Commit 71d84267 authored by Matthias Clasen's avatar Matthias Clasen

grand: formatting cleanups

parent 3bbd1538
......@@ -84,12 +84,13 @@
*
* If you just need a random number, you simply call the g_random_*
* functions, which will create a globally used #GRand and use the
* according g_rand_* functions internally. Whenever you
* need a stream of reproducible random numbers, you better create a
* #GRand yourself and use the g_rand_* functions directly, which will
* also be slightly faster. Initializing a #GRand with a certain seed
* will produce exactly the same series of random numbers on all
* platforms. This can thus be used as a seed for e.g. games.
* according g_rand_* functions internally. Whenever you need a
* stream of reproducible random numbers, you better create a
* #GRand yourself and use the g_rand_* functions directly, which
* will also be slightly faster. Initializing a #GRand with a
* certain seed will produce exactly the same series of random
* numbers on all platforms. This can thus be used as a seed for
* e.g. games.
*
* The g_rand*_range functions will return high quality equally
* distributed random numbers, whereas for example the
......@@ -97,23 +98,24 @@
* doesn't yield equally distributed numbers.
*
* GLib changed the seeding algorithm for the pseudo-random number
* generator Mersenne Twister, as used by #GRand and #GRandom.
* This was necessary, because some seeds would yield very bad
* pseudo-random streams. Also the pseudo-random integers generated
* by g_rand*_int_range() will have a slightly better equal
* distribution with the new version of GLib.
*
* The original seeding and generation algorithms, as found in GLib
* 2.0.x, can be used instead of the new ones by setting the
* environment variable <envar>G_RANDOM_VERSION</envar> to the value of
* '2.0'. Use the GLib-2.0 algorithms only if you have sequences of
* numbers generated with Glib-2.0 that you need to reproduce exactly.
**/
* generator Mersenne Twister, as used by #GRand. This was necessary,
* because some seeds would yield very bad pseudo-random streams.
* Also the pseudo-random integers generated by g_rand*_int_range()
* will have a slightly better equal distribution with the new
* version of GLib.
*
* The original seeding and generation algorithms, as found in
* GLib 2.0.x, can be used instead of the new ones by setting the
* environment variable <envar>G_RANDOM_VERSION</envar> to the value
* of '2.0'. Use the GLib-2.0 algorithms only if you have sequences
* of numbers generated with Glib-2.0 that you need to reproduce
* exactly.
*/
/**
* GRand:
*
* The #GRand struct is an opaque data structure. It should only be
* The GRand struct is an opaque data structure. It should only be
* accessed through the g_rand_* functions.
**/
......@@ -168,11 +170,11 @@ struct _GRand
/**
* g_rand_new_with_seed:
* @seed: a value to initialize the random number generator.
* @seed: a value to initialize the random number generator
*
* Creates a new random number generator initialized with @seed.
*
* Return value: the new #GRand.
* Return value: the new #GRand
**/
GRand*
g_rand_new_with_seed (guint32 seed)
......@@ -184,17 +186,19 @@ g_rand_new_with_seed (guint32 seed)
/**
* g_rand_new_with_seed_array:
* @seed: an array of seeds to initialize the random number generator.
* @seed_length: an array of seeds to initialize the random number generator.
* @seed: an array of seeds to initialize the random number generator
* @seed_length: an array of seeds to initialize the random number
* generator
*
* Creates a new random number generator initialized with @seed.
*
* Return value: the new #GRand.
* Return value: the new #GRand
*
* Since: 2.4
**/
*/
GRand*
g_rand_new_with_seed_array (const guint32 *seed, guint seed_length)
g_rand_new_with_seed_array (const guint32 *seed,
guint seed_length)
{
GRand *rand = g_new0 (GRand, 1);
g_rand_set_seed_array (rand, seed, seed_length);
......@@ -206,11 +210,12 @@ g_rand_new_with_seed_array (const guint32 *seed, guint seed_length)
*
* Creates a new random number generator initialized with a seed taken
* either from <filename>/dev/urandom</filename> (if existing) or from
* the current time (as a fallback). On Windows, the seed is taken from
* rand_s().
* the current time (as a fallback).
*
* On Windows, the seed is taken from rand_s().
*
* Return value: the new #GRand.
**/
* Return value: the new #GRand
*/
GRand*
g_rand_new (void)
{
......@@ -270,12 +275,12 @@ g_rand_new (void)
/**
* g_rand_free:
* @rand_: a #GRand.
* @rand_: a #GRand
*
* Frees the memory allocated for the #GRand.
**/
*/
void
g_rand_free (GRand* rand)
g_rand_free (GRand *rand)
{
g_return_if_fail (rand != NULL);
......@@ -284,18 +289,18 @@ g_rand_free (GRand* rand)
/**
* g_rand_copy:
* @rand_: a #GRand.
