Hi,
Please don't bump posts that are only two posts down! Eventually I come here and see all posts, and will reply to any that have not otherwise been answered - though sometimes I do not come here every day; even I have days off or have other things that I have to get done
To answer the question... While CEGUI is very much based upon the concept of rectangles, this may be possible, perhaps, depending upon the precise requirements
Not a very straight forward answer...
There obviously is no function, createNonRectangularWindow - so any solution is going to be more involved than that
Also, I would say it's reasonably doubtful that a 'generic non-rectangular window' is easily achieved; any solution will need to be tailored specifically to the problem at hand. The way I see this, there are two main issues to be overcome 1) hit-testing the window area, and 2) clipping of child content.
1) You can hook into this process by overriding the Window::isHit function and rather testing for a point in a Rect, you would have to go off and do something else (depending on the exact nature of the window). Here 'something else' just means determining whether a point is within the 'red bit' of the posted image - how to do that is left as an exercise for the user!
2) Clipping is maybe more of an issue where it's required. If it's not required; if the window will have no child content, you're home and dry. Otherwise, you'll need to come up with something special. Clipping in CEGUI is very much a rectangular thing, and no real hooks exist to do anything else. However, you may still be able to come up with a solution using the RenderEffect interface - perhaps using a shader of some kind - to mask imagery outside the visible region. Definitely not something that's straight forwards, though.
So, to conclude... Possible? Perhaps, depending on the exact needs. Easy? Certainly not something for the faint hearted
HTH
CE.
