<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Pdf

 * @subpackage Fonts

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

/** Internally used classes */

require_once 'Zend/Pdf/Element/Name.php';

/** Zend_Pdf_Resource_Font */

require_once 'Zend/Pdf/Resource/Font.php';

/**

 * Adobe PDF Simple fonts implementation

 *

 * PDF simple fonts functionality is presented by Adobe Type 1

 * (including standard PDF Type1 built-in fonts) and TrueType fonts support.

 *

 * Both fonts have the following properties:

 * - Glyphs in the font are selected by single-byte character codes obtained from a

 *   string that is shown by the text-showing operators. Logically, these codes index

 *   into a table of 256 glyphs; the mapping from codes to glyphs is called the font’s

 *   encoding.

 *   PDF specification provides a possibility to specify any user defined encoding in addition

 *   to the standard built-in encodings: Standard-Encoding, MacRomanEncoding, WinAnsiEncoding,

 *   and PDFDocEncoding, but Zend_Pdf simple fonts implementation operates only with

 *   Windows ANSI encoding (except Symbol and ZapfDingbats built-in fonts).

 *

 * - Each glyph has a single set of metrics, including a horizontal displacement or

 *   width. That is, simple fonts support only horizontal writing mode.

 *

 *

 * The code in this class is common to both types. However, you will only deal

 * directly with subclasses.

 *

 * Font objects should be normally be obtained from the factory methods

 * {@link Zend_Pdf_Font::fontWithName} and {@link Zend_Pdf_Font::fontWithPath}.

 *

 * @package    Zend_Pdf

 * @subpackage Fonts

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

abstract class Zend_Pdf_Resource_Font_Simple extends Zend_Pdf_Resource_Font

{

    /**

     * Object representing the font's cmap (character to glyph map).

     * @var Zend_Pdf_Cmap

     */

    protected $_cmap = null;

    /**

     * Array containing the widths of each of the glyphs contained in the font.

     *

     * Keys are integers starting from 0, which coresponds to Zend_Pdf_Cmap::MISSING_CHARACTER_GLYPH.

     *

     * Font character map may contain gaps for actually used glyphs, nevertheless glyphWidths array

     * contains widths for all glyphs even they are unused.

     *

     * @var array

     */

    protected $_glyphWidths = null;

    /**

     * Width for glyphs missed in the font

     *

     * Note: Adobe PDF specfication (V1.4 - V1.6) doesn't define behavior for rendering

     * characters missed in the standard PDF fonts (such us 0x7F (DEL) Windows ANSI code)

     * Adobe Font Metrics files doesn't also define metrics for "missed glyph".

     * We provide character width as "0" for this case, but actually it depends on PDF viewer

     * implementation.

     *

     * @var integer

     */

    protected $_missingGlyphWidth = 0;

    /**** Public Interface ****/

  /* Object Lifecycle */

    /**

     * Object constructor

     *

     */

    public function __construct()

    {

        parent::__construct();

        /**

         * @todo

         * It's easy to add other encodings support now (Standard-Encoding, MacRomanEncoding,

         * PDFDocEncoding, MacExpertEncoding, Symbol, and ZapfDingbats).

         * Steps for the implementation:

         * - completely describe all PDF single byte encodings in the documentation

         * - implement non-WinAnsi encodings processing into encodeString()/decodeString() methods

         *

         * These encodings will be automatically supported for standard builtin PDF fonts as well

         * as for external fonts.

         */

        $this->_resource->Encoding = new Zend_Pdf_Element_Name('WinAnsiEncoding');

    }

    /**

     * Returns an array of glyph numbers corresponding to the Unicode characters.

     *

     * If a particular character doesn't exist in this font, the special 'missing

     * character glyph' will be substituted.

     *

     * See also {@link glyphNumberForCharacter()}.

     *

     * @param array $characterCodes Array of Unicode character codes (code points).

     * @return array Array of glyph numbers.

     */

    public function glyphNumbersForCharacters($characterCodes)

    {

        return $this->_cmap->glyphNumbersForCharacters($characterCodes);

    }

    /**

     * Returns the glyph number corresponding to the Unicode character.

     *

     * If a particular character doesn't exist in this font, the special 'missing

     * character glyph' will be substituted.

