Digital Decomposition of 10 Ruston Close Installation - Source Code 
John Wild 2011 
john.wild@network.rca.ac.uk

The installation consisted of 3 elements. A programe, writen using Processing, that displays and processes a photograph stored on a webserver. A PHP program that allows Processing to upload and overwrite the photograph on the server. A MaxSona sonic range finder connected to an Arduino that registered the presence of a viewer in the Gallery and sends a message via the serial port.

Bellow is the Source Code for all 3 programes required to make the installation work: - 

1) house_installation_Final.pde - applet writen in processing. displays and processes the image.
2) Upload.php - php file stored on the webserver.
3) MaxSona_House.pde - arduino source code to sense the presence of a viewer.


/////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////

// house_installation_Final.pde Source Code.....

// Downloads an image from a webserver and displays it fullscreen. 
// If Arduino sensors a viewer - Delete a pixel, recompress as jpg, send back to webserver.

/////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////



// The program uses the, Post To Web Library v0.6, created by seltar [http://libraries.seltar.org/postToWeb/]
//and the FullScreen Library [http://www.superduper.org/processing/fullscreen_api/]
//Plus the Serial library to read data from the Arduino.

import fullscreen.*;
import processing.serial.*;
import processing.pdf.*;
import org.seltar.Bytes2Web.*;

FullScreen fs;
PDFToWeb pdf;
PImage img;
Serial myPort;  // Create object from Serial class
int val;      // Data received from the serial port
String Iurl = "http://www.***.***/***/saved/image/House.jpg";
int sec=59999; 

void setup() {
  size(720,576); 
  background(0, 0, 0);
  pdf = new PDFToWeb(this); 
  String portName = Serial.list()[3];
  myPort = new Serial(this, portName, 9600);
   frameRate(5);
   fs = new FullScreen(this); 
  fs.enter();    // enter fullscreen mode
}

void draw() 
{
  img = loadImage(Iurl);// Load the image from the web server into the program.
  image(img, 0, 0); // Displays the image
  
  while (sec < 60000){
      
  if ( myPort.available() > 0) // If serial data is available
  {  
    val = myPort.read();         // read it and store it in val
  
    if (val == 1) //If the Arduino detects someone
    { 
  
    color white = color(255,255,255);
    // Selects a random pixle
    int rand_width = int (random(width));
    int rand_height = int (random(height));
    color c = img.get(rand_width, rand_height); 

    // check pixel is not already white.

    if (c == white) 
    {
      int i=0;  
      while (i < 1)
      {  
        rand_width = int (random(width));
        rand_height = int (random(height));
        c = img.get(rand_width, rand_height); 
        if (c != white) 
        {
          i=2;
        }
      }
    }
    img.set(rand_width, rand_height, white); // Destroys random pixel
    image(img, 0, 0); // Displays the image
    pdf.addPage();
    save_to_web();
    sec=60000;
   }
  }
  sec++;
  }
  sec=0;
}

void save_to_web() // Sends the image back to the webserver and over rights the original
{
  String url = "http://www.***.***/***/Upload.php";
  ImageToWeb img = new ImageToWeb(this);
  img.save("jpg",true); // Recomposed the image in jpeg file format. This will cause the image quality to deteriate.
  img.post("image",url,"House",true,img.getBytes(g));
  println("sending Image");
}


/////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////

// Upload.php Source Code.....
// To make house_instalation_Final.pde work you will also have to have the file Upload.php on your server. More info about this code at:- http://libraries.seltar.org/postToWeb/

/////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////



<?

// Constants since these parameters are unlikely to change on each call...
// Maximum 100 chars for file name in input, after filtering
define('MAX_FILE_NAME_LENGTH', 100);
// Roughly 2MB
define('MAX_FILE_SIZE', 2000000);

// Where ever your save folder is located - from the place this file is places - no leading slash
$destDir = 'saved/';

// Folder from the root - for using the popup function
$rootDir = '/House/';

