Create a User-Profile Mini-Game [closed]

Question

Yesterday, I stumbled on a very clever thing.

Yes, that's a working implementation of Tic-Tac-Toe on a user profile page, from @minitech. Of course, the moment I saw it, I had to reverse engineer his idea and one-up him :P

Here's my own example embedded directly in the post. It's a tad buggy due to a couple of implementation details I haven't worked out a good solution for. Sometimes after you click a peg, it doesn't update properly until another page refresh:

Towers of Hanoi

Reset

Can you do better?

• Create a working game in your posted answer (or your user profile page). This is done via appropriately configuring a webserver you own (or writing a program that acts as a webserver), and embedding content from it in a post, using the referer to determine what commands the user is giving to the game.
• Coolest idea (most votes) wins the competition, by Canada Day (Sunday, July 1, 2012 @ 11:59 PM EST)
• In the event of a tie, the older answer wins.

Answer 1

C# - Stack Exchange Hangman

Guess names of Stack Exchange websites in this Hangman game:

_{(source: apphb.com)}

`A` `B` `C` `D` `E` `F` `G` `H` `I` `J` `K` `L` `M` `N` `O` `P` `Q` `R` `S` `T` `U` `V` `W` `X` `Y` `Z`
`New game`

---

This was done using ASP.NET MVC 3.0. Here's the code of the Controller that does the trick:

public class HangmanController : Controller
{
    public ActionResult Index()
    {
        var game = Session["hangman"] as HangmanGame ?? HangmanGame.New();

        game = ExecuteGameCommand(game);

        Session["hangman"] = game;

        var imageRenderer = new HangmanImageRenderer(game);
        return new ImageResult(imageRenderer.Render());
    }

    private HangmanGame ExecuteGameCommand(HangmanGame game)
    {
        var referrerQuery = Request.UrlReferrer != null ? Request.UrlReferrer.Query : string.Empty;

        if (referrerQuery.Contains("_new_hangman_"))
            return HangmanGame.New();

        if(game.IsOver())
            return game;

        var chosenLetter = HangmanGame.ValidLetters
            .FirstOrDefault(letter => referrerQuery.Contains(String.Format("_hangman_{0}_", letter)));

        if (chosenLetter != default(char))
            game.RegisterGuess(chosenLetter);

        return game;
    }
}

Other than this code, there are three more classes that I haven't included since they are pretty long and straightforward:

• HangmanGame - here's where the game business rules are implemented
• HangmanImageRenderer - the class that encapsulates all the GDI ugliness
• ImageResult - a custom ActionResult that is used to return a dynamically generated image

The entire code listing is available at http://pastebin.com/ccwZLknX

Answer 2

Conway's Game of Life

+1 generation - +5 generations - zoom in - zoom out

Load pattern: random - glider - gunstar - snail - lwss - lightspeedoscillator1 - tumbler

Used Python and SVG output. I have tried using single pixels at first (so you could toggle single cells), but it did not work out, because the browser does not load images in order. Also, much bigger patterns are possible like this without crashing my webserver.

Update:

I had some fun with python and added several features and improvements:

• Added HUD with population count, zoom and name
• Patterns in the rle format can now be loaded (long list, via) using the pattern parameter (e.g. ?pattern=glider). The filesize is limited to 1.5kB
• Can forward n generations, limited to 5 at a time, using the next parameter
• Slightly improved algorithm. It's not really fast though, I want this to stay simple
• It also works standalone now (uses either referer or its own query string): https://copy.sh/fcgi-bin/life2.py?pattern=gosperglidergun

sessions = {}

WIDTH = 130
HEIGHT = 130
RULE = (3,), (2, 3)

def read_pattern(filename, offset_x, offset_y):

    filename = PATH + filename + '.rle.gz'

    try:
        if os.stat(filename).st_size > 1500:
            return ['pattern too big', set()]
    except OSError as e:
        return ['could not find pattern', set()]

    file = gzip.open(filename)

    x, y = offset_x, offset_y
    name = ''
    pattern_string = ''
    field = []

    for line in file:
        if line[0:2] == '#N':
            name = line[2:-1]
        elif line[0] != '#' and line[0] != 'x':
            pattern_string += line[:-1]

