e<!DOCTYPE html>
<html>
<head>
 <title>TetNet</title>
 <link href='https://fonts.googleapis.com/css?family=Inconsolata' rel='stylesheet' type='text/css'>
 <style>
   
</style>
<script src="lib/cerebrum.js"></script>
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</head>
<body>
  <div id="output" class="text"></div>
  <div id="score" class="text"></div>
  <div id="instructions" class="text"><br /><b>[Key Commands]</b><br />Load Fully Evolved Archive: [CTRL]<br />Speed Up: [E]<br />Slow Down: [D]<br />Toggle AI: [A]<br />Move Shape: [Arrow Keys]<br />Rotate Shape: [Up Arrow]<br />Drop Shape: [Down Arrow]<br />Save State: [Q]<br />Load State: [W]<br />Get Archive: [G]<br />Load Archive: [R]<br />Pick Shape: [I,O,T,S,Z,J,L]</div>
  <div id="signature" class="text">Created By Idrees Hassan<br />Questions? Just ask!<br /><a href="mailto:&#105;&#100;&#114;&#101;&#101;&#115;&#064;&#105;&#100;&#114;&#101;&#101;&#115;&#105;&#110;&#099;&#046;&#099;&#111;&#109;" target="_top">&#105;&#100;&#114;&#101;&#101;&#115;&#064;&#105;&#100;&#114;&#101;&#101;&#115;&#105;&#110;&#099;&#046;&#099;&#111;&#109;</a></div>
  <script src="./tetnet.js"></script>
  <script>
    $(window).keydown(function (e){
      if (e.ctrlKey) {
        var archiveJSON = $.ajax({
          url: "./archive.json",
          async: false
        }).responseText;
        loadArchive(archiveJSON);
        alert("Archive loaded successfully!");
      }
    });
  </script>
  <script type="text/javascript">
  </script>
</body>
</html>
body {
    background-color: #272821;
  }
  .text {
    color: #706C5A;
    font-family: Inconsolata, Courier, monospace;
    font-size: 20px;
  }
  #output {
    float: left;
    padding-left: 20%;
  }
  #score {
    padding-left: 55%;
  }
  #instructions {
    float: left;
    position: absolute;
    left: 1.5%;
    bottom: 3%;
    font-size: small;
    line-height: 110%;
  }
  #signature {
    float: right;
    position: absolute;
    right: 1.5%;
    bottom: 3%;
    font-size: small;
    line-height: 110%;
  }
  a:link {
    color: inherit;
  }
//Define 10x20 grid as the board
var grid = [
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0],
];

//Block shapes
var shapes = {
  I: [[0,0,0,0], [1,1,1,1], [0,0,0,0], [0,0,0,0]],
  J: [[2,0,0], [2,2,2], [0,0,0]],
  L: [[0,0,3], [3,3,3], [0,0,0]],
  O: [[4,4], [4,4]],
  S: [[0,5,5], [5,5,0], [0,0,0]],
  T: [[0,6,0], [6,6,6], [0,0,0]],
  Z: [[7,7,0], [0,7,7], [0,0,0]]
};

//Block colors
var colors = ["F92338", "C973FF", "1C76BC", "FEE356", "53D504", "36E0FF", "F8931D"];

//Used to help create a seeded generated random number for choosing shapes. makes results deterministic (reproducible) for debugging
var rndSeed = 1;

//BLOCK SHAPES
//coordinates and shape parameter of current block we can update
var currentShape = {x: 0, y: 0, shape: undefined};
//store shape of upcoming block
var upcomingShape;
//stores shapes
var bag = [];
//index for shapes in the bag
var bagIndex = 0;

//GAME VALUES
//Game score
var score = 0;
// game speed
var speed = 500;
// boolean for changing game speed
var changeSpeed = false;
//for storing current state, we can load later
var saveState;
//stores current game state
var roundState;
//list of available game speeds
var speeds = [500,100,1,0];
//inded in game speed array
var speedIndex = 0;
//turn ai on or off
var ai = true;
//drawing game vs updating algorithms
var draw = true;
//how many so far?
var movesTaken = 0;
//max number of moves allowed in a generation
var moveLimit = 500;
//consists of move the 7 move parameters
var moveAlgorithm = {};
//set to highest rate move 
var inspectMoveSelection = false;


//GENETIC ALGORITHM VALUES
//stores number of genomes, init at 50 
var populationSize = 50;
//stores genomes
var genomes = [];
//index of current genome in genomes array
var currentGenome = -1;
//generation number
var generation = 0;
//stores values for a generation
var archive = {
  populationSize: 0,
  currentGeneration: 0,
  elites: [],
  genomes: []
};
//rate of mutation
var mutationRate = 0.05;
//helps calculate mutation
var mutationStep = 0.2;


//main function, called on load
function initialize() {
  //init pop size
  archive.populationSize = populationSize;
  //get the next available shape from the bag
  nextShape();
  //applies the shape to the grid
  applyShape();
  //set both save state and current state from the game
  saveState = getState();
  roundState = getState();
  //create an initial population of genomes
  createInitialPopulation();
  //the game loop
  var loop = function(){
    //boolean for changing game speed
    if (changeSpeed) {
      //restart the clock
      //stop time
      clearInterval(interval);
      //set time, like a digital watch
      interval = setInterval(loop, speed);
      //and don't change it
      changeInterval = false;
    }
    if (speed === 0) {
      //no need to draw on screen elements
      draw = false;
      //updates the game (update fitness, make a move, evaluate next move)
      update();
      update();
      update();
    } else {
      //draw the elements
      draw = true;
    }
    //update regardless
    update();
    if (speed === 0) {
      //now draw elements
      draw = true;
      //now update the score
      updateScore();
    }
  };
  //timer interval
  var interval = setInterval(loop, speed);
}
document.onLoad = initialize();


//key options
window.onkeydown = function (event) {

  var characterPressed = String.fromCharCode(event.keyCode);
  if (event.keyCode == 38) {
    rotateShape();
  } else if (event.keyCode == 40) {
    moveDown();
  } else if (event.keyCode == 37) {
    moveLeft();
  } else if (event.keyCode == 39) {
    moveRight();
  } else if (shapes[characterPressed.toUpperCase()] !== undefined) {
    removeShape();
    currentShape.shape = shapes[characterPressed.toUpperCase()];
    applyShape();
  } else if (characterPressed.toUpperCase() == "Q") {
    saveState = getState();
  } else if (characterPressed.toUpperCase() == "W") {
    loadState(saveState);
  } else if (characterPressed.toUpperCase() == "D") {
    //slow down
    speedIndex--;
    if (speedIndex < 0) {
      speedIndex = speeds.length - 1;
    }
    speed = speeds[speedIndex];
    changeSpeed = true;
  } else if (characterPressed.toUpperCase() == "E") {
    //speed up
    speedIndex++;
    if (speedIndex >= speeds.length) {
      speedIndex = 0;
    }
    //adjust speed index
    speed = speeds[speedIndex];
    changeSpeed = true;
    //Turn on/off AI
  } else if (characterPressed.toUpperCase() == "A") {
    ai = !ai;
  } else if (characterPressed.toUpperCase() == "R") {
    //load saved generation values
    loadArchive(prompt("Insert archive:"));
  } else if (characterPressed.toUpperCase() == "G") {
    if (localStorage.getItem("archive") === null) {
      alert("No archive saved. Archives are saved after a generation has passed, and remain across sessions. Try again once a generation has passed");
    } else {
      prompt("Archive from last generation (including from last session):", localStorage.getItem("archive"));
    }
  } else if (characterPressed.toUpperCase() == "F") {
    //?
    inspectMoveSelection = !inspectMoveSelection;
  } else {
    return true;
  }
  //outputs game state to the screen (post key press)
  output();
  return false;
};

/**
 * Creates the initial population of genomes, each with random genes.
 */
 function createInitialPopulation() {
  //inits the array
  genomes = [];
  //for a given population size
  for (var i = 0; i < populationSize; i++) {
    //randomly initialize the 7 values that make up a genome
    //these are all weight values that are updated through evolution
    var genome = {
      //unique identifier for a genome
      id: Math.random(),
      //The weight of each row cleared by the given move. the more rows that are cleared, the more this weight increases
      rowsCleared: Math.random() - 0.5,
      //the absolute height of the highest column to the power of 1.5
      //added so that the algorithm can be able to detect if the blocks are stacking too high
      weightedHeight: Math.random() - 0.5,
      //The sum of all the column’s heights
      cumulativeHeight: Math.random() - 0.5,
      //the highest column minus the lowest column
      relativeHeight: Math.random() - 0.5,
      //the sum of all the empty cells that have a block above them (basically, cells that are unable to be filled)
      holes: Math.random() * 0.5,
      // the sum of absolute differences between the height of each column 
      //(for example, if all the shapes on the grid lie completely flat, then the roughness would equal 0).
      roughness: Math.random() - 0.5,
    };
    //add them to the array
    genomes.push(genome);
  }
  evaluateNextGenome();
 }

