It sounds like you are seeing a 'feature' of modern hardware acceleration, double buffering, in action. Instead of drawing directly to screen Starling will be drawing into an offscreen buffer, which is swapped with the buffer being displayed at the end of the frame. This is how all hardware accelerated graphics work, you can’t normally disable it (and would not want to, it’s really needed for everything to draw properly).
What you could do is use Starling to draw everything. Your flash2D content could be drawn into one or more BitmapData
, which are then uploaded as Texture
s to Starling, and drawn with everything else. There is some overhead to this, but if everything is being drawn using Starling and Stage3D you should see better drawing performance, so the overall cost might be small or none.