Pseudo Random Number Generator - Revision history

ObviousAltIsObvious Resident: tag to

2015-01-25T18:17:43Z

← Older revision		Revision as of 11:17, 25 January 2015
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	= Script =		= Script =
	<~~lsl~~>integer lslPRNGState0 = 0;		<source lang="lsl2">integer lslPRNGState0 = 0;
	integer lslPRNGState1 = 0;		integer lslPRNGState1 = 0;
	integer lslPRNGState2 = 0;		integer lslPRNGState2 = 0;
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	llOwnerSay("Random key = "+(string)lslPRNGRandomKey(seed));		llOwnerSay("Random key = "+(string)lslPRNGRandomKey(seed));
	}		}
	}</~~lsl~~>		}</source>

	{{LSLC\|Encryption}}		{{LSLC\|Encryption}}

Haravikk Mistral: /* Description */

2010-11-22T23:13:29Z

Description

← Older revision		Revision as of 16:13, 22 November 2010
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	Generating random values can be useful in many applications, however all we are supplied with in [[LSL]] is a relatively inflexible floating-point number generator.		Generating random values can be useful in many applications, however all we are supplied with in [[LSL]] is a relatively inflexible floating-point number generator.

	To this end ~~I (~~[[User:Haravikk Mistral\|~~Haravikk Mistral~~]]) set-out to create a more useful random number generator based on a [http://en.wikipedia.org/wiki/Mersenne_Twister Mersenne Twister] [http://en.wikipedia.org/wiki/Pseudorandom_number_generator Pseudo Random Number Generator] (PRNG). The implementation in LSL uses a much smaller state of only four values, however it gives much the same distribution as the standard implementation which uses an array of some 624 values as its state, which of course is unfeasible to implement in LSL.		To this end [[User:Haravikk Mistral\|I]] set-out to create a more useful random number generator based on a [http://en.wikipedia.org/wiki/Mersenne_Twister Mersenne Twister] [http://en.wikipedia.org/wiki/Pseudorandom_number_generator Pseudo Random Number Generator] (PRNG). The implementation in LSL uses a much smaller state of only four values, however it gives much the same distribution as the standard implementation which uses an array of some 624 values as its state, which of course is unfeasible to implement in LSL.

	= Usage =		= Usage =

Haravikk Mistral: /* Script */

2010-11-22T23:08:34Z

Script

@@ Line 116: / Line 116: @@
+}
-string lslByteHexChars = "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
+string lslIntegerToHexFast(integer int) {
-string lslIntegerToHexFast(integer i) {
+	string hex = "";
-    integer t;
-    return llGetSubString(lslByteHexChars, t = ((i >> 23) & 0x1FE), 1 + t)
+		integer shift = 32; integer nybble; string char = "";
-         + llGetSubString(lslByteHexChars, t = ((i >> 15) & 0x1FE), 1 + t)
+		while (shift >= 4) {
-         + llGetSubString(lslByteHexChars, t = ((i >>  7) & 0x1FE), 1 + t)
+			nybble = (int >> (shift -= 4)) & 0xF;
-         + llGetSubString(lslByteHexChars, t = ((i <<  1) & 0x1FE), 1 + t);
+			if (nybble > 7) {
+}

Haravikk Mistral at 18:33, 30 November 2008

2008-11-30T18:33:00Z

← Older revision		Revision as of 11:33, 30 November 2008
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	}		}
	}</lsl>		}</lsl>

			{{LSLC\|Encryption}}

Strife Onizuka: /* Script / not fast enough :P cracks the whip* I don't think lslPRNGRandomFloat will give a good distribution

2008-10-20T00:46:47Z

Script: not fast enough :P *cracks the whip* I don't think lslPRNGRandomFloat will give a good distribution

← Older revision		Revision as of 17:46, 19 October 2008
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	string lslByteHexChars = "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";		string lslByteHexChars = "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
	string lslIntegerToHexFast(integer i) {		string lslIntegerToHexFast(integer i) {
	integer t = ((i >> 24) & ~~0xFF~~) << 1;		integer t;
	~~string s =~~ llGetSubString(lslByteHexChars, ~~t, ++t);~~		return llGetSubString(lslByteHexChars, t = ((i >> 23) & 0x1FE), 1 + t)
	t = ((i >> 16) & ~~0xFF~~) << 1;		+ llGetSubString(lslByteHexChars, t = ((i >> 15) & 0x1FE), 1 + t)
	s += llGetSubString(lslByteHexChars, ~~t, ++t);~~		+ llGetSubString(lslByteHexChars, t = ((i >> 7) & 0x1FE), 1 + t)
	t = ((i >> 8) & ~~0xFF~~) << 1;		+ llGetSubString(lslByteHexChars, t = ((i << 1) & 0x1FE), 1 + t);
	s += llGetSubString(lslByteHexChars, ~~t, ++t);~~
	t = (i ~~& 0xFF)~~ << 1;
	~~return s + llGetSubString(lslByteHexChars~~, ~~t, +~~+t);
	}		}

Haravikk Mistral: /* Script */

2008-09-03T12:09:50Z

Script

← Older revision		Revision as of 05:09, 3 September 2008
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	integer lslPRNGState2 = 0;		integer lslPRNGState2 = 0;
	integer lslPRNGState3 = 0;		integer lslPRNGState3 = 0;

	integer lslPRNGPosition = 0;		integer lslPRNGPosition = 0;
	integer lslPRNGSeed = 0;		integer lslPRNGSeed = 0;

	integer lslPRNGTwiddle(integer a, integer b) {		integer lslPRNGTwiddle(integer a, integer b) {
	integer c = (((a & 0x80000000) \| (b & 0x7FFFFFFF)) >> 1);		integer c = (((a & 0x80000000) \| (b & 0x7FFFFFFF)) >> 1);
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	return c;		return c;
	}		}

	lslPRNGGenState() {		lslPRNGGenState() {
	lslPRNGState0 = lslPRNGState2 ^		lslPRNGState0 = lslPRNGState2 ^
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	lslPRNGPosition = 0;		lslPRNGPosition = 0;
	}		}

	lslPRNGGenStateSeed(integer seed) {		lslPRNGGenStateSeed(integer seed) {
	lslPRNGState0 = seed;		lslPRNGState0 = seed;
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	lslPRNGPosition = 4;		lslPRNGPosition = 4;
	}		}

	integer lslPRNGRandomInteger(integer seed) {		integer lslPRNGRandomInteger(integer seed) {
	if (seed != lslPRNGSeed) {		if (seed != lslPRNGSeed) {
	lslPRNGGenStateSeed(seed);		lslPRNGGenStateSeed(seed);
	lslPRNGSeed = seed;		lslPRNGSeed = seed;

	lslPRNGGenState();		lslPRNGGenState();
	} else if (lslPRNGPosition >= 4) lslPRNGGenState();		} else if (lslPRNGPosition >= 4) lslPRNGGenState();

	integer x;		integer x;
	if (lslPRNGPosition == 0) x = lslPRNGState0;		if (lslPRNGPosition == 0) x = lslPRNGState0;
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	else if (lslPRNGPosition == 3) x = lslPRNGState3;		else if (lslPRNGPosition == 3) x = lslPRNGState3;
	++lslPRNGPosition;		++lslPRNGPosition;

	x = x ^ ((x >> 11) & 0x001FFFFF);		x = x ^ ((x >> 11) & 0x001FFFFF);
	x = x ^ ((x << 7) & 0x9D2C5680);		x = x ^ ((x << 7) & 0x9D2C5680);
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	return x ^ ((x >> 18) & 0x00002FFF);		return x ^ ((x >> 18) & 0x00002FFF);
	}		}

	// Returns a random float between 0.0 (inclusive) and 1.0 (exclusive)		// Returns a random float between 0.0 (inclusive) and 1.0 (exclusive)
	float lslPRNGRandomFloat(integer seed) {		float lslPRNGRandomFloat(integer seed) {
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	if (b < 0) b = -b;		if (b < 0) b = -b;
	else if (b == 0) return 0.0;		else if (b == 0) return 0.0;

	t %= b;		t %= b;
	return (float)t / (float)b;		return (float)t / (float)b;
	}		}

	~~// Returns a completely random key~~
	~~key lslPRNGRandomKey(integer seed) {~~
	~~string k = lslIntegerToHex(lslPRNGRandomInteger(seed)) +~~
	~~lslIntegerToHex(lslPRNGRandomInteger(seed)) +~~
	~~lslIntegerToHex(lslPRNGRandomInteger(seed)) +~~
	~~lslIntegerToHex(lslPRNGRandomInteger(seed));~~

