wined3d: Clarify the status of ORM_BACKBUFFER.

dlls/wined3d/directx.c

@@ -6547,6 +6547,10 @@ static BOOL wined3d_adapter_init(struct wined3d_adapter *adapter, UINT ordinal,
         return FALSE;
     }
 
+    if (wined3d_settings.offscreen_rendering_mode == ORM_BACKBUFFER)
+        ERR_(winediag)("You are using the backbuffer for offscreen rendering. "
+                "This is unsupported, and will be removed in a future version.\n");
+
     wined3d_adapter_init_fb_cfgs(adapter, caps_gl_ctx.dc);
     /* We haven't found any suitable formats. This should only happen in
      * case of GDI software rendering, which is pretty useless anyway. */

dlls/wined3d/wined3d_main.c

@@ -231,19 +231,9 @@ static BOOL wined3d_dll_init(HINSTANCE hInstDLL)
                 wined3d_settings.glslRequested = FALSE;
             }
         }
-        if ( !get_config_key( hkey, appkey, "OffscreenRenderingMode", buffer, size) )
-        {
-            if (!strcmp(buffer,"backbuffer"))
-            {
-                ERR_(winediag)("Using the backbuffer for offscreen rendering.\n");
-                wined3d_settings.offscreen_rendering_mode = ORM_BACKBUFFER;
-            }
-            else if (!strcmp(buffer,"fbo"))
-            {
-                TRACE("Using FBOs for offscreen rendering\n");
-                wined3d_settings.offscreen_rendering_mode = ORM_FBO;
-            }
-        }
+        if (!get_config_key(hkey, appkey, "OffscreenRenderingMode", buffer, size)
+                && !strcmp(buffer,"backbuffer"))
+            wined3d_settings.offscreen_rendering_mode = ORM_BACKBUFFER;
         if ( !get_config_key_dword( hkey, appkey, "VideoPciDeviceID", &tmpvalue) )
         {
             int pci_device_id = tmpvalue;