commit e4346ae56e5ea05e1604e6099536f2133e14abde
Author: Henry Wang <wanghenry1998@gmail.com>
Date:   Mon Feb 20 23:54:44 2017 -0600

    Initial tests

diff --git a/game.js b/game.js
new file mode 100644
index 0000000..5d466b7
--- /dev/null
+++ b/game.js
@@ -0,0 +1,617 @@
+
+
+//Thanks to https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random
+function getRandomInt(min, max) {
+  min = Math.ceil(min);
+  max = Math.floor(max);
+  return Math.floor(Math.random() * (max - min)) + min;
+}
+
+/**
+ * Provides requestAnimationFrame in a cross browser way.
+ * @author paulirish / http://paulirish.com/
+ */
+if ( !window.requestAnimationFrame ) {
+  window.requestAnimationFrame = ( function() {
+    return window.webkitRequestAnimationFrame ||
+    window.mozRequestAnimationFrame ||
+    window.oRequestAnimationFrame ||
+    window.msRequestAnimationFrame ||
+    function( /* function FrameRequestCallback */ callback, /* DOMElement Element */ element ) {
+      window.setTimeout( callback, 1000 / 60 );
+    };
+  })();
+}
+var Tail = (function() {
+  var CELL_WIDTH = 30;
+  var GRID_SIZE = 200;
+  
+  function TailMove(orientation)
+  {
+    this.move = 1;
+    Object.defineProperty(this, "orientation", {
+      value: orientation,
+      enumerable: true
+    });
+  }
+  
+  function Tail(player)
+  {
+    var _this = this;
+    var data = {
+      tail: [],
+      tailGrid: [],
+      prev: null,
+      startRow: 0,
+      startCol: 0,
+      prevRow: 0, 
+      prevCol: 0,
+      player: player
+    };
+    this.addTail = addTail.bind(this, data);
+    this.hitsTail = hitsTail.bind(this, data);
+    this.render = function(ctx) {var prev = []; iterate(data, render.bind(_this, data, prev, ctx), VOID); };
+    this.move = move.bind(this, data);
+    Object.defineProperty(this, "moves", {
+      get: function() {return data.tail.slice(0);},
+      enumerable: true
+    });
+  }
+  
+  //Instance methods.
+  function addTail(data, orientation)
+  {
+    var prev = data.prev;
+    var tail = data.tail;
+    if (!prev || prev.orientation !== orientation)
+    {
+      prev = data.prev = new TailMove(orientation);
+      data.tail.push(prev);
+    }
+    else
+      prev.move++;
+    
+    var r = data.prevRow, c = data.prevCol;
+    if (!data.tailGrid[r])
+      data.tailGrid[r] = [];
+    data.tailGrid[r][c] = true;
+    
+    switch (orientation)
+    {
+      case 0: data.prevRow--; break; //UP
+      case 1: data.prevCol++; break; //RIGHT
+      case 2: data.prevRow++; break; //DOWN
+      case 3: data.prevCol--; break; //LEFT
+    }
+  }
+  
+  function iterate(data, callback, reducer)
+  {
+    var r = data.startRow;
+    var c = data.startCol; 
+    var other;
+    
+    var val;
+    for (var i = 0; i < data.tail.length; i++) {
+      var sr = r;
+      var sc = c;
+      switch (data.tail[i].orientation)
+      {
+        case 0: r -= data.tail[i].move; break; //UP
+        case 1: c += data.tail[i].move; break; //RIGHT
+        case 2: r += data.tail[i].move; break; //DOWN
+        case 3: c -= data.tail[i].move; break; //LEFT
+      }
+      
+      if (i === 0)
+        val = {shortCircuit: false, value: callback(sr, sc, r - sr, c - sc)};
+      else
+        val = reducer(val, callback(sr, sc, r - sr, c - sc));
+      if (val.shortCircuit)
+        return val.value;
+      else
+        val = val.value;
