OpenGL for 2d purposes...

**WILL** · 28-10-2003, 10:44 PM

How easy/hard would it be to use OpenGL for 2D graphics like you would use DirectX3D for 2D?

I'm considering making my feature 360<sup>o</sup> Space Shooter type game cross-platform compatable, with the option to use either OpenGL/AL or DirectX, but not sure if existing libraries will do that for me and how smooth a time durring development will I have.

Any ideas, hints or suggestions?

**Paulius** · 29-10-2003, 07:09 AM

Very easy, once you get used to the style of OpenGl that is, and it?¢_Ts easy enough to not use any libraries.

**Alimonster** · 29-10-2003, 09:06 AM

It's pretty straightforward - you just need to set a 2d ortho view for the projection matrix (glMatrixMode(GL_PROJECTION); glOrtho(...)).

If I remember then I'll email you some of my code when I get home (after 5, UK time).

**WILL** · 29-10-2003, 10:08 AM

That would be great. I've been eyeing OpenGL for some time, but only slightly. Wantering into the unknown isn't easy sometimes. However considering that so far the games that I have seen on the commercial side of the coin(Unreal Tournament/2003 , Quake 2&3, etc) have all ran really fast and smooth, I see not a reason to stay away if it isn't too hard. Cross platform capability doesn't suck either.

Can I mix and match 3D effects with 2D? Or is that pretty much as taboo as Direct3D with 2D?

**Paulius** · 29-10-2003, 10:20 AM

As there?¢_Ts no special 2D mode or something that would disable 3D, you can really do anything, just remember to turn depth test and depth mask on/off where needed.

**WILL** · 29-10-2003, 11:21 AM

Hmm... someones really gotta lay out all of the settings of a basic OpenGL enviroment for me at some point. Perhaps a OpenGL for Beginners 101.

**Alimonster** · 29-10-2003, 11:37 AM

Originally Posted by WILL

Hmm... someones really gotta lay out all of the settings of a basic OpenGL enviroment for me at some point. Perhaps a OpenGL for Beginners 101.

I'm on it (and have been for a while, sigh). I've been meaning to do this recently but I've been smote with a cold over the past few days. :roll: I'll get back to writing stuff tomorrow with luck (today = maybe tidying up some code before letting you get your grubby mitts on it, tomorrow = coding, Friday = drinking, Saturday and Sunday afternoon = going back home to parents' house).

It will get done "real soon now".

**WILL** · 29-10-2003, 07:40 PM

Groovyness...

Tanks Ali.

**{MSX}** · 24-01-2004, 01:24 PM

Originally Posted by Alimonster

If I remember then I'll email you some of my code when I get home (after 5, UK time).

I'm interested in 2d opengl too, could you please post your example here ?

Thanks a lot!

**Alimonster** · 27-01-2004, 12:54 AM

No problem. I'll post a link to the code tomorrow (edit: hmm, today, actually - I mean Tuesday) night sometime around 6-ish GMT, hopefully. I've still got a little bit of tidying up to do (both of the code and of my flat in real life, doh), but it's just about there.