/*************************************************************************
* Compilation: javac PlayThatTune.java
* Execution: java PlayThatTune < input.txt
* Dependencies: StdAudio.java StdAudio.java
*
* This is a data-driven program that plays pure tones from
* the notes on the chromatic scale, specified on standard input
* by their distance from concert A.
*
* % java PlayThatTune < elise.txt
*
*
* Data files
* ----------
* http://www.cs.princeton.edu/introcs/21function/elise.txt
* http://www.cs.princeton.edu/introcs/21function/99luftballons.txt
* http://www.cs.princeton.edu/introcs/21function/freebird.txt
* http://www.cs.princeton.edu/introcs/21function/Ascale.txt
* http://www.cs.princeton.edu/introcs/21function/National_Anthem.txt
* http://www.cs.princeton.edu/introcs/21function/looney.txt
* http://www.cs.princeton.edu/introcs/21function/StairwayToHeaven.txt
* http://www.cs.princeton.edu/introcs/21function/entertainer.txt
* http://www.cs.princeton.edu/introcs/21function/old-nassau.txt
* http://www.cs.princeton.edu/introcs/21function/arabesque.txt
* http://www.cs.princeton.edu/introcs/21function/firstcut.txt
* http://www.cs.princeton.edu/introcs/21function/tomsdiner.txt
*
*************************************************************************/
public class PlayThatTune {
public static void main(String[] args) {
// repeat as long as there are more integers to read in
while (!StdIn.isEmpty()) {
// read in the pitch, where 0 = Concert A (A4)
int pitch = StdIn.readInt();
// read in duration in seconds
double duration = StdIn.readDouble();
// build sine wave with desired frequency
double hz = 440 * Math.pow(2, pitch / 12.0);
int N = (int) (StdAudio.SAMPLE_RATE * duration);
double[] a = new double[N+1];
for (int i = 0; i <= N; i++) {
a[i] = Math.sin(2 * Math.PI * i * hz / StdAudio.SAMPLE_RATE);
}
// play it using standard audio
StdAudio.play(a);
}
}
}