/**
 * Evaluates the next genome in the population. If there is none, evolves the population.
 */
 function evaluateNextGenome() {
  //increment index in genome array
  currentGenome++;
  //If there is none, evolves the population.
  if (currentGenome == genomes.length) {
    evolve();
  }
  //load current gamestate
  loadState(roundState);
  //reset moves taken
  movesTaken = 0;
  //and make the next move
  makeNextMove();
 }

/**
 * Evolves the entire population and goes to the next generation.
 */
 function evolve() {

  console.log("Generation " + generation + " evaluated.");
  //reset current genome for new generation
  currentGenome = 0;
  //increment generation
  generation++;
  //resets the game
  reset();
  //gets the current game state
  roundState = getState();
  //sorts genomes in decreasing order of fitness values
  genomes.sort(function(a, b) {
    return b.fitness - a.fitness;
  });
  //add a copy of the fittest genome to the elites list
  archive.elites.push(clone(genomes[0]));
  console.log("Elite's fitness: " + genomes[0].fitness);

  //remove the tail end of genomes, focus on the fittest
  while(genomes.length > populationSize / 2) {
    genomes.pop();
  }
  //sum of the fitness for each genome
  var totalFitness = 0;
  for (var i = 0; i < genomes.length; i++) {
    totalFitness += genomes[i].fitness;
  }

  //get a random index from genome array
  function getRandomGenome() {
    return genomes[randomWeightedNumBetween(0, genomes.length - 1)];
  }
  //create children array
  var children = [];
  //add the fittest genome to array
  children.push(clone(genomes[0]));
  //add population sized amount of children
  while (children.length < populationSize) {
    //crossover between two random genomes to make a child
    children.push(makeChild(getRandomGenome(), getRandomGenome()));
  }
  //create new genome array
  genomes = [];
  //to store all the children in
  genomes = genomes.concat(children);
  //store this in our archive
  archive.genomes = clone(genomes);
  //and set current gen
  archive.currentGeneration = clone(generation);
  console.log(JSON.stringify(archive));
  //store archive, thanks JS localstorage! (short term memory)
  localStorage.setItem("archive", JSON.stringify(archive));
}

/**
 * Creates a child genome from the given parent genomes, and then attempts to mutate the child genome.
 * @param  {Genome} mum The first parent genome.
 * @param  {Genome} dad The second parent genome.
 * @return {Genome}     The child genome.
 */
 function makeChild(mum, dad) {
  //init the child given two genomes (its 7 parameters + initial fitness value)
  var child = {
    //unique id
    id : Math.random(),
    //all these params are randomly selected between the mom and dad genome
    rowsCleared: randomChoice(mum.rowsCleared, dad.rowsCleared),
    weightedHeight: randomChoice(mum.weightedHeight, dad.weightedHeight),
    cumulativeHeight: randomChoice(mum.cumulativeHeight, dad.cumulativeHeight),
    relativeHeight: randomChoice(mum.relativeHeight, dad.relativeHeight),
    holes: randomChoice(mum.holes, dad.holes),
    roughness: randomChoice(mum.roughness, dad.roughness),
    //no fitness. yet.
    fitness: -1
  };
  //mutation time!

  //we mutate each parameter using our mutationstep
  if (Math.random() < mutationRate) {
    child.rowsCleared = child.rowsCleared + Math.random() * mutationStep * 2 - mutationStep;
  }
  if (Math.random() < mutationRate) {
    child.weightedHeight = child.weightedHeight + Math.random() * mutationStep * 2 - mutationStep;
  }
  if (Math.random() < mutationRate) {
    child.cumulativeHeight = child.cumulativeHeight + Math.random() * mutationStep * 2 - mutationStep;
  }
  if (Math.random() < mutationRate) {
    child.relativeHeight = child.relativeHeight + Math.random() * mutationStep * 2 - mutationStep;
  }
  if (Math.random() < mutationRate) {
    child.holes = child.holes + Math.random() * mutationStep * 2 - mutationStep;
  }
  if (Math.random() < mutationRate) {
    child.roughness = child.roughness + Math.random() * mutationStep * 2 - mutationStep;
  }
  return child;
 }

/**
 * Returns an array of all the possible moves that could occur in the current state, rated by the parameters of the current genome.
 * @return {Array} An array of all the possible moves that could occur.
 */
 function getAllPossibleMoves() {
  var lastState = getState();
  var possibleMoves = [];
  var possibleMoveRatings = [];
  var iterations = 0;
  //for each possible rotation
  for (var rots = 0; rots < 4; rots++) {

    var oldX = [];
    //for each iteration
    for (var t = -5; t <= 5; t++) {
      iterations++;
      loadState(lastState);
      //rotate shape
      for (var j = 0; j < rots; j++) {
        rotateShape();
      }
      //move left
      if (t < 0) {
        for (var l = 0; l < Math.abs(t); l++) {
          moveLeft();
        }
      //move right
      } else if (t > 0) {
        for (var r = 0; r < t; r++) {
          moveRight();
        }
      }
      //if the shape has moved at all
      if (!contains(oldX, currentShape.x)) {
        //move it down
        var moveDownResults = moveDown();
        while (moveDownResults.moved) {
          moveDownResults = moveDown();
        }
        //set the 7 parameters of a genome
        var algorithm = {
          rowsCleared: moveDownResults.rowsCleared,
          weightedHeight: Math.pow(getHeight(), 1.5),
          cumulativeHeight: getCumulativeHeight(),
          relativeHeight: getRelativeHeight(),
          holes: getHoles(),
          roughness: getRoughness()
        };
        //rate each move
        var rating = 0;
        rating += algorithm.rowsCleared * genomes[currentGenome].rowsCleared;
        rating += algorithm.weightedHeight * genomes[currentGenome].weightedHeight;
        rating += algorithm.cumulativeHeight * genomes[currentGenome].cumulativeHeight;
        rating += algorithm.relativeHeight * genomes[currentGenome].relativeHeight;
        rating += algorithm.holes * genomes[currentGenome].holes;
        rating += algorithm.roughness * genomes[currentGenome].roughness;
        //if the move loses the game, lower its rating
        if (moveDownResults.lose) {
          rating -= 500;
        }
        //push all possible moves, with their associated ratings and parameter values to an array
        possibleMoves.push({rotations: rots, translation: t, rating: rating, algorithm: algorithm});
        //update the position of old X value
        oldX.push(currentShape.x);
      }
    }
  }
  //get last state
  loadState(lastState);
  //return array of all possible moves
  return possibleMoves;
 }

/**
 * Returns the highest rated move in the given array of moves.
 * @param  {Array} moves An array of possible moves to choose from.
 * @return {Move}       The highest rated move from the moveset.
 */
 function getHighestRatedMove(moves) {
  //start these values off small
  var maxRating = -10000000000000;
  var maxMove = -1;
  var ties = [];
  //iterate through the list of moves
  for (var index = 0; index < moves.length; index++) {
    //if the current moves rating is higher than our maxrating
    if (moves[index].rating > maxRating) {
      //update our max values to include this moves values
      maxRating = moves[index].rating;
      maxMove = index;
      //store index of this move
      ties = [index];
    } else if (moves[index].rating == maxRating) {
      //if it ties with the max rating
      //add the index to the ties array
      ties.push(index);
    }
  }
  //eventually we'll set the highest move value to this move var
  var move = moves[ties[0]];
  //and set the number of ties
  move.algorithm.ties = ties.length;
  return move;
}

/**
 * Makes a move, which is decided upon using the parameters in the current genome.
 */
 function makeNextMove() {
  //increment number of moves taken
  movesTaken++;
  //if its over the limit of moves
  if (movesTaken > moveLimit) {
    //update this genomes fitness value using the game score
    genomes[currentGenome].fitness = clone(score);
    //and evaluates the next genome
    evaluateNextGenome();
  } else {
    //time to make a move

    //we're going to re-draw, so lets store the old drawing
    var oldDraw = clone(draw);
    draw = false;
    //get all the possible moves
    var possibleMoves = getAllPossibleMoves();
    //lets store the current state since we will update it
    var lastState = getState();
    //whats the next shape to play
    nextShape();
    //for each possible move 
    for (var i = 0; i < possibleMoves.length; i++) {
      //get the best move. so were checking all the possible moves, for each possible move. moveception.
      var nextMove = getHighestRatedMove(getAllPossibleMoves());
      //add that rating to an array of highest rates moves
      possibleMoves[i].rating += nextMove.rating;
    }
    //load current state
    loadState(lastState);
    //get the highest rated move ever
    var move = getHighestRatedMove(possibleMoves);
    //then rotate the shape as it says too
    for (var rotations = 0; rotations < move.rotations; rotations++) {
      rotateShape();
    }
    //and move left as it says
    if (move.translation < 0) {
      for (var lefts = 0; lefts < Math.abs(move.translation); lefts++) {
        moveLeft();
      }
      //and right as it says
    } else if (move.translation > 0) {
      for (var rights = 0; rights < move.translation; rights++) {
        moveRight();
      }
    }
    //update our move algorithm
    if (inspectMoveSelection) {
      moveAlgorithm = move.algorithm;
    }
    //and set the old drawing to the current
    draw = oldDraw;
    //output the state to the screen
    output();
    //and update the score
    updateScore();
  }
 }

