NetBSD/games/dab/random.cc

80 lines
2.2 KiB
C++

/* $NetBSD: random.cc,v 1.4 2021/12/05 09:22:45 rillig Exp $ */
/*-
* Copyright (c) 2003 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Randomizer for the dots program
*/
#include "defs.h"
RCSID("$NetBSD: random.cc,v 1.4 2021/12/05 09:22:45 rillig Exp $")
#include <time.h>
#include <string.h>
#include "random.h"
RANDOM::RANDOM(size_t ns) :
_bs(ns)
{
_bm = new char[(_bs >> 3) + 1];
clear();
}
RANDOM::~RANDOM()
{
delete[] _bm;
}
// Reinitialize
void RANDOM::clear(void)
{
_nv = 0;
::srand48(::time(NULL));
(void) ::memset(_bm, 0, (_bs >> 3) + 1);
}
// Return the next random value
size_t RANDOM::operator() (void)
{
// No more values
if (_nv == _bs)
return _bs;
for (;;) {
size_t r = ::lrand48();
size_t z = r % _bs;
if (!isset(z)) {
set(z);
_nv++;
return z;
}
}
}