New X

qing

The freedesktop.org X hacking is low-profile unstableware at the moment, but one particular proposal interests me the most. Here is how I understand it, I'll probably get it wrong:

The idea is to make the X server model-view. The server stores a tree of windows as it does now. However, unlike today, it keeps the full contents of each mapped window in memory at all times. For each window, the default view copies the window's contents over the contents of the parent window. This results in the same user-visible display you have today - but you could implement alpha blended windows by alpha compositing rather than copying each window into its parent, since we now have the parent window's contents.

To this we add the ability for a "compositing manager" to replace the default view for a given window, using the aXe and XDamage extensions. The window manager might be the compositing manager for toplevel windows, for example.

If a window has a compositing manager, it will not be composited into its parent automatically; the window is invisible until the compositing manager does something. An external compositing manager could emulate the default built-in compositing manager by using XCopyArea() (or alpha-aware equivalent) to copy windows into their parents.

However, a more exciting compositing manager might apply embellishments/transformations to the window contents prior to drawing them, possibly drawing them using an API such as OpenGL. For example, you could add drop shadows. Or you could do effects similar to fast user switching or Expose. Or you could double-buffer the entire screen as a whole making workspace-switching, opaque resize, and other tasks flicker free. The compositing manager is rendering a scene in which the window contents are one element, so the possibilities are endless.

Note that the window contents stay entirely on the server side, the compositing manager uses regular X protocol requests to manipulate them.

Apps other than the single compositing manager can also use the damage extension; possible applications include VNC (desktop sharing), magnifiers, pagers with thumbnailing, and so forth. The compositing manager is a special kind of view in that it disables the default paint of the window to its parent, and is thus responsible for replacing that default paint. But there can be any number of extra views of a window.

There are a lot of little complexities and open questions here, but the idea is pretty interesting. I'm waiting for something I can try out to appear in jhbuild so I can make metacity super-leet.


http://log.ometer.com/2003-11.html

Glue

说的是桌面，不是X本身。
我们只有期待的份 :p

qing

是吗？？？

Kingo

DirectFB X
有没有人用过？

lucida

可怜，MS 99年就实现了的东西，现在Linux下才勉强有了一点影子。。。