/**
 * Updates the game.
 */
 function update() {
  //if we have our AI turned on and the current genome is nonzero
  //make a move
  if (ai && currentGenome != -1) {
    //move the shape down
    var results = moveDown();
    //if that didn't do anything
    if (!results.moved) {
      //if we lost
      if (results.lose) {
        //update the fitness
        genomes[currentGenome].fitness = clone(score);
        //move on to the next genome
        evaluateNextGenome();
      } else {
        //if we didnt lose, make the next move
        makeNextMove();
      }
    }
  } else {
        //else just move down
    moveDown();
  }
  //output the state to the screen
  output();
  //and update the score
  updateScore();
 }

/**
 * Moves the current shape down if possible.
 * @return {Object} The results of the movement of the piece.
 */
 function moveDown() {
  //array of possibilities
  var result = {lose: false, moved: true, rowsCleared: 0};
  //remove the shape, because we will draw a new one
  removeShape();
  //move it down the y axis
  currentShape.y++;
  //if it collides with the grid
  if (collides(grid, currentShape)) {
    //update its position
    currentShape.y--;
    //apply (stick) it to the grid 
    applyShape();
    //move on to the next shape in the bag
    nextShape();
    //clear rows and get number of rows cleared
    result.rowsCleared = clearRows();
    //check again if this shape collides with our grid
    if (collides(grid, currentShape)) {
      //reset
      result.lose = true;
      if (ai) {
      } else {
        reset();
      }
    }
    result.moved = false;
  }
  //apply shape, update the score and output the state to the screen
  applyShape();
  score++;
  updateScore();
  output();
  return result;
 }

/**
 * Moves the current shape to the left if possible.
 */
 function moveLeft() {
  //remove current shape, slide it over, if it collides though, slide it back
  removeShape();
  currentShape.x--;
  if (collides(grid, currentShape)) {
    currentShape.x++;
  }
  //apply the new shape
  applyShape();
 }

/**
 * Moves the current shape to the right if possible.
 */
 //same deal
 function moveRight() {
  removeShape();
  currentShape.x++;
  if (collides(grid, currentShape)) {
    currentShape.x--;
  }
  applyShape();
 }

/**
 * Rotates the current shape clockwise if possible.
 */
 //slide it if we can, else return to original rotation
 function rotateShape() {
  removeShape();
  currentShape.shape = rotate(currentShape.shape, 1);
  if (collides(grid, currentShape)) {
    currentShape.shape = rotate(currentShape.shape, 3);
  }
  applyShape();
 }

/**
 * Clears any rows that are completely filled.
 */
 function clearRows() {
  //empty array for rows to clear
  var rowsToClear = [];
  //for each row in the grid
  for (var row = 0; row < grid.length; row++) {
    var containsEmptySpace = false;
    //for each column
    for (var col = 0; col < grid[row].length; col++) {
      //if its empty
      if (grid[row][col] === 0) {
        //set this value to true
        containsEmptySpace = true;
      }
    }
    //if none of the columns in the row were empty
    if (!containsEmptySpace) {
      //add the row to our list, it's completely filled!
      rowsToClear.push(row);
    }
  }
  //increase score for up to 4 rows. it maxes out at 12000
  if (rowsToClear.length == 1) {
    score += 400;
  } else if (rowsToClear.length == 2) {
    score += 1000;
  } else if (rowsToClear.length == 3) {
    score += 3000;
  } else if (rowsToClear.length >= 4) {
    score += 12000;
  }
  //new array for cleared rows
  var rowsCleared = clone(rowsToClear.length);
  //for each value
  for (var toClear = rowsToClear.length - 1; toClear >= 0; toClear--) {
    //remove the row from the grid
    grid.splice(rowsToClear[toClear], 1);
  }
  //shift the other rows
  while (grid.length < 20) {
    grid.unshift([0,0,0,0,0,0,0,0,0,0]);
  }
  //return the rows cleared
  return rowsCleared;
 }

/**
 * Applies the current shape to the grid.
 */
 function applyShape() {
  //for each value in the current shape (row x column)
  for (var row = 0; row < currentShape.shape.length; row++) {
    for (var col = 0; col < currentShape.shape[row].length; col++) {
      //if its non-empty
      if (currentShape.shape[row][col] !== 0) {
        //set the value in the grid to its value. Stick the shape in the grid!
        grid[currentShape.y + row][currentShape.x + col] = currentShape.shape[row][col];
      }
    }
  }
 }

/**
 * Removes the current shape from the grid.
 */
 //same deal but reverse
 function removeShape() {
  for (var row = 0; row < currentShape.shape.length; row++) {
    for (var col = 0; col < currentShape.shape[row].length; col++) {
      if (currentShape.shape[row][col] !== 0) {
        grid[currentShape.y + row][currentShape.x + col] = 0;
      }
    }
  }
 }

/**
 * Cycles to the next shape in the bag.
 */
 function nextShape() {
  //increment the bag index
  bagIndex += 1;
  //if we're at the start or end of the bag
  if (bag.length === 0 || bagIndex == bag.length) {
    //generate a new bag of genomes
    generateBag();
  }
  //if almost at end of bag
  if (bagIndex == bag.length - 1) {
    //store previous seed
    var prevSeed = rndSeed;
    //generate upcoming shape
    upcomingShape = randomProperty(shapes);
    //set random seed
    rndSeed = prevSeed;
  } else {
    //get the next shape from our bag
    upcomingShape = shapes[bag[bagIndex + 1]];
  }
  //get our current shape from the bag
  currentShape.shape = shapes[bag[bagIndex]];
  //define its position
  currentShape.x = Math.floor(grid[0].length / 2) - Math.ceil(currentShape.shape[0].length / 2);
  currentShape.y = 0;
 }

/**
 * Generates the bag of shapes.
 */
 function generateBag() {
  bag = [];
  var contents = "";
  //7 shapes
  for (var i = 0; i < 7; i++) {
    //generate shape randomly
    var shape = randomKey(shapes);
    while(contents.indexOf(shape) != -1) {
      shape = randomKey(shapes);
    }
    //update bag with generated shape
    bag[i] = shape;
    contents += shape;
  }
  //reset bag index
  bagIndex = 0;
 }

/**
 * Resets the game.
 */
 function reset() {
  score = 0;
  grid = [[0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0],
  ];
  moves = 0;
  generateBag();
  nextShape();
 }

/**
 * Determines if the given grid and shape collide with one another.
 * @param  {Grid} scene  The grid to check.
 * @param  {Shape} object The shape to check.
 * @return {Boolean} Whether the shape and grid collide.
 */
 function collides(scene, object) {
  //for the size of the shape (row x column)
  for (var row = 0; row < object.shape.length; row++) {
    for (var col = 0; col < object.shape[row].length; col++) {
      //if its not empty
      if (object.shape[row][col] !== 0) {
        //if it collides, return true
        if (scene[object.y + row] === undefined || scene[object.y + row][object.x + col] === undefined || scene[object.y + row][object.x + col] !== 0) {
          return true;
        }
      }
    }
  }
  return false;
 }

//for rotating a shape, how many times should we rotate
 function rotate(matrix, times) {
  //for each time
  for (var t = 0; t < times; t++) {
    //flip the shape matrix
    matrix = transpose(matrix);
    //and for the length of the matrix, reverse each column
    for (var i = 0; i < matrix.length; i++) {
      matrix[i].reverse();
    }
  }
  return matrix;
 }
//flip row x column to column x row
 function transpose(array) {
  return array[0].map(function(col, i) {
    return array.map(function(row) {
      return row[i];
    });
  });
 }

/**
 * Outputs the state to the screen.
 */
 function output() {
  if (draw) {
    var output = document.getElementById("output");
    var html = "<h1>TetNet</h1><h5>Evolutionary approach to Tetris AI</h5>var grid = [";
    var space = "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";
    for (var i = 0; i < grid.length; i++) {
      if (i === 0) {
        html += "[" + grid[i] + "]";
      } else {
        html += "<br />" + space + "[" + grid[i] + "]";
      }
    }
    html += "];";
    for (var c = 0; c < colors.length; c++) {
      html = replaceAll(html, "," + (c + 1), ",<font color=\"" + colors[c] + "\">" + (c + 1) + "</font>");
      html = replaceAll(html, (c + 1) + ",", "<font color=\"" + colors[c] + "\">" + (c + 1) + "</font>,");
    }
    output.innerHTML = html;
  }
 }

