Fixed effectwidget to work as RelativeLayout

kivy/data/style.kv

@@ -113,6 +113,9 @@
             pos: self.center_x - self.norm_image_size[0] / 2., self.center_y - self.norm_image_size[1] / 2.
 
 <EffectWidget>:
+    canvas.before:
+        Translate:
+            xy: -self.x, -self.y
     canvas:
         Color:
             rgba: 1, 1, 1, 1

kivy/uix/effectwidget.py

@@ -644,11 +644,10 @@ class EffectWidget(RelativeLayout):
 
         with self.fbo.before:
             PushMatrix()
-            self.fbo_translation = Translate(-self.x, -self.y, 0)
         with self.fbo:
-            ClearColor(1, 1, 1, 1)
-            Color(*self.background_color)
+            ClearColor(0, 0, 0, 0)
             ClearBuffers()
+            Color(*self.background_color)
             self.fbo_rectangle = Rectangle(size=self.size)
         with self.fbo.after:
             PopMatrix()
@@ -657,18 +656,11 @@ class EffectWidget(RelativeLayout):
 
         Clock.schedule_interval(self._update_glsl, 0)
 
-        self.bind(pos=self._update_translation,
-                  size=self.refresh_fbo_setup,
+        self.bind(size=self.refresh_fbo_setup,
                   effects=self.refresh_fbo_setup)
 
         self.refresh_fbo_setup()
 
-    def _update_translation(self, *args):
-        '''(internal) Makes sure everything is translated correctly to
-        appear in the fbo.'''
-        self.fbo_translation.x = -self.x
-        self.fbo_translation.y = -self.y
-
     def _update_glsl(self, *largs):
         '''(internal) Passes new time and resolution uniform
         variables to the shader.
@@ -692,7 +684,6 @@ class EffectWidget(RelativeLayout):
                 new_fbo = EffectFbo(size=self.size)
             with new_fbo:
                 ClearColor(1, 1, 1, 1)
-                Color(*self.background_color)
                 ClearBuffers()
                 new_fbo.texture_rectangle = Rectangle(size=self.size)