During a pre-show demonstration yesterday of the Longhorn graphics subsystem at the Windows Hardware Engineering Conference (WinHEC) 2003 trade show in New Orleans, I saw for the first time some of the advanced video effects that Microsoft will enable in the next Windows version. Longhorn, which is due in late 2004 or early 2005, includes a completely new desktop composition system that replaces the model earlier Windows versions used with one that is more technically advanced, visually appealing, and scalable. The early test versions Microsoft is showing at WinHEC include amazing animation effects, smooth window scaling, and advanced window translucency.
The change is startling. Earlier Windows versions rendered the Windows desktop as one display surface; each window was a region on that shared surface. In the new model, individual windows are responsible only for drawing their own surfaces and then only when other windows aren't hiding those surfaces. In Longhorn, each window has its own, full-featured surface, independent of the other windows, and each window acts as if it's always 100 percent visible, forcing it to redraw itself constantly. Likewise, the desktop is rendered many times a second by combining the contents of each open window. These changes require significantly more graphics resources than earlier Windows versions, but Microsoft notes that most modern PCs have 3-D graphics power to spare. For those PCs that don't have the hardware necessary to take advantage of the full Longhorn user experience, Microsoft will scale the graphics back into different modes.
In baseline mode, Longhorn will offer features similar to those in Windows 2000 and use software rendering only. The next step up, the so-called tier 1 experience, delivers the minimum hardware-acceleration and desktop-composition features required for the Longhorn user experience. This mode requires mainstream 3-D graphics hardware and offers 3-D capabilities equivalent to what was available in Microsoft DirectX 7. The tier 1 experience also supports low-power modes, making it ideal for mobile computers. In the tier 2 experience, users will get the full Windows Longhorn user experience on the desktop, which includes support for advanced 3-D graphics and animation. This mode requires the most advanced hardware, such as high-end 3-D hardware released in 2002 or later, and features capabilities equivalent to DirectX 9 and later DirectX versions.
The demonstration I saw was performed on a Longhorn build 4015 desktop. When windows moved across the screen, they visually "shuttered," bending under the speed of the movement, like a flag billowing in a breeze. The windows had various translucency levels, but in a much more fine-grained and visually stunning way than earlier Windows versions. And, best of all, you can visually scale windows up and down with no loss in quality as you resize them, an effect that's impossible on today's Windows desktop. Microsoft told me that none of these effects were designed for the final Longhorn product, but that the company is simply testing them. Microsoft could use the scaling feature for window minimization: Instead of using a standard taskbar button to represent a minimized window, Longhorn will probably display a miniature version of the window so that you can visually differentiate among the various minimized windows and more easily select the one you want. The shutter feature will also likely evolve into a minimize effect, Microsoft said.
One of the most important aspects of this technology is that application developers won't need to rewrite their software to support the new features. Instead, Microsoft will automatically provide the new animations, transparencies, and effects to any existing Windows application running under Longhorn. All the applications I saw during the demonstration were available today in Windows XP, including Notepad, Command Prompt, Paint, and Task Manager. Another interesting part of the demonstration involved a set of movie clips from "Star Wars, Episode II: Attack of the Clones" that played in realtime while they flipped about on the screen; during this process, applications were launched and ran, all without affecting the speed or rendering quality of the animating, spinning movie clips. The underlying hardware that powered this graphical wonder was a relatively low-level 1.5GHz Pentium 4 with 384MB of RAM and ATI's RADEON 9700 3-D graphics card.
The effects I've described above are hard to explain in text, but I took dozens of pictures and will post them on the SuperSite for Windows later this week. Although the show hasn't even officially started yet, I'm already quite impressed with what I've seen of Longhorn.