/*
* Klang – a node+text-based synthesizer library
*
* This file is part of the *wellen* library (https://github.com/dennisppaul/wellen).
* Copyright (c) 2022 Dennis P Paul.
*
* This library 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, version 3.
*
* This library 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/>.
*/
/**
* [ NODE_DELAY ]
* +---------------------+
* | |
* IN00--| SIGNAL SIGNAL |--OUT00
* IN01--| FEEDBACK |
* IN02--| WET |
* IN03--| DURATION |
* | |
* +---------------------+
*
* use `#define NODE_DELAY_BUFFER_SIZE` to globally define maximum
* delay ( line ) length in samples.
*
*/
// @TODO(implement `FEEDBACK` + `WET` + `DURATION` as inputs)
#ifndef NodeDelay_hpp
#define NodeDelay_hpp
#include "KlangNode.hpp"
namespace klang {
class NodeDelay : public Node {
public:
static const CHANNEL_ID NUM_CH_IN = 1;
// static const CHANNEL_ID CH_IN_FEEDBACK = 1;
// static const CHANNEL_ID CH_IN_WET = 2;
// static const CHANNEL_ID CH_IN_DURATION = 3;
// static const CHANNEL_ID NUM_CH_IN = 4;
static const CHANNEL_ID NUM_CH_OUT = 1;
NodeDelay() {
/* initialize pointers positions for delay effect */
shift = INIT_DELAY;
readpos = delayline;
writepos = delayline + INIT_DELAY;
set_duration(mDuration);
}
bool connect(Connection* pConnection, CHANNEL_ID pInChannel) {
if (pInChannel == CH_IN_SIGNAL) {
mConnection_CH_IN_SIGNAL = pConnection;
return true;
}
return false;
}
bool disconnect(CHANNEL_ID pInChannel) {
if (pInChannel == CH_IN_SIGNAL) {
mConnection_CH_IN_SIGNAL = nullptr;
return true;
}
return false;
}
void update(CHANNEL_ID pChannel, float* pAudioBlock) {
if (is_not_updated()) {
if (mConnection_CH_IN_SIGNAL != nullptr) {
mConnection_CH_IN_SIGNAL->update(pAudioBlock);
}
flag_updated();
}
if (pChannel == CH_OUT_SIGNAL) {
for (uint16_t i = 0; i < KLANG_SAMPLES_PER_AUDIO_BLOCK; i++) {
pAudioBlock[i] = kernel(pAudioBlock[i]);
}
}
}
void set_duration(float pDuration) { // duration in percent of maximum delay. TODO convert this to seconds
float* pos;
mDuration = KlangMath::clamp(pDuration, 0.0, 1.0);
shift = (uint32_t)lrintf((DELAYLINE_LEN - 1 - MIN_DELAY) * mDuration + MIN_DELAY);
pos = writepos - shift;
if (pos >= delayline) {
readpos = pos;
} else {
readpos = pos + DELAYLINE_LEN - 1;
}
}
void set_wet(float pWet) { // ratio between original signal and delayed signal
mWet = KlangMath::clamp(pWet, 0.0, 1.0);
}
void set_feedback(float pFeedback) {
mFeedback = pFeedback;
}
void set_filter(float pFilter) { // coefficient for one pole low-pass filter. 0…1 = no filtering … max filtering
mFilter = KlangMath::clamp(pFilter, 0.0, 1.0);
}
float get_duration() { return mDuration; }
float get_wet() { return mWet; }
float get_feedback() { return mFeedback; }
float get_filter() { return mFilter; }
void set_command(KLANG_CMD_TYPE pCommand, KLANG_CMD_TYPE* pPayLoad) {
switch (pCommand) {
case KLANG_SET_DURATION_F32:
set_duration(KlangMath::FLOAT_32(pPayLoad));
break;
case KLANG_SET_WET_F32:
set_wet(KlangMath::FLOAT_32(pPayLoad));
break;
case KLANG_SET_FEEDBACK_F32:
set_feedback(KlangMath::FLOAT_32(pPayLoad));
break;
case KLANG_SET_FILTER_F32:
set_filter(KlangMath::FLOAT_32(pPayLoad));
break;
}
}
private:
Connection* mConnection_CH_IN_SIGNAL = nullptr;
// Connection* mConnection_FEEDBACK;
// Connection* mConnection_WET;
// Connection* mConnection_DURATION;
#ifdef NODE_DELAY_BUFFER_SIZE
static const uint16_t DELAYLINE_LEN = NODE_DELAY_BUFFER_SIZE;
#else
static const uint16_t DELAYLINE_LEN = KLANG_AUDIO_RATE_UINT16 / 2; // max delay in samples
#endif
static const uint16_t INIT_DELAY = DELAYLINE_LEN / 4;
static const uint16_t MIN_DELAY = 250;
/* Delay effect variables */
float delayline[DELAYLINE_LEN + 2];
float* readpos; // output pointer of delay line
float* writepos; // input pointer of delay line
uint32_t shift;
float mFilter = 0.6;
float old_dy; // previous delayed sample
float mFeedback = 0.4;
float mWet = 0.5;
float mDuration = 0.25;
float kernel(float pInput) {
float y, dy;
// (*readpos) : delayed sample read at the output of the delay line
dy = (1.f - mFilter) * (*readpos) + mFilter * old_dy; // apply lowpass filter in the loop
old_dy = dy;
y = pInput + mFeedback * dy;
y = KlangMath::clamp(y, -1.0, 1.0);
*writepos = y; // write new computed sample at the input of the delay line
/* update the delay line pointers : */
writepos++;
readpos++;
if ((writepos - delayline) >= DELAYLINE_LEN) {
writepos = delayline; // wrap pointer
}
if ((readpos - delayline) >= DELAYLINE_LEN) {
readpos = delayline; // wrap pointer
}
return (mWet * y + (1 - mWet) * pInput);
}
};
} // namespace klang
#endif /* NodeDelay_hpp */