The problem is, as always, to get the pixel data to GPU memory and out of it. Or store all of it in GPU memory indefinitely, but then layer and image sizes will be limited. We’ve been discussing this well over fifteen years and have gone through a lot of experiments already. It’s not like we’re not aware of it…
An additional problem is that various GPU’s and drivers actually produce slightly different results using the same shaders, and that’s of course a big problem.
As for Daishishi’s remarks – I guess the misuse of “pretend” is just the result of English-as-a-second-language and not meant as an insult. But Qt6 doesn’t only have support for Vulkan, it has its own GPU abstraction layer, which, however, is not meant to be used by applications. The one thing that happened is that the Qt project removed the Angle build option from Qt, and we probably will have to put that back, since OpenGL drivers on Windows and macOS are detoriating and we want to keep our existing OpenGL canvas code working.