    for count, chr in re.findall('(\d*)(b|o|\$|!)', pattern_string):
        count = int(count) if count else 1

        if chr == 'o':
            for i in range(x, x + count):
                field.append( (i, y) )
            x += count
        elif chr == 'b':
            x += count
        elif chr == '$':
            y += count
            x = offset_x
        elif chr == '!':
            break

    file.close()

    return [name, set(field)]



def next_generation(field, n):

    for _ in range(n):

        map = {}

        for (x, y) in field:
            for (i, j) in ( (x-1, y-1), (x, y-1), (x+1, y-1), (x-1, y), (x+1, y), (x-1, y+1), (x, y+1), (x+1, y+1) ):
                map[i, j] = map[i, j] + 1 if (i, j) in map else 1

        field = [
            (x, y)
            for x in range(0, WIDTH)
            for y in range(0, HEIGHT)
            if (x, y) in map
            if ( (map[x, y] in RULE[1]) if (x, y) in field else (map[x, y] in RULE[0]) )
        ]

    return field


def life(env, start):


    if 'REMOTE_ADDR' in env:
        client_ip = env['REMOTE_ADDR']
    else:
        client_ip = '0'

    if not client_ip in sessions:
        sessions[client_ip] = read_pattern('trueperiod22gun', 10, 10) + [2]

    session = sessions[client_ip]

    if 'HTTP_REFERER' in env:
        query = urlparse.parse_qs(urlparse.urlparse(env['HTTP_REFERER']).query, True)
    elif 'QUERY_STRING' in env:
        query = urlparse.parse_qs(env['QUERY_STRING'], True)
    else:
        query = None

    timing = time.time()

    if query:
        if 'next' in query:
            try:
                count = min(5, int(query['next'][0]))
            except ValueError as e:
                count = 1
            session[1] = set( next_generation(session[1], count) )
        elif 'random' in query:
            session[0:2] = 'random', set([ (random.randint(0, WIDTH), random.randint(0, HEIGHT)) for _ in range(800) ])
        elif 'pattern' in query:
            filename = query['pattern'][0]
            if filename.isalnum():
                session[0:2] = read_pattern(filename, 10, 10)
        elif 'zoomin' in query:
            session[2] += 1
        elif 'zoomout' in query and session[2] > 1:
            session[2] -= 1

    timing = time.time() - timing

    start('200 Here you go', [
        ('Content-Type', 'image/svg+xml'), 
        ('Cache-Control', 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0'), 
        ('Expires', 'Tue, 01 Jan 2000 12:12:12 GMT')
    ])

    pattern_name, field, zoom = session

    yield '<?xml version="1.0" encoding="UTF-8"?>'
    yield '<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">'
    yield '<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" baseProfile="full" width="400px" height="200px">'
    yield '<!-- finished in %f -->' % timing
    yield '<text x="0" y="10" style="font-size:10px">Population: %d</text>' % len(field)
    yield '<text x="100" y="10" style="font-size:10px">Zoom: %d</text>' % zoom
    yield '<text x="180" y="10" style="font-size:10px; font-weight:700">%s</text>' % pattern_name
    yield '<line x1="0" y1="15" x2="666" y2="15" style="stroke:#000; stroke-width:1px" />'

    for (x, y) in field:
        yield '<rect x="%d" y="%d" width="%d" height="%d"/>' % (zoom * x, zoom * y + 20, zoom, zoom)

    yield '</svg>'


from flup.server.fcgi import WSGIServer
import random
import re
import gzip
import os
import urlparse
import time

WSGIServer(life).run()

You can take my code as a template for further python fastcgi submissions.

Answer 3

Clojoban! [WIP]

I wanted to make a bigger game out of this to learn Clojure, so this took a while to pull off (and got pretty big.) I've had a lot of fun doing it, btw!

Restart levelNew game

. . ↑

← → - No-op*

. . ↓

*(click here if game becomes unresponsive)

Instructions

You are Robby , a hard-working robot. You work at a FlipCo Industries as a heavy load carrier. Your job is to move each box to a goal spending as few steps as possible. FlipCo's facilities are DANGEROUS. There are lots of challenges and special places to discover.