+    }
+    return val;
+  }
+  
+  function move(data, row, col)
+  {
+    data.prevRow = data.startRow = row;
+    data.prevCol = data.startCol = col;
+    if (data.tail.length === 0)
+      return;
+    else 
+    {
+      var ret = data.tail;
+      data.tail = [];
+      data.tailGrid = [];
+      return ret;
+    }
+  }
+  
+  function render(data, prev, ctx, srow, scol, drow, dcol)
+  {
+    if (drow === 0 && dcol === 0)
+      return;
+    if (drow !== 0 && dcol !== 0)
+      throw new Error("Invalid tail path.");
+    
+    ctx.fillStyle = data.player.tailColor;
+    
+    var startPos = [
+      {x: scol * CELL_WIDTH, y: srow * CELL_WIDTH},
+      {x: scol * CELL_WIDTH, y: srow * CELL_WIDTH}
+    ];
+    var finishPos = [
+      {x: (scol + dcol) * CELL_WIDTH, y: (srow + drow) * CELL_WIDTH},
+      {x: (scol + dcol) * CELL_WIDTH, y: (srow + drow) * CELL_WIDTH}
+    ];
+    
+    if (drow === 0)
+    {
+      startPos[1].y += CELL_WIDTH;
+      startPos[0].x += CELL_WIDTH * Math.sign(dcol);
+      startPos[1].x += CELL_WIDTH * Math.sign(dcol);
+      finishPos[1].y += CELL_WIDTH;
+    }
+    else
+    {
+      startPos[1].x += CELL_WIDTH;
+      startPos[0].y += CELL_WIDTH * Math.sign(drow);
+      startPos[1].y += CELL_WIDTH * Math.sign(drow);
+      finishPos[1].x += CELL_WIDTH;
+    }
+    
+    if (prev.length != 0)
+    {
+      //Draw the fold triangle.
+      var coords = [];
+      var ind = 0;
+      for (var i = 0; i < startPos.length; i++)
+        for (var j = 0; j < prev.length; j++)
+          if (startPos[i].x === prev[j].x || startPos[i].y === prev[j].y)
+            coords = [startPos[i], startPos[(i == 0 ? 1 : 0)], prev[(j == 0 ? 1 : 0)]];
+      
+      for (i = 0; i < 2; i++)
+      {
+        ctx.moveTo(coords[0].x, coords[0].y);
+        ctx.lineTo(coords[1].x, coords[1].y);
+        ctx.lineTo(coords[2].x, coords[2].y);
+        ctx.closePath();
+        ctx.fill();
+      }
+    }
+    else 
+    {
+      //Draw starting rectangle.
+      fillNegRect(ctx, scol * CELL_WIDTH, srow * CELL_WIDTH, 
+        CELL_WIDTH * (dcol >= 0 ? 1 : 0), CELL_WIDTH * (drow >= 0 ? 1 : 0));
+    }
+    
+    //Draw main tail line.
+    var x = startPos[0].x, y = startPos[0].y;
+    fillNegRect(ctx, x, y, finishPos[1].x - x, finishPos[1].y - y);
+    
+    prev[0] = finishPos[0];
+    prev[1] = finishPos[1];
+  }
+  
+  function fillNegRect(ctx, x, y, width, height)
+  {
+    if (width < 0)
+    {
+      x += width;
+      width = -width;
+    }
+    if (height < 0)
+    {
+      y += height;
+      height = -height;
+    }
+    ctx.fillRect(x, y, width, height);
+  }
+  
+  function hitsTail(data, other)
+  {
+    var r = data.prevRow;
+    var c = data.prevCol; 
+    return !!(data.tailGrid[other.row] && data.tailGrid[other.row][other.col]);
+  }
+  
+  function VOID()
+  {
+    return {shortCircuit: false, value: undefined};
+  }
+  
+  //Helper methods.
+  function inRange(check, a, b)
+  {
+    if (a === b)
+      return a === check;
+    else if (a < b)
+      return a <= check && check < b;
+    else
+      return b <= check && check < a;
+  }
+  
+  return Tail;
+}());
+var Player = (function() {
+  var CELL_WIDTH = 30;
+  var SPEED = 5;
+  var SHADOW_OFFSET = 10;
+  
+  function Player(socket, grid, num) {
+    var data = {};
+    
+    //TODO: load player data and color.
