NetBSD/games/dab/random.h

67 lines
2.2 KiB
C++

/* $NetBSD: random.h,v 1.5 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; returns a random sequence of values from [0..fx) returning each
* value exactly once. After fx calls it returns fx.
*/
#ifndef _H_RANDOM
#define _H_RANDOM
#include <stdlib.h>
class RANDOM {
public:
// Constructor and destructor
RANDOM(size_t fx);
~RANDOM();
size_t operator () (void); // Next random
void clear(void); // Reset
private:
int isset(size_t z) {
return (_bm[z >> 3] & (1 << (z & 7))) != 0;
}
void set(size_t z) {
_bm[z >> 3] |= (1 << (z & 7));
}
char* _bm; // Bitmap indicating the numbers used
size_t _nv; // Number of values returned so far
size_t _bs; // Maximum value
};
#endif