If you get stuck, click Restart level (but your step count won't be reset!)

---

You can also play at Clojoban's front page (although it kind of ruins the purpose of the challenge.) It fixes the infamous anchor problem, doesn't require cross-site cookies and you can play with your keyboard arrow keys! You can also play at my user profile page without the annoying anchor problem.

In Firefox the image doesn't flicker while it's loading so it's a bit more comfortable to play.

This game is FAR from completion, Clojoban is still a work in progress. You can see the complete sourcecode at Clojoban's GitHub project page. There's some info in the README about contributing. I need levels too! See the level format at the example levels. You can peek at Clojoban's issue tracker and see what's coming next!

Answer 4

Maze

_{(source: t15.org)}

_{New ← ↑ ↓ → - Noop button}

I started from the PHP maze generator I found here: http://dev.horemag.net/2008/03/01/php-maze-generation-class/.

EDIT: changed the output to PNG instead of SVG (for better cross browser compatibility).

EDIT 2: added a header for fixing IE cookie compatibility. Should now work correctly in all major browsers.

The image does not refresh if you take the same direction twice (due to the anchor links). Press F5 the second time, or play the maze on my stackoverflow profile.

EDIT 3: Added a no-op button for easily being able to take the same direction twice (see comments below).

<?php
// based upon the maze generator by Evgeni Vasilev (PHP Adaptation)
// see http://dev.horemag.net/2008/03/01/php-maze-generation-class/
class Maze
{
  var $maze = array();
  var $mx = 0;
  var $my = 0;
  var $xplayer = 1;
  var $yplayer = 1;

  function Maze($mx, $my)
  {
    $mx +=2;
    $my +=2;
    $this->mx = $mx;
    $this->my = $my;
    $dx = array( 0, 0, -1, 1 );
    $dy = array( -1, 1, 0, 0 );
    $todo = array(); 
    $todonum = 0;

    for ($x = 0; $x < $mx; ++$x){
      for ($y = 0; $y < $my; ++$y){
        if ($x == 0 || $x == $mx-1 || $y == 0 || $y == $my-1) {
          $this->maze[$x][$y] = 32;
        } else {
          $this->maze[$x][$y] = 63;
        }
      }
    }
    $x = rand(1, $mx-2); $y = rand(1, $my-2);
    $x = 1; $y = 1;
    $this->maze[$x][$y] &= ~48;
    for ($d = 0; $d < 4; ++$d){
      if (($this->maze[$x + $dx[$d]][$y + $dy[$d]] & 16) != 0) {
        $todo[$todonum++] = (($x + $dx[$d]) << 16) | ($y + $dy[$d]);
        $this->maze[$x + $dx[$d]][$y + $dy[$d]] &= ~16;
      }
    }

    while ($todonum > 0) {
      $n = rand(0, $todonum-1);
      $x = $todo[$n] >> 16;
      $y = $todo[$n] & 65535;
      $todo[$n] = $todo[--$todonum];
      do {
        $d = rand(0, 3);
      } while (($this->maze[$x + $dx[$d]][$y + $dy[$d]] & 32) != 0);
      $this->maze[$x][$y] &= ~((1 << $d) | 32);
      $this->maze[$x + $dx[$d]][$y + $dy[$d]] &= ~(1 << ($d ^ 1));
      for ($d = 0; $d < 4; ++$d){
        if (($this->maze[$x + $dx[$d]][$y + $dy[$d]] & 16) != 0) {
          $todo[$todonum++] = (($x + $dx[$d]) << 16) | ($y + $dy[$d]);
          $this->maze[$x + $dx[$d]][$y + $dy[$d]] &= ~16;
        }
      }
    }
    $this->maze[1][1] &= ~1;
    $this->maze[$mx-2][$my-2] &= ~2;
  }

  function _drawLine($img,$color, $x1, $y1, $x2, $y2)
  {
    imageline($img, $x1, $y1, $x2, $y2, $color);
  }
  
  function _drawPlayer($img, $x, $y, $r, $colorborder, $colorfill)
  {
    imagefilledellipse($img, $x, $y, $r, $r, $colorfill);
    imageellipse($img, $x, $y, $r, $r, $colorborder);
  }
  
