mirror of
https://github.com/eried/portapack-mayhem.git
synced 2024-09-20 16:15:51 +00:00
75 lines
1.8 KiB
C++
75 lines
1.8 KiB
C++
/*
|
|
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
|
|
*
|
|
* This file is part of PortaPack.
|
|
*
|
|
* 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, 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; see the file COPYING. If not, write to
|
|
* the Free Software Foundation, Inc., 51 Franklin Street,
|
|
* Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#ifndef __BIT_PATTERN_H__
|
|
#define __BIT_PATTERN_H__
|
|
|
|
#include <cstdint>
|
|
#include <cstddef>
|
|
|
|
class BitPattern {
|
|
public:
|
|
constexpr BitPattern(
|
|
const uint32_t code,
|
|
const size_t code_length,
|
|
const size_t maximum_hanning_distance = 0
|
|
) : code_ { code },
|
|
mask_ { (1U << code_length) - 1U },
|
|
maximum_hanning_distance_ { maximum_hanning_distance }
|
|
{
|
|
}
|
|
|
|
uint32_t code() const {
|
|
return code_;
|
|
}
|
|
|
|
uint32_t mask() const {
|
|
return mask_;
|
|
}
|
|
|
|
size_t maximum_hanning_distance() const {
|
|
return maximum_hanning_distance_;
|
|
}
|
|
|
|
private:
|
|
uint32_t code_;
|
|
uint32_t mask_;
|
|
size_t maximum_hanning_distance_;
|
|
};
|
|
|
|
class BitHistory {
|
|
public:
|
|
void add(const uint_fast8_t bit) {
|
|
history = (history << 1) | (bit & 1);
|
|
}
|
|
|
|
bool matches(const BitPattern& pattern) const {
|
|
const auto delta_bits = (history ^ pattern.code()) & pattern.mask();
|
|
const size_t count = __builtin_popcountl(delta_bits);
|
|
return (count <= pattern.maximum_hanning_distance());
|
|
}
|
|
|
|
private:
|
|
uint32_t history { 0 };
|
|
};
|
|
|
|
#endif/*__BIT_PATTERN_H__*/
|