OPEN Graphics Language Still Supported in Windows Vista

Despite what seems to become a generalized belief, Microsoft did not drop support for the OPEN Graphics Language with the introduction of Windows Vista. Quite on the contrary in fact as some of the Microsoft representatives have stated that the claims of the Redmond Company dropping OpenGL support from Windows Vista has left them scratching their heads.

"Microsoft doesn't implement hardware-accelerated OpenGL directly - we offer a mechanism that allows hardware vendors to integrate a hardware-accelerated implementation of OpenGL (called an ICD or installable client driver) that utilizes their hardware into Windows. This has been the case since Windows 2000, and hasn't changed much in Windows Vista," revealed a product manager on the Microsoft graphics team.

One thing that indeed changed with Windows Vista is the WDDM. You may already be aware of the fact that Windows Vista comes with an overhauled Windows Display Driver Model. And if not, then you are now. The Windows Display Driver Model refers to the new DirectX driver architecture in the operating system.

The bottom line is that the installable client drivers do not ship inbox with the operating system. Windows Vista users will only install the ICDs together with the driver package from the hardware manufacturer. But the changes introduced to the WDDM impacted directly all display drivers. What this means is that because of the new WDDM, all the display drivers had to be re-written together with the OpenGL implementations. Not an easy task for the hardware manufacturers, but not Microsoft's responsibility.

"Another thing that has left a lot of people confused has been around OpenGL applications and how they work with the new desktop composition system, called DWM. DWM is implemented using Direct3D 9, and as such it was originally thought that OpenGL applications could not interoperate with DWM and DWM would need to shut down in the presence of an OpenGL application. This is not the case. Windows Vista provides a mechanism for hardware vendors to use to integrate an OpenGL application with DWM, which acts in the exact same manner as D3D9 and GDI integration with DWM via shared surfaces (a new feature of WDDM)," the PM added.