* @rand_: a #GRand
*
* Copies a #GRand into a new one with the same exact state as before.
* This way you can take a snapshot of the random number generator for
* replaying later.
*
* Return value: the new #GRand.
* Return value: the new #GRand
*
* Since: 2.4
**/
GRand *
g_rand_copy (GRand* rand)
*/
GRand*
g_rand_copy (GRand *rand)
{
GRand* new_rand;
......@@ -309,13 +314,14 @@ g_rand_copy (GRand* rand)
/**
* g_rand_set_seed:
* @rand_: a #GRand.
* @seed: a value to reinitialize the random number generator.
* @rand_: a #GRand
* @seed: a value to reinitialize the random number generator
*
* Sets the seed for the random number generator #GRand to @seed.
**/
*/
void
g_rand_set_seed (GRand* rand, guint32 seed)
g_rand_set_seed (GRand *rand,
guint32 seed)
{
g_return_if_fail (rand != NULL);
......@@ -352,20 +358,22 @@ g_rand_set_seed (GRand* rand, guint32 seed)
/**
* g_rand_set_seed_array:
* @rand_: a #GRand.
* @rand_: a #GRand
* @seed: array to initialize with
* @seed_length: length of array
*
* Initializes the random number generator by an array of longs.
* Array can be of arbitrary size, though only the
* first 624 values are taken. This function is useful
* if you have many low entropy seeds, or if you require more then
* 32 bits of actual entropy for your application.
* Array can be of arbitrary size, though only the first 624 values
* are taken. This function is useful if you have many low entropy
* seeds, or if you require more then 32 bits of actual entropy for
* your application.
*
* Since: 2.4
**/
*/
void
g_rand_set_seed_array (GRand* rand, const guint32 *seed, guint seed_length)
g_rand_set_seed_array (GRand *rand,
const guint32 *seed,
guint seed_length)
{
int i, j, k;
......@@ -410,24 +418,24 @@ g_rand_set_seed_array (GRand* rand, const guint32 *seed, guint seed_length)
/**
* g_rand_boolean:
* @rand_: a #GRand.
* @rand_: a #GRand
*
* Returns a random #gboolean from @rand_. This corresponds to a
* unbiased coin toss.
* Returns a random #gboolean from @rand_.
* This corresponds to a unbiased coin toss.
*
* Returns: a random #gboolean.
**/
* Returns: a random #gboolean
*/
/**
* g_rand_int:
* @rand_: a #GRand.
* @rand_: a #GRand
*
* Returns the next random #guint32 from @rand_ equally distributed over
* the range [0..2^32-1].
*
* Return value: A random number.
**/
* Return value: a random number
*/
guint32
g_rand_int (GRand* rand)
g_rand_int (GRand *rand)
{
guint32 y;
static const guint32 mag01[2]={0x0, MATRIX_A};
......@@ -438,11 +446,11 @@ g_rand_int (GRand* rand)
if (rand->mti >= N) { /* generate N words at one time */
int kk;
for (kk=0;kk<N-M;kk++) {
for (kk = 0; kk < N - M; kk++) {
y = (rand->mt[kk]&UPPER_MASK)|(rand->mt[kk+1]&LOWER_MASK);
rand->mt[kk] = rand->mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1];
}
for (;kk<N-1;kk++) {
for (; kk < N - 1; kk++) {
y = (rand->mt[kk]&UPPER_MASK)|(rand->mt[kk+1]&LOWER_MASK);
rand->mt[kk] = rand->mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1];
}
......@@ -466,17 +474,19 @@ g_rand_int (GRand* rand)
/**
* g_rand_int_range:
* @rand_: a #GRand.
* @begin: lower closed bound of the interval.
* @end: upper open bound of the interval.
* @rand_: a #GRand
* @begin: lower closed bound of the interval
* @end: upper open bound of the interval
*
* Returns the next random #gint32 from @rand_ equally distributed over
* the range [@begin..@end-1].
*
* Return value: A random number.
**/
* Return value: a random number
*/
gint32
g_rand_int_range (GRand* rand, gint32 begin, gint32 end)
g_rand_int_range (GRand *rand,
gint32 begin,
gint32 end)
{
guint32 dist = end - begin;
guint32 random;
......@@ -491,9 +501,9 @@ g_rand_int_range (GRand* rand, gint32 begin, gint32 end)
{
/* This method, which only calls g_rand_int once is only good
* for (end - begin) <= 2^16, because we only have 32 bits set
* from the one call to g_rand_int (). */
/* we are using (trans + trans * trans), because g_rand_int only
* from the one call to g_rand_int ().
