Re[2]: OpenGL+GLUT the future

[Paul Matthews <paulmatthews@yahoo.com>]

---Ian Crawford <icrawfor@uoguelph.ca> wrote:
>
>> Glut is built on top of Mesa/OpenGL. If Mesa/OpenGL
>> has glide support (yes it does) then GLUT has glide
>> support.
> 
> I'm not so sure about that.  I mean, glut manages the
> hardware side of things, right?
>
GLUT handles the display window, mouse and keyboard. MesaGL handles
all the drawing hardware, if thats what you meant. GLUT does no
drawing, GL does that.

>
> Using X as an example, GLUT opens a window and
> processes all the events.  Now, you are right in that
> I don't know much about GLUT and I'm sure I under 
> estimate it, but wouldn't the ability to interface 
> with the 3dfx card (through glide) be a job for 
> GLUT?  
>
No, actually MesaGL does that. It does it with the rush in a native
way (like in Win32), and the normal glide cards in a buffer copy
kludge way (like in Win32)

> If what you're saying is correct, I should be able to
> take a program out of the red book and compile it 
> _as is_ and when I say "go" it will switch to full 
> screen mode and draw pretty things using my 3dfx 
> card.
> 
I believe so. glQuake does ;-). The only change might be to
glutWindowSize() to make it either 640x480 or 800x600.

> Now, having Mesa/OpenGL run through glide is a
> requirement, but I suspect there is more on the GLUT
> side of things.
> 
GLUT doesn't care about the display hardware.

> I might be wrong here.  I don't claim to be an expert
> in this field. However, assuming I'm not wrong, my 
> original question remains: is there a glide version
> of GLUT?
>
Answered above.
 
> Cool.  Out of curiosity, is there an official GLUT 
> homepage?  Some where on SGI's site, maybe?
> 
Check out www.opengl.org

>> Not really, a Messa/GLUT/GUI can be faster than 
>> X11, simply because it can take advantage of the 
>> hardware in a way X11 cannot.
> 
> Could you expand on this?  This probably isn't for 
> the list, so you can reply directly to me.
> 
Some windows programmers have discovered that its faster to draw 2d
stuff in OpenGl than using the GDI functions. Its faster because the
voodoo is faster at drawing 2d stuff than most 2d cards. And GDI a dog
as well.

> Can GLUT allow me (a lowly PC user) to use that?
> 
GLUT doesn't talk to the hardware for drawing, it uses MesaGL. Hence
if MesaGL is accelerated, GLUT is accelerated.

> GLUT lacks is the ability to give up control of the 
> window/screen (in whole or in part) to be used by a 
> different display mechanism (cut scenes and an a 
> general purpose OpenGL widget come to mind).
> 
GLUT help you do floating subwindows on the display. Or you can change
the idel and draw functions to do cut scenes for example.

> GLUT has a predefined "main loop" (I think...) than
> cannot be overridden (to allow you to handle events 
> differently, etc.).  This may just add another rule 
> to the design of your  program, but I'm sure
> this is, somehow, limiting.
> 
I dont think is a problem. You write the event handlers. 
==
--
Paul Matthews
nudge@samba.anu.edu.au


_________________________________________________________
DO YOU YAHOO!?
Get your free @yahoo.com address at http://mail.yahoo.com