On Mon Aug 12 10:04:21 2024 +0000, Rémi Bernon wrote:
I don't think we want to allow drivers to create window surfaces for child windows, why is this needed for Wayland?
This was used in https://gitlab.winehq.org/wine/wine/-/merge_requests/6107/diffs?commit_id=ab...
In short, the client area subsurface that contains the accelerated content will obscure any GDI rendering of child windows (which by default end up on the parent window_surface behind the GL/VK subsurface). Using a separate window_surface (and wayland_surface) allows us to place the child window contents above the GL/VK subsurface.
I came across this scenario while testing your `wglchild` example program. Without this fix (or some other solution) the decoration of the child window is obscured.