First look at Longhorn graphics

In a pre-show demonstration of the Longhorn graphics subsystem at the WinHEC trade show in New Orleans Monday night, I saw for the first time some of the advanced video effects that Microsoft will enable in the next Windows version. Longhorn, due in late 2004 or early 2005, includes a completely new desktop composition system that replaces the model used in previous Windows versions 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. In previous Windows versions, the Windows desktop was rendered as a single display surface and each window is a region on that shared surface. In this model, individual windows are only responsible for drawing their own surfaces, and then only when those surfaces are not hidden by other windows. In Longhorn, each window has its own, full-featured surface, independent of the other windows and each window thinks it is 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 requires significantly more graphics resources than previous Windows versions, of course, but Microsoft notes that most modern PCs have 3D 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.

Here's how the modes work. 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 Windows Longhorn user experience. This mode requires mainstream 3D graphics hardware and offers 3D capabilities equivalent to what was available with 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 3D graphics and animation. Naturally, this mode requires the most advanced hardware, such as high-end 3D hardware released in 2002 or later; this mode features capabilities equivalent to DirectX 9 and later DirectX versions.

The demonstration I received was performed on a Longhorn build 4015 desktop. When moved across the screen, windows would visually "shutter" across the screen, bending under the speed of the movement, like a flag billowing in a breeze. Windows could have various translucency levels, but in a much more fine-grained and visually stunning way than previous Windows versions. And best of all, windows could be visually scaled up and down with no loss in quality as they were resized, an effect that is impossible on today's Windows desktop. I was told that none of these effects were designed for the final Longhorn product, but that Microsoft was simply testing them for now. One way in which the scaling feature might be used, however, is for window minimization: Instead of a standard taskbar button to represent a minimized window, Longhorn will probably display a miniature version of the window so you can visually differentiate between the various minimized windows and more easily pick the one you want. The "shutter" feature will likely evolve into a minimize effect as well, I was told.

One of the most important aspects of this new technology is that applications will not need to be rewritten to support the new features. Instead, any existing Windows application running under Longhorn will be provided with the new animations, transparencies, and effects, automatically. All of the applications I saw during the demo were applications available today in 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 that played in real time, while flipping about on the screen; during this process, applications were started and run, all without affecting the speed or rendering quality of the animating, spinning movie clips. The underlying hardware that powered this graphical wonder? A relatively low-level 1.5 GHz Pentium 4 with 384 MB of RAM, burnished by an ATI Radeon 9700 3D graphics card.

The effects I've described above are hard to explain textually, but I took dozens of pictures and will post them on the SuperSite later this week. Though the show hasn't even officially begun yet, I'm already quite impressed with what I've seen of Longhorn so far. Hopefully the rest of the show will be as exciting.

Here's a first shot, detailing window scaling.