<?php
/*************************
  Coppermine Photo Gallery
  ************************
  Copyright (c) 2003-2009 Coppermine Dev Team
  v1.1 originally written by Gregory DEMAR

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License version 3
  as published by the Free Software Foundation.
  
  ********************************************
  Coppermine version: 1.4.20
  $HeadURL: https://coppermine.svn.sourceforge.net/svnroot/coppermine/trunk/cpg1.4.x/include/makers/gps.php $
  $Revision: 5705 $
  $Author: gaugau $
  $Date: 2009-01-28 10:52:43 +0100 (Mi, 28 Jan 2009) $
**********************************************/

/*

        Exifer

        Extracts EXIF information from digital photos.



        Copyright © 2003 Jake Olefsky

        http://www.offsky.com/software/exif/index.php

        jake@olefsky.com



        Please see exif.php for the complete information about this software.



        ------------



        This program is free software; you can redistribute it and/or modify it under the terms of

        the GNU General Public License as published by the Free Software Foundation; either version 2

        of the License, or 



        This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

        without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

        See the GNU General Public License for more details. http://www.gnu.org/copyleft/gpl.html

*/


//=================

// Looks up the name of the tag

//====================================================================

function lookup_GPS_tag($tag) {



        switch($tag) {

                case "0000": $tag = "Version";break;

                case "0001": $tag = "Latitude Reference";break;                        //north or south

                case "0002": $tag = "Latitude";break;                                        //dd mm.mm or dd mm ss

                case "0003": $tag = "Longitude Reference";break;                //east or west

                case "0004": $tag = "Longitude";break;                                        //dd mm.mm or dd mm ss

                case "0005": $tag = "Altitude Reference";break;                        //sea level or below sea level

                case "0006": $tag = "Altitude";break;                                        //positive rational number

                case "0007": $tag = "Time";break;                                                //three positive rational numbers

                case "0008": $tag = "Satellite";break;                                        //text string up to 999 bytes long

                case "0009": $tag = "ReceiveStatus";break;                                //in progress or interop

                case "000a": $tag = "MeasurementMode";break;                        //2D or 3D

                case "000b": $tag = "MeasurementPrecision";break;                //positive rational number

                case "000c": $tag = "SpeedUnit";break;                                        //KPH, MPH, knots

                case "000d": $tag = "ReceiverSpeed";break;                                //positive rational number

                case "000e": $tag = "MovementDirectionRef";break;                //true or magnetic north

                case "000f": $tag = "MovementDirection";break;                        //positive rational number

                case "0010": $tag = "ImageDirectionRef";break;                        //true or magnetic north

                case "0011": $tag = "ImageDirection";break;                                //positive rational number

                case "0012": $tag = "GeodeticSurveyData";break;                        //text string up to 999 bytes long

                case "0013": $tag = "DestLatitudeRef";break;                        //north or south

                case "0014": $tag = "DestinationLatitude";break;                //three positive rational numbers

                case "0015": $tag = "DestLongitudeRef";break;                        //east or west

                case "0016": $tag = "DestinationLongitude";break;                //three positive rational numbers

                case "0017": $tag = "DestBearingRef";break;                                //true or magnetic north

                case "0018": $tag = "DestinationBearing";break;                        //positive rational number

                case "0019": $tag = "DestDistanceRef";break;                        //km, miles, knots

                case "001a": $tag = "DestinationDistance";break;                //positive rational number

                case "001b": $tag = "ProcessingMethod";break;

                case "001c": $tag = "AreaInformation";break;

                case "001d": $tag = "Datestamp";break;                                        //text string 10 bytes long

                case "001e": $tag = "DifferentialCorrection";break;                //integer in range 0-65535





                default: $tag = "unknown:".$tag;break;

        }



        return $tag;

}



//=================

// Formats a rational number

//====================================================================

function GPSRational($data, $intel) {



        if($intel==1) $top = hexdec(substr($data,8,8));         //intel stores them bottom-top

        else  $top = hexdec(substr($data,0,8));                                //motorola stores them top-bottom



        if($intel==1) $bottom = hexdec(substr($data,0,8));        //intel stores them bottom-top

        else  $bottom = hexdec(substr($data,8,8));                        //motorola stores them top-bottom



        if($bottom!=0) $data=$top/$bottom;

        else if($top==0) $data = 0;

        else $data=$top."/".$bottom;



        return $data;

