Sample theSound;
Sample revSound;

float xPlayHead = 256;

void setup(){

  size(512,100);
  Sonia.start(this); // Start Sonia engine.
  
  // create a new sample object.
  theSound = new Sample("bjork.aiff");
  int sampleLength = theSound.getNumFrames();
  
  revSound = new Sample(sampleLength);

  float[] data = new float[sampleLength];
  float[] other = new float[sampleLength];
  
  theSound.read(data);

  int counter = 0;
  for (int i = sampleLength - 1; i>=0; i--){
    other[counter] = data[i];
    counter ++;
  }

  revSound.write(other);
}


void loop(){
  background(80,0,0);
  fill(51,0,0);
  noStroke();
  rect(width/2, 0, width/2, height);

  moveMeanderer();            
}


float x1p = 206f;
float x1v = random(-2.0f,-1.0f);
float x2p = 306f;
float x2v = random(1.0f,2.0f);
void moveMeanderer(){
  x1p += x1v;
  x2p += x2v;
  
  if (x1p < 10 || x1p > (xPlayHead - 10)){
    x1v *= -1f;
  }
  if (x2p < (xPlayHead + 10) || x2p > (width - 10)){
    x2v *= -1f;
  }
  
  findDistance(x1p,x2p);
  renderStuff();
}

float dist = 100;
float oldDist = 100;
boolean playing = false;

void findDistance(float x1, float x2){
  oldDist = dist;
  dist = x2 - x1;
  
  findPlayFrames(dist, oldDist, x1, x2);
}


float speedDist;
float seg, oldSeg;
void findPlayFrames(float d, float od, float x1, float x2){
  oldSeg = seg;
  seg = 256 - x1;

  int xVar = int((88200 * seg)/d);
  int oldxVar = int((88200 * oldSeg)/d);
  
  speedDist = abs(xVar - oldxVar);
    
  theSound.setRate(speedDist * 4.0f);
  revSound.setRate(speedDist * 4.0f);

  if (xVar > oldxVar){
    theSound.play(oldxVar,xVar);
  } else {
    revSound.play(xVar,oldxVar);
  }

}

void renderStuff(){

  // draw connecting line
  stroke(0);
  noFill();
  strokeWeight(1);
  line(x1p,50,xPlayHead,50);
  stroke(102,0,0);
  line(xPlayHead,50,x2p,50);
  
  //draw left dot
  stroke(0);
  fill(150,0,0);
  strokeWeight(1);
  rect(x1p - 2, 48, 4, 4);
  
  //draw right dot
  stroke(102,0,0);
  fill(0);
  strokeWeight(1);
  rect(x2p - 2, 48, 4, 4);
}


// Safely close the sound engine upon Browser shutdown.
public void stop(){
  Sonia.stop();
  super.stop();
}