mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-27 15:30:07 +00:00
50 lines
1.5 KiB
C
50 lines
1.5 KiB
C
/* Compute projection of complex float value to Riemann sphere.
|
|
Copyright (C) 1997, 1999 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
|
|
|
|
The GNU C 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 GNU C 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 GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <complex.h>
|
|
#include <math.h>
|
|
|
|
|
|
__complex__ float
|
|
__cprojf (__complex__ float x)
|
|
{
|
|
__complex__ float res;
|
|
|
|
if (isnan (__real__ x) && isnan (__imag__ x))
|
|
return x;
|
|
else if (!isfinite (__real__ x) || !isfinite (__imag__ x))
|
|
{
|
|
__real__ res = INFINITY;
|
|
__imag__ res = __copysignf (0.0, __imag__ x);
|
|
}
|
|
else
|
|
{
|
|
float den = __real__ x * __real__ x + __imag__ x * __imag__ x + 1.0;
|
|
|
|
__real__ res = (2.0 * __real__ x) / den;
|
|
__imag__ res = (2.0 * __imag__ x) / den;
|
|
}
|
|
|
|
return res;
|
|
}
|
|
#ifndef __cprojf
|
|
weak_alias (__cprojf, cprojf)
|
|
#endif
|