/**
 * Updates the side information.
 */
 function updateScore() {
  if (draw) {
    var scoreDetails = document.getElementById("score");
    var html = "<br /><br /><h2>&nbsp;</h2><h2>Score: " + score + "</h2>";
    html += "<br /><b>--Upcoming--</b>";
    for (var i = 0; i < upcomingShape.length; i++) {
      var next =replaceAll((upcomingShape[i] + ""), "0", "&nbsp;");
      html += "<br />&nbsp;&nbsp;&nbsp;&nbsp;" + next;
    }
    for (var l = 0; l < 4 - upcomingShape.length; l++) {
      html += "<br />";
    }
    for (var c = 0; c < colors.length; c++) {
      html = replaceAll(html, "," + (c + 1), ",<font color=\"" + colors[c] + "\">" + (c + 1) + "</font>");
      html = replaceAll(html, (c + 1) + ",", "<font color=\"" + colors[c] + "\">" + (c + 1) + "</font>,");
    }
    html += "<br />Speed: " + speed;
    if (ai) {
      html += "<br />Moves: " + movesTaken + "/" + moveLimit;
      html += "<br />Generation: " + generation;
      html += "<br />Individual: " + (currentGenome + 1)  + "/" + populationSize;
      html += "<br /><pre style=\"font-size:12px\">" + JSON.stringify(genomes[currentGenome], null, 2) + "</pre>";
      if (inspectMoveSelection) {
        html += "<br /><pre style=\"font-size:12px\">" + JSON.stringify(moveAlgorithm, null, 2) + "</pre>";
      }
    }
    html = replaceAll(replaceAll(replaceAll(html, "&nbsp;,", "&nbsp;&nbsp;"), ",&nbsp;", "&nbsp;&nbsp;"), ",", "&nbsp;");
    scoreDetails.innerHTML = html;
  }
 }

/**
 * Returns the current game state in an object.
 * @return {State} The current game state.
 */
 function getState() {
  var state = {
    grid: clone(grid),
    currentShape: clone(currentShape),
    upcomingShape: clone(upcomingShape),
    bag: clone(bag),
    bagIndex: clone(bagIndex),
    rndSeed: clone(rndSeed),
    score: clone(score)
  };
  return state;
 }

/**
 * Loads the game state from the given state object.
 * @param  {State} state The state to load.
 */
 function loadState(state) {
  grid = clone(state.grid);
  currentShape = clone(state.currentShape);
  upcomingShape = clone(state.upcomingShape);
  bag = clone(state.bag);
  bagIndex = clone(state.bagIndex);
  rndSeed = clone(state.rndSeed);
  score = clone(state.score);
  output();
  updateScore();
 }

/**
 * Returns the cumulative height of all the columns.
 * @return {Number} The cumulative height.
 */
 function getCumulativeHeight() {
  removeShape();
  var peaks = [20,20,20,20,20,20,20,20,20,20];
  for (var row = 0; row < grid.length; row++) {
    for (var col = 0; col < grid[row].length; col++) {
      if (grid[row][col] !== 0 && peaks[col] === 20) {
        peaks[col] = row;
      }
    }
  }
  var totalHeight = 0;
  for (var i = 0; i < peaks.length; i++) {
    totalHeight += 20 - peaks[i];
  }
  applyShape();
  return totalHeight;
 }

/**
 * Returns the number of holes in the grid.
 * @return {Number} The number of holes.
 */
 function getHoles() {
  removeShape();
  var peaks = [20,20,20,20,20,20,20,20,20,20];
  for (var row = 0; row < grid.length; row++) {
    for (var col = 0; col < grid[row].length; col++) {
      if (grid[row][col] !== 0 && peaks[col] === 20) {
        peaks[col] = row;
      }
    }
  }
  var holes = 0;
  for (var x = 0; x < peaks.length; x++) {
    for (var y = peaks[x]; y < grid.length; y++) {
      if (grid[y][x] === 0) {
        holes++;
      }
    }
  }
  applyShape();
  return holes;
 }

/**
 * Returns an array that replaces all the holes in the grid with -1.
 * @return {Array} The modified grid array.
 */
 function getHolesArray() {
  var array = clone(grid);
  removeShape();
  var peaks = [20,20,20,20,20,20,20,20,20,20];
  for (var row = 0; row < grid.length; row++) {
    for (var col = 0; col < grid[row].length; col++) {
      if (grid[row][col] !== 0 && peaks[col] === 20) {
        peaks[col] = row;
      }
    }
  }
  for (var x = 0; x < peaks.length; x++) {
    for (var y = peaks[x]; y < grid.length; y++) {
      if (grid[y][x] === 0) {
        array[y][x] = -1;
      }
    }
  }
  applyShape();
  return array;
 }

/**
 * Returns the roughness of the grid.
 * @return {Number} The roughness of the grid.
 */
 function getRoughness() {
  removeShape();
  var peaks = [20,20,20,20,20,20,20,20,20,20];
  for (var row = 0; row < grid.length; row++) {
    for (var col = 0; col < grid[row].length; col++) {
      if (grid[row][col] !== 0 && peaks[col] === 20) {
        peaks[col] = row;
      }
    }
  }
  var roughness = 0;
  var differences = [];
  for (var i = 0; i < peaks.length - 1; i++) {
    roughness += Math.abs(peaks[i] - peaks[i + 1]);
    differences[i] = Math.abs(peaks[i] - peaks[i + 1]);
  }
  applyShape();
  return roughness;
 }

/**
 * Returns the range of heights of the columns on the grid.
 * @return {Number} The relative height.
 */
 function getRelativeHeight() {
  removeShape();
  var peaks = [20,20,20,20,20,20,20,20,20,20];
  for (var row = 0; row < grid.length; row++) {
    for (var col = 0; col < grid[row].length; col++) {
      if (grid[row][col] !== 0 && peaks[col] === 20) {
        peaks[col] = row;
      }
    }
  }
  applyShape();
  return Math.max.apply(Math, peaks) - Math.min.apply(Math, peaks);
 }

/**
 * Returns the height of the biggest column on the grid.
 * @return {Number} The absolute height.
 */
 function getHeight() {
  removeShape();
  var peaks = [20,20,20,20,20,20,20,20,20,20];
  for (var row = 0; row < grid.length; row++) {
    for (var col = 0; col < grid[row].length; col++) {
      if (grid[row][col] !== 0 && peaks[col] === 20) {
        peaks[col] = row;
      }
    }
  }
  applyShape();
  return 20 - Math.min.apply(Math, peaks);
 }

/**
 * Loads the archive given.
 * @param  {String} archiveString The stringified archive.
 */
 function loadArchive(archiveString) {
  archive = JSON.parse(archiveString);
  genomes = clone(archive.genomes);
  populationSize = archive.populationSize;
  generation = archive.currentGeneration;
  currentGenome = 0;
  reset();
  roundState = getState();
  console.log("Archive loaded!");
 }

/**
 * Clones an object.
 * @param  {Object} obj The object to clone.
 * @return {Object}     The cloned object.
 */
 function clone(obj) {
  return JSON.parse(JSON.stringify(obj));
 }

/**
 * Returns a random property from the given object.
 * @param  {Object} obj The object to select a property from.
 * @return {Property}     A random property.
 */
 function randomProperty(obj) {
  return(obj[randomKey(obj)]);
 }

/**
 * Returns a random property key from the given object.
 * @param  {Object} obj The object to select a property key from.
 * @return {Property}     A random property key.
 */
 function randomKey(obj) {
  var keys = Object.keys(obj);
  var i = seededRandom(0, keys.length);
  return keys[i];
 }

 function replaceAll(target, search, replacement) {
  return target.replace(new RegExp(search, 'g'), replacement);
 }

/**
 * Returns a random number that is determined from a seeded random number generator.
 * @param  {Number} min The minimum number, inclusive.
 * @param  {Number} max The maximum number, exclusive.
 * @return {Number}     The generated random number.
 */
 function seededRandom(min, max) {
  max = max || 1;
  min = min || 0;

  rndSeed = (rndSeed * 9301 + 49297) % 233280;
  var rnd = rndSeed / 233280;

  return Math.floor(min + rnd * (max - min));
 }

 function randomNumBetween(min, max) {
  return Math.floor(Math.random() * (max - min + 1) + min);
 }

 function randomWeightedNumBetween(min, max) {
  return Math.floor(Math.pow(Math.random(), 2) * (max - min + 1) + min);
 }

 function randomChoice(propOne, propTwo) {
  if (Math.round(Math.random()) === 0) {
    return clone(propOne);
  } else {
    return clone(propTwo);
  }
 }

 function contains(a, obj) {
  var i = a.length;
  while (i--) {
    if (a[i] === obj) {
      return true;
    }
  }
  return false;
 }

/**
 * A node, representing a biological neuron.
 * @param {Number} ID  The ID of the node.
 * @param {Number} val The value of the node.
 */
 function Node(ID, val) {
  this.id = ID;
  this.incomingConnections = [];
  this.outgoingConnections = [];
  if (val === undefined) {
    val = 0;
  }
  this.value = val;
  this.bias = 0;
 }

/**
 * A connection, representing a biological synapse.
 * @param {String} inID   The ID of the incoming node.
 * @param {String} outID  The ID of the outgoing node.
 * @param {Number} weight The weight of the connection.
 */
 function Connection(inID, outID, weight) {
  this.in = inID;
  this.out = outID;
  if (weight === undefined) {
    weight = 1;
  }
  this.id = inID + ":" + outID;
  this.weight = weight;
 }

/**
 * The neural network, containing nodes and connections.
 * @param {Object} config The configuration to use.
 */
 function Network(config) {
  this.nodes = {};
  this.inputs = [];
  this.hidden = [];
  this.outputs = [];
  this.connections = {};
  this.nodes.BIAS = new Node("BIAS", 1);

  if (config !== undefined) {
    var inputNum = config.inputNodes || 0;
    var hiddenNum = config.hiddenNodes || 0;
    var outputNum = config.outputNodes || 0;
    this.createNodes(inputNum, hiddenNum, outputNum);

    if (config.createAllConnections) {
      this.createAllConnections(true);
    }
  }
 }

/**
 * Populates the network with the given number of nodes of each type.
 * @param  {Number} inputNum The number of input nodes to create.
 * @param  {Number} hiddenNum The number of hidden nodes to create.
 * @param  {Number} outputNum The number of output nodes to create.
 */
 Network.prototype.createNodes = function(inputNum, hiddenNum, outputNum) {
  for (var i = 0; i < inputNum; i++) {
    this.addInput();
  }
  for (var j = 0; j < hiddenNum; j++) {
    this.addHidden();
  }
  for (var k = 0; k < outputNum; k++) {
    this.addOutput();
  }
 };

/**
 * @param {Number} [value] The value to set the node to [Default is 0].
 */
 Network.prototype.addInput = function(value) {
  var nodeID = "INPUT:" + this.inputs.length;
  if (value === undefined) {
    value = 0;
  }
  this.nodes[nodeID] = new Node(nodeID, value);
  this.inputs.push(nodeID);
 };

/**
 * Creates a hidden node.
 */
 Network.prototype.addHidden = function() {
  var nodeID = "HIDDEN:" + this.hidden.length;
  this.nodes[nodeID] = new Node(nodeID);
  this.hidden.push(nodeID);
 };

/**
 * Creates an output node.
 */
 Network.prototype.addOutput = function() {
  var nodeID = "OUTPUT:" + this.outputs.length;
  this.nodes[nodeID] = new Node(nodeID);
  this.outputs.push(nodeID);
 };

/**
 * Returns the node with the given ID.
 * @param  {String} nodeID The ID of the node to return.
 * @return {Node} The node with the given ID.
 */
 Network.prototype.getNodeByID = function(nodeID) {
  return this.nodes[nodeID];
 };

/**
 * Returns the node of the given type at the given index.
 * @param  {String} type  The type of node requested [Accepted arguments: "INPUT", "HIDDEN", "OUTPUT"].
 * @param  {Number} index The index of the node (from the array containing nodes of the requested type).
 * @return {Node} The node requested. Will return null if no node is found.
 */
 Network.prototype.getNode = function(type, index) {
  if (type.toUpperCase() == "INPUT") {
    return this.nodes[this.inputs[index]];
  } else  if (type.toUpperCase() == "HIDDEN") {
    return this.nodes[this.hidden[index]];
  } else  if (type.toUpperCase() == "OUTPUT") {
    return this.nodes[this.outputs[index]];
  }
  return null;
 };

/**
 * Returns the connection with the given ID.
 * @param  {String} connectionID The ID of the connection to return.
 * @return {Connection} The connection with the given ID.
 */
 Network.prototype.getConnection = function(connectionID) {
  return this.connections[connectionID];
 };

/**
 * Calculates the values of the nodes in the neural network.
 */
 Network.prototype.calculate = function calculate() {
  this.updateNodeConnections();
  for (var i = 0; i < this.hidden.length; i++) {
    this.calculateNodeValue(this.hidden[i]);
  }
  for (var j = 0; j < this.outputs.length; j++) {
    this.calculateNodeValue(this.outputs[j]);
  }
 };

/**
 * Updates the node's to reference the current connections.
 */
 Network.prototype.updateNodeConnections = function() {
  for (var nodeKey in this.nodes) {
    this.nodes[nodeKey].incomingConnections = [];
    this.nodes[nodeKey].outgoingConnections = [];
  }
  for (var connectionKey in this.connections) {
    this.nodes[this.connections[connectionKey].in].outgoingConnections.push(connectionKey);
    this.nodes[this.connections[connectionKey].out].incomingConnections.push(connectionKey);
  }
 };

/**
 * Calculates and updates the value of the node with the given ID. Node values are computed using a sigmoid function.
 * @param  {String} nodeId The ID of the node to update.
 */
 Network.prototype.calculateNodeValue = function(nodeID) {
  var sum = 0;
  for (var incomingIndex = 0; incomingIndex < this.nodes[nodeID].incomingConnections.length; incomingIndex++) {
    var connection = this.connections[this.nodes[nodeID].incomingConnections[incomingIndex]];
    sum += this.nodes[connection.in].value * connection.weight;
  }
  this.nodes[nodeID].value = sigmoid(sum);
 };

/**
 * Creates a connection with the given values.
 * @param {String} inID The ID of the node that the connection comes from. 
 * @param {String} outID The ID of the node that the connection enters.
 * @param {Number} [weight] The weight of the connection [Default is 1].
 */
 Network.prototype.addConnection = function(inID, outID, weight) {
  if (weight === undefined) {
    weight = 1;
  }
  this.connections[inID + ":" + outID] = new Connection(inID, outID, weight);
 };

 /**
 * Creates all possible connections between nodes, not including connections to the bias node.
 * @param  {Boolean} randomWeights Whether to choose a random weight between -1 and 1, or to default to 1.
 */
 Network.prototype.createAllConnections = function(randomWeights) {
  if (randomWeights === undefined) {
    randomWeights = false;
  }
  var weight = 1;
  for (var i = 0; i < this.inputs.length; i++) {
    for (var j = 0; j < this.hidden.length; j++) {
      if (randomWeights) {
        weight = Math.random() * 4 - 2;
      }
      this.addConnection(this.inputs[i], this.hidden[j], weight);
    }
    if (randomWeights) {
      weight = Math.random() * 4 - 2;
    }
    this.addConnection("BIAS", this.inputs[i], weight);
  }
  for (var k = 0; k < this.hidden.length; k++) {
    for (var l = 0; l < this.outputs.length; l++) {
      if (randomWeights) {
        weight = Math.random() * 4 - 2;
      }
      this.addConnection(this.hidden[k], this.outputs[l], weight);
    }
    if (randomWeights) {
      weight = Math.random() * 4 - 2;
    }
    this.addConnection("BIAS", this.hidden[k], weight);
  }
 };

/**
 * Sets the value of the node with the given ID to the given value.
 * @param {String} nodeID The ID of the node to modify.
 * @param {Number} value The value to set the node to.
 */
 Network.prototype.setNodeValue = function(nodeID, value) {
  this.nodes[nodeID].value = value;
 };

/**
 * Sets the values of the input neurons to the given values.
 * @param {Array} array An array of values to set the input node values to.
 */
 Network.prototype.setInputs = function(array) {
  for (var i = 0; i < array.length; i++) {
    this.nodes[this.inputs[i]].value = array[i];
  }
 };

/**
 * Sets the value of multiple nodes, given an object with node ID's as parameters and node values as values.
 * @param {Object} valuesByID The values to set the nodes to.
 */
 Network.prototype.setMultipleNodeValues = function(valuesByID) {
  for (var key in valuesByID) {
    this.nodes[key].value = valuesByID[key];
  }
 };


/**
 * A visualization of the neural network, showing all connections and nodes.
 * @param {Object} config The configuration to use.
 */
 function NetworkVisualizer(config) {
  this.canvas = "NetworkVisualizer";
  this.backgroundColor = "#FFFFFF";
  this.nodeRadius = -1;
  this.nodeColor = "grey";
  this.positiveConnectionColor = "green";
  this.negativeConnectionColor = "red";
  this.connectionStrokeModifier = 1;
  if (config !== undefined) {
    if (config.canvas !== undefined) {
      this.canvas = config.canvas;
    }
    if (config.backgroundColor !== undefined) {
      this.backgroundColor = config.backgroundColor;
    }
    if (config.nodeRadius !== undefined) {
      this.nodeRadius = config.nodeRadius;
    }
    if (config.nodeColor !== undefined) {
      this.nodeColor = config.nodeColor;
    }
    if (config.positiveConnectionColor !== undefined) {
      this.positiveConnectionColor = config.positiveConnectionColor;
    }
    if (config.negativeConnectionColor !== undefined) {
      this.negativeConnectionColor = config.negativeConnectionColor;
    }
    if (config.connectionStrokeModifier !== undefined) {
      this.connectionStrokeModifier = config.connectionStrokeModifier;
    }
  }
 }

/**
 * Draws the visualized network upon the canvas.
 * @param  {Network} network The network to visualize.
 */
 NetworkVisualizer.prototype.drawNetwork = function(network) {
  var canv = document.getElementById(this.canvas); 
  var ctx = canv.getContext("2d");
  var radius;
  ctx.fillStyle = this.backgroundColor;
  ctx.fillRect(0, 0, canv.width, canv.height);
  if (this.nodeRadius != -1) {
    radius = this.nodeRadius;
  } else {
    radius = Math.min(canv.width, canv.height) / (Math.max(network.inputs.length, network.hidden.length, network.outputs.length, 3)) / 2.5;
  }
  var nodeLocations = {};
  var inputX = canv.width / 5;
  for (var inputIndex = 0; inputIndex < network.inputs.length; inputIndex++) {
    nodeLocations[network.inputs[inputIndex]] = {x: inputX, y: canv.height / (network.inputs.length) * (inputIndex + 0.5)};
  }
  var hiddenX = canv.width / 2;
  for (var hiddenIndex = 0; hiddenIndex < network.hidden.length; hiddenIndex++) {
    nodeLocations[network.hidden[hiddenIndex]] = {x: hiddenX, y: canv.height / (network.hidden.length) * (hiddenIndex + 0.5)};
  }
  var outputX = canv.width / 5 * 4;
  for (var outputIndex = 0; outputIndex < network.outputs.length; outputIndex++) {
    nodeLocations[network.outputs[outputIndex]] = {x: outputX, y: canv.height / (network.outputs.length) * (outputIndex + 0.5)};
  }
  nodeLocations.BIAS = {x: canv.width / 3, y: radius / 2};
  for (var connectionKey in network.connections) {
    var connection = network.connections[connectionKey];
    //if (connection.in != "BIAS" && connection.out != "BIAS") {
      ctx.beginPath();
      ctx.moveTo(nodeLocations[connection.in].x, nodeLocations[connection.in].y);
      ctx.lineTo(nodeLocations[connection.out].x, nodeLocations[connection.out].y);
      if (connection.weight > 0) {
        ctx.strokeStyle = this.positiveConnectionColor;
      } else {
        ctx.strokeStyle = this.negativeConnectionColor;
      }
      ctx.lineWidth = connection.weight * this.connectionStrokeModifier;
      ctx.lineCap = "round";
      ctx.stroke();
    //}
  }
  for (var nodeKey in nodeLocations) {
    var node = network.getNodeByID(nodeKey);
    ctx.beginPath();
    if (nodeKey == "BIAS") {
      ctx.arc(nodeLocations[nodeKey].x, nodeLocations[nodeKey].y, radius / 2.2, 0, 2 * Math.PI);
    } else {
      ctx.arc(nodeLocations[nodeKey].x, nodeLocations[nodeKey].y, radius, 0, 2 * Math.PI);
    }
    ctx.fillStyle = this.backgroundColor;
    ctx.fill();
    ctx.strokeStyle = this.nodeColor;
    ctx.lineWidth = 3;
    ctx.stroke();
    ctx.globalAlpha = node.value;
    ctx.fillStyle = this.nodeColor;
    ctx.fill();
    ctx.globalAlpha = 1;  
  }
 };


 BackpropNetwork.prototype = new Network();
 BackpropNetwork.prototype.constructor = BackpropNetwork;

/**
 * Neural network that is optimized via backpropagation.
 * @param {Object} config The configuration to use.
 */
 function BackpropNetwork(config) {
  Network.call(this, config);
  this.inputData = {};
  this.targetData = {};
  this.learningRate = 0.5;
  this.step = 0;
  this.totalErrorSum = 0;
  this.averageError = [];

  if (config !== undefined) {
    if (config.learningRate !== undefined) {
      this.learningRate = config.learningRate;
    }
    if (config.inputData !== undefined) {
      this.setInputData(config.inputData);
    }
    if (config.targetData !== undefined) {
      this.setTargetData(config.targetData);
    }
  }
 }

/**
 * Backpropagates the neural network, using the input and training data given. Currently does not affect connections to the bias node.
 */
 BackpropNetwork.prototype.backpropagate = function() {
  this.step++;
  if (this.inputData[this.step] === undefined) {
    this.averageError.push(this.totalErrorSum / this.step);
    this.totalErrorSum = 0;
    this.step = 0;
  }
  for (var inputKey in this.inputData[this.step]) {
    this.nodes[inputKey].value = this.inputData[this.step][inputKey];
  }
  this.calculate();
  var currentTargetData = this.targetData[this.step];
  var totalError = this.getTotalError();
  this.totalErrorSum += totalError;
  var newWeights = {};
  for (var i = 0; i < this.outputs.length; i++) {
    var outputNode = this.nodes[this.outputs[i]];
    for (var j = 0; j < outputNode.incomingConnections.length; j++) {
      var hiddenToOutput = this.connections[outputNode.incomingConnections[j]];
      var deltaRuleResult = -(currentTargetData[this.outputs[i]] - outputNode.value) * outputNode.value * (1 - outputNode.value) * this.nodes[hiddenToOutput.in].value;
      newWeights[hiddenToOutput.id] = hiddenToOutput.weight - this.learningRate * deltaRuleResult;
    }
  }
  for (var k = 0; k < this.hidden.length; k++) {
    var hiddenNode = this.nodes[this.hidden[k]];
    for (var l = 0; l < hiddenNode.incomingConnections.length; l++) {
      var inputToHidden = this.connections[hiddenNode.incomingConnections[l]];
      var total = 0;
      for (var m = 0; m < hiddenNode.outgoingConnections.length; m++) {
        var outgoing = this.connections[hiddenNode.outgoingConnections[m]];
        var outgoingNode = this.nodes[outgoing.out];
        total += ((-(currentTargetData[outgoing.out] - outgoingNode.value)) * (outgoingNode.value * (1 - outgoingNode.value))) * outgoing.weight;
      }
      var outOverNet = hiddenNode.value * (1 - hiddenNode.value);
      var netOverWeight = this.nodes[inputToHidden.in].value;
      var result = total * outOverNet * netOverWeight;
      newWeights[inputToHidden.id] = inputToHidden.weight - this.learningRate * result;
    }
  }
  for (var key in newWeights) {
    this.connections[key].weight = newWeights[key];
  }
 };

/**
 * Adds a target result to the target data. This will be compared to the output in order to determine error.
 * @param {String} outputNodeID The ID of the output node whose value will be compared to the target.
 * @param {Number} target The value to compare against the output when checking for errors.
 */
 BackpropNetwork.prototype.addTarget = function(outputNodeID, target) {
  this.targetData[outputNodeID] = target;
 };

/**
 * Sets the input data that will be compared to the target data.
 * @param {Array} array An array containing the data to be inputted (ex. [0, 1] will set the first input node
 * to have a value of 0 and the second to have a value of 1). Each array argument represents a single
 * step, and will be compared against the parallel set in the target data.
 */
 BackpropNetwork.prototype.setInputData = function() {
  var all = arguments;
  if (arguments.length == 1 && arguments[0].constructor == Array) {
    all = arguments[0];
  } 
  this.inputData = {};
  for (var i = 0; i < all.length; i++) {
    var data = all[i];
    var instance = {};
    for (var j = 0; j < data.length; j++) {
      instance["INPUT:" + j] = data[j]; 
    }
    this.inputData[i] = instance;
  }
 };

/**
 * Sets the target data that will be used to check for total error.
 * @param {Array} array An array containing the data to be compared against (ex. [0, 1] will compare the first
 * output node against 0 and the second against 1). Each array argument represents a single step.
 */
 BackpropNetwork.prototype.setTargetData = function() {
  var all = arguments;
  if (arguments.length == 1 && arguments[0].constructor == Array) {
    all = arguments[0];
  } 
  this.targetData = {};
  for (var i = 0; i < all.length; i++) {
    var data = all[i];
    var instance = {};
    for (var j = 0; j < data.length; j++) {
      instance["OUTPUT:" + j] = data[j]; 
    }
    this.targetData[i] = instance;
  }
 };

/**
 * Calculates the total error of all the outputs' values compared to the target data.
 * @return {Number} The total error.
 */
 BackpropNetwork.prototype.getTotalError = function() {
  var sum = 0;
  for (var i = 0; i < this.outputs.length; i++) {
    sum += Math.pow(this.targetData[this.step][this.outputs[i]] - this.nodes[this.outputs[i]].value, 2) / 2;
  }
  return sum;
 };

/**
 * A gene containing the data for a single connection in the neural network.
 * @param {String} inID       The ID of the incoming node.
 * @param {String} outID      The ID of the outgoing node.
 * @param {Number} weight     The weight of the connection to create.
 * @param {Number} innovation The innovation number of the gene.
 * @param {Boolean} enabled   Whether the gene is expressed or not.
 */ 
 function Gene(inID, outID, weight, innovation, enabled) {
  if (innovation === undefined) {
    innovation = 0;
  }
  this.innovation = innovation;
  this.in = inID;
  this.out = outID;
  if (weight === undefined) {
    weight = 1;
  }
  this.weight = weight;
  if (enabled === undefined) {
    enabled = true;
  }
  this.enabled = enabled;
 }

/**
 * Returns the connection that the gene represents.
 * @return {Connection} The generated connection.
 */
 Gene.prototype.getConnection = function() {
  return new Connection(this.in, this.out, this.weight);
 };

/**
 * A genome containing genes that will make up the neural network.
 * @param {Number} inputNodes  The number of input nodes to create.
 * @param {Number} outputNodes The number of output nodes to create.
 */
 function Genome(inputNodes, outputNodes) {
  this.inputNodes = inputNodes;
  this.outputNodes = outputNodes;
  this.genes = [];
  this.fitness = -Number.MAX_VALUE;
  this.globalRank = 0;
  this.randomIdentifier = Math.random();
 }

