More info: I currently have this setup for painting in Unity:

1. Screen texture (e.g. 1280x720), Image texture (e.g. 2000x2000), noesis renderer to screen
2. A camera that never deletes the screen, I only redraw changes

On paint:

1. Calculate dirty rects (the region painted by the user)
2. Update ImageTexture
3. DrawOnScreen(ImageTexture, dirty rects) -> redraws only the changes
4. DrawNoesisXamlThatIsCurrentlyVisible()

The issue is that on Step 4, noesis ends up drawing overlaying text, especially when I have animations. That's because my camera never deletes the scene, and only draws the changes. I'd have to add a step 3.5 and change step 4:
3.5. noesisDirtyRects = GetNoesisDirtyRectsThisFrame()

4. If (noesisDirtyRects is not empty) { DrawOnScreen(ImageTexture, noesisDirtyRects); DrawNoesisXamlThatIsCurrentlyVisible(noesisDirtyRects); }

Without dirty rects, I'd have to redraw my texture on every frame and the XAML on every frame, which will impact battery life significantly.

Another possible simplification (not optimal but much better) could be:

4. If Noesis_HasChangedSinceLastFrame() { RedrawImageTexture(); DrawNoesisXamlThatIsCurrentlyVisible() }

Is there a better solution that I can currently use without having to redraw the whole screen twice on every frame?

I answered in the forums, let follow the discussion there so the rest of member can read about it and whenever we have a clear conclusion you can track it here.

http://www.noesisengine.com/forums/viewtopic.php?f=3&t=866

Thanks a lot for your feedback!

Agreed - will post in the forum! Thank you for your prompt responses - they are very helpful!

So, for now we implemented a solution with no dirty regions. Just painting everything or nothing. NoesisView now expose a method 'NeedsRendering' for that purpose.

thanks, this is great news. In the middle of development with 2.1 right now, however will try 2.2 later this week in Unity.

I am going to close this. If you find issues please create a new ticket.

Thanks for your feedback!