  function _drawWin($img, $color)
  {
    imagestring($img, 5, 170, 90, "YOU WIN!", $color);
  }
  
  function movePlayerDown()
  {
    if ($this->yplayer+1 < $this->my-1 && ($this->maze[$this->xplayer][$this->yplayer] & 2) == 0)
    $this->yplayer++;
  }

  function movePlayerUp()
  {
    if ($this->yplayer-1 > 0 && ($this->maze[$this->xplayer][$this->yplayer] & 1) == 0)
      $this->yplayer--;
  }

  function movePlayerRight()
  {
    if ($this->xplayer+1 < $this->mx-1 && ($this->maze[$this->xplayer][$this->yplayer] & 8) == 0)
      $this->xplayer++;
  }  

  function movePlayerLeft()
  {
    if ($this->xplayer-1 > 0 && ($this->maze[$this->xplayer][$this->yplayer] & 4) == 0)
      $this->xplayer--;
  }  
  
  function renderImage($xs, $ys)
  {
    $off = 0;
    $w = ($this->mx*$xs)+($off*2); $h = ($this->my*$ys)+($off*2);
    $img = imagecreatetruecolor($w, $h);
    imagesetthickness($img, 2);
    $fg = imagecolorallocate($img, 0, 0, 0);
    $bg = imagecolorallocate($img, 248, 248, 248);
    $red = imagecolorallocate($img, 255, 0, 0);
    imagefill($img, 0, 0, $bg);
    if (($this->xplayer == $this->mx-2) && ($this->yplayer == $this->my-2)) {
      $this->_drawWin($img, $red);
      return $img;
    }
    
    for ($y = 1; $y < $this->my-1; ++$y) {
      for ($x = 1; $x < $this->mx-1; ++$x){
        if (($this->maze[$x][$y] & 1) != 0)
          $this->_drawLine ($img, $fg, $x * $xs + $off, $y * $ys + $off, $x * $xs + $xs + $off, $y * $ys + $off);
        if (($this->maze[$x][$y] & 2) != 0)
          $this->_drawLine ($img, $fg, $x * $xs + $off, $y * $ys + $ys + $off, $x * $xs + $xs + $off, $y * $ys + $ys + $off);
        if (($this->maze[$x][$y] & 4) != 0)
          $this->_drawLine ($img, $fg, $x * $xs + $off, $y * $ys + $off, $x * $xs + $off, $y * $ys + $ys + $off);
        if (($this->maze[$x][$y] & 8) != 0)
          $this->_drawLine ($img, $fg, $x * $xs + $xs + $off, $y * $ys + $off, $x * $xs + $xs + $off, $y * $ys + $ys + $off);
        if ($x == $this->xplayer && $y == $this->yplayer) {
          $this->_drawPlayer ($img, $x * $xs + ($xs/2), $y * $ys + ($ys/2), 14, $fg, $red);
        }
      }
    }
    return $img;
  }
}
header('P3P: CP="CURa ADMa DEVa PSAo PSDo OUR BUS UNI PUR INT DEM STA PRE COM NAV OTC NOI DSP COR"');
session_start();
$orig_url = $_SERVER['HTTP_REFERER'];
if (!isset($_SESSION['maze']) || strpos($orig_url, 'resetmaze')){
    $_SESSION['maze'] = new Maze(25,10);
}
$maze = $_SESSION['maze'];
if (strpos($orig_url, 'playerdown')) { $maze->movePlayerDown(); }
if (strpos($orig_url, 'playerup')) { $maze->movePlayerUp(); }
if (strpos($orig_url, 'playerright')) { $maze->movePlayerRight(); }
if (strpos($orig_url, 'playerleft')) { $maze->movePlayerLeft(); }
$img = $maze->renderImage(16,16);
header("Content-Type: image/png");
imagepng($img);
imagedestroy($img);
?>

Answer 5

2-Player Pokémon Chess [Work in progress]

Because it's more fun this way. Coming up some day: AI, isometric grid, and shadows!

