I'm writing the gui for my editor from scratch (C++, DirextX11, Win 7 and newer). Everything worked out pretty nicely up to this point, but there is one thing I can't get my head around. The unreal engine for instance can render ui elements like context menus, menu bar items and tool tips outside of the window frame. The first thought that came to my mind was to disable the visual representation of my native window and scretch it over the whole screen. And then scale the DirectX framebuffer to the same size and draw my own window element. And so I did and I was able to make every blank cleared part of my framebuffer transparent with the DwmExtendFrameIntoClientArea function. An obvious probem that occurs is that user input in the transparent regions is still routed to my window and not to the underlying elements. But even if I would solve this issue there is probably a more reliable and cleaner way.
Any ideas and/or suggestions are very welcome.