Quick question... (OpenGL support)

Giniu · Post by **Giniu** » Sun Sep 10, 2006 9:32 pm

Hi,

this is my first post there, I'd like to welcome everyone there and say two words about myself before proceding: I'm student of mathematics and as hobby I'm preparing game - mainly I take care for organization, contacts, etc, but also I take care for AI... hard work it is but still not so bad

so now let's go to my question...

I'm preparing some kind of engine comparsion for in-house use, Irrlicht is one of engines we are looking at right now. As with our point it recieved low note (under 50% in Graphics API) I would like to ask if informations on feature page are current? I'm talking about:

# Direct3D 9.0
# OpenGL 1.5
# The Irrlicht Engine software renderer.

So... Irrlicht really don't support OpenGL 2.0 features or this is old information?

Thanks in advance for your answers...

best regards,
Giniu.

hybrid · Post by **hybrid** » Sun Sep 10, 2006 10:43 pm

Irrlicht does not call OpenGL commands from newer versions, although I think that Irrlicht should be able to run with OpenGL 1.2 quite well. All the other stuff is used via OpenGL extension pointers, so all the stuff is available if required. That's the good thing with OpenGL's extensible interface

NB: In fact this is not really true anymore, because Irrlicht for OSX does not use extension pointers, so you might find all the calls there. With some checks and defines added it should be possible to make even more calls direct, saving maybe some more cycles each frame. But this also makes the code messy, introduces some dynamic checks and might not really supply the effects wanted.

pinballwizard · Post by **pinballwizard** » Wed Sep 13, 2006 9:05 am

I'd like to point out that Irrlicht has a better chance of working on a wider range of hardware because the core library works with OpenGL 1.2. Older hardware or older drivers might cause an engine based completely on cutting-edge graphics features to fail (like Ogre - its cutting-edge OpenGL usage apparently exercises a bug on my laptop's graphics card driver, leading to massive flickering. The response from the Ogre forums: "get a better driver, or get a better card; Ogre uses cutting-edge graphics techniques and not all cards or drivers can keep up").

In my case I prefer Irrlicht's approach: a solid OpenGL 1.2 base plus extensions if you want to do cutting edge stuff.

Depends on your target platform and audience though.

hybrid · Post by **hybrid** » Wed Sep 13, 2006 10:23 am

But having extensions pointers would not prevent those driver failures to occur. If these things happen for special techniques only you can simply avoid them, but if, e.g., the texture handling causes those bugs it would be the same with or without pointers. It could be made optional so anyone having problems can avoid it, or if it is a well-known driver problem one could add in bugfixes. But the latter is quite tedious and hardly maintainable. And in such cases I'd also suggest to use a better driver, since I'm not being paid to overcome bugs from NVidia or ATI (or Intel which gains so much popularity with onboard chips that are problematic at least with OpenGL)

Giniu · Post by **Giniu** » Tue Sep 19, 2006 6:05 pm

Thank you for your answers,

so to sum up - if we talk about OpenGL 1.2 is required, but new things from 2.0 still can be used through extensions, so 2.0 is supported to say it one word?

hybrid · Post by **hybrid** » Tue Sep 19, 2006 7:05 pm

Yes, all OpenGL features could be used, but many are currently not accessible via Irrlicht methods, but would require some implementations or OpenGL code within your draw loop.