is it possible to use openGL to write to the desktop-window of Windows OS. The target is the overlay, where 2D/3D objects will animate behind all those icons. The user still able to click or drag the icons. your advise please. thanks.

well winamp's does it so im sure you can, perhaps render to a file/memory and then use normals windows bitmap functions

ok im not 100% sure about this, but doesnt windows render the desktop to its own frame buffer? if someone can find out what buffer it is then thats where u should direct your rendering to.

are you looking for the background to be interactive or what?

I've wanted to do something similar myself but had only found info on doing it in directX, but I did a bit of a search and I came across this page in google:

SIGGRAPH '97 Course Notes: Overlays & Underlays

It seems to use the WGL_ARB_pixel_format extensions to get an overlay plane and then draw a triangle scene(haven't tried it out yet, but as its connected to SIGGRAPH it should work).

Hope that helps [smile]

That c-code is useful though but its still is better to have one that had worked to show the real result.

BTW, can we directly compile the code in VC6 or cBuilder without amendment.
Is there a version for Delphi ?

ciao

Hmmm... It seems that the link to the c file is unavailable, so unfortunately the code on the page will probably not compile directy in VC or builder as there are some functions that are not shown on the page (like the oglCreateWindow function). Also the appropriate extension loading functionality is not there. [depressed]

That said, all the important stuff for getting the overlay seems to be there so with a bit of work you could be able to get it up and running with your own window creation, extension loading, etc. etc. functions.

Sorry, I don't know of any delphi version.