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authorDave Chapman <dave@dchapman.com>2006-03-28 15:44:01 +0000
committerDave Chapman <dave@dchapman.com>2006-03-28 15:44:01 +0000
commit47f4a458d636a889e955e68f896708f1276febc0 (patch)
tree99f770c02ef606f0abbdcd332ac39e69830d8007 /apps/plugins/doom/m_random.c
parentfff7d6157d56f233cad5c2003475e47a5ff809a7 (diff)
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Patch #2969 - Doom! Currently only working on the H300.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@9312 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/plugins/doom/m_random.c')
-rw-r--r--apps/plugins/doom/m_random.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/apps/plugins/doom/m_random.c b/apps/plugins/doom/m_random.c
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+/* Emacs style mode select -*- C++ -*-
+ *-----------------------------------------------------------------------------
+ *
+ *
+ * PrBoom a Doom port merged with LxDoom and LSDLDoom
+ * based on BOOM, a modified and improved DOOM engine
+ * Copyright (C) 1999 by
+ * id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman
+ * Copyright (C) 1999-2000 by
+ * Jess Haas, Nicolas Kalkhof, Colin Phipps, Florian Schulze
+ *
+ * This program 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.
+ *
+ * This program 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
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * DESCRIPTION:
+ * Random number LUT.
+ *
+ * 1/19/98 killough: Rewrote random number generator for better randomness,
+ * while at the same time maintaining demo sync and backward compatibility.
+ *
+ * 2/16/98 killough: Made each RNG local to each control-equivalent block,
+ * to reduce the chances of demo sync problems.
+ *
+ *-----------------------------------------------------------------------------*/
+
+
+#include "doomstat.h"
+#include "m_random.h"
+
+//
+// M_Random
+// Returns a 0-255 number
+//
+static const unsigned char rndtable[256] = { // 1/19/98 killough -- made const
+ 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
+ };
+
+rng_t rng; // the random number state
+
+unsigned long rngseed = 1993; // killough 3/26/98: The seed
+
+int P_Random(pr_class_t pr_class)
+{
+ // killough 2/16/98: We always update both sets of random number
+ // generators, to ensure repeatability if the demo_compatibility
+ // flag is changed while the program is running. Changing the
+ // demo_compatibility flag does not change the sequences generated,
+ // only which one is selected from.
+ //
+ // All of this RNG stuff is tricky as far as demo sync goes --
+ // it's like playing with explosives :) Lee
+
+ int compat = pr_class == pr_misc ?
+ (rng.prndindex = (rng.prndindex + 1) & 255) :
+ (rng. rndindex = (rng. rndindex + 1) & 255) ;
+
+ unsigned long boom;
+
+ // killough 3/31/98:
+ // If demo sync insurance is not requested, use
+ // much more unstable method by putting everything
+ // except pr_misc into pr_all_in_one
+
+ if (pr_class != pr_misc && !demo_insurance) // killough 3/31/98
+ pr_class = pr_all_in_one;
+
+ boom = rng.seed[pr_class];
+
+ // killough 3/26/98: add pr_class*2 to addend
+
+ rng.seed[pr_class] = boom * 1664525ul + 221297ul + pr_class*2;
+
+ if (demo_compatibility)
+ return rndtable[compat];
+
+ boom >>= 20;
+
+ /* killough 3/30/98: use gametic-levelstarttic to shuffle RNG
+ * killough 3/31/98: but only if demo insurance requested,
+ * since it's unnecessary for random shuffling otherwise
+ * killough 9/29/98: but use basetic now instead of levelstarttic
+ * cph - DEMOSYNC - this change makes MBF demos work,
+ * but does it break Boom ones?
+ */
+
+ if (demo_insurance)
+ boom += (gametic-basetic)*7;
+
+ return boom & 255;
+}
+
+// Initialize all the seeds
+//
+// This initialization method is critical to maintaining demo sync.
+// Each seed is initialized according to its class, so if new classes
+// are added they must be added to end of pr_class_t list. killough
+//
+
+void M_ClearRandom (void)
+{
+ int i;
+ unsigned long seed = rngseed*2+1; // add 3/26/98: add rngseed
+ for (i=0; i<NUMPRCLASS; i++) // go through each pr_class and set
+ rng.seed[i] = seed *= 69069ul; // each starting seed differently
+ rng.prndindex = rng.rndindex = 0; // clear two compatibility indices
+}