Last active
April 18, 2016 02:11
-
-
Save leegrey/112b238e1ba6d9be62728b511c2064aa to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/** | |
* @author Lee Grey / Jonathan Hopcroft | |
* | |
* seeded random number generator | |
* based on Rndm by Grant Skinner | |
* https://github.com/gskinner/AS3Libs/blob/master/Rndm/com/gskinner/utils/Rndm.as | |
* | |
* Incorporates implementation of the Park Miller ( 1988 ) "minimal standard" linear | |
* congruential pseudo-random number generator by Michael Baczynski, www.polygonal.de. | |
* ( seed * 16807 ) % 2147483647 | |
* | |
* Converted to C# and expanded by By Lee Grey and Jonathan Hopcroft | |
* | |
* Original copyright notice: | |
* Copyright (c) 2008 Grant Skinner | |
* | |
* Permission is hereby granted, free of charge, to any person | |
* obtaining a copy of this software and associated documentation | |
* files (the "Software"), to deal in the Software without | |
* restriction, including without limitation the rights to use, | |
* copy, modify, merge, publish, distribute, sublicense, and/or sell | |
* copies of the Software, and to permit persons to whom the | |
* Software is furnished to do so, subject to the following | |
* conditions: | |
* | |
* The above copyright notice and this permission notice shall be | |
* included in all copies or substantial portions of the Software. | |
* | |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES | |
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND | |
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT | |
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, | |
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
* OTHER DEALINGS IN THE SOFTWARE. | |
* | |
*/ | |
using System; | |
public class SeededRandom | |
{ | |
private const int Multiplier = 16807; // this is a float so it can contain the massive value | |
private const int Modulus = 2147483647; | |
protected long initialSeed; | |
protected long currentSeed; | |
protected int useCount = 0; | |
public static bool reportUsecountFlag = false; | |
/** | |
* | |
* @param seed cannot be zero | |
*/ | |
public SeededRandom(uint seed = 1) | |
{ | |
currentSeed = initialSeed = seed; | |
} | |
// accept int seeds for convenience | |
public SeededRandom(int seed = 1) | |
{ | |
currentSeed = initialSeed = seed; | |
} | |
/** | |
* | |
* @param seed cannot be zero | |
*/ | |
public void setSeed(uint seed) | |
{ | |
if (reportUsecountFlag) | |
{ | |
ReportUseCount(); | |
} | |
currentSeed = initialSeed = seed; | |
useCount = 0; | |
} | |
public void ReportUseCount() | |
{ | |
Console.WriteLine("Random has been used " + useCount + " times since last set seed."); | |
} | |
/** | |
* returns an integer 0 <= n < int.MAX_VALUE, | |
* or 0 <= n < limit if specified | |
* @param limit the exclusive upper limit to the result ( must be positive ) | |
* @return | |
*/ | |
public int Next() | |
{ | |
useCount++; | |
currentSeed = (currentSeed * Multiplier) % Modulus; | |
return (int)currentSeed; | |
} | |
/** | |
* returns a number 0 <= n < 1, | |
* or 0 <= n < limit if specified | |
* @param limit the exclusive upper limit to the result ( must be positive ) | |
* @return | |
*/ | |
public float NextFloat() | |
{ | |
return (float)Next() / (int.MaxValue - 1); | |
} | |
// duplicate UnityEngine.Random's value getter: | |
public float value { get { return NextFloat(); } private set { } } | |
public int Range(int min, int max) | |
{ | |
// make sure min is less than max | |
if (min > max) | |
{ | |
int tmp = max; | |
max = min; | |
min = tmp; | |
} | |
if (min == max) | |
{ | |
return min; | |
} | |
return (Next() % (max - min)) + min; | |
} | |
public float Range(float min, float max) | |
{ | |
// make sure min is less than max | |
if (min > max) | |
{ | |
float tmp = max; | |
max = min; | |
min = tmp; | |
} | |
return (NextFloat() * (max - min)) + min; | |
} | |
/** | |
* returns either -1 or 1 | |
* Use for assigning a random sign to a value. | |
* @return | |
*/ | |
public int sign() | |
{ | |
if (NextFloat() < 0.5) | |
{ | |
return 1; | |
} | |
else { | |
return -1; | |
} | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment