/*
* Copyright (C) 2012 Brendan Robert (BLuRry) brendan.robert@gmail.com.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
package jace.hardware.mockingboard;
/**
* Noise generator of the PSG sound chip.
* Created on April 18, 2006, 5:47 PM
* @author Brendan Robert (BLuRry) brendan.robert@gmail.com
*/
public class NoiseGenerator extends TimedGenerator {
int rng = 0x003333;
public NoiseGenerator(int _clock,int _sampleRate) {
super(_clock, _sampleRate);
}
@Override
public int stepsPerCycle() {
return 4;
}
public void step() {
int stateChanges = updateCounter();
for (int i=0; i < stateChanges; i++)
updateRng();
}
public static final int BIT17 = 0x010000;
public void updateRng() {
rng = ((rng & 1) != 0 ? rng ^ 0x24000 : rng) >> 1;
if ((rng & 1) == 1) {
state = !state;
}
}
boolean state = false;
public boolean isOn() {
return state;
}
}