Capturing egui's frames

[amfaber]

Hi, loving the crate!
Question / feature request: Is it possible to capture the frame rendered by egui?

Context:
I've built a simple UI to visualize some image processing for microscopy, and everything is working flawlessly!
I am using a custom wgpu shader to map the intensities of the data to an image with a colormap, and then adding some circles and lines on top with epaint. However, at this point it would be awesome if I could export the visuals as a video, for embedding in presentations and the like. I had initially hoped that I could simply get a handle to the surface texture that egui is rendering to (I'm using the wgpu backend). From that I would be able to get the final image back from the GPU to the CPU and do anything with it I like from there (save to an image, concatenate multiple images for a video, cut out parts of the frame that is UI and not video etc). However I have not been able to find a way to access the surface texture from egui / egui-wgpu / eframe / egui-winit.

Is it possible? If not, is it a feature that is plausible to add?
Is there some other, better way to accomplish what I want to do?

Thanks for the awesome work :)