Re: Programming with gtkmm: problem with Arcs and Circles, Clock examples

[Wenzel <wgwenzel t-online de>]

Marko Anastasov schrieb:
> У пет, 27. 04 2007. у 11:38 -0500, Jonathon Jongsma пише:
> > On 4/27/07, Wenzel <wgwenzel t-online de> wrote:
> > > The example applications "Drawing Arcs and Circles" and "Creating a
> > > Clock with Cairo" won't compile (under Windows XP, only !?).
> > >
> > > "M_PI" isn't defined.
> > >
> > > Inserting "#define pi 3.14159265359" (compare
> > > http://www.gtkmm.org/docs/gtkmm-2.4/examples/gdk/radar.cc)
> > > or - more C++ish - "const double pi = 3.14159265359;" fixes this issue.
> > I was under the impression that M_PI was pretty standard.  Is it just
> > a matter of a missing include (i.e. does it work if you explicitly
> > include <cmath>)?  Or alternately what about changing it from M_PI to
> > G_PI (which is defined by glib I believe, so should be available on
> > windows and linux)
>
> I searched a bit now, M_PI is definitely not part of the C standard [1].
> So G_PI is preferred then.
>
> Marko
>
> [1] http://c-faq.com/fp/mpi.html
Including "(c)math(.h)" doesn't do. Neither Microsoft's nor GCC's math 
include files define pi.

But changing "M_PI" to "G_PI" works fine.

Thank you for your vivid response.

Werner Wenzel