mirror of
https://github.com/eried/portapack-mayhem.git
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56 lines
1.4 KiB
C++
56 lines
1.4 KiB
C++
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/*
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* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
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*
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* This file is part of PortaPack.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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#include "encoder.hpp"
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#include "utility.hpp"
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static const int8_t transition_map[] = {
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0, // 0000: noop
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0, // 0001: start
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0, // 0010: start
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0, // 0011: rate
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1, // 0100: end
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0, // 0101: noop
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0, // 0110: rate
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-1, // 0111: end
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-1, // 1000: end
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0, // 1001: rate
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0, // 1010: noop
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1, // 1011: end
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0, // 1100: rate
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0, // 1101: start
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0, // 1110: start
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0, // 1111: noop
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};
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int_fast8_t Encoder::update(
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const uint_fast8_t phase_0,
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const uint_fast8_t phase_1
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) {
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state <<= 1;
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state |= phase_0;
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state <<= 1;
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state |= phase_1;
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return transition_map[state & 0xf];
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}
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