<?php

/**

 * BCGDrawJPG.php

 *--------------------------------------------------------------------

 *

 * Image Class to draw JPG images with possibility to set DPI

 *

 *--------------------------------------------------------------------

 * Revision History

 * v2.1.0	8  nov	2009	Jean-Sébastien Goupil

 *--------------------------------------------------------------------

 * $Id: BCGDrawJPG.php,v 1.1 2009/11/09 04:14:37 jsgoupil Exp $

 *--------------------------------------------------------------------

 * Copyright (C) Jean-Sebastien Goupil

 * http://www.barcodephp.com

 */

include_once('BCGDraw.php');



if (!function_exists('file_put_contents')) {

	function file_put_contents($filename, $data) {

		$f = @fopen($filename, 'w');

		if (!$f) {

			return false;

		} else {

			$bytes = fwrite($f, $data);

			fclose($f);

			return $bytes;

		}

	}

}



class BCGDrawJPG extends BCGDraw {

	private $dpi;

	private $quality;



	/**

	 * Constructor

	 *

	 * @param resource $im

	 */

	public function __construct($im) {

		parent::__construct($im);

	}



	/**

	 * Sets the DPI

	 *

	 * @param int $dpi

	 */

	public function setDPI($dpi) {

		if(is_int($dpi)) {

			$this->dpi = max(1, $dpi);

		} else {

			$this->dpi = null;

		}

	}



	/**

	 * Sets the quality of the JPG

	 *

	 * @param int $quality

	 */

	public function setQuality($quality) {

		$this->quality = $quality;

	}



	/**

	 * Draws the JPG on the screen or in a file

	 */

	public function draw() {

		ob_start();

		imagejpeg($this->im, null, $this->quality);

		$bin = ob_get_contents();

		ob_end_clean();



		$this->setInternalProperties($bin);



		if (empty($this->filename)) {

			echo $bin;

		} else {

			file_put_contents($this->filename, $bin);

		}

	}



	private function setInternalProperties(&$bin) {

		$this->internalSetDPI($bin);

		$this->internalSetC($bin);

	}



	private function internalSetDPI(&$bin) {

		if($this->dpi !== null) {

			$bin = substr_replace($bin, pack("Cnn", 0x01, $this->dpi, $this->dpi), 13, 5);

		}

	}



	private function internalSetC(&$bin) {

		if(strcmp(substr($bin, 0, 4), pack('H*', 'FFD8FFE0')) === 0) {

			$offset = 4 + (ord($bin[4]) << 8 | ord($bin[5]));

			$firstPart = substr($bin, 0, $offset);

			$secondPart = substr($bin, $offset);

			$cr = pack('H*', 'FFFE004447656E657261746564207769746820426172636F64652047656E657261746F7220666F722050485020687474703A2F2F7777772E626172636F64657068702E636F6D');

			$bin = $firstPart;

			$bin .= $cr;

			$bin .= $secondPart;

		}

	}

}

?>