dgui: Fix ability to create OnscreenGeom/Image/Text without ShowBase

direct/src/gui/OnscreenGeom.py

@@ -47,8 +47,9 @@ class OnscreenGeom(DirectObject, NodePath):
         """
         # We ARE a node path.  Initially, we're an empty node path.
         NodePath.__init__(self)
-        if parent == None:
-            parent = aspect2d
+        if parent is None:
+            from direct.showbase import ShowBaseGlobal
+            parent = ShowBaseGlobal.aspect2d
 
         self.setGeom(geom, parent = parent, sort = sort, color = color)
 

direct/src/gui/OnscreenImage.py

@@ -54,8 +54,9 @@ class OnscreenImage(DirectObject, NodePath):
         # We ARE a node path.  Initially, we're an empty node path.
         NodePath.__init__(self)
 
-        if parent == None:
-            parent = aspect2d
+        if parent is None:
+            from direct.showbase import ShowBaseGlobal
+            parent = ShowBaseGlobal.aspect2d
         self.setImage(image, parent = parent, sort = sort)
 
         # Adjust pose

direct/src/gui/OnscreenText.py

@@ -104,8 +104,9 @@ class OnscreenText(NodePath):
           direction: this can be set to 'ltr' or 'rtl' to override the
               direction of the text.
         """
-        if parent == None:
-            parent = aspect2d
+        if parent is None:
+            from direct.showbase import ShowBaseGlobal
+            parent = ShowBaseGlobal.aspect2d
 
         # make a text node
         textNode = TextNode('')