Avalon and Aero in Longhorn...

I attended a session on "Advances in Display and Composition Architecture for Windows" this morning. Kam Vedbrat, whom many of us have seen before in a couple of Channel9 videos, talked about Avalon and Aero in Longhorn and gave us a few neat demonstrations. We noticed a really nice-looking, new reflection-like effect in the upper glass border that we didn't see during the keynote presentation on Monday. It was subtle, but beautiful. A few of us also met up with Kam after the session to get some questions answered.

Avalon:

With Avalon, window contents are rendered to an off-screen buffer and composed to a back-buffer, which is then displayed on the screen. This enables significant improvements in quality, productivity and style. Avalon also aims to bring one consistent programming model for UI, graphics, media, and documents.

However, Microsoft realizes that not all applications will be Avalon-based, and that many Win32 apps will continue to be used on Longhorn systems. Longhorn will still provide automatic scaling of legacy Win32 applications to provide resolution-independence. To demonstrate this, Kam showed us how Longhorn nicely scales the legacy Calculator application and the Command Prompt window for high-resolution displays.

Kam also talked about possibilities for new tools that would help end-users manage a large number of open windows and the clutter associated with it.

Aero:

Finally, we were given a very clear explanation of the various tiers of the user experience. The tier that you use will depend on the type of graphics card you have in your system. The first two tiers are called "baseline" tiers, while the last two are meant to provide a "premium" experience.

1. Classic - This will be the classic Windows 2000 look that many corporations still prefer to use. The Classic tier will work with XPDDM (XP Display Driver Model) as well as the new LDDM (Longhorn Display Driver Model)
2. To Go - This is the second baseline tier. "To Go" will feature a new Longhorn look, but will not include any compositing or fancy effects. Again, this tier will work with both XPDDM and LDDM.
3. Aero Express - This is the lower premium tier. Aero Express was internally named "Metal" and the name still appears within certain files in Build 5048. Aero Express will include composition-based DPI scaling, and will only work with LDDM/DX9.
4. Aero Glass - Aero Glass, as you can imagine, is the highest user-experience tier that showcases the glass effect, 3D transitions and animations, and composition-based DPI scaling. This tier will function on higher-end graphics cards with LDDM/DX9 only.

Kam also later confirmed that "Diamond" is related to Longhorn's Media Center and doesn't really count as one of the Aero tiers.

The following slides summarize the four tiers and the system requirements: