portapack-mayhem/firmware/common/volume.hpp

/*
 * Copyright (C) 2014 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 Fvoranklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef __VOLUME_H__
#define __VOLUME_H__

#include <cstdint>

class volume_t {
   public:
    constexpr volume_t operator-() const {
        return {-cb};
    }

    constexpr volume_t operator+(const volume_t& other) const {
        return {cb + other.cb};
    }

    constexpr volume_t operator-(const volume_t& other) const {
        return {cb - other.cb};
    }

    volume_t& operator+=(const volume_t& other) {
        cb += other.cb;
        return *this;
    }

    constexpr bool operator<(const volume_t& other) const {
        return cb < other.cb;
    }

    constexpr bool operator>(const volume_t& other) const {
        return cb > other.cb;
    }

    static constexpr volume_t centibel(const int cb) {
        return {cb};
    }

    static constexpr volume_t decibel(const int db) {
        return {db * 10};
    }

    int32_t centibel() const {
        return cb;
    }

    int32_t decibel() const {
        return cb / 10;
    }

   private:
    int32_t cb;

    constexpr volume_t(
        const int cb)
        : cb(cb) {
    }
};

constexpr volume_t operator"" _cB(long double v) {
    return volume_t::centibel(v);
}

constexpr volume_t operator"" _dB(long double v) {
    return volume_t::centibel(v * 10);
}

struct volume_range_t {
    volume_t min;
    volume_t max;

    volume_t limit(const volume_t value) const {
        if (value < min) {
            return min;
        }
        if (value > max) {
            return max;
        }
        return value;
    }

    volume_t normalize(const volume_t value) const {
        /* Limit volume to specified range, and adjust minimum value to 0. */
        return limit(value) - min;
    }
};

#endif /*__VOLUME_H__*/