My project has a lot of Polygon2Ds which are generated in code. They're static - created in the editor with tool scripts but they don't change in game. It runs at 60fps on my high-end laptop, but below 20 on my Android.
According to this bug, 2d drawing performance is quite poor at the moment. I've tried GLES2 and 3, and using _draw instead of Polygon2Ds, but all were the same.
I looked at 2D shaders but I don't have any experience with that, and it didn't seem like I could easily draw filled polygons from a list of vertices (would happily be wrong).
Also wondering about drawing with GDNative, if it would be faster or just face the same issues?