write an openGL ICD for windows ?

has anyone got documentation on how to make an opengl ICD for winXP,win2K or Winnt ?

Or has anyone understood how windows switch from one opengl ICD to another (if you install and nvidia card and an ati card in the same computer for example (not at the same time of course ) both opengl icd are installed in the system directory (nvoglnt.dll and Atioglxx.dll) but the system automatically switch between the 2 ? any info ?

Originally posted by amanieux:
has anyone got documentation on how to make an opengl ICD for winXP,win2K or Winnt ?

The DDK used to come with an OpenGL ICD DDK, written by SGI for Microsoft and with a sample source for S3 cards.

There’s was a good topic on the MSDN explaining the ICD architecture, but I haven’t been able to find it recently.

You may find interesting information in this thread .

There are subtle differences between 2K, NT and 9x, and some behaviour is registry controlled.

Originally posted by amanieux:

Or has anyone understood how windows switch from one opengl ICD to another (if you install and nvidia card and an ati card in the same computer for example (not at the same time of course ) both opengl icd are installed in the system directory (nvoglnt.dll and Atioglxx.dll) but the system automatically switch between the 2 ? any info ?

Look at HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\OpenGLdrivers