Make BView::PopState() (executed at least on every call to Draw()) a lot

cheaper by preventing to rebuild the clipping on the app_server side.
I think this was commented out, because user clipping was broken until
some point and I forgot to reenable it after I fixed it. At least I cannot
spot any regressions when running with this patch now would I expect to
see regressions, since DrawStates do not mess with the screen clipping,
unless they get a clipping region assigned when the (user) clipping changes
during the state's life time.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29773 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/app/DrawState.cpp

@@ -341,6 +341,13 @@ DrawState::HasClipping() const
 }
 
 
+bool
+DrawState::HasAdditionalClipping() const
+{
+	return fClippingRegion != NULL;
+}
+
+
 bool
 DrawState::GetCombinedClippingRegion(BRegion* region) const
 {

src/servers/app/DrawState.h

@@ -65,6 +65,7 @@ public:
 		void				SetClippingRegion(const BRegion* region);
 
 		bool				HasClipping() const;
+		bool				HasAdditionalClipping() const;
 		bool				GetCombinedClippingRegion(BRegion* region) const;
 
 							// coordinate transformations

src/servers/app/View.cpp

@@ -1260,7 +1260,7 @@ View::PopState()
 		return;
 	}
 
-	bool rebuildClipping = true; //fDrawState->ClippingRegion() != NULL;
+	bool rebuildClipping = fDrawState->HasAdditionalClipping();
 
 	fDrawState = fDrawState->PopState();
 	fDrawState->SetSubPixelPrecise(fFlags & B_SUBPIXEL_PRECISE);