tsiry-sandratraina.com
A modern Music Player Daemon based on Rockbox open source high quality audio player
libadwaita
audio
rust
zig
deno
mpris
rockbox
mpd
1/* Emacs style mode select -*- C++ -*-
2 *-----------------------------------------------------------------------------
3 *
4 *
5 * PrBoom a Doom port merged with LxDoom and LSDLDoom
6 * based on BOOM, a modified and improved DOOM engine
7 * Copyright (C) 1999 by
8 * id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman
9 * Copyright (C) 1999-2000 by
10 * Jess Haas, Nicolas Kalkhof, Colin Phipps, Florian Schulze
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
25 * 02111-1307, USA.
26 *
27 * DESCRIPTION:
28 * Random number LUT.
29 *
30 * 1/19/98 killough: Rewrote random number generator for better randomness,
31 * while at the same time maintaining demo sync and backward compatibility.
32 *
33 * 2/16/98 killough: Made each RNG local to each control-equivalent block,
34 * to reduce the chances of demo sync problems.
35 *
36 *-----------------------------------------------------------------------------*/
37
38
39#include "doomstat.h"
40#include "m_random.h"
41
42//
43// M_Random
44// Returns a 0-255 number
45//
46static const unsigned char rndtable[256] = { // 1/19/98 killough -- made const
47 0, 8, 109, 220, 222, 241, 149, 107, 75, 248, 254, 140, 16, 66 ,
48 74, 21, 211, 47, 80, 242, 154, 27, 205, 128, 161, 89, 77, 36 ,
49 95, 110, 85, 48, 212, 140, 211, 249, 22, 79, 200, 50, 28, 188 ,
50 52, 140, 202, 120, 68, 145, 62, 70, 184, 190, 91, 197, 152, 224 ,
51 149, 104, 25, 178, 252, 182, 202, 182, 141, 197, 4, 81, 181, 242 ,
52 145, 42, 39, 227, 156, 198, 225, 193, 219, 93, 122, 175, 249, 0 ,
53 175, 143, 70, 239, 46, 246, 163, 53, 163, 109, 168, 135, 2, 235 ,
54 25, 92, 20, 145, 138, 77, 69, 166, 78, 176, 173, 212, 166, 113 ,
55 94, 161, 41, 50, 239, 49, 111, 164, 70, 60, 2, 37, 171, 75 ,
56 136, 156, 11, 56, 42, 146, 138, 229, 73, 146, 77, 61, 98, 196 ,
57 135, 106, 63, 197, 195, 86, 96, 203, 113, 101, 170, 247, 181, 113 ,
58 80, 250, 108, 7, 255, 237, 129, 226, 79, 107, 112, 166, 103, 241 ,
59 24, 223, 239, 120, 198, 58, 60, 82, 128, 3, 184, 66, 143, 224 ,
60 145, 224, 81, 206, 163, 45, 63, 90, 168, 114, 59, 33, 159, 95 ,
61 28, 139, 123, 98, 125, 196, 15, 70, 194, 253, 54, 14, 109, 226 ,
62 71, 17, 161, 93, 186, 87, 244, 138, 20, 52, 123, 251, 26, 36 ,
63 17, 46, 52, 231, 232, 76, 31, 221, 84, 37, 216, 165, 212, 106 ,
64 197, 242, 98, 43, 39, 175, 254, 145, 190, 84, 118, 222, 187, 136 ,
65 120, 163, 236, 249
66 };
67
68rng_t rng; // the random number state
69
70unsigned long rngseed = 1993; // killough 3/26/98: The seed
71
72int P_Random(pr_class_t pr_class)
73{
74 // killough 2/16/98: We always update both sets of random number
75 // generators, to ensure repeatability if the demo_compatibility
76 // flag is changed while the program is running. Changing the
77 // demo_compatibility flag does not change the sequences generated,
78 // only which one is selected from.
79 //
80 // All of this RNG stuff is tricky as far as demo sync goes --
81 // it's like playing with explosives :) Lee
82
83 int compat = pr_class == pr_misc ?
84 (rng.prndindex = (rng.prndindex + 1) & 255) :
85 (rng. rndindex = (rng. rndindex + 1) & 255) ;
86
87 unsigned long boom;
88
89 // killough 3/31/98:
90 // If demo sync insurance is not requested, use
91 // much more unstable method by putting everything
92 // except pr_misc into pr_all_in_one
93
94 if (pr_class != pr_misc && !demo_insurance) // killough 3/31/98
95 pr_class = pr_all_in_one;
96
97 boom = rng.seed[pr_class];
98
99 // killough 3/26/98: add pr_class*2 to addend
100
101 rng.seed[pr_class] = boom * 1664525ul + 221297ul + pr_class*2;
102
103 if (demo_compatibility)
104 return rndtable[compat];
105
106 boom >>= 20;
107
108 /* killough 3/30/98: use gametic-levelstarttic to shuffle RNG
109 * killough 3/31/98: but only if demo insurance requested,
110 * since it's unnecessary for random shuffling otherwise
111 * killough 9/29/98: but use basetic now instead of levelstarttic
112 * cph - DEMOSYNC - this change makes MBF demos work,
113 * but does it break Boom ones?
114 */
115
116 if (demo_insurance)
117 boom += (gametic-basetic)*7;
118
119 return boom & 255;
120}
121
122// Initialize all the seeds
123//
124// This initialization method is critical to maintaining demo sync.
125// Each seed is initialized according to its class, so if new classes
126// are added they must be added to end of pr_class_t list. killough
127//
128
129void M_ClearRandom (void)
130{
131 int i;
132 unsigned long seed = rngseed*2+1; // add 3/26/98: add rngseed
133 for (i=0; i<NUMPRCLASS; i++) // go through each pr_class and set
134 rng.seed[i] = seed *= 69069ul; // each starting seed differently
135 rng.prndindex = rng.rndindex = 0; // clear two compatibility indices
136}