diff options
| -rw-r--r-- | src/common/random.c | 34 | ||||
| -rw-r--r-- | src/common/random.h | 68 |
2 files changed, 76 insertions, 26 deletions
diff --git a/src/common/random.c b/src/common/random.c index dbb2ca830..b3a13e054 100644 --- a/src/common/random.c +++ b/src/common/random.c @@ -36,10 +36,14 @@ # include <unistd.h> #endif +/** @file + * Implementation of the random number generator interface. + */ + struct rnd_interface rnd_s; struct rnd_interface *rnd; -/// Initializes the random number generator with an appropriate seed. +/// @copydoc rnd_interface::init() void rnd_init(void) { unsigned long seed = (unsigned long)timer->gettick(); @@ -58,61 +62,53 @@ void rnd_init(void) init_genrand(seed); // Also initialize the stdlib rng, just in case it's used somewhere. - srand((unsigned int)timer->gettick()); + srand((unsigned int)seed); } +/// @copydoc rnd_interface::final() void rnd_final(void) { } -/// Initializes the random number generator. +/// @copydoc rnd_interface::seed() void rnd_seed(uint32 seed) { init_genrand(seed); } - -/// Generates a random number in the interval [0, SINT32_MAX] +/// @copydoc rnd_interface::random() int32 rnd_random(void) { return (int32)genrand_int31(); } - -/// Generates a random number in the interval [0, dice_faces) -/// NOTE: interval is open ended, so dice_faces is excluded (unless it's 0) +/// @copydoc rnd_interface::roll() uint32 rnd_roll(uint32 dice_faces) { return (uint32)(rnd->uniform()*dice_faces); } - -/// Generates a random number in the interval [min, max] -/// Returns min if range is invalid. +/// @copydoc rnd_interface::value() int32 rnd_value(int32 min, int32 max) { - if( min >= max ) + if (min >= max) return min; return min + (int32)(rnd->uniform()*(max-min+1)); } - -/// Generates a random number in the interval [0.0, 1.0) -/// NOTE: interval is open ended, so 1.0 is excluded +/// @copydoc rnd_interface::uniform() double rnd_uniform(void) { return ((uint32)genrand_int32())*(1.0/4294967296.0);// divided by 2^32 } - -/// Generates a random number in the interval [0.0, 1.0) with 53-bit resolution -/// NOTE: interval is open ended, so 1.0 is excluded -/// NOTE: 53 bits is the maximum precision of a double +/// @copydoc rnd_interface::uniform53() double rnd_uniform53(void) { return genrand_res53(); } +/// Interface base initialization. void rnd_defaults(void) { rnd = &rnd_s; diff --git a/src/common/random.h b/src/common/random.h index 41bdb4083..1b249ef19 100644 --- a/src/common/random.h +++ b/src/common/random.h @@ -23,25 +23,79 @@ #include "common/hercules.h" +/** @file + * The random number generator interface. + */ + +/// Random interface. struct rnd_interface { + /** + * Interface initialization. + * + * During initialization, the RNG is seeded with a random seed. + */ void (*init) (void); + + /// Interface finalization. void (*final) (void); - void (*seed) (uint32); + /** + * Re-seeds the random number generator. + * + * @param seed The new seed. + */ + void (*seed) (uint32 seed); + + /** + * Generates a random number in the interval [0, SINT32_MAX]. + */ + int32 (*random) (void); + + /** + * Generates a random number in the interval [0, dice_faces). + * + * @remark + * interval is open ended, so dice_faces is excluded (unless it's 0) + */ + uint32 (*roll) (uint32 dice_faces); - int32 (*random) (void);// [0, SINT32_MAX] - uint32 (*roll) (uint32 dice_faces);// [0, dice_faces) - int32 (*value) (int32 min, int32 max);// [min, max] - double (*uniform) (void);// [0.0, 1.0) - double (*uniform53) (void);// [0.0, 1.0) + /** + * Generates a random number in the interval [min, max]. + * + * @retval min if range is invalid. + */ + int32 (*value) (int32 min, int32 max); + + /** + * Generates a random number in the interval [0.0, 1.0) + * + * @remark + * interval is open ended, so 1.0 is excluded + */ + double (*uniform) (void); + + /** + * Generates a random number in the interval [0.0, 1.0) with 53-bit resolution. + * + * 53 bits is the maximum precision of a double. + * + * @remark + * interval is open ended, so 1.0 is excluded + */ + double (*uniform53) (void); }; +/** + * Utlity macro to call the frequently used rnd_interface#random(). + * + * @related rnd_interface. + */ #define rnd() rnd->random() #ifdef HERCULES_CORE void rnd_defaults(void); #endif // HERCULES_CORE -HPShared struct rnd_interface *rnd; +HPShared struct rnd_interface *rnd; ///< Pointer to the random interface. #endif /* COMMON_RANDOM_H */ |