http://minite.ch/chess/?i=1http://minite.ch/chess/?i=2http://minite.ch/chess/?i=3http://minite.ch/chess/?i=4http://minite.ch/chess/?i=5http://minite.ch/chess/?i=6http://minite.ch/chess/?i=7http://minite.ch/chess/?i=8
http://minite.ch/chess/?i=9http://minite.ch/chess/?i=10http://minite.ch/chess/?i=11http://minite.ch/chess/?i=12http://minite.ch/chess/?i=13http://minite.ch/chess/?i=14http://minite.ch/chess/?i=15http://minite.ch/chess/?i=16
http://minite.ch/chess/?i=17http://minite.ch/chess/?i=18http://minite.ch/chess/?i=19http://minite.ch/chess/?i=20http://minite.ch/chess/?i=21http://minite.ch/chess/?i=22http://minite.ch/chess/?i=23http://minite.ch/chess/?i=24
http://minite.ch/chess/?i=25http://minite.ch/chess/?i=26http://minite.ch/chess/?i=27http://minite.ch/chess/?i=28http://minite.ch/chess/?i=29http://minite.ch/chess/?i=30http://minite.ch/chess/?i=31http://minite.ch/chess/?i=32
http://minite.ch/chess/?i=33http://minite.ch/chess/?i=34http://minite.ch/chess/?i=35http://minite.ch/chess/?i=36http://minite.ch/chess/?i=37http://minite.ch/chess/?i=38http://minite.ch/chess/?i=39http://minite.ch/chess/?i=40
http://minite.ch/chess/?i=41http://minite.ch/chess/?i=42http://minite.ch/chess/?i=43http://minite.ch/chess/?i=44http://minite.ch/chess/?i=45http://minite.ch/chess/?i=46http://minite.ch/chess/?i=47http://minite.ch/chess/?i=48
http://minite.ch/chess/?i=49http://minite.ch/chess/?i=50http://minite.ch/chess/?i=51http://minite.ch/chess/?i=52http://minite.ch/chess/?i=53http://minite.ch/chess/?i=54http://minite.ch/chess/?i=55http://minite.ch/chess/?i=56
http://minite.ch/chess/?i=57http://minite.ch/chess/?i=58http://minite.ch/chess/?i=59http://minite.ch/chess/?i=60http://minite.ch/chess/?i=61http://minite.ch/chess/?i=62http://minite.ch/chess/?i=63http://minite.ch/chess/?i=64

No en passant or castling, sorry. Checkmate/check/stalemate detection to be implemented. Sprites from here: http://floatzel.net/pokemon/black-white/sprites/

Here's the source:

<?php
session_start();

function kick() {
    header("Status: Forbidden\r\n", true, 403);
    header("Content-Type: text/plain\r\n");
    die('Go away.');
}

function isEnemy($item) {
    return $item !== -1 && $item & 8;
}

function iValidMoves($board, $type, $x, $y) {
    $results = array();

    switch($type) {
        case 0:
            # Pawn
            if($board[$y - 1][$x] === -1) {
                $results[] = array($x, $y - 1);

                if($y == 6 && $board[$y - 2][$x] === -1) $results[] = array($x, $y - 2);
            }

            if($x > 0 && isEnemy($board[$y - 1][$x - 1])) $results[] = array($x - 1, $y - 1);
            if($x < 7 && isEnemy($board[$y - 1][$x + 1])) $results[] = array($x + 1, $y - 1);

            break;
        case 1:
            # King
            if($x > 0 && $board[$y][$x - 1] & 8) $results[] = array($x - 1, $y);
            if($x > 0 && $y > 0 && $board[$y - 1][$x - 1] & 8) $results[] = array($x - 1, $y - 1);
            if($x > 0 && $y < 7 && $board[$y + 1][$x - 1] & 8) $results[] = array($x - 1, $y + 1);
            if($x < 7 && $board[$y][$x + 1] & 8) $results[] = array($x + 1, $y);
            if($x < 7 && $y > 0 && $board[$y - 1][$x + 1] & 8) $results[] = array($x + 1, $y - 1);
            if($x < 7 && $y < 7 && $board[$y + 1][$x + 1] & 8) $results[] = array($x + 1, $y + 1);
            if($y > 0 && $board[$y - 1][$x] & 8) $results[] = array($x, $y - 1);
            if($y < 7 && $board[$y + 1][$x] & 8) $results[] = array($x, $y + 1);