}

//=================

// Formats Data for the data type

//====================================================================

function formatGPSData($type,$tag,$intel,$data) {



        if($type=="ASCII") {





        } else if($type=="URATIONAL" || $type=="SRATIONAL") {

                $data = bin2hex($data);

                if($intel==1) $data = intel2Moto($data);



                if($intel==1) $top = hexdec(substr($data,8,8));         //intel stores them bottom-top

                else  $top = hexdec(substr($data,0,8));                                //motorola stores them top-bottom



                if($intel==1) $bottom = hexdec(substr($data,0,8));        //intel stores them bottom-top

                else  $bottom = hexdec(substr($data,8,8));                        //motorola stores them top-bottom



                if($type=="SRATIONAL" && $top>2147483647) $top = $top - 4294967296;                //this makes the number signed instead of unsigned



                if($tag=="0002" || $tag=="0004") { //Latitude



                        $seconds = GPSRational(substr($data,0,16),$intel);

                        $minutes = GPSRational(substr($data,16,16),$intel);

                        $hour = GPSRational(substr($data,32,16),$intel);



                        $data = $hour+$minutes/60+$seconds/3600;

                } else if($tag=="0007") { //Time

                        $seconds = GPSRational(substr($data,0,16),$intel);

                        $minutes = GPSRational(substr($data,16,16),$intel);

                        $hour = GPSRational(substr($data,32,16),$intel);



                        $data = $hour.":".$minutes.":".$seconds;

                } else {

                        if($bottom!=0) $data=$top/$bottom;

                        else if($top==0) $data = 0;

                        else $data=$top."/".$bottom;

                }

        } else if($type=="USHORT" || $type=="SSHORT" || $type=="ULONG" || $type=="SLONG" || $type=="FLOAT" || $type=="DOUBLE") {

                $data = bin2hex($data);

                if($intel==1) $data = intel2Moto($data);

                $data=hexdec($data);





        } else if($type=="UNDEFINED") {







        } else if($type=="UBYTE") {

                $data = bin2hex($data);

                if($intel==1) $num = intel2Moto($data);



                if($tag=="0000") { //Latitude

                        $data =  hexdec(substr($data,0,2)).".". hexdec(substr($data,2,2)).".". hexdec(substr($data,4,2)).".". hexdec(substr($data,6,2));

                }



        } else {

                $data = bin2hex($data);

                if($intel==1) $data = intel2Moto($data);

        }



        return $data;

}





//=================

// GPS Special data section

// Useful websites

// http://drewnoakes.com/code/exif/sampleOutput.html

// http://www.geosnapper.com

//====================================================================

function parseGPS($block,&$result,$offset,$seek, $globalOffset) {



        if($result['Endien']=="Intel") $intel=1;

        else $intel=0;



        $v = fseek($seek,$globalOffset+$offset);  //offsets are from TIFF header which is 12 bytes from the start of the file

        if($v==-1) {

                $result['Errors'] = $result['Errors']++;

        }



        $num = bin2hex(fread( $seek, 2 ));

        if($intel==1) $num = intel2Moto($num);

        $num=hexdec($num);

        $result['GPS']['NumTags'] = $num;



        $block = fread( $seek, $num*12 );

        $place = 0;



        //loop thru all tags  Each field is 12 bytes

        for($i=0;$i<$num;$i++) {

                        //2 byte tag

                $tag = bin2hex(substr($block,$place,2));$place+=2;

                if($intel==1) $tag = intel2Moto($tag);

                $tag_name = lookup_GPS_tag($tag);



                //2 byte datatype

                $type = bin2hex(substr($block,$place,2));$place+=2;

                if($intel==1) $type = intel2Moto($type);

                lookup_type($type,$size);



                //4 byte number of elements

                $count = bin2hex(substr($block,$place,4));$place+=4;

                if($intel==1) $count = intel2Moto($count);

                $bytesofdata = $size*hexdec($count);



                //4 byte value or pointer to value if larger than 4 bytes

                $value = substr($block,$place,4);$place+=4;



                if($bytesofdata<=4) {

                        $data = $value;

                } else {

                        $value = bin2hex($value);

                        if($intel==1) $value = intel2Moto($value);



                        $v = fseek($seek,$globalOffset+hexdec($value));  //offsets are from TIFF header which is 12 bytes from the start of the file

                        if($v==0) {

                                $data = fread($seek, $bytesofdata);

                        } else if($v==-1) {

                                $result['Errors'] = $result['Errors']++;

                        }

                }



                if($result['VerboseOutput']==1) {

                        $result['GPS'][$tag_name] = formatGPSData($type,$tag,$intel,$data);

                        $result['GPS'][$tag_name."_Verbose"]['RawData'] = bin2hex($data);

                        $result['GPS'][$tag_name."_Verbose"]['Type'] = $type;

                        $result['GPS'][$tag_name."_Verbose"]['Bytes'] = $bytesofdata;

                } else {

                        $result['GPS'][$tag_name] = formatGPSData($type,$tag,$intel,$data);

                }

        }

}





?>