/**
 * Handle an upload field/file.
 * Reject files too big (constant MAX_FILE_SIZE), filter out uploaded file name
 * (remove path, reduce charset, reject incorrect file types (actually, extensions),
 * truncate given name), then prepend unique identifier (date/time, good for sorting)
 * and move the uploaded file to the given directory.
 *
 * @param $fieldName   the name of the input type="file" tag in HTML.
 *        There can be several such inputs in a form.
 * @param $destinationDir   where to put the uploaded file (absolute path).
 *        Might be always the same place or depend on other parameters like a login name.
 * @param $allowedExtensions   an array looking like array('.png', '.gif', '.jpg', '.jpeg')
 * @return An array with two elements. If error, the first element is an empty string,
 *         the second one is the error message. Otherwise, the first element is the file name
 *         and the second one is the uploaded file path.
 */

function HandleUploadedFile($fieldName, $destinationDir, $allowedExtensions)
{
	global $debugData; // To trace actions. Comment out the lines with this variable for real use
    if (isset($_FILES[$fieldName]))
    {
        // Handle error code
        $error = $_FILES[$fieldName]['error'];
        switch ($error)
        {
        case UPLOAD_ERR_OK: // zero
            break;  // No error, continue process
        case UPLOAD_ERR_INI_SIZE: // 1
        case UPLOAD_ERR_FORM_SIZE: // 2
            return array('', 'File too big!'); // The Web page should indicate upfront the maximum size...
        case UPLOAD_ERR_PARTIAL: // 3
            return array('', 'Incomplete upload, please retry.');
        case UPLOAD_ERR_NO_FILE: // 4
            return array('', 'No file! Give a file in the upload field...');
        case UPLOAD_ERR_TMP_DIR: // 6 - No temp folder! :(
        case UPLOAD_ERR_CANT_WRITE: // 7 - Can't write! chmod error?
            return array('', 'Bad server config! Sorry...');
        case UPLOAD_ERR_EXTENSION: // 8 - File upload stopped by extension
            return array('', 'Bad file extension.');
        default:    // Future version of PHP?
            return array('', "Error when uploading: $error");
        }

        // Check size of uploaded file
        $tempLocation = $_FILES[$fieldName]['tmp_name'];
        $debugData .= "Uploaded file is in: $tempLocation<br>\n";
        $debugData .= "Other info given by browser (size, type): {$_FILES[$fieldName]['size']}, {$_FILES[$fieldName]['type']}<br>\n";
        $fileSize = filesize($tempLocation);
        $debugData .= "Real file size: $fileSize<br>\n";
        // Strangely enough, if IE is given a path leading to nowhere, it just sends a 0 byte file!
        if ($fileSize == 0) // Might test a minimum size (smallest header size for graphics...)
        {
            return array('', 'File is empty!');
        }
        if ($fileSize > MAX_FILE_SIZE)
        {
            return array('', 'File too big!');
        }

        // Get original file name
        $file = $_FILES[$fieldName]['name'];
        $debugData .= "Original file name: $file<br>\n"; // No HTML escape! :(
        // Strip out the path (given by IE, perhaps other browsers -- Firefox and Opera just give the name)
        // Most samples I saw use basename() but I found out that it fails to strip a Windows path on a Unix server
        // I could have used a str_replace, but I like REs...
        // (I gobble anything up to the last sequence of characters not having slash or anti-slash in it)
        // Note: ensure magic quotes are disabled or neutralized
        $file = preg_replace('!.*?([^\\/]+)$!', '$1', $file);
        $debugData .= "Filter 1: $file<br>\n";
        // Filter out all characters that are not alphanumerical, dot and dash
        // as they can be troublesome in some OSes.
        // A sequence of such chars is replaced by a unique underscore.
        $file = preg_replace('/[^a-zA-Z0-9.-]+/', '_', $file);
        $debugData .= "Filter 2: $file<br>\n";
        // Split name and extension: gobble everything up to the last dot (file name), then dot and remainder (extension)
        // Note that .htaccess has no extension and is a pure filename
        if (preg_match('/^(.+)\.([^.]+)$/', $file, $m) == 0)
        {
            // No match => No dot or nothing before the dot
            $extension = '';
        }
        else
        {
            $file = $m[1];
            $extension = $m[2];
        }
        $debugData .= "Split: $file $extension<br>\n";
        // Ensure name isn't too long: just truncate it
        $file = substr($file, 0, MAX_FILE_NAME_LENGTH);
        $debugData .= "Truncated: $file<br>\n";
        // If extension not allowed (could be a CGI file...), discard it
        if ($extension != '' && !in_array($extension, $allowedExtensions))
        {
            return array('', 'File format not allowed.');
        }

