ConstantLoopBuffer.java

package jass.generators;
import jass.engine.*;
import java.net.*;

/**
   Loop through a buffer, loaded from an audio
   file or provided by caller. No speed or volume control is provided.
   @author Kees van den Doel (kvdoel@cs.ubc.ca)
*/
public class ConstantLoopBuffer extends Out {
    /** Buffer to loop */
    protected float[] loopBuffer;

    /** Buffer length */
    protected int loopBufferLength;

    /** Current integer position of pointer in buffer. */
    protected int ix = 0;

    /** Sampling rate in Hertz of Out. */
    public float srate;
    
    /** Construct loop force from named file.
        @param srate sampling rate in Hertz.
        @param bufferSize bufferSize of this Out
        @param fn Audio file name.
    */
    public ConstantLoopBuffer(float srate,int bufferSize, String fn) {
        super(bufferSize); // this is the internal buffer size
        AudioFileBuffer afBuffer = new AudioFileBuffer(fn);
        loopBuffer = afBuffer.buf;
        loopBufferLength = loopBuffer.length;
        this.srate = srate;
    }

    /** Construct loop force from url.
        @param srate sampling rate in Hertz.
        @param bufferSize bufferSize of this Out
        @param url Audio file url.
    */
    public ConstantLoopBuffer(float srate,int bufferSize, URL url) {
        super(bufferSize); // this is the internal buffer size
        AudioFileBuffer afBuffer = new AudioFileBuffer(url);
        loopBuffer = afBuffer.buf;
        loopBufferLength = loopBuffer.length;
        this.srate = srate;
    }

    /** Get loopBuffer
        @return loop buffer as float array 
     */
    public float[] getLoopBuffer() {
        return loopBuffer;
    }
    
    /** Get sampling rate
        @return sampling rate in Hertz
     */
    public float getSamplingRate() {
        return srate;
    }

    /** Construct loop force and provide buffer
        @param srate sampling rate in Hertz.
        @param bufferSize bufferSize of this Out.
        @param loopBuffer looping buffer.
    */
    public ConstantLoopBuffer(float srate,int bufferSize, float[] loopBuffer) {
        super(bufferSize); // this is the internal buffer size
        this.loopBuffer = loopBuffer;
        this.srate = srate;
        loopBufferLength = loopBuffer.length;
    }

    /** Compute the next buffer.
     */
    public void computeBuffer() {
        int bufsz = getBufferSize();
        for(int k=0;k<bufsz;k++) {
            buf[k] = loopBuffer[ix];
            ix++;
            if(ix == loopBufferLength) {
                ix = 0;
            }
        }
    }

}