fixed transitionalpha for dialogs

src/flow/Scene.h

@@ -106,6 +106,7 @@ namespace oxygine
             void removeTransitions() { _transitionIn = _transitionOut = 0; }
 
             spActor         getHolder() const { return _holder; }
+            bool            isDialog() const { return _dialog; }
 
         protected:
 

src/flow/Transition.cpp

@@ -138,7 +138,8 @@ namespace oxygine
         {
             spScene target = back ? current : next;
 
-            spTween tween = target->getHolder()->addTween(TweenAlphaFade(!back, PostProcessOptions().fullscreen().clear(Color(0, 0, 0, 255))), _tweenOpt._duration, 1, false, 0);
+            Color cl = Color(0, 0, 0, target->isDialog() ? 0 : 255);
+            spTween tween = target->getHolder()->addTween(TweenAlphaFade(!back, PostProcessOptions().fullscreen().clear(cl)), _tweenOpt._duration, 1, false, 0);
             waitTween(tween);
         }