ErraticLoopBuffer.java

package jass.generators;
import jass.engine.*;
import java.net.*;
/**
   A force model based on looping through a buffer, loaded from an audio
   file or provided by caller.  Adds a probablility to "misfire", i.e.,
   skip a section of the loop.
   @author Kees van den Doel (kvdoel@cs.ubc.ca)
*/
public class ErraticLoopBuffer extends LoopBuffer {
    /** misfire probability per buffer */
    private float misfireProb = 0;
    
    /** Set probability of misfiring per call to computeBuffer
        @param val probability.
    */
    public void setMisfireProb(float val) {
        misfireProb = val;
    }

    /** Get probability of misfiring per call to computeBuffer
        @return  probability.
    */
    public float getMisfireProb() {
        return misfireProb;
    }

    /**
       For derived classes
       @param bufferSize biffer size
     */
    public ErraticLoopBuffer(int bufferSize) {
        super(bufferSize); // this is the internal buffer size
    }
    
    /** Construct loop force from named file.
        @param srate sampling rate in Hertz.
        @param bufferSize bufferSize of this Out
        @param fn Audio file name.
    */
    public ErraticLoopBuffer(float srate,int bufferSize, String fn) {
        super(srate,bufferSize,fn);
    }

    
    /** Construct loop force from url
        @param srate sampling rate in Hertz.
        @param bufferSize bufferSize of this Out
        @param url Audio file url.
    */
    public ErraticLoopBuffer(float srate,int bufferSize, URL url) {
        super(srate,bufferSize,url);
    }

    /** Construct loop force and provide buffer
        @param srate sampling rate in Hertz.
        @param bufferSize bufferSize of this Out.
        @param loopBuffer looping buffer.
    */
    public ErraticLoopBuffer(float srate,int bufferSize, float[] loopBuffer) {
        super(srate,bufferSize,loopBuffer);
    }

    /** Compute the next buffer.
        Skip 1/2 loop with probability misfireProb.
     */
    public void computeBuffer() {
        if(Math.random() < misfireProb) {
            // Skip 1/3 a sample forward
            int bufsz = getBufferSize();
            ix += loopBufferLength/3;
            if(ix >= loopBufferLength) {
                ix -= loopBufferLength;
            }
        }
        super.computeBuffer();
    }

}