+2007-09-25 Tim-Philipp Müller <tim at centricular dot net>
+
+ * gst-libs/gst/floatcast/floatcast.h:
+ Don't include config.h in an installed public header, this
+ might break compilation of applications that don't have such
+ a header and doesn't necessarily do what it's supposed to do
+ anyway (ie. check for the lrint/lrintf defines) (#442065).
+ Add docs for the various macros and document how this header
+ has to be used (link against libm, etc.); add a few FIXMEs;
+ include math.h for non-c99 code path. Based on patch by
+ Jan Schmidt.
+
2007-09-25 Sebastian Dröge <slomo@circular-chaos.org>
* configure.ac:
/**
* 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's or library'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__
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
-
#include <string.h>
#include <glib/gtypes.h>
#include <glib/gutils.h> /* to make sure inline is defined properly */
G_BEGIN_DECLS
-#if (HAVE_LRINT && HAVE_LRINTF)
+/* 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
#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)
{
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)
{
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))