// Daniel Shiffman

// http://natureofcode.com

​

// Koch Curve

// A class to manage the list of line segments in the snowflake pattern

​

function KochFractal() {

  this.start = createVector(0,height-20);   // A p5.Vector for the start

  this.end = createVector(width,height-20); // A p5.Vector for the end

  this.lines = [];                         // An array to keep track of all the lines

  this.count = 0;

  this.nextLevel = function() {  

    // For every line that is in the arraylist

    // create 4 more lines in a new arraylist

    this.lines = this.iterate(this.lines);

    this.count++;

  }

​

  this.restart = function() { 

    this.count = 0;      // Reset count

    this.lines = [];  // Empty the array list

    this.lines.push(new KochLine(this.start,this.end));  // Add the initial line (from one end p5.Vector to the other)

  }

  this.restart();

​

  this.getCount = function() {

    return this.count;

  }

​

  // This is easy, just draw all the lines

  this.render = function() {

    for(var i = 0; i < this.lines.length; i++) {

      this.lines[i].display();

    }

  }

​

  // This is where the **MAGIC** happens

  // Step 1: Create an empty arraylist

  // Step 2: For every line currently in the arraylist

  //   - calculate 4 line segments based on Koch algorithm

  //   - add all 4 line segments into the new arraylist

  // Step 3: Return the new arraylist and it becomes the list of line segments for the structure

​

  // As we do this over and over again, each line gets broken into 4 lines, which gets broken into 4 lines, and so on. . . 

  this.iterate = function(before) {

    var now = [];    // Create emtpy list

    for(var i = 0; i < this.lines.length; i++) {

      var l = this.lines[i];

      // Calculate 5 koch p5.Vectors (done for us by the line object)

      var a = l.kochA();                 

      var b = l.kochB();

      var c = l.kochC();

      var d = l.kochD();

      var e = l.kochE();

      // Make line segments between all the p5.Vectors and add them

      now.push(new KochLine(a,b));

      now.push(new KochLine(b,c));

      now.push(new KochLine(c,d));

      now.push(new KochLine(d,e));

    }

    return now;

  }

}