guitfx/gate.c

#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include "gate.h"
#include <math.h>

void gate_init(
    struct gate * gate
) {
    gate->threshold = 0.0;
    gate->enable_calibration = false;
    gate->cur_state = false;
    gate->cur_avg = 0;
}

void gate_process(
    struct gate * gate,
    size_t frame_size,
    float const * in,
    float * out
) {
  float sum = 0.0;

  for( size_t i = 0; i < frame_size; ++i ) {
    sum += fabs( in[i] );
  }

  gate->cur_avg = sum / frame_size;

  if( gate->cur_avg > gate->threshold ) {

    if( ! gate->cur_state ) {
      gate->cur_state = true;
      printf("GATE on\n");
    }
    
    for( size_t i = 0; i < frame_size; ++i ) {
      out[i] = in[i];
    }
  }
  else
  {
    if( gate->cur_state ) {
      gate->cur_state = false;
      printf("GATE off\n");
    }

    for( size_t i = 0; i < frame_size; ++i ) {
      out[i] = 0.0;
    }
  }
}