gstreamer/gst-libs/gst/floatcast/floatcast.h

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/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
* Library <2002> Steve Baker <stevebaker_org@yahoo.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstfloatcast
* @short_description: Floating point platform independence macros
*
* The floatcast.h header file contains a couple of convenience macros for
* floating point numbers.
*
* If you include this header, your application or library must link against
* libm (for maths.h support).
*
* For optimal results, your application&apos;s or library&apos;s build
* system should check whether the C99 functions lrint and lrintf are supported
* and define the preprocessor symbols HAVE_LRINT and HAVE_LRINTF if so. If
* you are using autoconf, you can do this by using the AC_C99_FUNC_LRINT and
* AC_C99_FUNC_LRINTF checks in your configure.ac or configure.in file and
* including your application's config.h header before you include floatcast.h.
*/
#ifndef __FLOATCAST_H__
#define __FLOATCAST_H__
#include <string.h>
#include <glib/gtypes.h>
#include <glib/gutils.h> /* to make sure inline is defined properly */
#if defined (_MSC_VER) && !defined (inline)
#define inline __inline
#endif
G_BEGIN_DECLS
/* FIXME 0.11: these gst_cast_*() functions are not used anywhere, so we could
* just as well get rid of them and move the float/double swap macros into
* gstutils.h in core */
/**
* gst_cast_float:
* @x: input value
*
* Casts a 32-bit floating point value (float) to an integer without bias.
*/
/**
* gst_cast_double:
* @x: input value
*
* Casts a 64-bit floating point value (double) to an integer without bias.
*/
/* FIXME: HAVE_LRINT && HAVE_LRINTF are defined by config.h - they should
* not be used in an installed header. */
#if defined(HAVE_LRINT) && defined(HAVE_LRINTF)
/* These defines enable functionality introduced with the 1999 ISO C
** standard. They must be defined before the inclusion of math.h to
** engage them. If optimisation is enabled, these functions will be
** inlined. With optimisation switched off, you have to link in the
** maths library using -lm.
*/
#define _ISOC9X_SOURCE 1
#define _ISOC99_SOURCE 1
#define __USE_ISOC9X 1
#define __USE_ISOC99 1
#include <math.h>
#define gst_cast_float(x) ((gint)lrintf(x))
#define gst_cast_double(x) ((gint)lrint(x))
#else
#include <math.h>
/* use a standard c cast, but do rounding correctly */
#define gst_cast_float(x) ((gint)floor((x)+0.5))
#define gst_cast_double(x) ((gint)floor((x)+0.5))
#endif
/* FIXME 0.11: don't use GLib namespace (GDOUBLE_SWAP_LE_BE, GFLOAT_TO_LE,
* GFLOAT_TO_BE, GDOUBLE_TO_LE, GDOUBLE_TO_BE) */
/**
* GFLOAT_SWAP_LE_BE:
* @in: input value
*
* Swap byte order of a 32-bit floating point value (float).
*/
inline static gfloat
GFLOAT_SWAP_LE_BE(gfloat in)
{
union
{
guint32 i;
gfloat f;
} u;
u.f = in;
u.i = GUINT32_SWAP_LE_BE (u.i);
return u.f;
}
/**
* GDOUBLE_SWAP_LE_BE:
* @in: input value
*
* Swap byte order of a 64-bit floating point value (double).
*/
inline static gdouble
GDOUBLE_SWAP_LE_BE(gdouble in)
{
union
{
guint64 i;
gdouble d;
} u;
u.d = in;
u.i = GUINT64_SWAP_LE_BE (u.i);
return u.d;
}
/**
* GDOUBLE_TO_LE:
* @val: value
*
* Convert 64-bit floating point value (double) from native byte order into
* little endian byte order.
*/
/**
* GDOUBLE_TO_BE:
* @val: value
*
* Convert 64-bit floating point value (double) from native byte order into
* big endian byte order.
*/
/**
* GDOUBLE_FROM_LE:
* @val: value
*
* Convert 64-bit floating point value (double) from little endian byte order
* into native byte order.
*/
/**
* GDOUBLE_FROM_BE:
* @val: value
*
* Convert 64-bit floating point value (double) from big endian byte order
* into native byte order.
*/
/**
* GFLOAT_TO_LE:
* @val: value
*
* Convert 32-bit floating point value (float) from native byte order into
* little endian byte order.
*/
/**
* GFLOAT_TO_BE:
* @val: value
*
* Convert 32-bit floating point value (float) from native byte order into
* big endian byte order.
*/
/**
* GFLOAT_FROM_LE:
* @val: value
*
* Convert 32-bit floating point value (float) from little endian byte order
* into native byte order.
*/
/**
* GFLOAT_FROM_BE:
* @val: value
*
* Convert 32-bit floating point value (float) from big endian byte order
* into native byte order.
*/
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define GFLOAT_TO_LE(val) ((gfloat) (val))
#define GFLOAT_TO_BE(val) (GFLOAT_SWAP_LE_BE (val))
#define GDOUBLE_TO_LE(val) ((gdouble) (val))
#define GDOUBLE_TO_BE(val) (GDOUBLE_SWAP_LE_BE (val))
#elif G_BYTE_ORDER == G_BIG_ENDIAN
#define GFLOAT_TO_LE(val) (GFLOAT_SWAP_LE_BE (val))
#define GFLOAT_TO_BE(val) ((gfloat) (val))
#define GDOUBLE_TO_LE(val) (GDOUBLE_SWAP_LE_BE (val))
#define GDOUBLE_TO_BE(val) ((gdouble) (val))
#else /* !G_LITTLE_ENDIAN && !G_BIG_ENDIAN */
#error unknown ENDIAN type
#endif /* !G_LITTLE_ENDIAN && !G_BIG_ENDIAN */
#define GFLOAT_FROM_LE(val) (GFLOAT_TO_LE (val))
#define GFLOAT_FROM_BE(val) (GFLOAT_TO_BE (val))
#define GDOUBLE_FROM_LE(val) (GDOUBLE_TO_LE (val))
#define GDOUBLE_FROM_BE(val) (GDOUBLE_TO_BE (val))
G_END_DECLS
#endif /* __FLOATCAST_H__ */