MickFilter.java

package com.codefixia.audio;

import com.codefixia.drumcloud.DrumCloud;

/** https://github.com/micknoise/Maximilian/blob/master/maximilian.cpp */

class MickFilter implements Filter {

  private float f, res;
  private float cutoff, z, c, x, y, out;
  private float sampleRate;

  MickFilter(float sampleRate) {
    this.sampleRate = sampleRate;
  }

  public void setFilter(float f, float r) {
    f = DrumCloud.constrain(f, 0, 1);
    res = DrumCloud.constrain(r, 0, 1);
    f = DrumCloud.map(f, 0, 1, 25, sampleRate / 4);
    r = DrumCloud.map(r, 0, 1, 1, 25);
    this.f = f;
    this.res = r;    

    //println("mickF: f "+f+" r "+r);
  }
  public float applyFilter(float in) {
    return lores(in, f, res);
  }

  public float lores(float input, float cutoff1, float resonance) {
    //cutoff=cutoff1*0.5;
    //if (cutoff<10) cutoff=10;
    //if (cutoff>(sampleRate*0.5)) cutoff=(sampleRate*0.5);
    //if (resonance<1.) resonance = 1.;

    //if (resonance>2.4) resonance = 2.4;
    z=DrumCloud.cos(DrumCloud.TWO_PI*cutoff/sampleRate);
    c=2-2*z;
    float r=(DrumCloud.sqrt(2.0f)*DrumCloud.sqrt(-DrumCloud.pow((z-1.0f), 3.0f))+resonance*(z-1))/(resonance*(z-1));
    x=x+(input-y)*c;
    y=y+x;
    x=x*r;
    out=y;
    return out;
  }
}
/*
 * Copyright (C) 2011 Jacquet Wong
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */