getter();
+  const CoglWinsysVtable *winsys;
   CoglError *tmp_error = NULL;
   GString *error_message;
 
+  winsys = renderer->custom_winsys_vtable_getter (renderer);
   renderer->winsys_vtable = winsys;
 
   error_message = g_string_new ("");
diff --git a/src/backends/native/meta-renderer-native.c b/src/backends/native/meta-renderer-native.c
index 8dba727..9dae6dc 100644
--- a/src/backends/native/meta-renderer-native.c
+++ b/src/backends/native/meta-renderer-native.c
@@ -1563,7 +1563,7 @@ meta_renderer_native_set_legacy_view_size (MetaRendererNative *renderer_native,
 }
 
 static const CoglWinsysVtable *
-get_native_cogl_winsys_vtable (void)
+get_native_cogl_winsys_vtable (CoglRenderer *cogl_renderer)
 {
   static gboolean vtable_inited = FALSE;
   static CoglWinsysVtable vtable;
diff --git a/src/backends/x11/meta-renderer-x11.c b/src/backends/x11/meta-renderer-x11.c
index b6b682f..da06133 100644
--- a/src/backends/x11/meta-renderer-x11.c
+++ b/src/backends/x11/meta-renderer-x11.c
@@ -48,12 +48,25 @@ struct _MetaRendererX11
 G_DEFINE_TYPE (MetaRendererX11, meta_renderer_x11, META_TYPE_RENDERER)
 
 static const CoglWinsysVtable *
-get_x11_cogl_winsys_vtable (void)
+get_x11_cogl_winsys_vtable (CoglRenderer *renderer)
 {
   if (meta_is_wayland_compositor ())
     return _cogl_winsys_egl_xlib_get_vtable ();
-  else
-    return _cogl_winsys_glx_get_vtable ();
+
+  switch (renderer->driver)
+    {
+    case COGL_DRIVER_GLES1:
+    case COGL_DRIVER_GLES2:
+      return _cogl_winsys_egl_xlib_get_vtable ();
+    case COGL_DRIVER_GL:
+    case COGL_DRIVER_GL3:
+      return _cogl_winsys_glx_get_vtable ();
+    case COGL_DRIVER_ANY:
+    case COGL_DRIVER_NOP:
+    case COGL_DRIVER_WEBGL:
+      break;
+    }
+  g_assert_not_reached ();
 }
 
 static CoglRenderer *