llrand.h File Reference
Information, functions, and typedefs for randomness. More...
#include <boost/random/lagged_fibonacci.hpp>
#include <boost/random/mersenne_twister.hpp>
Go to the source code of this file.
Typedefs | |
| typedef boost::lagged_fibonacci607 | LLRandLagFib607 |
| typedefs for good boost lagged fibonacci. | |
| typedef boost::lagged_fibonacci2281 | LLRandLagFib2281 |
| typedef boost::mt11213b | LLRandMT19937 |
Functions | |
| S32 | ll_rand () |
| Generate a float from [0, RAND_MAX). | |
| S32 | ll_rand (S32 val) |
| Generate a float from [0, val) or (val, 0]. | |
| F32 | ll_frand () |
| Generate a float from [0, 1.0). | |
| F32 | ll_frand (F32 val) |
| Generate a float from [0, val) or (val, 0]. | |
| F64 | ll_drand () |
| Generate a double from [0, 1.0). | |
| F64 | ll_drand (F64 val) |
| Generate a double from [0, val) or (val, 0]. | |
Detailed Description
Information, functions, and typedefs for randomness.
- LicenseInfo
- firstyear=2000&license=viewergpl
Copyright (c) 2000-2008, Linden Research, Inc.
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Definition in file llrand.h.
Typedef Documentation
| typedef boost::lagged_fibonacci2281 LLRandLagFib2281 |
| typedef boost::lagged_fibonacci607 LLRandLagFib607 |
typedefs for good boost lagged fibonacci.
- See also:
- boost::lagged_fibonacci
| typedef boost::mt11213b LLRandMT19937 |
Function Documentation
Generate a double from [0, val) or (val, 0].
Definition at line 163 of file llrand.cpp.
References ll_internal_random_double().
| F64 ll_drand | ( | ) |
Generate a double from [0, 1.0).
Definition at line 158 of file llrand.cpp.
References ll_internal_random_double().
Generate a float from [0, val) or (val, 0].
Definition at line 143 of file llrand.cpp.
References ll_internal_random_float().
| F32 ll_frand | ( | ) |
Generate a float from [0, 1.0).
Definition at line 138 of file llrand.cpp.
References ll_internal_random_float().
Referenced by LLSkipList< DATA_TYPE, BINARY_DEPTH >::addData(), LLPtrSkipMap< INDEX_T, DATA_T, BINARY_DEPTH >::addData(), LLPtrSkipList< DATA_TYPE, BINARY_DEPTH >::addData(), LLToolPlacer::addObject(), continue_file_receive(), LLAgent::fidget(), LLPtrSkipMap< INDEX_T, DATA_T, BINARY_DEPTH >::getData(), LLVOGrass::initClass(), LLVOWLSky::initStars(), LLCircuitData::LLCircuitData(), LLVOTreeNew::llfrand_signed(), LLVOTreeNew::llfrand_unsigned(), LLEyeMotion::onUpdate(), randomize_sphere(), LLPacketRing::receivePacket(), LLHUDEffectBeam::setupParticle(), LLViewerPartSim::shouldAddPart(), trigger_hippo_bug(), LLViewerPartSourceChat::update(), LLViewerPartSourceSpiral::update(), LLViewerPartSourceScript::update(), LLCloudGroup::updatePuffCount(), LLViewerPartSim::updateSimulation(), LLVOWLSky::updateStarColors(), LLCircuit::updateWatchDogTimers(), and windCallback().
Generate a float from [0, val) or (val, 0].
Definition at line 130 of file llrand.cpp.
References ll_internal_random_double(), and S32.
| S32 ll_rand | ( | ) |
Generate a float from [0, RAND_MAX).
Use the boost random number generators if you want a stateful random numbers. If you want more random numbers, use the c-functions since they will generate faster/better randomness across the process.
I tested some of the boost random engines, and picked a good double generator and a good integer generator. I also took some timings for them on linux using gcc 3.3.5. The harness also did some other fairly trivial operations to try to limit compiler optimizations, so these numbers are only good for relative comparisons.
usec/inter algorithm 0.21 boost::minstd_rand0 0.039 boost:lagged_fibonacci19937 0.036 boost:lagged_fibonacci607 0.44 boost::hellekalek1995 0.44 boost::ecuyer1988 0.042 boost::rand48 0.043 boost::mt11213b 0.028 stdlib random() 0.05 stdlib lrand48() 0.034 stdlib rand() 0.020 the old & lame LLRand
Definition at line 125 of file llrand.cpp.
References ll_rand().
Referenced by LLFetchInWelcomeArea::done(), encode_vorbis_file(), LLAgent::fidget(), LLUUID::generate(), get_random_bytes(), LLDir_Solaris::getRandomFileInDir(), LLDir_Linux::getRandomFileInDir(), LLAgent::heardChat(), ll_rand(), LLVOTreeNew::llrand_signed(), lsa_randomize(), random_sort(), LLDoubleLinkedList< DATA_TYPE >::scramble(), LLGestureManager::triggerAndReviseString(), and LLGestureManager::triggerGesture().
