/*
* Created on Feb 19, 2005
*
* Copyright (c) 2005 Peter Johan Salomonsen (http://www.petersalomonsen.com)
*
* http://www.frinika.com
*
* This file is part of Frinika.
*
* Frinika is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* Frinika is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with Frinika; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.frinika.synth.filters;
import javax.swing.JFrame;
import com.frinika.audio.Decibel;
/**
* @author Peter Johan Salomonsen
*
*/
public final class LoPass {
float previousSample = 0;
float cutOff = 0.1f;
public final void setCutOff(float cutOff)
{
this.cutOff = cutOff;
}
public final float filter(float sample)
{
float delta = sample-previousSample;
if(delta>cutOff)
sample=previousSample+cutOff;
else if(delta<-cutOff)
sample=previousSample-cutOff;
previousSample = sample;
return(sample);
}
public static void main(String[] args)
{
final LoPass loPass = new LoPass();
loPass.setCutOff(0.001f);
final JFrame frame = new JFrame()
{
public void paint(java.awt.Graphics g)
{
g.clearRect(0,0,600,600);
int prevX = 0;
int prevY = 300;
for(float n = 0;n<Math.PI*2;n+=0.01)
{
float w1 = (float)Math.sin(n)*2;
float w2 = (float)Math.sin(n*32)/4f;
float w = loPass.filter(w1+w2);
int x = (int)((n/(Math.PI*2)) * 600f);
int y = (int)(((w)*100f)+300);
System.out.println(x+" "+y+" "+loPass.cutOff);
g.drawLine(prevX,prevY,x,y);
prevX = x;
prevY = y;
}
}
};
frame.setVisible(true);
frame.setSize(600,600);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
new Thread()
{
public void run()
{
float cutOff = -1;
while(cutOff>-100f)
{
frame.repaint();
cutOff-=0.5;
loPass.setCutOff(Decibel.getAmplitudeRatio(cutOff));
try
{
Thread.sleep(500);
} catch(Exception e) {}
}
}
}.start();
}
}