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| | return ret; | | return ret; |
| | } | | } |
| - | // seedrandom.js version 2.0.
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| - | // Author: David Bau 4/2/2011
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| - | //
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| - | // Defines a method Math.seedrandom() that, when called, substitutes
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| - | // an explicitly seeded RC4-based algorithm for Math.random(). Also
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| - | // supports automatic seeding from local or network sources of entropy.
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| - | //
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| - | // Usage:
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| - | //
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| - | // <script src=http://davidbau.com/encode/seedrandom-min.js></script>
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| - | //
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| - | // Math.seedrandom('yipee'); Sets Math.random to a function that is
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| - | // initialized using the given explicit seed.
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| - | //
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| - | // Math.seedrandom(); Sets Math.random to a function that is
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| - | // seeded using the current time, dom state,
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| - | // and other accumulated local entropy.
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| - | // The generated seed string is returned.
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| - | //
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| - | // Math.seedrandom('yowza', true);
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| - | // Seeds using the given explicit seed mixed
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| - | // together with accumulated entropy.
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| - | //
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| - | // <script src="http://bit.ly/srandom-512"></script>
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| - | // Seeds using physical random bits downloaded
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| - | // from random.org.
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| - | //
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| - | // <script src="https://jsonlib.appspot.com/urandom?callback=Math.seedrandom">
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| - | // </script> Seeds using urandom bits from call.jsonlib.com,
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| - | // which is faster than random.org.
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| - | //
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| - | // Examples:
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| - | //
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| - | // Math.seedrandom("hello"); // Use "hello" as the seed.
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| - | // document.write(Math.random()); // Always 0.5463663768140734
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| - | // document.write(Math.random()); // Always 0.43973793770592234
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| - | // var rng1 = Math.random; // Remember the current prng.
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| - | //
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| - | // var autoseed = Math.seedrandom(); // New prng with an automatic seed.
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| - | // document.write(Math.random()); // Pretty much unpredictable.
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| - | //
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| - | // Math.random = rng1; // Continue "hello" prng sequence.
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| - | // document.write(Math.random()); // Always 0.554769432473455
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| - | //
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| - | // Math.seedrandom(autoseed); // Restart at the previous seed.
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| - | // document.write(Math.random()); // Repeat the 'unpredictable' value.
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| - | //
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| - | // Notes:
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| - | //
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| - | // Each time seedrandom('arg') is called, entropy from the passed seed
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| - | // is accumulated in a pool to help generate future seeds for the
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| - | // zero-argument form of Math.seedrandom, so entropy can be injected over
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| - | // time by calling seedrandom with explicit data repeatedly.
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| - | //
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| - | // On speed - This javascript implementation of Math.random() is about
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| - | // 3-10x slower than the built-in Math.random() because it is not native
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| - | // code, but this is typically fast enough anyway. Seeding is more expensive,
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| - | // especially if you use auto-seeding. Some details (timings on Chrome 4):
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| - | //
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| - | // Our Math.random() - avg less than 0.002 milliseconds per call
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| - | // seedrandom('explicit') - avg less than 0.5 milliseconds per call
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| - | // seedrandom('explicit', true) - avg less than 2 milliseconds per call
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| - | // seedrandom() - avg about 38 milliseconds per call
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| - | //
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| - | // LICENSE (BSD):
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| - | //
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| - | // Copyright 2010 David Bau, all rights reserved.
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| - | //
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| - | // Redistribution and use in source and binary forms, with or without
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| - | // modification, are permitted provided that the following conditions are met:
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| - | //
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| - | // 1. Redistributions of source code must retain the above copyright
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| - | // notice, this list of conditions and the following disclaimer.
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| - | //
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| - | // 2. Redistributions in binary form must reproduce the above copyright
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| - | // notice, this list of conditions and the following disclaimer in the
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| - | // documentation and/or other materials provided with the distribution.
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| - | //
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| - | // 3. Neither the name of this module nor the names of its contributors may
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| - | // be used to endorse or promote products derived from this software
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| - | // without specific prior written permission.
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| - | //
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| - | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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| - | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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| - | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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| - | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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| - | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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| - | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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| - | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| - | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| - | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| - | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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| - | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| - | //
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| - | /**
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| - | * All code is in an anonymous closure to keep the global namespace clean.
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| - | *
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| - | * @param {number=} overflow
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| - | * @param {number=} startdenom
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| - | */
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| | | | |
| - | // Patched by Seb so that seedrandom.js does not pollute the Math object.
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| - | // My tests suggest that doing Math.trouble = 1 makes Math lookups about 5%
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| - | // slower.
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| | numeric.seedrandom = { pow:Math.pow, random:Math.random }; | | numeric.seedrandom = { pow:Math.pow, random:Math.random }; |
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"