     *

     * See also {@link glyphNumbersForCharacters()} which is optimized for bulk

     * operations.

     *

     * @param integer $characterCode Unicode character code (code point).

     * @return integer Glyph number.

     */

    public function glyphNumberForCharacter($characterCode)

    {

        return $this->_cmap->glyphNumberForCharacter($characterCode);

    }

    /**

     * Returns a number between 0 and 1 inclusive that indicates the percentage

     * of characters in the string which are covered by glyphs in this font.

     *

     * Since no one font will contain glyphs for the entire Unicode character

     * range, this method can be used to help locate a suitable font when the

     * actual contents of the string are not known.

     *

     * Note that some fonts lie about the characters they support. Additionally,

     * fonts don't usually contain glyphs for control characters such as tabs

     * and line breaks, so it is rare that you will get back a full 1.0 score.

     * The resulting value should be considered informational only.

     *

     * @param string $string

     * @param string $charEncoding (optional) Character encoding of source text.

     *   If omitted, uses 'current locale'.

     * @return float

     */

    public function getCoveredPercentage($string, $charEncoding = '')

    {

        /* Convert the string to UTF-16BE encoding so we can match the string's

         * character codes to those found in the cmap.

         */

        if ($charEncoding != 'UTF-16BE') {

            if (PHP_OS != 'AIX') { // AIX doesnt know what UTF-16BE is

                $string = iconv($charEncoding, 'UTF-16BE', $string);

            }

        }

        $charCount = (PHP_OS != 'AIX') ? iconv_strlen($string, 'UTF-16BE') : strlen($string);

        if ($charCount == 0) {

            return 0;

        }

        /* Fetch the covered character code list from the font's cmap.

         */

        $coveredCharacters = $this->_cmap->getCoveredCharacters();

        /* Calculate the score by doing a lookup for each character.

         */

        $score = 0;

        $maxIndex = strlen($string);

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

            /**

             * @todo Properly handle characters encoded as surrogate pairs.

             */

            $charCode = (ord($string[$i]) << 8) | ord($string[++$i]);

            /* This could probably be optimized a bit with a binary search...

             */

            if (in_array($charCode, $coveredCharacters)) {

                $score++;

            }

        }

        return $score / $charCount;

    }

    /**

     * Returns the widths of the glyphs.

     *

     * The widths are expressed in the font's glyph space. You are responsible

     * for converting to user space as necessary. See {@link unitsPerEm()}.

     *

     * See also {@link widthForGlyph()}.

     *

     * @param array &$glyphNumbers Array of glyph numbers.

     * @return array Array of glyph widths (integers).

     */

    public function widthsForGlyphs($glyphNumbers)

    {

        $widths = array();

        foreach ($glyphNumbers as $key => $glyphNumber) {

            if (!isset($this->_glyphWidths[$glyphNumber])) {

                $widths[$key] = $this->_missingGlyphWidth;

            } else {

                $widths[$key] = $this->_glyphWidths[$glyphNumber];

            }

        }

        return $widths;

    }

    /**

     * Returns the width of the glyph.

     *

     * Like {@link widthsForGlyphs()} but used for one glyph at a time.

     *

     * @param integer $glyphNumber

     * @return integer

     */

    public function widthForGlyph($glyphNumber)

    {

        if (!isset($this->_glyphWidths[$glyphNumber])) {

            return $this->_missingGlyphWidth;

        }

        return $this->_glyphWidths[$glyphNumber];

    }

    /**

     * Convert string to the font encoding.

     *

     * The method is used to prepare string for text drawing operators

     *

     * @param string $string

     * @param string $charEncoding Character encoding of source text.

     * @return string

     */

    public function encodeString($string, $charEncoding)

    {

        if (PHP_OS == 'AIX') {

            return $string; // returning here b/c AIX doesnt know what CP1252 is

        }

        return iconv($charEncoding, 'CP1252//IGNORE', $string);

    }

    /**

     * Convert string from the font encoding.

     *

     * The method is used to convert strings retrieved from existing content streams

     *

     * @param string $string

     * @param string $charEncoding Character encoding of resulting text.

     * @return string

     */

    public function decodeString($string, $charEncoding)

    {

        return iconv('CP1252', $charEncoding, $string);

    }

}