	~~return (key)llInsertString(~~
	~~llInsertString(~~
	~~llInsertString(~~
	~~llInsertString((k = "") + k, 8,"-"),~~
	~~13,~~
	~~"-"~~
	),
	~~18,~~
	~~"-"~~
	),
	~~23,~~
	~~"-"~~
	);
	}



	// Returns a completely random key		// Returns a completely random key
	key lslPRNGRandomKey(integer seed) {		key lslPRNGRandomKey(integer seed) {
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	lslIntegerToHexFast(lslPRNGRandomInteger(seed)) +		lslIntegerToHexFast(lslPRNGRandomInteger(seed)) +
	lslIntegerToHexFast(lslPRNGRandomInteger(seed));		lslIntegerToHexFast(lslPRNGRandomInteger(seed));

	return (key)llInsertString(		return (key)llInsertString(
	llInsertString(		llInsertString(
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	);		);
	}		}

	string lslByteHexChars = "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";		string lslByteHexChars = "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
	string lslIntegerToHexFast(integer i) {		string lslIntegerToHexFast(integer i) {
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	return s + llGetSubString(lslByteHexChars, t, ++t);		return s + llGetSubString(lslByteHexChars, t, ++t);
	}		}

	default {		default {
	state_entry() {		state_entry() {

Haravikk Mistral: /* Usage */

2008-09-02T21:51:28Z

Usage

← Older revision		Revision as of 14:51, 2 September 2008
Line 20:		Line 20:
	\|-		\|-
	\|<code>string lslIntegerToHex(integer i)</code>		\|<code>string lslIntegerToHex(integer i)</code>
	\|Allows you to output an integer value as hex, useful for [[~~Category:LSL Encryption\|Encryption~~]].		\|Allows you to output an integer value as hex, useful for [[Cryptography]].
	\|}		\|}

Haravikk Mistral: /* Usage */

2008-09-02T21:50:56Z

Usage

← Older revision		Revision as of 14:50, 2 September 2008
Line 20:		Line 20:
	\|-		\|-
	\|<code>string lslIntegerToHex(integer i)</code>		\|<code>string lslIntegerToHex(integer i)</code>
	\|Allows you to output an integer value as hex, useful for [[Category:LSL Encryption\|~~Cryptography~~]].		\|Allows you to output an integer value as hex, useful for [[Category:LSL Encryption\|Encryption]].
	\|}		\|}

Haravikk Mistral: /* Usage */

2008-09-02T21:50:01Z

Usage

← Older revision		Revision as of 14:50, 2 September 2008
Line 20:		Line 20:
	\|-		\|-
	\|<code>string lslIntegerToHex(integer i)</code>		\|<code>string lslIntegerToHex(integer i)</code>
	\|Allows you to output an integer value as hex, useful for [[Category:~~LSL_Encryption~~\|Cryptography]].		\|Allows you to output an integer value as hex, useful for [[Category:LSL Encryption\|Cryptography]].
	\|}		\|}

Haravikk Mistral: /* Usage */

2008-09-02T21:49:11Z

Usage

← Older revision		Revision as of 14:49, 2 September 2008
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	\|-		\|-
	\|<code>string lslIntegerToHex(integer i)</code>		\|<code>string lslIntegerToHex(integer i)</code>
	\|Allows you to output an integer value as hex, useful for [[Cryptography]].		\|Allows you to output an integer value as hex, useful for [[Category:LSL_Encryption\|Cryptography]].
	\|}		\|}

Pseudo Random Number Generator - Revision history

ObviousAltIsObvious Resident: tag to

Haravikk Mistral: /* Description */

Haravikk Mistral: /* Script */

Haravikk Mistral at 18:33, 30 November 2008

Strife Onizuka: /* Script */ not fast enough :P *cracks the whip* I don't think lslPRNGRandomFloat will give a good distribution

Haravikk Mistral: /* Script */

Haravikk Mistral: /* Usage */

Haravikk Mistral: /* Usage */

Haravikk Mistral: /* Usage */

Haravikk Mistral: /* Usage */

Strife Onizuka: /* Script / not fast enough :P cracks the whip* I don't think lslPRNGRandomFloat will give a good distribution