/*
* Copyright (c) 2007 by Damien Di Fede <ddf@compartmental.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package ddf.minim.signals;
/**
* A triangle wave oscillates between 1 and -1 following a straight line.
*
* @author Damien Di Fede
* @see <a href="http://en.wikipedia.org/wiki/Triangle_wave">Triangle Wave</a>
*/
public class TriangleWave extends Oscillator
{
/**
* Constructs a triangle wave with the given frequency, amplitude and sample
* rate.
*
* @param frequency
* the frequency of the pulse wave
* @param amplitude
* the amplitude of the pulse wave
* @param sampleRate
* the sample rate of the pulse wave
*/
public TriangleWave(float frequency, float amplitude, float sampleRate)
{
super(frequency, amplitude, sampleRate);
}
protected float value(float step)
{
float ta = step * frequency();
return 1 - 4 * Math.abs(Math.round(ta) - ta);
}
}