            break;
        case 2:
            # Queen
            # Downwards diagonal
            for($d = 1; $x + $d < 8 && $y + $d < 8; $d++) {
                if($board[$y + $d][$x + $d] & 8) {
                    $results[] = array($x + $d, $y + $d);

                    if($board[$y + $d][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            for($d = -1; $x + $d >= 0 && $y + $d >= 0; $d--) {
                if($board[$y + $d][$x + $d] & 8) {
                    $results[] = array($x + $d, $y + $d);

                    if($board[$y + $d][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            # Upwards diagonal
            for($d = 1; $x + $d < 8 && $y - $d >= 0; $d++) {
                if($board[$y - $d][$x + $d] & 8) {
                    $results[] = array($x + $d, $y - $d);

                    if($board[$y - $d][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            for($d = -1; $x + $d >= 0 && $y - $d < 8; $d--) {
                if($board[$y - $d][$x + $d] & 8) {
                    $results[] = array($x + $d, $y - $d);

                    if($board[$y - $d][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            # Horizontal
            for($d = 1; $x + $d < 8; $d++) {
                if($board[$y][$x + $d] & 8) {
                    $results[] = array($x + $d, $y);

                    if($board[$y][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            for($d = -1; $x + $d >= 0; $d--) {
                if($board[$y][$x + $d] & 8) {
                    $results[] = array($x + $d, $y);

                    if($board[$y][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            # Vertical
            for($d = 1; $y + $d < 8; $d++) {
                if($board[$y + $d][$x] & 8) {
                    $results[] = array($x, $y + $d);

                    if($board[$y + $d][$x] !== -1) break;
                } else {
                    break;
                }
            }

            for($d = -1; $y + $d >= 0; $d--) {
                if($board[$y + $d][$x] & 8) {
                    $results[] = array($x, $y + $d);

                    if($board[$y + $d][$x] !== -1) break;
                } else {
                    break;
                }
            }

            break;
        case 3:
            # Bishop
            # Downwards diagonal
            for($d = 1; $x + $d < 8 && $y + $d < 8; $d++) {
                if($board[$y + $d][$x + $d] & 8) {
                    $results[] = array($x + $d, $y + $d);

                    if($board[$y + $d][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            for($d = -1; $x + $d >= 0 && $y + $d >= 0; $d--) {
                if($board[$y + $d][$x + $d] & 8) {
                    $results[] = array($x + $d, $y + $d);

                    if($board[$y + $d][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            # Upwards diagonal
            for($d = 1; $x + $d < 8 && $y - $d >= 0; $d++) {
                if($board[$y - $d][$x + $d] & 8) {
                    $results[] = array($x + $d, $y - $d);

                    if($board[$y - $d][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            for($d = -1; $x + $d >= 0 && $y - $d < 8; $d--) {
                if($board[$y - $d][$x + $d] & 8) {
                    $results[] = array($x + $d, $y - $d);

                    if($board[$y - $d][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            break;
        case 4:
            # Knight
            if($x > 1 && $y > 0 && $board[$y - 1][$x - 2] & 8) $results[] = array($x - 2, $y - 1);
            if($x > 0 && $y > 1 && $board[$y - 2][$x - 1] & 8) $results[] = array($x - 1, $y - 2);
            if($x < 7 && $y > 1 && $board[$y - 2][$x + 1] & 8) $results[] = array($x + 1, $y - 2);
            if($x < 6 && $y > 0 && $board[$y - 1][$x + 2] & 8) $results[] = array($x + 2, $y - 1);
            if($x < 6 && $y < 7 && $board[$y + 1][$x + 2] & 8) $results[] = array($x + 2, $y + 1);
            if($x < 7 && $y < 6 && $board[$y + 2][$x + 1] & 8) $results[] = array($x + 1, $y + 2);
            if($x > 0 && $y < 6 && $board[$y + 2][$x - 1] & 8) $results[] = array($x - 1, $y + 2);
            if($x > 1 && $y < 7 && $board[$y + 1][$x - 2] & 8) $results[] = array($x - 2, $y + 1);

            break;
        case 5:
            # Rook
            # Horizontal
            for($d = 1; $x + $d < 8; $d++) {
                if($board[$y][$x + $d] & 8) {
                    $results[] = array($x + $d, $y);

                    if($board[$y][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            for($d = -1; $x + $d >= 0; $d--) {
                if($board[$y][$x + $d] & 8) {
                    $results[] = array($x + $d, $y);

                    if($board[$y][$x + $d] !== -1) break;
                } else {
                    break;
                }
            }

