kml.php

<?php
session_start();

header("Content-type: application/vnd.google-earth.kml+xml");
header("Content-disposition: attachment; filename=\"openflights-" . date("Y-m-d").".kml\"");

include 'greatcircle.php';
include 'helper.php';
include 'filter.php';
include 'db_pdo.php';

$METERSPERFOOT = 0.3048;

$uid = $_SESSION["uid"];
// Logged in?
if(!$uid or empty($uid)) {
  $uid = 1;
}

$sql = "SELECT DISTINCT s.x AS sx,s.y AS sy,s.elevation AS sz,s.iata AS siata,s.icao AS sicao,d.x AS dx,d.y AS dy,d.elevation AS dz,d.iata AS diata,d.icao AS dicao,code,distance,mode FROM flights AS f, airports AS s, airports AS d WHERE f.src_apid=s.apid AND f.dst_apid=d.apid AND f.uid=:uid" . getFilterString($dbh, $_GET) . " GROUP BY f.fid,s.apid,d.apid";

$sth = $dbh->prepare($sql);
$sth->execute(compact('uid'));

readfile("../kml/header.kml");

print "<Folder>\n<name>Flights</name>\n";

// Plot flights on map
while($row = $sth->fetch()) {
  $x1 = $row["sx"];
  $y1 = $row["sy"];
  $z1 = $row["sz"] * $METERSPERFOOT;
  $x2 = $row["dx"];
  $y2 = $row["dy"];
  $z2 = $row["dz"] * $METERSPERFOOT;
  $distance = $row["distance"];

  // Skip flights where src==dest
  if($x1 != $x2 && $y1 != $y2) {
    $src_ap = format_apcode2($row["siata"], $row["sicao"]);
    $dst_ap = format_apcode2($row["diata"], $row["dicao"]);
    $code = $row["code"];
    $mode = $row["mode"];

    print "<Placemark>\n";
    print "  <name>$src_ap-$dst_ap</name>\n  <description>$modes[$mode] $code</description>\n";
    print "  <styleUrl>#$mode</styleUrl>\n";

    $points = gcPath(array("x" => $x1, "y" => $y1, "z" => $z1), 
		     array("x" => $x2, "y" => $y2, "z" => $z2),
		     $distance, true);
    
    if($row["mode"] == "F") {
      $altitudeMode = "absolute";
    } else {
      $altitudeMode = "clampToGround";
    }
    print "  <MultiGeometry>\n    <LineString>\n      <altitudeMode>$altitudeMode</altitudeMode><coordinates>\n";
    foreach($points as $loc) {
      if(! $loc) continue; // skip breaks
      print $loc["x"] . "," . $loc["y"] . "," . $loc["z"] . "\n";
    }
    print "      </coordinates>\n    </LineString>\n";
    print "  </MultiGeometry>\n</Placemark>\n";
  }
}

print "</Folder>\n";
print "<Folder><name>Airports</name>\n";

// Draw airports from largest to smallest
$airportColors = array ("black", "gray", "purple", "cyan", "cyan", "green");

$sql = "SELECT DISTINCT x,y,elevation,iata,icao,name,city,country,count(name) AS visits FROM flights AS f, airports AS a WHERE (f.src_apid=a.apid OR f.dst_apid=a.apid) AND f.uid=:uid" . getFilterString($dbh, $_GET) . " GROUP BY a.apid,name ORDER BY visits DESC";
$sth = $dbh->prepare($sql);
$sth->execute(compact('uid'));
$first = true;
while ($row = $sth->fetch()) {
  $count = $row["visits"];
  if($first) {
    $maxFlights = $count;
    $first = false;
  }

  $colorIndex = floor(($count / $maxFlights) * sizeof($airportColors)) + 1;
  if($count <= 2 || $colorIndex < 0) {
    $colorIndex = 0;
  }
  // More than two flights: at least 2nd smallest
  if($count > 2) {
    $colorIndex = max(1, $colorIndex);
  }
  // Max out at top color
  if($colorIndex >= sizeof($airportColors)) {
    $colorIndex = sizeof($airportColors) - 1;
  }

  print "<Placemark>\n";
  print "  <name>" . format_apcode($row) . "</name>\n";
  printf("  <description>\n    <![CDATA[\n<b>%s</b><br><i>Elevation</i>: %s ft<br><i>Flights</i>: %s\n]]>\n  </description>\n",
	 format_airport($row), $row["elevation"], $count);
  print "  <Point>\n";
  printf("    <coordinates>%s,%s,%s</coordinates>\n", $row["x"], $row["y"], $row["elevation"]);
  print "  </Point>\n";
  print "  <styleUrl>#" . $airportColors[$colorIndex] . "-pushpin</styleUrl>\n";
  print "</Placemark>\n";
}
print "</Folder>\n";
readfile("../kml/footer.kml");

?>