First the video card maker writes the openGL drivers and if you have a Nvada or ATI will have drivers that support the most up todate openGL features. And the openGL driver will be loaded with the standard windows drivers. But note maybe on older cards, check to see if they have updated the openGL drivers for them, by download the lastest drivers or checking on there openGL support for that card.
Platform support for openGL is by the OS maker. MicroSoft pushing Direct X only has support for I think only openGL 1.2 in there library’s, but if you current video card supports the newest opengl features, you can access them using openGL extensions. People like ATI and Nvada have these examples on there websites.
Hardware use is automatic, there are ways to poll your card to see what features are hardware accerated and which will be done via software. Also I have seen a utility that will poll them for you, and let you know your video cards openGL support.
As for Alpha support, I think maybe he is talking about windows BMP files format?
Which does not support an alpha channel, I use TGA file format for my images which has a alpha support.
But in windows openGL rendering, alpha and transparentcy are supported just the same as in all other platforms.
Originally posted by mpratscher:
[b]A couple of questions:
Where can I find a good starter explanation for using opengl in windows? I have ‘the white book’, but I didn’t know if there was something a little more up-to-date out there.
How do I know if the generic implementation of opengl is being used, or if the card’s driver is being used? I have used opengl on sgi’s and most of my dev has also been on that platform, so all this dll and icd and so on is new to me.
where can i get opengl 1.2? I read about something called glsetup (?) to install the proper drivers, but it has been beta for like 2 years? is it safe to use?
From the little I have read in the white book (Ron Fosner), it mentions something about the PIXELFORMATDESCRIPTOR not supporting alpha? Does this mean you can’t use alpha values when using RGBA? Is there any way to get alpha / transparency support on the win platform?
Last one… does the rendering context work through the device context? I guess I’m asking, can opengl not do anymore than the device context will allow it too? (I guess this would explain no alpha support, if it’s true, since a device context does not support alpha, correct?)
Thanks for spending some time helping me out.