        // Add trailing slash to dest dir, supposed in Unix format
        // (if not slash at end, replace last char by itself followed by a slash)
        $destinationDir = preg_replace('!([^/])$!', '$1/', $destinationDir);

		if(!file_exists($destinationDir)){
			if(!mkdir_recursive($destinationDir, 0777)){
				return array('', 'Cannot create project folder.' . " (dest.: $destinationDir)");
			}
			chmod($destinationDir, 0777);
		}
        // Create a time stamp used as prefix to make the file name unique.
        // Might have a conflict if you have millions of users, ie. a probability of having two users
        // uploading a file in the same second, supposing they go in the same dir.
        // If so, you are able to improve this code! ;-)
        // One might want to pass a prefix (or suffix) parameter to this function, eg. to tag the file name
        // with the name of the author. Just do it!

		
		//$prefix = date('Ymd-His-');
		//$prefix = '';
		
		$destinationFile =  $file . ($extension != '' ? '.' . $extension : '');
        $debugData .= "Destination file: $destinationFile<br>\n";
        $destinationPath = $destinationDir . $destinationFile;
        $debugData .= "Destination path: $destinationPath<br>\n";
        // Move uploaded file from temporary folder to destination
        // Overwrite a file of same name there, if any (unless, perhaps server is on Windows, might just fail to move).
//        if (!file_exists($destinationFile))
//        {
            if (!move_uploaded_file($tempLocation, $destinationPath))
            {
                return array('', 'Failed to move upload file.' . " (dest.: $destinationPath)");
            }
		 chmod($destinationDir.$destinationFile, 0777);
		 return array($destinationFile, $destinationPath);
//        }
    }
    else
    {
        return array('', 'Field not found');
    }
}

function mkdir_recursive($pathname, $mode)
{
    is_dir(dirname($pathname)) || mkdir_recursive(dirname($pathname), $mode);
    return is_dir($pathname) || @mkdir($pathname, $mode);
}

$debugData = '';

// Get the title
foreach($_FILES as $title=>$file){
	break;
}
unset($file); // just to be sure

$destDir .= $title.'/';


/*
$maxFiles = 1000;   // Max number of files accepted in the dest dir

// First, check if we don't have too much files. Not a bad test: since we fix the max size of files, the max total size of the files
// is under control.

$files = @scandir($destDir); 
if(is_array($files)){
	$files = array_slice($files, 2);    // Shift out . and ..
	while (count($files) > $maxFiles)
	{
	    $file = array_shift($files);
	    echo $file . " to remove\n";
	    unlink($destDir . '/' . $file);
	}
}
*/

$result = HandleUploadedFile($title, './'.$destDir, array('jpg', 'jpeg'));
/*
if ($debugData != '')
{
    echo "<p><b>Debug data:</b><br>$debugData</p>\n";
}
*/
echo "<p><b>uploader</p>\n";
if ($result[0] == '')
{
    echo "<p><b>Error:</b> {$result[1]}</p>\n";
}
else
{
    $page="result.php";
	$imageURL = 'http://' . $_SERVER['SERVER_NAME'] . $rootDir . $destDir . $result[0];
	
   // echo $imageURL;
	
	
}
?>

/////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////

// Arduino Source Code.....
// MaxSona_House.pde 

// Reads a MaxSona range finder. If a person is 410cm or less 1byte is send on the serial bus.

/////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////

// Wire LV MaxSonar-EZ0
// GRD -> GRD
// +5 -> 5v
// pw -> Arduino pin 7
//Digital pin 7 for reading in the pulse width from the MaxSonar device.
//This variable is a constant because the pin will not change throughout execution of this code.
const int pwPin = 7; 
//variables needed to store values
long pulse, inches, cm;

void setup() {

  //This opens up a serial connection to shoot the results back to the PC console
  Serial.begin(9600);
  Serial.print("started");
}

void loop() {

  pinMode(pwPin, INPUT);
    //Used to read in the pulse that is being sent by the MaxSonar device.
  //Pulse Width representation with a scale factor of 147 uS per Inch.
  pulse = pulseIn(pwPin, HIGH);
  
  //147uS per inch
  inches = pulse/147;
  //change inches to centimetres
  cm = inches * 2.54;
  if (cm < 410){
    Serial.print(1, BYTE);               // send 1 to Processing
    delay(2000);
  } else {                               // If the switch is not ON,
    Serial.print(0, BYTE);
  }

}