Dave Andrews
Although Microsoft has incorporated the OpenGL API into Windows NT, the developers of hardware 3-D acceleration products are eagerly anticipating the release of the 3-D DDI (device driver interface) this year. ``When Microsoft implements the 3-D DDI, it will provide a set of standard 3-D functions for a board to accelerate that are not specific to OpenGL,'' says Chris Smith, systems engineer for OmniComp Graphics (Austin, TX), which makes graphics accelerators, such as the 3 Demon 3-D PCI (Peripheral Component Interconnect) graphics acceleration card.
Microsoft has a DDI layer in place that offers a set of Microsof
t-defined 2-D graphics functions that graphics hardware can accelerate. A vendor's graphics board driver can provide acceleration by implementing these functions in graphics hardware. ``But in the current release of Windows NT 3.5,'' Smith says, ``there is no equivalent 3-D DDI layer.'' That means that for the compute-intensive functions of OpenGL, there is no standard set of defined Microsoft functions for acceleration boards.
If a hardware vendor wants to accelerate Windows 3-D functions, the vendor has to invest considerable resources in writing its own proprietary low-level interface to its hardware that won't support other manufacturers' boards, says Carolyn De Bie, media relations representative for Matrox Graphics. To write such an interface, a hardware vendor needs to buy an OpenGL source code license from Silicon Graphics. For a board vendor, the $100,000 price tag for this source code can be cost prohibitive.
Microsoft says it expects to release the 3-D DDI at about the same time as it
releases NT for the PowerPC. ``We're gathering feedback, we're making sure we're getting it right,'' says Jeff Camp, product marketing manager for Windows Multimedia. Once Microsoft releases the DDI, says De Bie, ``The user doesn't have to worry about incompatibilities between 3-D software and hardware.''
3-D Hardware Vendors Anticipate Microsoft's 3-D DDI
