Re: [Plib-devel] plib, glut and sdl

[Steve B. <sjb...@ai...>]

Ben Woodhead wrote:

> A while ago I was talking with serveral people regarding glut 3.7 (game
> glut). From what they where saying is that the glut libraries can't handle a
> large amount of load and would not be good to us in games.

This nonsense is repeated often - but NEVER with specific details of
WHY and WHERE GLUT is supposedly so slow.  In fact, it's complete B.S which
has "become true" by virtue only of having been oft repeated.

You only use GLUT calls to open the windows initially - to read low-speed
peripherals (like keyboard and mouse) - and to handle window events.

Games dont *do* enough of those things for GLUT to be a load.

If in doubt, look at the GLUT code for the main event loop - it scarcely
executes a dozen lines of C per event.  I would be VERY suprised if GLUT
consumed more than a hundred lines of code per frame.  On anything post-Z80
that's negligable!

The *only* place I've heard remotely believably, specific complaints - is
that under Windoze, GLUT uses one of the less good API's for reading the
mouse.  I'm told that red-hot Quake-heads can tell the difference...however,
who has done the same studies for alternative window-handlers like SDL?

Honestly, I'd use GLUT - or possibly even 'freeglut' (freeglut.sourceforge.net).
If you genuinely find the mouse mechanism to be too slow under windoze - then
switch to the fast mechanism and offer your change as a patch for each of those
versions of GLUT....I don't think you'll ever find a need to do that.

> So I was able to hack the tux_example to us SDL instead and it seemed to
> work fine, but plib was still compiled to use glut. I also read some plib
> docs and somewere I read that plib can be used with or without glut, is that
> the case. Would sdl be a better option then glut, would it take a lot of
> work to change plib to sdl instead.

Well, the only things PLIB uses GLUT for is:

a) In PUI: Finding the size of the current window.
b) Optionally - in PUI: to render fonts when you don't
   want to use PLIB's own font library.

However, if your only reason for going to all this trouble is because
you've heard that GLUT is no good for games - then I'm afraid you have
been wasting your time.

Morover (and more seriously IMHO), SDL is not generally installed by
default with OpenGL implementations - where GLUT is.  Hence you've
added a significant additional dependancy to your program - which will
make it much harder for your poor users.

I've had a heck of a lot of problems with SDL in applications I've
downloaded.  Because SDL is (like PLIB) made of a bunch of component
libraries, but (unlike PLIB) releases each component out-of-sync
with the others, you tend to find that each game needs a different
set of versions of the sub-packages.  Since some versions of some
SDL modules are incompatible with other versions of others - I think
that maintenance of a package that uses SDL is going to be quite
challenging!

Also, I don't think SDL is as portable as GLUT...although I could
be wrong about that.

SDL is getting quite popular though - so I suppose these things
will eventually settle down.

-- 
Steve Baker   HomeEmail: <sjb...@ai...>
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