+    
+    var hue = Math.random();
+    var base = hslToRgb(hue, .8, .5);
+    this.baseColor = rgbString(base);
+    this.shadowColor = rgbString(hslToRgb(hue, .8, .2));
+    base[3] = .5;
+    this.tailColor = rgbaString(base);
+    
+    this.name = 'Player ' + (num + 1);
+    
+    data.grid = grid;
+    data.curHeading = 0;
+    data.row = Math.floor(Math.random() * 20) + 10;
+    data.col = num;
+    data.dead = false;
+    
+    data.tail = new Tail(this);
+    data.tail.move(data.row, data.col);
+    
+    //Positions
+    this.heading = 0; //0 is up, 1 is right, 2 is down, 3 is left.
+    this.posX = data.col * CELL_WIDTH;
+    this.posY = data.row * CELL_WIDTH;
+    this.move = move.bind(this, data);
+    
+    //Properties.
+    Object.defineProperties(this, {
+      currentHeading: defineGetter(function() {return data.curHeading;}),
+      dead: defineGetter(function() {return !!data.dead;}),
+      row: defineGetter(function() {return data.row;}),
+      col: defineGetter(function() {return data.col;}),
+      num: defineGetter(function() {return num;}),
+      tail:  defineGetter(function() {return data.tail;})
+    });
+  }
+  
+  //Instance methods
+  Player.prototype.render = function(ctx)
+  {
+    //Render tail.
+    function a() {};
+    this.tail.render({
+      moveTo: a, lineTo: a, closePath: a, fill: a, stroke: a, fillRect : a
+    }/*ctx*/);
+    
+    //Render player.
+    ctx.fillStyle = this.shadowColor;
+    ctx.fillRect(this.posX, this.posY, CELL_WIDTH, CELL_WIDTH);
+    ctx.fillStyle = this.baseColor;
+    ctx.fillRect(this.posX, this.posY - SHADOW_OFFSET, CELL_WIDTH, CELL_WIDTH);
+  }
+  
+  function move(data)
+  {
+    //Move to new position.
+    var heading = this.heading;
+    var row = Math.floor(this.posY / CELL_WIDTH);
+    var col = Math.floor(this.posX / CELL_WIDTH);
+    
+    if (this.posX % CELL_WIDTH !== 0 || this.posY % CELL_WIDTH !== 0)
+      heading = data.curHeading;
+    switch (heading)
+    {
+      case 0: //UP
+        this.posY -= SPEED;
+        row = Math.floor(this.posY / CELL_WIDTH);
+        break;
+      case 1: //RIGHT
+        this.posX += SPEED;
+        col = Math.floor(this.posX / CELL_WIDTH);
+        break;
+      case 2: //DOWN
+        this.posY += SPEED;
+        row = Math.ceil(this.posY / CELL_WIDTH);
+        break;
+      case 3: //LEFT
+        this.posX -= SPEED;
+        col = Math.ceil(this.posX / CELL_WIDTH);
+    }
+    
+    //Update front position.
+    data.row = row;
+    data.col = col;
+    
+    if (row < 0 || row > data.grid.length || col < 0 || col > data.grid[row].length)
+    {
+      data.dead = true;
+      return;
+    }
+    
+    if (data.grid[row][col] === this)
+    {
+      //Safe zone!
+      var tail = this.tail.move(row, col);
+      if (tail)
+      {
+        //TODO: floodfill area.
+      }
+    }
+    //If we are completely in a new cell (not in our safe zone), we add to the tail.
+    else if (this.posX % CELL_WIDTH === 0 && this.posY % CELL_WIDTH === 0)
+      this.tail.addTail(heading);
+    
+    data.curHeading = heading;
+  }
+  
+  //Helper methods.
+  function defineGetter(getter) {
+    return {
+      get: getter,
+      enumerable: true
+    };
+  }
+  
+  //http://stackoverflow.com/a/9493060/7344257
+  function hslToRgb(h, s, l){
+    var r, g, b;
+
+    if(s == 0){
+      r = g = b = l; // achromatic
+    }else{
+      var hue2rgb = function hue2rgb(p, q, t){
+        if(t < 0) t += 1;
+        if(t > 1) t -= 1;
+        if(t < 1/6) return p + (q - p) * 6 * t;
+        if(t < 1/2) return q;
+        if(t < 2/3) return p + (q - p) * (2/3 - t) * 6;
+        return p;
+      }
+
+      var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
+      var p = 2 * l - q;
+      r = hue2rgb(p, q, h + 1/3);
+      g = hue2rgb(p, q, h);
+      b = hue2rgb(p, q, h - 1/3);
+    }
+
+    return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
+  }
+
+  function rgbString(rgb) {
+    return 'rgb(' + rgb[0] + ', ' + rgb[1] + ', ' + rgb[2] + ')';
+  }
+  
+  function rgbaString(rgb) {
+    return 'rgba(' + rgb[0] + ', ' + rgb[1] + ', ' + rgb[2] + ', ' + rgb[3] + ')';
+  }
+  
+  return Player;
+})();
+
+$(function() {
+  var GRID_SIZE = 200;
+  var CELL_WIDTH = 30;
+  var SPEED = 5;
+  var SHADOW_OFFSET = 5;
+  
+  var canvas = $("#main-ui")[0];
+  var ctx = canvas.getContext('2d');
+
+  var width = canvas.width = window.innerWidth - 20;
+  var height = canvas.height = window.innerHeight - 20;
+
+  var players = [];
+  var grid = []; 
+  
+  //Load players.
+  for (var p = 0; p < 9; p++)
+  {
+    //TODO: socket loading.
+    players[p] = new Player(null, grid, p);
+  }
+  
+  //Load grid.
+  for (var r = 0; r < GRID_SIZE; r++)
+  {
+    grid[r] = [];
+    for (var c = 0; c < GRID_SIZE; c++)
+    {
+      //TODO: load data.
+      if (Math.random() < 1)
+        grid[r][c] = -1;
+      else
+        grid[r][c] = players[getRandomInt(0, players.length)];
+    }
+  }
+
+  var frameCount = 0;
+  var animateTo = [0, 0];
+  var offset = [0, 0];
+  
+  
+  function update()
+  {
+    //Change grid offsets.
+    for (var i = 0; i < 1; i++)
+    {
+      if (animateTo[i] !== offset[i])
+      {
+        var delta = animateTo[i] - offset[i];
+        var dir = Math.sign(delta);
+        var mag = Math.min(SPEED, Math.abs(delta));
+        
+        offset[i] += dir * mag;
+      }
+    }
+    
+    //Move players.
+    var dead = [];
+    players = players.filter(function(val) {
+      val.move();
+      if (val.dead)
+        dead.push(val);
+      return !val.dead;
+    });
+    
+    //Remove players with collisions.
+    var removing = [];
+    for (var i = 0; i < players.length; i++)
+    {
+      for (var j = i; j < players.length; j++)
+      {
+        
+        //Remove those players when other players have hit their tail.
+        if (!removing[j] && players[j].tail.hitsTail(players[i]))
+          removing[j] = true;
+        if (!removing[i] && players[i].tail.hitsTail(players[j]))
+          removing[i] = true;
+        
+        //Remove players with collisons...
+        if (i !== j && squaresIntersect(players[i].startX, players[j].startX) &&
+          squaresIntersect(players[i].startY, players[j].startY))
+        {
+          //...if one player is own his own territory, the other is out.
+          if (grid[players[i].row][players[i].col] === players[i])
+            removing[j] = true;
+          else if (grid[players[j].row][players[j].col] === players[j])
+            removing[i] = true;
+          else
+          {
+            //...otherwise, the one that sustains most of the collision will be removed.
