//Example from Processing Handbook 2nd Edition
//P.421 Chapter 28 Example 15
//Shifting data to the right

int[] y;

void setup() {
  size(800, 600);
  y = new int[width];
}

void draw() {
  background(204);
  // Read the array from the end to the 
  // beginning to avoid overwriting the data
  for (int i = y.length-1; i > 0; i--) { 
    y[i] = y[i-1];
  } 
  // Add new values to the beginning
  y[0] = mouseY;
  // Display each pair of values as a line
  for (int i = 1; i < y.length; i++) {
    line(i, y[i], i-1, y[i-1]);
  }
}