 Genome.prototype.containsGene = function(inID, outID) {
  for (var i = 0; i < this.genes.length; i++) {
    if (this.genes[i].inID == inID && this.genes[i].outID == outID) {
      return true;
    }
  }
  return false;
 };

/**
 * A species of genomes that contains genomes which closely resemble one another, enough so that they are able to breed.
 */
 function Species() {
  this.genomes = [];
  this.averageFitness = 0;
 }

/**
 * Culls the genomes to the given amount by removing less fit genomes.
 * @param  {Number} [remaining] The number of genomes to cull to [Default is half the size of the species (rounded up)].
 */
 Species.prototype.cull = function(remaining) {
  this.genomes.sort(compareGenomesDescending);
  if (remaining === undefined) {
    remaining = Math.ceil(this.genomes.length / 2);
  }
  while (this.genomes.length > remaining) {
    this.genomes.pop();
  }
 };

/**
 * Calculates the average fitness of the species.
 */
 Species.prototype.calculateAverageFitness = function() {
  var sum = 0;
  for (var j = 0; j < this.genomes.length; j++) {
    sum += this.genomes[j].fitness;
  }
  this.averageFitness = sum / this.genomes.length;
 };

/**
 * Returns the network that the genome represents.
 * @return {Network} The generated network.
 */
 Genome.prototype.getNetwork = function() {
  var network = new Network();
  network.createNodes(this.inputNodes, 0, this.outputNodes);
  for (var i = 0; i < this.genes.length; i++) {
    var gene = this.genes[i];
    if (gene.enabled) {
      if (network.nodes[gene.in] === undefined && gene.in.indexOf("HIDDEN") != -1) {
        network.nodes[gene.in] = new Node(gene.in);
        network.hidden.push(gene.in);
      }
      if (network.nodes[gene.out] === undefined && gene.out.indexOf("HIDDEN") != -1) {
        network.nodes[gene.out] = new Node(gene.out);
        network.hidden.push(gene.out);
      }
      network.addConnection(gene.in, gene.out, gene.weight);
    }
  }
  return network;
 };

/**
 * Creates and optimizes neural networks via neuroevolution, using the Neuroevolution of Augmenting Topologies method.
 * @param {Object} config The configuration to use.
 */
 function Neuroevolution(config) {
  this.genomes = [];
  this.populationSize = 100;
  this.mutationRates = {
    createConnection: 0.05,
    createNode: 0.02,
    modifyWeight: 0.15,
    enableGene: 0.05,
    disableGene: 0.1,
    createBias: 0.1,
    weightMutationStep: 2
  };
  this.inputNodes = 0;
  this.outputNodes = 0;
  this.elitism = true;
  this.deltaDisjoint = 2;
  this.deltaWeights = 0.4;
  this.deltaThreshold = 2;
  this.hiddenNodeCap = 10;
  this.fitnessFunction = function (network) {log("ERROR: Fitness function not set"); return -1;};
  this.globalInnovationCounter = 1;
  this.currentGeneration = 0;
  this.species = [];
  this.newInnovations = {};
  if (config !== undefined) {
    if (config.populationSize !== undefined) {
      this.populationSize = config.populationSize;
    }
    if (config.inputNodes !== undefined) {
      this.inputNodes = config.inputNodes;
    }
    if (config.outputNodes !== undefined) {
      this.outputNodes = config.outputNodes;
    }
    if (config.mutationRates !== undefined) {
      var configRates = config.mutationRates;
      if (configRates.createConnection !== undefined) {
        this.mutationRates.createConnection = configRates.createConnection;
      }
      if (configRates.createNode !== undefined) {
        this.mutationRates.createNode = configRates.createNode;
      }
      if (configRates.modifyWeight !== undefined) {
        this.mutationRates.modifyWeight = configRates.modifyWeight;
      }
      if (configRates.enableGene !== undefined) {
        this.mutationRates.enableGene = configRates.enableGene;
      }
      if (configRates.disableGene !== undefined) {
        this.mutationRates.disableGene = configRates.disableGene;
      }
      if (configRates.createBias !== undefined) {
        this.mutationRates.createBias = configRates.createBias;
      }
      if (configRates.weightMutationStep !== undefined) {
        this.mutationRates.weightMutationStep = configRates.weightMutationStep;
      }
    }
    if (config.elitism !== undefined) {
      this.elitism = config.elitism;
    }
    if (config.deltaDisjoint !== undefined) {
      this.deltaDisjoint = config.deltaDisjoint;
    }
    if (config.deltaWeights !== undefined) {
      this.deltaWeights = config.deltaWeights;
    }
    if (config.deltaThreshold !== undefined) {
      this.deltaThreshold = config.deltaThreshold;
    }
    if (config.hiddenNodeCap !== undefined) {
      this.hiddenNodeCap = config.hiddenNodeCap;
    }
  }
 }

/**
 * Populates the population with empty genomes, and then mutates the genomes.
 */
 Neuroevolution.prototype.createInitialPopulation = function() {
  this.genomes = [];
  for (var i = 0; i < this.populationSize; i++) {
    var genome = this.linkMutate(new Genome(this.inputNodes, this.outputNodes));
    this.genomes.push(genome);
  }
  this.mutate();
 };

/**
 * Mutates the entire population based on the mutation rates.
 */
 Neuroevolution.prototype.mutate = function() {
  for (var i = 0; i < this.genomes.length; i++) {
    var network = this.genomes[i].getNetwork();
    if (Math.random() < this.mutationRates.createConnection) {
      this.genomes[i] = this.linkMutate(this.genomes[i]);
    }
    if (Math.random() < this.mutationRates.createNode && this.genomes[i].genes.length > 0 && network.hidden.length < this.hiddenNodeCap) {
      var geneIndex = randomNumBetween(0, this.genomes[i].genes.length - 1);
      var gene = this.genomes[i].genes[geneIndex];
      if (gene.enabled && gene.in.indexOf("INPUT") != -1 && gene.out.indexOf("OUTPUT") != -1) {
        var newNum = -1;
        var found = true;
        while (found) {
          newNum++;
          found = false;
          for (var j = 0; j < this.genomes[i].genes.length; j++) {
            if (this.genomes[i].genes[j].in.indexOf("HIDDEN:" + newNum) != -1 || this.genomes[i].genes[j].out.indexOf("HIDDEN:" + newNum) != -1) {
              found = true;
            }
          }
        }
        if (newNum < this.hiddenNodeCap) {
          var nodeName = "HIDDEN:" + newNum;
          this.genomes[i].genes[geneIndex].enabled = false;
          this.genomes[i].genes.push(new Gene(gene.in, nodeName, 1, this.globalInnovationCounter));
          this.globalInnovationCounter++;
          this.genomes[i].genes.push(new Gene(nodeName, gene.out, gene.weight, this.globalInnovationCounter));
          this.globalInnovationCounter++;
          network = this.genomes[i].getNetwork();
        }
      }
    }
    if (Math.random() < this.mutationRates.createBias) {
      if (Math.random() > 0.5 && network.inputs.length > 0) {
        var inputIndex = randomNumBetween(0, network.inputs.length - 1);
        if (network.getConnection("BIAS:" + network.inputs[inputIndex]) === undefined) {
          this.genomes[i].genes.push(new Gene("BIAS", network.inputs[inputIndex]));
        }
      } else if (network.hidden.length > 0) {
        var hiddenIndex = randomNumBetween(0, network.hidden.length - 1);
        if (network.getConnection("BIAS:" + network.hidden[hiddenIndex]) === undefined) {
          this.genomes[i].genes.push(new Gene("BIAS", network.hidden[hiddenIndex]));
        }
      }
    }
    for (var k = 0; k < this.genomes[i].genes.length; k++) {
      this.genomes[i].genes[k] = this.pointMutate(this.genomes[i].genes[k]);
    }

  }
 };

/**
 * Attempts to create a new connection gene in the given genome.
 * @param  {Genome} genome The genome to mutate.
 * @return {Genome} The mutated genome.
 */
 Neuroevolution.prototype.linkMutate = function(genome) {
  var network = genome.getNetwork();
  var inNode = "";
  var outNode = "";
  if (Math.random() < 1/3 || network.hidden.length <= 0) {
    inNode = network.inputs[randomNumBetween(0, this.inputNodes - 1)];
    outNode = network.outputs[randomNumBetween(0, this.outputNodes - 1)];
  } else if (Math.random() < 2/3) {
    inNode = network.inputs[randomNumBetween(0, this.inputNodes - 1)];
    outNode = network.hidden[randomNumBetween(0, network.hidden.length - 1)];
  } else {
    inNode = network.hidden[randomNumBetween(0, network.hidden.length - 1)];
    outNode = network.outputs[randomNumBetween(0, this.outputNodes - 1)];
  }
  if (!genome.containsGene(inNode, outNode)) {
    var newGene = new Gene(inNode, outNode, Math.random() * 2 - 1);
    if (this.newInnovations[newGene.in + ":" + newGene.out] === undefined) {
      this.newInnovations[newGene.in + ":" + newGene.out] = this.globalInnovationCounter;
      newGene.innovation = this.globalInnovationCounter;
      this.globalInnovationCounter++;
    } else {
      newGene.innovation = this.newInnovations[newGene.in + ":" + newGene.out];
    }
    genome.genes.push(newGene);
  }
  return genome;
 };

