make sure pp-filter gets the same fb props as the main win - fixes antialiasing failure with FilterManager

direct/src/filter/FilterManager.py

@@ -276,8 +276,7 @@ class FilterManager(DirectObject):
 
         winprops = WindowProperties()
         winprops.setSize(xsize, ysize)
-        props = FrameBufferProperties()
-        props.setRgbColor(1)
+        props = FrameBufferProperties(self.win.getFbProperties())
         props.setDepthBits(depthbits)
         depthtex, colortex, auxtex0, auxtex1 = texgroup
         if (auxtex0 != None):
@@ -332,4 +331,3 @@ class FilterManager(DirectObject):
         self.nextsort = self.win.getSort() - 1000
         self.basex = 0
         self.basey = 0
-