OpenGL and Windows Vista

mayers — Thu, 05 Apr 2007 00:20:00 GMT

Good afternoon,

One area that I get asked about quite a bit is graphics in Windows Vista - most recently, OpenGL. Despite having a graphics background, I'm not too current wrt Vista. To get more info about OGL in Windows Vista, I asked Michael, a PM on the graphics team, and Prashant an analyst who focuses on graphics perf, what the real scoop was. Here's what they had to say:

We get a lot of questions along the lines of “Why did Microsoft drop OpenGL support from Windows Vista?” that leave us scratching our 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. These ICDs are not included inbox with Windows, and are installed when you get the latest driver package either off a hardware vendor’s website or pre-installed in an OEM machine. The major difference this time around was WDDM, which required that all display drivers be re-written for Windows Vista. This also meant that the OpenGL implementations be re-written, which is something that hardware vendors are continuing to work on as we speak to get the best performance.

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).

'Till next time,

-M

Windows Performance Blog : graphics opengl

OpenGL and Windows Vista