*
* We are using (trans + trans * trans), because g_rand_int only
* covers [0..2^32-1] and thus g_rand_int * trans only covers
* [0..1-2^-32], but the biggest double < 1 is 1-2^-52.
*/
......@@ -506,9 +516,10 @@ g_rand_int_range (GRand* rand, gint32 begin, gint32 end)
}
else
{
/* Now we use g_rand_double_range (), which will set 52 bits for
us, so that it is safe to round and still get a decent
distribution */
/* Now we use g_rand_double_range (), which will set 52 bits
* for us, so that it is safe to round and still get a decent
* distribution
*/
random = (gint32) g_rand_double_range (rand, 0, dist);
}
break;
......@@ -518,7 +529,8 @@ g_rand_int_range (GRand* rand, gint32 begin, gint32 end)
else
{
/* maxvalue is set to the predecessor of the greatest
* multiple of dist less or equal 2^32. */
* multiple of dist less or equal 2^32.
*/
guint32 maxvalue;
if (dist <= 0x80000000u) /* 2^31 */
{
......@@ -547,15 +559,15 @@ g_rand_int_range (GRand* rand, gint32 begin, gint32 end)
/**
* g_rand_double:
* @rand_: a #GRand.
* @rand_: a #GRand
*
* Returns the next random #gdouble from @rand_ equally distributed over
* the range [0..1).
*
* Return value: A random number.
**/
* Return value: a random number
*/
gdouble
g_rand_double (GRand* rand)
g_rand_double (GRand *rand)
{
/* We set all 52 bits after the point for this, not only the first
32. Thats why we need two calls to g_rand_int */
......@@ -572,17 +584,19 @@ g_rand_double (GRand* rand)
/**
* g_rand_double_range:
* @rand_: a #GRand.
* @begin: lower closed bound of the interval.
* @end: upper open bound of the interval.
* @rand_: a #GRand
* @begin: lower closed bound of the interval
* @end: upper open bound of the interval
*
* Returns the next random #gdouble from @rand_ equally distributed over
* the range [@begin..@end).
*
* Return value: A random number.
**/
* Return value: a random number
*/
gdouble
g_rand_double_range (GRand* rand, gdouble begin, gdouble end)
g_rand_double_range (GRand *rand,
gdouble begin,
gdouble end)
{
gdouble r;
......@@ -606,18 +620,19 @@ get_global_random (void)
/**
* g_random_boolean:
*
* Returns a random #gboolean. This corresponds to a unbiased coin toss.
* Returns a random #gboolean.
* This corresponds to a unbiased coin toss.
*
* Returns: a random #gboolean.
**/
* Returns: a random #gboolean
*/
/**
* g_random_int:
*
* Return a random #guint32 equally distributed over the range
* [0..2^32-1].
*
* Return value: A random number.
**/
* Return value: a random number
*/
guint32
g_random_int (void)
{
......@@ -630,16 +645,17 @@ g_random_int (void)
/**
* g_random_int_range:
* @begin: lower closed bound of the interval.
* @end: upper open bound of the interval.
* @begin: lower closed bound of the interval
* @end: upper open bound of the interval
*
* Returns a random #gint32 equally distributed over the range
* [@begin..@end-1].
*
* Return value: A random number.
**/
* Return value: a random number
*/
gint32
g_random_int_range (gint32 begin, gint32 end)
g_random_int_range (gint32 begin,
gint32 end)
{
gint32 result;
G_LOCK (global_random);
......@@ -653,8 +669,8 @@ g_random_int_range (gint32 begin, gint32 end)
*
* Returns a random #gdouble equally distributed over the range [0..1).
*
* Return value: A random number.
**/
* Return value: a random number
*/
gdouble
g_random_double (void)
{
......@@ -667,15 +683,17 @@ g_random_double (void)
/**
* g_random_double_range:
* @begin: lower closed bound of the interval.
* @end: upper open bound of the interval.
* @begin: lower closed bound of the interval
* @end: upper open bound of the interval
*
* Returns a random #gdouble equally distributed over the range [@begin..@end).
* Returns a random #gdouble equally distributed over the range
* [@begin..@end).
*
* Return value: A random number.
**/
* Return value: a random number
*/
gdouble
g_random_double_range (gdouble begin, gdouble end)
g_random_double_range (gdouble begin,
gdouble end)
{
double result;
G_LOCK (global_random);
......@@ -686,11 +704,11 @@ g_random_double_range (gdouble begin, gdouble end)
/**
* g_random_set_seed:
* @seed: a value to reinitialize the global random number generator.
* @seed: a value to reinitialize the global random number generator
*
* Sets the seed for the global random number generator, which is used
* by the g_random_* functions, to @seed.
**/
*/
void
g_random_set_seed (guint32 seed)
{
......
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