delay.cpp

/*
 * Copyright (C) 2023 Liu An Lin <liuanlin-mx@qq.com>
 * 
 * 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.
 */


#include <stdlib.h>
#include <delay.h>

delay::delay(std::uint32_t max_delay)
    : _max_delay(max_delay)
    , _delay(0)
    , _idx(0)
    , _data(NULL)
{
    _data = (float *)calloc(_max_delay, sizeof(float));
}

delay::~delay()
{
    free(_data);
}

void delay::set_delay(std::uint32_t delay)
{
    if (delay > _max_delay)
    {
        _delay = _max_delay;
    }
    else
    {
        _delay = delay;
    }
    
    for (std::uint32_t i = 0; i < _delay; i++)
    {
        _data[i] = 0.;
    }
}

float delay::process(float v)
{
    if (_delay == 0)
    {
        return v;
    }
    
    std::uint32_t idx = _idx % _delay;
    _idx++;
    float tmp = _data[idx];
    _data[idx] = v;
    return tmp;
}