mutter/clutter/cogl/cogl/cogl-util.h
Emmanuele Bassi 79acb088e7 Remove mentions of the FSF address
Since using addresses that might change is something that finally
the FSF acknowledge as a plausible scenario (after changing address
twice), the license blurb in the source files should use the URI
for getting the license in case the library did not come with it.

Not that URIs cannot possibly change, but at least it's easier to
set up a redirection at the same place.

As a side note: this commit closes the oldes bug in Clutter's bug
report tool.

http://bugzilla.openedhand.com/show_bug.cgi?id=521
2010-03-01 12:56:10 +00:00

64 lines
2.1 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009,2010 Intel Corporation.
*
* This 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 of the License, or (at your option) any later version.
*
* This 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 this library. If not, see <http://www.gnu.org/licenses/>.
*
*
*/
#ifndef __COGL_UTIL_H
#define __COGL_UTIL_H
#include <glib.h>
#include <math.h>
int
cogl_util_next_p2 (int a);
/* The signbit macro is defined by ISO C99 so it should be available,
however if it's not we can fallback to an evil hack */
#ifdef signbit
#define cogl_util_float_signbit(x) signbit(x)
#else
/* This trick was stolen from here:
http://lists.boost.org/Archives/boost/2006/08/108731.php
It xors the integer reinterpretations of -1.0f and 1.0f. In theory
they should only differ by the signbit so that gives a mask for the
sign which we can just test against the value */
static inline gboolean
cogl_util_float_signbit (float x)
{
static const union { float f; guint32 i; } negative_one = { -1.0f };
static const union { float f; guint32 i; } positive_one = { +1.0f };
union { float f; guint32 i; } value = { x };
return !!((negative_one.i ^ positive_one.i) & value.i);
}
#endif
/* This is a replacement for the nearbyint function which always
rounds to the nearest integer. nearbyint is apparently a C99
function so it might not always be available but also it seems in
glibc it is defined as a function call so this macro could end up
faster anyway. We can't just add 0.5f because it will break for
negative numbers. */
#define COGL_UTIL_NEARBYINT(x) ((int) ((x) < 0.0f ? (x) - 0.5f : (x) + 0.5f))
#endif /* __COGL_UTIL_H */