/* mpc_proj -- projection of a complex number onto the Riemann sphere.
Copyright (C) INRIA, 2008, 2009
This file is part of the MPC Library.
The MPC Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.
The MPC Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the MPC Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include "mpc-impl.h"
int
mpc_proj (mpc_ptr a, mpc_srcptr b, mpc_rnd_t rnd)
{
if (mpc_inf_p (b))
{
/* infinities projects to +Inf +i* copysign(0.0, cimag(z)) */
int inex;
mpfr_set_inf (MPC_RE (a), +1);
inex = mpfr_set_ui (MPC_IM (a), 0, MPC_RND_IM (rnd));
if (mpfr_signbit (MPC_IM (b)))
{
mpc_conj (a, a, MPC_RNDNN);
inex = -inex;
}
return MPC_INEX (0, inex);
}
else
return mpc_set (a, b, rnd);
}