            # Vertical
            for($d = 1; $y + $d < 8; $d++) {
                if($board[$y + $d][$x] & 8) {
                    $results[] = array($x, $y + $d);

                    if($board[$y + $d][$x] !== -1) break;
                } else {
                    break;
                }
            }

            for($d = -1; $y + $d >= 0; $d--) {
                if($board[$y + $d][$x] & 8) {
                    $results[] = array($x, $y + $d);

                    if($board[$y + $d][$x] !== -1) break;
                } else {
                    break;
                }
            }

            break;
    }

    return $results;
}

function invertRelationship($piece) {
    return $piece === -1 ? -1 : $piece ^ 8;
}

function invertPosition($position) {
    return array($position[0], 7 - $position[1]);
}

function invertBoard($board) {
    $invertedBoard = array();

    for($i = 7; $i > -1; $i--) {
        $invertedBoard[] = array_map('invertRelationship', $board[$i]);
    }

    return $invertedBoard;
}

function validMoves($x, $y) {
    global $board;

    $type = $board[$y][$x];

    if($type & 8) {
        return array_map('invertPosition', iValidMoves(invertBoard($board), $type & ~8, $x, 7 - $y));
    } else {
        return iValidMoves($board, $type, $x, $y);
    }
}

function shouldHighlight($x, $y) {
    global $highlight;

    foreach($highlight as $position) {
        if($position[0] == $x && $position[1] == $y) {
            return true;
        }
    }

    return false;
}

if(isset($_SESSION['board'])) {
    $board = $_SESSION['board'];
} else {
    $board = array(
        array(5 | 8, 4 | 8, 3 | 8, 1 | 8, 2 | 8, 3 | 8, 4 | 8, 5 | 8),
        array(0 | 8, 0 | 8, 0 | 8, 0 | 8, 0 | 8, 0 | 8, 0 | 8, 0 | 8),
        array(-1, -1, -1, -1, -1, -1, -1, -1),
        array(-1, -1, -1, -1, -1, -1, -1, -1),
        array(-1, -1, -1, -1, -1, -1, -1, -1),
        array(-1, -1, -1, -1, -1, -1, -1, -1),
        array(0, 0, 0, 0, 0, 0, 0, 0),
        array(5, 4, 3, 1, 2, 3, 4, 5)
    );
}

$back = array(
    imagecreatefrompng('back/16.png'),  # pawn
    imagecreatefrompng('back/6.png'),   # king
    imagecreatefrompng('back/149.png'), # queen
    imagecreatefrompng('back/37.png'),  # bishop
    imagecreatefrompng('back/25.png'),  # knight
    imagecreatefrompng('back/75.png')   # rook
);

$front = array(
    imagecreatefrompng('front/16.png'),     # pawn
    imagecreatefrompng('front/6.png'),      # king
    imagecreatefrompng('front/149.png'),    # queen
    imagecreatefrompng('front/37.png'),     # bishop
    imagecreatefrompng('front/25.png'),     # knight
    imagecreatefrompng('front/75.png')      # rook
);

$image = $_GET['i'];

if(ctype_digit($image)) {
    $image = (int)$image;
} else {
    kick();
}

if($image < 1 || $image > 64) {
    kick();
}

$highlight = array();

$referrer = $_SERVER['HTTP_REFERER'];
$action = null;

if(strpos($referrer, '?a=') > -1) {
    $action = substr($referrer, strpos($referrer, '?a=') + 3);
}

if($action !== null && $image === 1) { # Only do this once!
    if(!ctype_digit($action)) kick();
    $action = (int)$action;

    if($action < 1 || $action > 64) kick();

