<?php
/**
* PEL: PHP Exif Library.
* A library with support for reading and
* writing all Exif headers in JPEG and TIFF images using PHP.
*
* Copyright (C) 2004, 2005, 2006 Martin Geisler.
*
* 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
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program in the file COPYING; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
namespace lsolesen\pel;
/**
* Classes used to manipulate rational numbers.
*
* @author Martin Geisler <mgeisler@users.sourceforge.net>
* @license http://www.gnu.org/licenses/gpl.html GNU General Public
* License (GPL)
* @package PEL
*/
/**
* Class for holding unsigned rational numbers.
*
* This class can hold rational numbers, consisting of a numerator and
* denominator both of which are of type unsigned long. Each rational
* is represented by an array with just two entries: the numerator and
* the denominator, in that order.
*
* The class can hold either just a single rational or an array of
* rationals. The class will be used to manipulate any of the Exif
* tags which can have format {@link PelFormat::RATIONAL} like in this
* example:
*
* <code>
* $resolution = $ifd->getEntry(PelTag::X_RESOLUTION);
* $resolution->setValue([1, 300]);
* </code>
*
* Here the x-resolution is adjusted to 1/300, which will be 300 DPI,
* unless the {@link PelTag::RESOLUTION_UNIT resolution unit} is set
* to something different than 2 which means inches.
*
* @author Martin Geisler <mgeisler@users.sourceforge.net>
* @package PEL
*/
class PelEntryRational extends PelEntryLong
{
/**
* Make a new entry that can hold an unsigned rational.
*
* @param
* int the tag which this entry represents. This should
* be one of the constants defined in {@link PelTag}, e.g., {@link
* PelTag::X_RESOLUTION}, or any other tag which can have format
* {@link PelFormat::RATIONAL}.
*
* @param array $value...
* the rational(s) that this entry will
* represent. The arguments passed must obey the same rules as the
* argument to {@link setValue}, namely that each argument should be
* an array with two entries, both of which must be within range of
* an unsigned long (32 bit), that is between 0 and 4294967295
* (inclusive). If not, then a {@link PelOverflowException} will be
* thrown.
*/
public function __construct($tag, $value = null)
{
$this->tag = $tag;
$this->format = PelFormat::RATIONAL;
$this->dimension = 2;
$this->min = 0;
$this->max = 4294967295;
$value = func_get_args();
array_shift($value);
$this->setValueArray($value);
}
/**
* Format a rational number.
*
* The rational will be returned as a string with a slash '/'
* between the numerator and denominator.
*
* @param
* array the rational which will be formatted.
*
* @param
* boolean not used.
*
* @return string the rational formatted as a string suitable for
* display.
*/
public function formatNumber($number, $brief = false)
{
return $number[0] . '/' . $number[1];
}
/**
* Get the value of an entry as text.
*
* The value will be returned in a format suitable for presentation,
* e.g., rationals will be returned as 'x/y', ASCII strings will be
* returned as themselves etc.
*
* @param
* boolean some values can be returned in a long or more
* brief form, and this parameter controls that.
*
* @return string the value as text.
*/
public function getText($brief = false)
{
if (isset($this->value[0])) {
$v = $this->value[0];
}
switch ($this->tag) {
case PelTag::FNUMBER:
// CC (e->components, 1, v);
return Pel::fmt('f/%.01f', $v[0] / $v[1]);
case PelTag::APERTURE_VALUE:
// CC (e->components, 1, v);
// if (!v_rat.denominator) return (NULL);
return Pel::fmt('f/%.01f', pow(2, $v[0] / $v[1] / 2));
case PelTag::FOCAL_LENGTH:
// CC (e->components, 1, v);
// if (!v_rat.denominator) return (NULL);
return Pel::fmt('%.1f mm', $v[0] / $v[1]);
case PelTag::SUBJECT_DISTANCE:
// CC (e->components, 1, v);
// if (!v_rat.denominator) return (NULL);
return Pel::fmt('%.1f m', $v[0] / $v[1]);
case PelTag::EXPOSURE_TIME:
// CC (e->components, 1, v);
// if (!v_rat.denominator) return (NULL);
if ($v[0] / $v[1] < 1) {
return Pel::fmt('1/%d sec.', $v[1] / $v[0]);
} else {
return Pel::fmt('%d sec.', $v[0] / $v[1]);
}
break;
case PelTag::GPS_LATITUDE:
case PelTag::GPS_LONGITUDE:
$degrees = $this->value[0][0] / $this->value[0][1];
$minutes = $this->value[1][0] / $this->value[1][1];
$seconds = $this->value[2][0] / $this->value[2][1];
return sprintf('%s° %s\' %s" (%.2f°)', $degrees, $minutes, $seconds, $degrees + $minutes / 60 + $seconds / 3600);
default:
return parent::getText($brief);
}
}
}
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