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author | B. Watson <yalhcru@gmail.com> | 2015-05-07 16:32:32 -0400 |
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committer | B. Watson <yalhcru@gmail.com> | 2015-05-07 16:32:32 -0400 |
commit | 013ac7742311556022304e8b30ca170d48b3a016 (patch) | |
tree | 53faa33e75991363f1a6dcc7edc83a66b70e6995 /rogue/random.c | |
download | bsd-games-extra-013ac7742311556022304e8b30ca170d48b3a016.tar.gz |
initial commit
Diffstat (limited to 'rogue/random.c')
-rw-r--r-- | rogue/random.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/rogue/random.c b/rogue/random.c new file mode 100644 index 0000000..f119c0f --- /dev/null +++ b/rogue/random.c @@ -0,0 +1,146 @@ +/* $NetBSD: random.c,v 1.8 2009/08/12 08:44:45 dholland Exp $ */ + +/* + * Copyright (c) 1988, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Timothy C. Stoehr. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +#ifndef lint +#if 0 +static char sccsid[] = "@(#)random.c 8.1 (Berkeley) 5/31/93"; +#else +__RCSID("$NetBSD: random.c,v 1.8 2009/08/12 08:44:45 dholland Exp $"); +#endif +#endif /* not lint */ + +#include "rogue.h" + +/* + * random.c + * + * This source herein may be modified and/or distributed by anybody who + * so desires, with the following restrictions: + * 1.) No portion of this notice shall be removed. + * 2.) Credit shall not be taken for the creation of this source. + * 3.) This code is not to be traded, sold, or used for personal + * gain or profit. + * + */ + +static long rntb[32] = { + 3, 0x9a319039, 0x32d9c024, 0x9b663182, 0x5da1f342, + 0xde3b81e0, 0xdf0a6fb5, 0xf103bc02, 0x48f340fb, 0x7449e56b, + 0xbeb1dbb0, 0xab5c5918, 0x946554fd, 0x8c2e680f, 0xeb3d799f, + 0xb11ee0b7, 0x2d436b86, 0xda672e2a, 0x1588ca88, 0xe369735d, + 0x904f35f7, 0xd7158fd6, 0x6fa6f051, 0x616e6b96, 0xac94efdc, + 0x36413f93, 0xc622c298, 0xf5a42ab8, 0x8a88d77b, 0xf5ad9d0e, + 0x8999220b, 0x27fb47b9 +}; + +static long *fptr = &rntb[4]; +static long *rptr = &rntb[1]; +static long *state = &rntb[1]; +static int rand_type = 3; +static int rand_deg = 31; +static int rand_sep = 3; +static long *end_ptr = &rntb[32]; + +static long rrandom(void); + +void +srrandom(int x) +{ + int i; + + state[0] = x; + if (rand_type != 0) { + for (i = 1; i < rand_deg; i++) { + state[i] = 1103515245 * state[i - 1] + 12345; + } + fptr = &state[rand_sep]; + rptr = &state[0]; + for (i = 0; i < 10 * rand_deg; i++) { + (void)rrandom(); + } + } +} + +static long +rrandom(void) +{ + long i; + + if (rand_type == 0) { + i = state[0] = (state[0]*1103515245 + 12345) & 0x7fffffff; + } else { + *fptr += *rptr; + i = (*fptr >> 1) & 0x7fffffff; + if (++fptr >= end_ptr) { + fptr = state; + ++rptr; + } else { + if (++rptr >= end_ptr) { + rptr = state; + } + } + } + return(i); +} + +int +get_rand(int x, int y) +{ + int r, t; + long lr; + + if (x > y) { + t = y; + y = x; + x = t; + } + lr = rrandom(); + lr &= 0x00003fffL; + r = (int)lr; + r = (r % ((y - x) + 1)) + x; + return(r); +} + +int +rand_percent(int percentage) +{ + return(get_rand(1, 100) <= percentage); +} + +int +coin_toss(void) +{ + return(((rrandom() & 01) ? 1 : 0)); +} |