[openbeos] Re: POSIX headers
- From: François Revol <revol@xxxxxxx>
- To: openbeos@xxxxxxxxxxxxx
- Date: Thu, 18 Sep 2003 01:42:15 +0200
Selon Adi Oanca <e2joseph@xxxxxxxxxx>:
> From: "Ingo Weinhold"
> >
> > On 2003-09-17 at 20:25:36 [+0200], Adi Oanca wrote:
> > > ...forgot about round(). But then again... we don't have such a
> function.
> > > :-)
> > >
> > > From: "Adi Oanca" <e2joseph@xxxxxxxxxx>
> > > > From: "Matthijs Hollemans"> > Why do we use our POSIX headers, if they
> are
> > > > not completely
> > > > > > functional?
> > > > > > for example I want to use 'lroundf()' function found in math.h.
> > > > >
> > > > > According to a quick Google search I just did, lroundf() was added
> to
> > > the
> > > > > C99 standard. I don't think our version of gcc supports that
> standard,
> > > or
> > > > > does it?
> > > > >
> > > > > Then again, R5 only supports a fraction of POSIX anyway.
> > > >
> > > > OK, be it like so.
> > > >
> > > > Please tell me: how can I have a float's rounded value in an
> int32...
> > > > float y = 3.14f;
> > > > int32 z = (int32)round( y );
> > > > ... without a compiler warning?
> >
> > I wonder, what is the warning you get? It looks like perfectly legal code
> to
> > me. Or are you referring to the `implicit declaration...' error?
>
> Nope. That's strange, I went to BeOS and run an example... without
> warnings. A while back, I remember to have seen such a warning. I think I
> saw something else, maybe from:
> msg->AddInt32("xxx", (int32)round(f));
> ?
>
> Oh well.. it does not matter any more... the code above work just fine,
> so I'll use it.
>
> > I wonder, why round() isn't declared for x86 in the R5 <math.h> header.
> The
> > symbol is in libroot and it seems to work, too.
>
> :-) In our math.h it isn't declared at all!
> We need that guys, or should we use:
> v = floorf( value>=0.0f? value+0.5f : value-0.5f );
> ? :-)
>
>
WARNING
I remember trying to use one of those undeclared-but-existing
funcs once (for ffmpeg), but it appeared that the func was
broken, and didn't give correct results.
lrintf() or something IIRC.
François.
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