+            areaI = area(players[i]);
+            areaJ = area(players[j]);
+            
+            if (areaI === areaJ)
+              removing[i] = removing[j] = true;
+            else if (areaI > areaJ)
+              removing[i] = true;
+            else
+              removing[j] = true;
+          }
+        }
+      }
+    }
+    
+    players = players.filter(function(val, i) {
+      if (removing[i])
+        dead.push(val);
+      return !removing[i];
+    });
+    
+    dead.forEach(function(val) {
+      console.log(val.name + " is dead");
+    });
+    
+    //TODO: animate dead, and if this player is dead.
+    //TODO: Center on player.
+  }
+  
+  function area(player)
+  {
+    var xDest = player.col * CELL_WIDTH;
+    var yDest = player.row * CELL_WIDTH;
+    
+    if (player.startX === xDest)
+      return Math.abs(player.startY - yDest);
+    else
+      return Math.abs(player.startX - xDest);
+  }
+  
+  function modRotate(val, mod)
+  {
+    var res = val % mod;
+    if (res >= 0)
+      return res;
+    else
+      return mod + res;
+  }
+  
+  function squaresIntersect(a, b)
+  {
+    if (a < b)
+      return b < a + CELL_WIDTH;
+    else
+      return a < b + CELL_WIDTH;
+  }
+  
+  function paintGrid()
+  {
+    //Paint bottom grid lines.
+    //ctx.fillStyle = 'lightgray';
+    //ctx.beginPath();
+    //for (var x = modRotate(-offset[0], CELL_WIDTH); x < width; x += CELL_WIDTH)
+    //{
+    //  ctx.moveTo(x, 0);
+    //  ctx.lineTo(x, height);
+    //}
+    //for (var y = modRotate(-offset[1], CELL_WIDTH); y < height; y+= CELL_WIDTH)
+    //{
+    //  ctx.moveTo(0, y);
+    //  ctx.lineTo(width, y);
+    //}
+    //ctx.stroke();
+    
+    //Paint occupied areas.
+    for (var r = Math.floor(offset[1] / CELL_WIDTH); r * CELL_WIDTH - offset[1] < height; r++)
+    {
+      for (var c = Math.floor(offset[0] / CELL_WIDTH); c * CELL_WIDTH - offset[0] < width; c++)
+      {
+        if (grid[r][c] !== -1)
+        {
+          var x = c * CELL_WIDTH, 
+                y = r * CELL_WIDTH,
+                p = grid[r][c];
+          ctx.fillStyle = p.shadowColor;
+          ctx.fillRect(x, y + SHADOW_OFFSET, CELL_WIDTH, CELL_WIDTH);
+          ctx.fillStyle = p.baseColor;
+          ctx.fillRect(x, y, CELL_WIDTH, CELL_WIDTH);
+        }
+      }
+    }
+  }
+  
+  function paintLoop()
+  {
+    ctx.fillStyle = 'whitesmoke';
+    ctx.fillRect(0, 0, width, height);
+    
+    ctx.translate(-offset[0], -offset[1]);
+    paintGrid();
+    players.forEach(function (p) {
+      p.render(ctx);
+    });
+    ctx.setTransform(1, 0, 0, 1, 0, 0); //Reset transform.
+    
+    //TODO: sync each loop with server. (server will give frame count.)
+    frameCount++;
+    update();
+    requestAnimationFrame(paintLoop);
+  }
+  paintLoop();
+  
+  //Event listeners
+  $(document).keydown(function(e) {
+    var newHeading = -1;
+    switch (e.which)
+    {
+      case 37: newHeading = 3; break; //LEFT
+      case 38: newHeading = 0; break; //UP
+      case 39: newHeading = 1; break; //RIGHT
+      case 40: newHeading = 2; break; //DOWN
+      default: return; //exit handler for other keys.
+    }
+    
+    //TODO: current player index, and notify server.
+    players[0].heading = newHeading;
+    e.preventDefault();
+  });
+});
\ No newline at end of file
diff --git a/test.html b/test.html
new file mode 100644
index 0000000..261029d
--- /dev/null
+++ b/test.html
@@ -0,0 +1,3 @@
+<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
+<script src="game.js"></script>
+<canvas id="main-ui"></canvas>
\ No newline at end of file