#include "linden_common.h"
#include "llrand.h"
#include "lluuid.h"
Include dependency graph for llrand.cpp:
Go to the source code of this file.
Defines | |
| #define | LL_USE_SYSTEM_RAND 0 |
Functions | |
| static LLRandLagFib2281 | gRandomGenerator (LLUUID::getRandomSeed()) |
| F64 | ll_internal_random_double () |
| F32 | ll_internal_random_float () |
| 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]. | |
Copyright (c) 2000-2007, Linden Research, Inc.
Second Life Viewer Source Code The source code in this file ("Source Code") is provided by Linden Lab to you under the terms of the GNU General Public License, version 2.0 ("GPL"), unless you have obtained a separate licensing agreement ("Other License"), formally executed by you and Linden Lab. Terms of the GPL can be found in doc/GPL-license.txt in this distribution, or online at http://secondlife.com/developers/opensource/gplv2
There are special exceptions to the terms and conditions of the GPL as it is applied to this Source Code. View the full text of the exception in the file doc/FLOSS-exception.txt in this software distribution, or online at http://secondlife.com/developers/opensource/flossexception
By copying, modifying or distributing this software, you acknowledge that you have read and understood your obligations described above, and agree to abide by those obligations.
ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY, COMPLETENESS OR PERFORMANCE. $/LicenseInfo$
Definition in file llrand.cpp.
| #define LL_USE_SYSTEM_RAND 0 |
Through analysis, we have decided that we want to take values which are close enough to 1.0 to map back to 0.0. We came to this conclusion from noting that:
[0.0, 1.0)
when scaled to the integer set:
[0, 4)
there is some value close enough to 1.0 that when multiplying by 4, gets truncated to 4. Therefore:
[0,1-eps] => 0 [1,2-eps] => 1 [2,3-eps] => 2 [3,4-eps] => 3
So 0 gets uneven distribution if we simply clamp. The actual clamp utilized in this file is to map values out of range back to 0 to restore uniform distribution.
Also, for clamping floats when asking for a distribution from [0.0,g) we have determined that for values of g < 0.5, then rand*g=g, which is not the desired result. As above, we clamp to 0 to restore uniform distribution.
Definition at line 67 of file llrand.cpp.
| static LLRandLagFib2281 gRandomGenerator | ( | LLUUID:: | getRandomSeed() | ) | [static] |
Referenced by ll_internal_random_double(), and ll_internal_random_float().
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 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.
Referenced by add_object(), continue_file_receive(), LLAgent::fidget(), LLCacheName::getName(), LLVOGrass::initClass(), LLVOStars::initStars(), LLCircuitData::LLCircuitData(), LLVOTreeNew::llfrand_signed(), LLVOTreeNew::llfrand_unsigned(), LLVOPartGroup::LLVOPartGroup(), LLEyeMotion::onUpdate(), LLPacketRing::receivePacket(), LLHUDEffectBeam::setupParticle(), LLViewerPartSim::shouldAddPart(), trigger_hippo_bug(), LLViewerPartSourceChat::update(), LLViewerPartSourceSpiral::update(), LLViewerPartSourceScript::update(), LLCloudGroup::updatePuffCount(), LLViewerPartSim::updateSimulation(), LLVOStars::updateStarColors(), LLCircuit::updateWatchDogTimers(), and windCallback().
| F64 ll_internal_random_double | ( | ) | [inline] |
Definition at line 105 of file llrand.cpp.
References gRandomGenerator().
Referenced by ll_drand(), and ll_rand().
| F32 ll_internal_random_float | ( | ) | [inline] |
Definition at line 116 of file llrand.cpp.
References f, and gRandomGenerator().
Referenced by ll_frand().
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).
Definition at line 125 of file llrand.cpp.
Referenced by LLFetchInWelcomeArea::done(), encode_vorbis_file_at(), LLAgent::fidget(), LLUUID::generate(), get_random_bytes(), LLDir_Solaris::getRandomFileInDir(), LLDir_Linux::getRandomFileInDir(), LLAgent::heardChat(), ll_rand(), LLVOTreeNew::llrand_signed(), lsa_randomize(), LLDoubleLinkedList< DATA_TYPE >::scramble(), LLGestureManager::triggerAndReviseString(), and LLGestureManager::triggerGesture().
1.4.7