I don’t see why you’d have to copy all that much. Depending on the rendering architecture, once all the glyphs are there you’d only need to send the relevant text data to be rendered. I don’t see that being much of a problem even when using SDFs. It’s an extremely small amount of data by today’s standards and it can be updated on demand, but even if it couldn’t it would still be extremely fast to send over every frame. If games do it, so can text editors. Real time text rendering on the GPU is a fairly common practice nowadays, unfortunately not in most GUI applications…