OK, thanks for your answers!
The changes I had to make to have the GUI displayed with D3D11 included setting the TU_DYNAMIC flag on the textures instead of the TU_DEFAULT flag (TU_DEFAULT = TU_AUTOMIPMAP | TU_STATIC_WRITE_ONLY).
The cause of this change is likely to be a bug in the D3D11 render system in OGRE 2.1 (to be confirmed). Anyway, this makes me wonder: should the TU_DEFAULT flag be kept for textures if possible, or would the TU_DYNAMIC flag better?
From what I have understood, the TU_STATIC flag (included in the TU_DEFAULT flag) has better performances for textures that are not updated often but is slower to update a texture.
So I guess the questions are:
- In CEGUI, are most of the textures updated often or rarely?
- Is it better to have a higher update time but better performances when the texture is not updated, or the contrary?
The details of the impact of setting the dynamic flag can be found in this post
PS: as for the previous PR, these changes are between macros and will only affect CEGUI on OGRE 2.1.