Re: [Freeglut-developer] Misc. topics.

[Dam B. <db...@gm...>]

Still trying to catch up with email.

> > To Dam Backer: As I read the OpenGL specs, there is nothing that
> > says that GLdouble can't be the same as GLfloat.  I am less clear
> > about whether fixed point arith. is generally okay.
> 
> No, it's definitely not OK.
> 
> If I say:
> 
>    glColor3f ( 1, 0, 0 ) ;
> 
> ...I expect C to automatically promote '1' to '1.0f' - so I get bright
> red.  It the underlying OpenGL implementation was using fixed point
> integers as float with (say) 8 bits to the right of the decimal point,
> then instead of bright red, I'd get almost black.
> 
> So whilst you would be able to write programs especially for such an
> implementation, it would in no way be portable (either backwards or
> forwards) with standard OpenGL - so you should not *call* it OpenGL
> at all.   If you are going to do that then you might as well simply
> not define GLfloat and GLdouble at all - and instead use something
> liky GLfixed8, GLfixed16 and so on.

Not exactly sure what my point was, but OpenGL ES (note the "ES") is
allready defined as not having GLdouble, and adding GLfixed. Not
really open for discussion. Actually, it is totaly open for
discussion, but this here would be the wrong forum :-) The point is
that I am in the middle of porting freeglut to support OpenGL ES on
WinCE and BREW. I am currently not considering checking in my changes
to freeglut, though all my contributions will remain open source. I
just don't have enough time to discuss implementation decisions at the
moment. Maybe later.

On the other hand, now would be a wonderfull time to become an early
adaptor of OpenGL ES. It is in it's infancy and in need of good tools.
From what I have seen, freeglut should be one of those tools. The
first few OpenGL ES coding competitions are underway and hint that the
(phone) market is allready warming up to push this 3D graphics API
which could well be a big thing on cellphones soon.

One of the coding competition with lots of coders in need of GLUT for
OpenGL ES: http://www.khronos.org/devu/opengles_challenge/