contextapi/website/data.php

<?PHP

 require('common.php');

 if (isset($_GET['graph'])) {
  $imei = isset($_GET['imei']) ? $_GET['imei'] : decodeIMEI($_GET['code']);

  $sql = 'SELECT log_data FROM sensorlogger WHERE log_id = ' . ((int) $_GET['graph']) . ' AND log_imei = \'' . m($imei) . '\'';
  $res = mysql_query($sql);

  if (mysql_num_rows($res) == 0) {
   die('Data not found');
  }

  $row = mysql_fetch_assoc($res);

  $datax = array();
  $datay = array();
  $dataz = array();
  foreach (explode("\n", $row['log_data']) as $line) {
   if (preg_match('/([0-9]+):(?:.*?,.*?,.*?,){'.($_GET['ds']-1).'}([0-9\.\-]+),([0-9\.\-]+),([0-9\.\-]+)/', $line, $m)) {
    $datax[] = (double) $m[2];
    $datay[] = (double) $m[3];
    $dataz[] = (double) $m[4];
   }
  }
  
  $im = imagecreatetruecolor(count($datax) * 2, 330);
  $w = imagecolorallocate($im, 255, 255, 255);
  imagefill($im, 0, 0, $w);
 
  $r = imagecolorallocate($im, 255, 0, 0);
  $g = imagecolorallocate($im, 0, 255, 0);
  $b = imagecolorallocate($im, 0, 0, 255);

  $grey = imagecolorallocate($im, 200, 200, 200);
  $lgrey = imagecolorallocate($im, 230, 230, 230);
 
  $minx = min($datax); $maxx = max($datax); $rangex = max(0.01, $maxx - $minx);
  $miny = min($datay); $maxy = max($datay); $rangey = max(0.01, $maxy - $miny);
  $minz = min($dataz); $maxz = max($dataz); $rangez = max(0.01, $maxz - $minz);
  $lastx = $lasty = $lastz = -0;

  imagestring($im, 1, 2, 6, 'Min: ' . $minx . '; Max: ' . $maxx . '; Range: ' . $rangex, $grey);
  imagestring($im, 1, 2, 116, 'Min: ' . $miny . '; Max: ' . $maxy . '; Range: ' . $rangey, $grey);
  imagestring($im, 1, 2, 226, 'Min: ' . $minz . '; Max: ' . $maxz . '; Range: ' . $rangez, $grey);

  imageline($im, 0, 5, count($datax) * 2, 5, $grey);
  imageline($im, 0, 105, count($datax) * 2, 105, $grey);
  imageline($im, 0, 115, count($datax) * 2, 115, $grey);
  imageline($im, 0, 215, count($datax) * 2, 215, $grey);
  imageline($im, 0, 225, count($datax) * 2, 225, $grey);
  imageline($im, 0, 325, count($datax) * 2, 325, $grey);

  for ($i = 0; $i < count($datax); $i++) {
   $x = ($datax[$i] - $minx) * 100 / $rangex + 5;
   $y = ($datay[$i] - $miny) * 100 / $rangey + 115;
   $z = ($dataz[$i] - $minz) * 100 / $rangez + 225;

   if ($i > 0) {
    imageline($im, 2 * $i - 2, $lastx, $i * 2, $x, $r);
    imageline($im, 2 * $i - 2, $lasty, $i * 2, $y, $g);
    imageline($im, 2 * $i - 2, $lastz, $i * 2, $z, $b);
   }

   $lastx = $x; $lasty = $y; $lastz = $z;
  }

  header('Expires: ' . date(DateTime::RFC822, strtotime('+10 years')));
  header('Cache-control: public');
  header('Content-type: image/png');
  imagecolortransparent($im, $w); 
  imagepng($im);
  return;
 }

?>