text: /* Audio Library for Teensy 3.X
   * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
   * Extended by Chip Audette, Open Audio, Apr 2018
   *
   * 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 AudioEffecDelay_F32_h_
  #define AudioEffecDelay_F32_h_
  
  #include <Arduino.h>
  #include "AudioStream_F32.h"
  #include "utility/dspinst.h"
  
  #define AUDIO_BLOCK_SIZE_F32 AUDIO_BLOCK_SAMPLES    //what is the maximum length of the F32 audio blocks
  
  
  #if defined(__MK66FX1M0__)
    // 2.41 second maximum on Teensy 3.6
    #define DELAY_QUEUE_SIZE_F32  (106496 / AUDIO_BLOCK_SIZE_F32)
  #elif defined(__MK64FX512__)
    // 1.67 second maximum on Teensy 3.5
    #define DELAY_QUEUE_SIZE_F32  (73728 / AUDIO_BLOCK_SIZE_F32)
  #elif defined(__MK20DX256__)
    // 0.45 second maximum on Teensy 3.1 & 3.2
    #define DELAY_QUEUE_SIZE_F32  (19826 / AUDIO_BLOCK_SIZE_F32)
  #else
    // 0.14 second maximum on Teensy 3.0
    #define DELAY_QUEUE_SIZE_F32  (6144 / AUDIO_BLOCK_SIZE_F32)
  #endif
  
  
  class AudioEffectDelay_F32 : public AudioStream_F32
  {
  //GUI: inputs:1, outputs:1  //this line used for automatic generation of GUI node
  //GUI: shortName:delay
  public:
  	AudioEffectDelay_F32() : AudioStream_F32(1, inputQueueArray) {
  		activemask = 0;
  		headindex = 0;
  		tailindex = 0;
  		maxblocks = 0;
  		memset(queue, 0, sizeof(queue));
  	}
  	AudioEffectDelay_F32(const AudioSettings_F32 &settings) : 
  		AudioStream_F32(1,inputQueueArray) {
  			activemask = 0;
  			headindex = 0;
  			tailindex = 0;
  			maxblocks = 0;
  			memset(queue, 0, sizeof(queue));
  			setSampleRate_Hz(settings.sample_rate_Hz);
  	}	
  	void setSampleRate_Hz(float _fs_Hz) { 
  		//Serial.print("AudioEffectDelay_F32: setSampleRate_Hz to ");
  		//Serial.println(_fs_Hz);
  		sampleRate_Hz = _fs_Hz; 
  		//audio_block_len_samples = block_size;  //this is the actual size that is being used in each audio_block_f32 
  	}
  	float getSampleRate_Hz(void) { return sampleRate_Hz; }
  	
  	void delay(uint8_t channel, float milliseconds) {
  		if (channel >= 8) return;
  		if (milliseconds < 0.0) milliseconds = 0.0;
  		uint32_t n = (milliseconds*(sampleRate_Hz/1000.0))+0.5;
  		uint32_t nmax = AUDIO_BLOCK_SIZE_F32 * (DELAY_QUEUE_SIZE_F32-1);
  		if (n > nmax) n = nmax;
  		uint32_t blks = (n + (AUDIO_BLOCK_SIZE_F32-1)) / AUDIO_BLOCK_SIZE_F32 + 1;
  		if (!(activemask & (1<<channel))) {
  			// enabling a previously disabled channel
  			delay_samps[channel] = n;
  			if (blks > maxblocks) maxblocks = blks;
  			activemask |= (1<<channel);
  		} else {
  			if (n > delay_samps[channel]) {
  				// new delay is greater than previous setting
  				if (blks > maxblocks) maxblocks = blks;
  				delay_samps[channel] = n;
  			} else {
  				// new delay is less than previous setting
  				delay_samps[channel] = n;
  				recompute_maxblocks();
  			}
  		}
  	}
  	void disable(uint8_t channel) {
  		if (channel >= 8) return;
  		// diable this channel
  		activemask &= ~(1<<channel);
  		// recompute maxblocks for remaining enabled channels
  		recompute_maxblocks();
  	}
  	virtual void update(void);
  	virtual void processData(audio_block_f32_t *input,audio_block_f32_t *output);
  	virtual void processData(audio_block_f32_t *input,audio_block_f32_t *all_output[8]);
  	
  private:
  	void recompute_maxblocks(void) {
  		uint32_t max=0;
  		uint32_t channel = 0;
  		do {
  			if (activemask & (1<<channel)) {
  				uint32_t n = delay_samps[channel];
  				n = (n + (AUDIO_BLOCK_SIZE_F32-1)) / AUDIO_BLOCK_SIZE_F32 + 1;
  				if (n > max) max = n;
  			}
  		} while(++channel < 8);
  		maxblocks = max;
  	}
  	uint8_t activemask;   // which output channels are active
  	uint16_t headindex;    // head index (incoming) data in queue
  	uint16_t tailindex;    // tail index (outgoing) data from queue
  	uint16_t maxblocks;    // number of blocks needed in queue
  //#if DELAY_QUEUE_SIZE_F32 * AUDIO_BLOCK_SAMPLES < 65535
  //	uint16_t writeposition;
  //	uint16_t delay_samps[8]; // # of samples to delay for each channel
  //#else
  	int writeposition;	   //position within current head buffer in the queue
  	uint32_t delay_samps[8]; // # of samples to delay for each channel
  //#endif
  	audio_block_f32_t *queue[DELAY_QUEUE_SIZE_F32];
  	audio_block_f32_t *inputQueueArray[1];
  	float sampleRate_Hz = AUDIO_SAMPLE_RATE_EXACT; //default.  from AudioStream.h??
  	//int audio_block_len_samples = AUDIO_BLOCK_SAMPLES;
  	void receiveIncomingData(audio_block_f32_t *input);
  	void discardUnneededBlocksFromQueue(void);
  	void transmitOutgoingData(audio_block_f32_t *all_output[]);
  	unsigned long last_received_block_id = 0;
  };
  
  #endif