    $aX = ($action - 1) % 8;
    $aY = floor(($action - 1) / 8);

    if(isset($_SESSION['selected'])) {
        if($_SESSION['selected'] !== $action) {
            # Make sure the piece can actually move there.
            # If it can, move.
            # "Highlight" the places that the piece can move:
            $highlight = validMoves(($_SESSION['selected'] - 1) % 8, floor(($_SESSION['selected'] - 1) / 8));

            if(shouldHighlight($aX, $aY)) {
                # The move is good!
                $sX = ($_SESSION['selected'] - 1) % 8;
                $sY = floor(($_SESSION['selected'] - 1) / 8);
                $board[$aY][$aX] = $board[$sY][$sX];
                $board[$sY][$sX] = -1;

                # Now, rotate the board for the next person to play:
                $invertedBoard = invertBoard($board);
                $rotatedBoard = array();

                foreach($invertedBoard as $row) {
                    for($i = 0; $i < 4; $i++) {
                        $row[$i] ^= $row[7 - $i];
                        $row[7 - $i] ^= $row[$i];
                        $row[$i] ^= $row[7 - $i];
                    }

                    $rotatedBoard[] = $row;
                }

                $board = $rotatedBoard;
            }
        }

        unset($_SESSION['selected']);
    } elseif(($board[$aY][$aX] & 8) === 0) {
        # Select a piece:
        $_SESSION['selected'] = $action;
    }
}

if(isset($_SESSION['selected'])) {
    # Highlight the places that the piece can move:
    $highlight = validMoves(($_SESSION['selected'] - 1) % 8, floor(($_SESSION['selected'] - 1) / 8));
}

# Draw the background:
$background = imagecreatetruecolor(96, 96);
$black = imagecolorallocate($background, 0, 0, 0);
$white = imagecolorallocate($background, 255, 255, 255);
$red = imagecolorallocatealpha($background, 255, 0, 0, 100);

if(($image + floor(($image - 1) / 8)) % 2) {
    imagefilledrectangle($background, 0, 0, 96, 96, $black);
} else {
    imagefilledrectangle($background, 0, 0, 96, 96, $white);
}

# Draw a piece, if there is one:
$piece = $board[floor(($image - 1) / 8)][($image - 1) % 8];

if($piece > -1) {
    if($piece & 8) {
        $piece &= ~8;
        $draw = $front[$piece];
    } else {
        $draw = $back[$piece];
    }

    imagecopy($background, $draw, 0, 0, 0, 0, 96, 96);
}

# Should we highlight this place?
if(shouldHighlight(($image - 1) % 8, floor(($image - 1) / 8))) {
    imagefilledrectangle($background, 0, 0, 96, 96, $red);
}

header("Content-Type: image/png\r\n");

imagepng($background);

$_SESSION['board'] = $board;
?>

Answer 6

"Simon says" game

Unfortunately, I could not get this submission in on time by the (somewhat arbitrary) deadline, but I really wanted to demonstrate animation in such a user profile game, and none of the previous submissions are animated. This game is a clone of the classic Milton Bradley game Simon, in which the player tries to repeat an increasingly long sequence of signals.

Information about this game, including its source code, is available at its GitHub page. There may be occasional graphical glitches (especially on Windows computers) arising from the hackish "palette animation" that avoids the need for a graphics drawing library. The existence of these glitches can serve as a useful excuse for quickly losing this game because of terrible memory.

Additionally, the effects of high latency and limited bandwidth can make this game much more challenging than the original as well. I think that in order to get much more than five points (when the game first speeds up), you will need to determine which light flashes one more time than in the previous round rather than depending on the correct sequence (which is very hard to do).

If this game fails to work for you (it restarts every time you click a button), your browser might be blocking its cookie. I have not yet added a workaround, so for the time being, please either use Chrome, Opera, or Firefox or temporarily change your Internet Explorer or Safari cookie settings.

Edit 2018-05-24: At this time, I have deleted the publicly accessible Heroku instance of this app. I may or may not put the app back online at a later date. The app's code is still available on GitHub, so you can either run it locally or create your own Heroku app instance if you wish to play the game.