wolf3d-browser/js/random.js

/*
* ===========================================================================
* 
* Wolf3D Browser Version GPL Source Code
* Copyright (C) 2012 id Software LLC, a ZeniMax Media company. 
* 
* This file is part of the Wolf3D Browser Version GPL Source Code ("Wolf3D Browser Source Code").  
* 
* Wolf3D Browser Source Code is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
* 
* Wolf3D Browser Source Code is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
* 
* You should have received a copy of the GNU General Public License version 2
* along with Wolf3D Browser Source Code.  If not, see <http://www.gnu.org/licenses/>.
* 
* If you have questions concerning this license, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
* 
* ===========================================================================
*/

Wolf.Random = (function() {

/* This is just John Carmack's table driven pseudo-random number generator */
var rndtable = [
      0,   8, 109, 220, 222, 241, 149, 107,  75, 248, 254, 140,  16,  66,
     74,  21, 211,  47,  80, 242, 154,  27, 205, 128, 161,  89,  77,  36,
     95, 110,  85,  48, 212, 140, 211, 249,  22,  79, 200,  50,  28, 188,
     52, 140, 202, 120,  68, 145,  62,  70, 184, 190,  91, 197, 152, 224,
    149, 104,  25, 178, 252, 182, 202, 182, 141, 197,   4,  81, 181, 242,
    145,  42,  39, 227, 156, 198, 225, 193, 219,  93, 122, 175, 249,   0,
    175, 143,  70, 239,  46, 246, 163,  53, 163, 109, 168, 135,   2, 235,
     25,  92,  20, 145, 138,  77,  69, 166,  78, 176, 173, 212, 166, 113,
     94, 161,  41,  50, 239,  49, 111, 164,  70,  60,   2,  37, 171,  75,
    136, 156,  11,  56,  42, 146, 138, 229,  73, 146,  77,  61,  98, 196,
    135, 106,  63, 197, 195,  86,  96, 203, 113, 101, 170, 247, 181, 113,
     80, 250, 108,   7, 255, 237, 129, 226,  79, 107, 112, 166, 103, 241,
     24, 223, 239, 120, 198,  58,  60,  82, 128,   3, 184,  66, 143, 224,
    145, 224,  81, 206, 163,  45,  63,  90, 168, 114,  59,  33, 159,  95,
     28, 139, 123,  98, 125, 196,  15,  70, 194, 253,  54,  14, 109, 226,
     71,  17, 161,  93, 186,  87, 244, 138,  20,  52, 123, 251,  26,  36,
     17,  46,  52, 231, 232,  76,  31, 221,  84,  37, 216, 165, 212, 106,
    197, 242,  98,  43,  39, 175, 254, 145, 190,  84, 118, 222, 187, 136,
    120, 163, 236, 249
];

var rndindex = 0;

function init(randomize) {
  	if (randomize ) {
  		rndindex = (new Date).getTime() & 0xFF;
	} else {
		rndindex = 0;
	}
}

function rnd() {
	rndindex++;
	rndindex &= 0xFF;
	return rndtable[rndindex];
}


return {
    init : init,
    rnd : rnd
}

})();