effect_delay_ext.h

/* Audio Library for Teensy 3.X
 * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
 *
 * Development of this audio library was funded by PJRC.COM, LLC by sales of
 * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
 * open source software by purchasing Teensy or other PJRC products.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice, development funding notice, and this permission
 * notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef effect_delay_ext_h_
#define effect_delay_ext_h_
#include <Arduino.h>     // github.com/PaulStoffregen/cores/blob/master/teensy4/Arduino.h
#include <AudioStream.h> // github.com/PaulStoffregen/cores/blob/master/teensy4/AudioStream.h
#include "spi_interrupt.h"
#include "extmem.h"


class AudioEffectDelayExternal : public AudioStream, public AudioExtMem
{
	static const int   CHANNEL_COUNT = 8;
public:
	AudioEffectDelayExternal(AudioEffectDelayMemoryType_t type, 
							 float milliseconds=1e6,
							 bool forceInitialize = true)
	  : AudioStream(1, inputQueueArray), 
		AudioExtMem(type, (milliseconds*(AUDIO_SAMPLE_RATE_EXACT/1000.0f))+0.5f, forceInitialize),
		activemask(0)
		{}
	AudioEffectDelayExternal() : AudioEffectDelayExternal(AUDIO_MEMORY_23LC1024) {}
	
	~AudioEffectDelayExternal() {}
	void delay(uint8_t channel, float milliseconds) {
		if (channel >= CHANNEL_COUNT || memory_type >= AUDIO_MEMORY_UNDEFINED) return;
		if (!initialisationDone)
			initialize();
		if (milliseconds < 0.0f) milliseconds = 0.0f;
		uint32_t n = (milliseconds*(AUDIO_SAMPLE_RATE_EXACT/1000.0f))+0.5f;
		n += AUDIO_BLOCK_SAMPLES;
		if (n > memory_length - AUDIO_BLOCK_SAMPLES)
			n = memory_length - AUDIO_BLOCK_SAMPLES;
		delay_length[channel] = n;
		uint8_t mask = activemask;
		if (activemask == 0 && IS_SPI_TYPE) AudioStartUsingSPI();
		activemask = mask | (1<<channel);
	}
	void disable(uint8_t channel) {
		if (channel >= CHANNEL_COUNT) return;
		if (!initialisationDone)
			initialize();
		uint8_t mask = activemask & ~(1<<channel);
		activemask = mask;
		if (mask == 0 && IS_SPI_TYPE) AudioStopUsingSPI();
	}
	virtual void update(void);
private:
	uint32_t delay_length[CHANNEL_COUNT]; // # of sample delay for each channel (128 = no delay)
	uint8_t  activemask;      // which output channels are active
	audio_block_t *inputQueueArray[1];
};

#endif