import ddf.minim.*;

AudioPlayer [] players = new AudioPlayer[3];
Minim minim;
int currfile=0;

void setup()
{
  size(512, 200, P2D);

  minim = new Minim(this);
  
  // load a file, give the AudioPlayer buffers that are 1024 samples long
  // player = minim.loadFile("groove.mp3");
  
  // load a file, give the AudioPlayer buffers that are 2048 samples long
  for(int i=0; i<players.length; i++) 
    players[i] = minim.loadFile("groove.mp3", 2048);
  // play the file
  players[currfile].play();
}

void draw()
{
  background(0);
  stroke(255);
  // draw the waveforms
  // the values returned by left.get() and right.get() will be between -1 and 1,
  // so we need to scale them up to see the waveform
  // note that if the file is MONO, left.get() and right.get() will return the same value
  for(int i = 0; i < players[currfile].left.size()-1; i++)
  {
    line(i, 50 + players[currfile].left.get(i)*50, i+1, 50 + players[currfile].left.get(i+1)*50);
    line(i, 150 + players[currfile].right.get(i)*50, i+1, 150 + players[currfile].right.get(i+1)*50);
  }
}

void keyPressed() {
  // close current file
  players[currfile].close();
  
  // advance counter
  currfile++;
  if(currfile>=players.length)currfile=0;
  
  // open next file
  players[currfile].play();
}

void stop()
{
  // always close Minim audio classes when you are done with them
  for(int i=0; i<players.length; i++) 
    players[i].close();
  minim.stop();
  
  super.stop();
}