DoomRandom.cs

/*
 * C# derivative of m_random.c used in DOOM
 * https://github.com/id-Software/DOOM/blob/master/linuxdoom-1.10/m_random.c
 *
 * Copyright (C) 1993-1996 by id Software, Inc.
 *
 * This source is available for distribution and/or modification
 * only under the terms of the DOOM Source Code License as
 * published by id Software. All rights reserved.
 *
 * The source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
 * for more details.
 *
 */

public static class DoomRandom
{
	private static int[] RandomTable = {
		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
	};
	
	private static int _index = 0;
	private static int _pindex = 0;
	
	public static int PRandom()
	{
		_pindex = (_pindex+1)&0xff;
		return RandomTable[_pindex];
	}

	public static int MRandom()
	{
		_index = (_index+1)&0xff;
		return RandomTable[_index];
	}
	
	public static void Clear()
	{
		_pindex = _index = 0;
	}
}