/* Accurate Vibrato object 2
 * Copyright (c) 2020, Mark Tillotson, markt@chaos.org.uk
 *
 * 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 __ACCURATE_VIBRATO2_h__
#define __ACCURATE_VIBRATO2_h__

#include <Arduino.h>
#include <Audio.h>
#include <AudioStream.h>

#if AUDIO_BLOCK_SAMPLES != 128
#  error "Only works for AUDIO_BLOCK_SAMPLES == 128 currently"
#endif

#define VIBRATO_SINC_SAMPLES      16  // assumed in code to be even
#define VIBRATO_SINC_SAMPLES_FULL 10  // the range of sinc samples with no tapering applied
// so the sinc index varies -16 -- +16, with cosine tapering applied outside the range -10 -- +10
// Reasonable compromise between speed and effect accuracy.  For better accuracy use 24 & 16
// about 10% CPU on 600MHz T4, 40% CPU on 150MHz T4

class AudioEffectHighQualityVibrato : public AudioStream
{
public:
  AudioEffectHighQualityVibrato(void) ;// : AudioStream(1, inputQueueArray) {}

  void modulation (float hertz, float percent) ;
  
  virtual void update(void);


private:
  audio_block_t * inputQueueArray[1];
  uint32_t mod_phase_acc ;
  uint32_t mod_phase_inc ;
  float buffer [4 * AUDIO_BLOCK_SAMPLES] ;
  int bptr, cptr ;   // circular buffer indices
  float mod_depth ;  // fixpoint 8.24 modulation depth in samples, must stay in range -126.0 -> +126.0
  static float cos_table [VIBRATO_SINC_SAMPLES+1] ;
};

#endif