 /**
 * Mutates the given gene based on the mutation rates.
 * @param  {Gene} gene The gene to mutate.
 * @return {Gene} The mutated gene.
 */
 Neuroevolution.prototype.pointMutate = function(gene) {
  if (Math.random() < this.mutationRates.modifyWeight) {
    gene.weight = gene.weight + Math.random() * this.mutationRates.weightMutationStep * 2 - this.mutationRates.weightMutationStep; 
  }
  if (Math.random() < this.mutationRates.enableGene) {
    gene.enabled = true;
  }
  if (Math.random() < this.mutationRates.disableGene) {
    gene.enabled = false;
  }
  return gene;
 };

/**
 * Crosses two parent genomes with one another, forming a child genome.
 * @param  {Genome} firstGenome  The first genome to mate.
 * @param  {Genome} secondGenome The second genome to mate.
 * @return {Genome} The resultant child genome.
 */
 Neuroevolution.prototype.crossover = function(firstGenome, secondGenome) {
  var child = new Genome(firstGenome.inputNodes, firstGenome.outputNodes);
  var firstInnovationNumbers = {};
  for (var h = 0; h < firstGenome.genes.length; h++) {
    firstInnovationNumbers[firstGenome.genes[h].innovation] = h;
  }
  var secondInnovationNumbers = {};
  for (var j = 0; j < secondGenome.genes.length; j++) {
    secondInnovationNumbers[secondGenome.genes[j].innovation] = j;
  }
  for (var i = 0; i < firstGenome.genes.length; i++) {
    var geneToClone;
    if (secondInnovationNumbers[firstGenome.genes[i].innovation] !== undefined) {
      if (Math.random() < 0.5) {
        geneToClone = firstGenome.genes[i];
      } else {
        geneToClone = secondGenome.genes[secondInnovationNumbers[firstGenome.genes[i].innovation]];
      }
    } else {
      geneToClone = firstGenome.genes[i];
    }
    child.genes.push(new Gene(geneToClone.in, geneToClone.out, geneToClone.weight, geneToClone.innovation, geneToClone.enabled));     
  }
  for (var k = 0; k < secondGenome.genes.length; k++) {
    if (firstInnovationNumbers[secondGenome.genes[k].innovation] === undefined) {
      var secondDisjoint = secondGenome.genes[k];
      child.genes.push(new Gene(secondDisjoint.in, secondDisjoint.out, secondDisjoint.weight, secondDisjoint.innovation, secondDisjoint.enabled));    
    }
  }
  return child;
 };

/**
 * Evolves the population by creating a new generation and mutating the children.
 */
 Neuroevolution.prototype.evolve = function() {
  this.currentGeneration++;
  this.newInnovations = {};
  this.genomes.sort(compareGenomesDescending);
  var children = [];
  this.speciate();
  this.cullSpecies();
  this.calculateSpeciesAvgFitness();

  var totalAvgFitness = 0;
  var avgFitnesses = [];
  for (var s = 0; s < this.species.length; s++) {
    totalAvgFitness += this.species[s].averageFitness;
    avgFitnesses.push(this.species[s].averageFitness);
  }
  var arr = [];
  for (var j = 0; j < this.species.length; j++) {
    var childrenToMake = Math.floor(this.species[j].averageFitness / totalAvgFitness * this.populationSize);
    arr.push(childrenToMake);
    if (childrenToMake > 0) {
      children.push(this.species[j].genomes[0]);
    }
    for (var c = 0; c < childrenToMake - 1; c++) {
      children.push(this.makeBaby(this.species[j]));
    }
  }
  while (children.length < this.populationSize) {
    children.push(this.makeBaby(this.species[randomNumBetween(0, this.species.length - 1)]));
  }
  this.genomes = [];
  this.genomes = this.genomes.concat(children);
  this.mutate();
  this.speciate();
  log(this.species.length);
 };

/**
 * Sorts the genomes into different species.
 */
 Neuroevolution.prototype.speciate = function() {
  this.species = [];
  for (var i = 0; i < this.genomes.length; i++) {
    var placed = false;
    for (var j = 0; j < this.species.length; j++) {
      if (!placed && this.species[j].genomes.length > 0 && this.isSameSpecies(this.genomes[i], this.species[j].genomes[0])) {
        this.species[j].genomes.push(this.genomes[i]);
        placed = true;
      }
    }
    if (!placed) {
      var newSpecies = new Species();
      newSpecies.genomes.push(this.genomes[i]);
      this.species.push(newSpecies);
    }
  }
 };

/**
 * Culls all the species to the given amount by removing less fit members of each species.
 * @param  {Number} [remaining] The number of genomes to cull all the species to [Default is half the size of the species].
 */
 Neuroevolution.prototype.cullSpecies = function(remaining) {
  var toRemove = [];
  for (var i = 0; i < this.species.length; i++) {
    this.species[i].cull(remaining);
    if (this.species[i].genomes.length < 1) {
      toRemove.push(this.species[i]);
    }
  }
  for (var r = 0; r < toRemove.length; r++) {
    this.species.remove(toRemove[r]);
  }
 };

/**
 * Calculates the average fitness of all the species.
 */
 Neuroevolution.prototype.calculateSpeciesAvgFitness = function() {
  for (var i = 0; i < this.species.length; i++) {
    this.species[i].calculateAverageFitness();
  }
 };

/**
 * Creates a baby in the given species, with fitter genomes having a higher chance to reproduce.
 * @param  {Species} species The species to create a baby in.
 * @return {Genome} The resultant baby.
 */
 Neuroevolution.prototype.makeBaby = function(species) {
  var mum = species.genomes[randomWeightedNumBetween(0, species.genomes.length - 1)];
  var dad = species.genomes[randomWeightedNumBetween(0, species.genomes.length - 1)];
  return this.crossover(mum, dad);
 };

/**
 * Calculates the fitness of all the genomes in the population.
 */
 Neuroevolution.prototype.calculateFitnesses = function() {
  for (var i = 0; i < this.genomes.length; i++) {
    this.genomes[i].fitness = this.fitnessFunction(this.genomes[i].getNetwork());
  }
 };

/**
 * Returns the relative compatibility metric for the given genomes.
 * @param  {Genome} genomeA The first genome to compare.
 * @param  {Genome} genomeB The second genome to compare.
 * @return {Number} The relative compatibility metric. 
 */
 Neuroevolution.prototype.getCompatibility = function(genomeA, genomeB) {
  var disjoint = 0;
  var totalWeight = 0;
  var aInnovationNums = {};
  for (var i = 0; i < genomeA.genes.length; i++) {
    aInnovationNums[genomeA.genes[i].innovation] = i;
  }
  var bInnovationNums = [];
  for (var j = 0; j < genomeB.genes.length; j++) {
    bInnovationNums[genomeB.genes[j].innovation] = j;
  }
  for (var k = 0; k < genomeA.genes.length; k++) {
    if (bInnovationNums[genomeA.genes[k].innovation] === undefined) {
      disjoint++;
    } else {
      totalWeight += Math.abs(genomeA.genes[k].weight - genomeB.genes[bInnovationNums[genomeA.genes[k].innovation]].weight);
    }
  }
  for (var l = 0; l < genomeB.genes.length; l++) {
    if (aInnovationNums[genomeB.genes[l].innovation] === undefined) {
      disjoint++;
    }
  }
  var n = Math.max(genomeA.genes.length, genomeB.genes.length);
  return this.deltaDisjoint * (disjoint / n) + this.deltaWeights * (totalWeight / n);
 };

/**
 * Determines whether the given genomes are from the same species.
 * @param  {Genome}  genomeA The first genome to compare.
 * @param  {Genome}  genomeB The second genome to compare.
 * @return {Boolean} Whether the given genomes are from the same species.
 */
 Neuroevolution.prototype.isSameSpecies = function(genomeA, genomeB) {
  return this.getCompatibility(genomeA, genomeB) < this.deltaThreshold;
 };

/**
 * Returns the genome with the highest fitness in the population.
 * @return {Genome} The elite genome.
 */
 Neuroevolution.prototype.getElite = function() {
  this.genomes.sort(compareGenomesDescending);
  return this.genomes[0];
 };


//Private static functions
function sigmoid(t) {
  return 1 / (1 + Math.exp(-t));
}

function randomNumBetween(min, max) {
  return Math.floor(Math.random() * (max - min + 1) + min);
}

function randomWeightedNumBetween(min, max) {
  return Math.floor(Math.pow(Math.random(), 2) * (max - min + 1) + min);
}

function compareGenomesAscending(genomeA, genomeB) {
  return genomeA.fitness - genomeB.fitness;
}

function compareGenomesDescending(genomeA, genomeB) {
  return genomeB.fitness - genomeA.fitness;
}

Array.prototype.remove = function() {
  var what, a = arguments, L = a.length, ax;
  while (L && this.length) {
    what = a[--L];
    while ((ax = this.indexOf(what)) !== -1) {
      this.splice(ax, 1);
    }
  }
  return this;
};


function log(text) {
  console.log(text);
}

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