[Sommaire] [Imprimer]

   1  <?php
   2  
   3  require_once dirname(__FILE__) . '/../Image.php';
   4  
   5  /**
   6   * This class implements the Horde_Image:: API for PNG images. It
   7   * mainly provides some utility functions, such as the ability to make
   8   * pixels or solid images for now.
   9   *
  10   * $Horde: framework/Image/Image/png.php,v 1.19.10.8 2006/05/31 17:06:36 selsky Exp $
  11   *
  12   * Copyright 2003-2006 Mike Cochrane <mike@graftonhall.co.nz>
  13   *
  14   * See the enclosed file COPYING for license information (LGPL). If you
  15   * did not receive this file, see http://www.fsf.org/copyleft/lgpl.html.
  16   *
  17   * @author  Mike Cochrane <mike@graftonhall.co.nz>
  18   * @since   Horde 3.0
  19   * @package Horde_Image
  20   */
  21  class Horde_Image_png extends Horde_Image {
  22  
  23      /**
  24       * The array of pixel data.
  25       *
  26       * @var array
  27       */
  28      var $_img = array();
  29  
  30      /**
  31       * Color depth (only 8 and 16 implemented).
  32       *
  33       * @var integer
  34       */
  35      var $_colorDepth = 8;
  36  
  37      /**
  38       * Color type (only 2 (true color) implemented).
  39       *
  40       * @var integer
  41       */
  42      var $_colorType = 2;
  43  
  44      /**
  45       * Compression method (0 is the only current valid value).
  46       *
  47       * @var integer
  48       */
  49      var $_compressionMethod = 0;
  50  
  51      /**
  52       * Filter method (0 is the only current valid value).
  53       *
  54       * @var integer
  55       */
  56      var $_filterMethod = 0;
  57  
  58      /**
  59       * Interlace method (only 0 (no interlace) implemented).
  60       *
  61       * @var integer
  62       */
  63      var $_interlaceMethod = 0;
  64  
  65      /**
  66       * PNG image constructor.
  67       */
  68      function Horde_Image_png($params)
  69      {
  70          parent::Horde_Image($params);
  71  
  72          if (!empty($params['width'])) {
  73              $this->rectangle(0, 0, $params['width'], $params['height'], $this->_background, $this->_background);
  74          }
  75      }
  76  
  77      function getContentType()
  78      {
  79          return 'image/png';
  80      }
  81  
  82      /**
  83       * Return the raw data for this image.
  84       *
  85       * @return string  The raw image data.
  86       */
  87      function raw()
  88      {
  89          return
  90              $this->_header() .
  91              $this->_IHDR() .
  92  
  93              /* Say what created the image file. */
  94              $this->_tEXt('Software', 'Horde Framework Image_png Class') .
  95  
  96              /* Set the last modified date/time. */
  97              $this->_tIME() .
  98  
  99              $this->_IDAT() .
 100              $this->_IEND();
 101      }
 102  
 103      /**
 104       * Reset the image data.
 105       */
 106      function reset()
 107      {
 108          parent::reset();
 109          $this->_img = array();
 110      }
 111  
 112      /**
 113       * Draw a rectangle.
 114       *
 115       * @param integer $x       The left x-coordinate of the rectangle.
 116       * @param integer $y       The top y-coordinate of the rectangle.
 117       * @param integer $width   The width of the rectangle.
 118       * @param integer $height  The height of the rectangle.
 119       * @param string $color    The line color of the rectangle.
 120       * @param string $fill     The color to fill the rectangle with.
 121       */
 122      function rectangle($x, $y, $width, $height, $color = 'black', $fill = 'none')
 123      {
 124          list($r, $g, $b) = $this->getRGB($color);
 125          if ($fill != 'none') {
 126              list($fR, $fG, $fB) = $this->getRGB($fill);
 127          }
 128  
 129          $x2 = $x + $width;
 130          $y2 = $y + $height;
 131  
 132          for ($h = $y; $h <= $y2; $h++) {
 133              for ($w = $x; $w <= $x2; $w++) {
 134                  // See if we're on an edge.
 135                  if ($w == $x || $h == $y || $w == $x2 || $h == $y2) {
 136                      $this->_img[$h][$w] = array('r' => $r, 'g' => $g, 'b' => $b);
 137                  } elseif ($fill != 'none') {
 138                      $this->_img[$h][$w] = array('r' => $fR, 'g' => $fG, 'b' => $fB);
 139                  }
 140              }
 141          }
 142      }
 143  
 144      /**
 145       * Create the PNG file header.
 146       */
 147      function _header()
 148      {
 149          return pack('CCCCCCCC', 137, 80, 78, 71, 13, 10, 26, 10);
 150      }
 151  
 152      /**
 153       * Create Image Header block.
 154       */
 155      function _IHDR()
 156      {
 157          $data = pack('a4NNCCCCC', 'IHDR', $this->_width, $this->_height, $this->_colorDepth, $this->_colorType, $this->_compressionMethod, $this->_filterMethod, $this->_interlaceMethod);
 158          return pack('Na' . strlen($data) . 'N', strlen($data) - 4, $data, crc32($data));
 159      }
 160  
 161      /**
 162       * Create IEND block.
 163       */
 164      function _IEND()
 165      {
 166          $data = 'IEND';
 167          return pack('Na' . strlen($data) . 'N', strlen($data) - 4, $data, crc32($data));
 168      }
 169  
 170      /**
 171       * Create Image Data block.
 172       */
 173      function _IDAT()
 174      {
 175          $data = '';
 176          $prevscanline = null;
 177          $filter = 0;
 178          for ($i = 0; $i < $this->_height; $i++) {
 179              $scanline = array();
 180              $data .= chr($filter);
 181              for ($j = 0; $j < $this->_width; $j++) {
 182                  if ($this->_colorDepth == 8) {
 183                      $scanline[$j] = pack('CCC', $this->_img[$i][$j]['r'], $this->_img[$i][$j]['g'], $this->_img[$i][$j]['b']);
 184                  } elseif ($this->_colorDepth == 16) {
 185                      $scanline[$j] = pack('nnn', $this->_img[$i][$j]['r'] << 8, $this->_img[$i][$j]['g'] << 8, $this->_img[$i][$j]['b'] << 8);
 186                  }
 187  
 188                  if ($filter == 0) {
 189                      /* No Filter. */
 190                      $data .= $scanline[$j];
 191                  } elseif ($filter == 2) {
 192                      /* Up Filter. */
 193                      $pixel = $scanline[$j] - $prevscanline[$j];
 194                      if ($this->_colorDepth == 8) {
 195                          $data .= pack('CCC', $pixel >> 16, ($pixel >> 8) & 0xFF, $pixel & 0xFF);
 196                      } elseif ($this->_colorDepth == 16) {
 197                          $data .= pack('nnn', ($pixel >> 32), ($pixel >> 16) & 0xFFFF, $pixel & 0xFFFF);
 198                      }
 199                  }
 200              }
 201              $prevscanline = $scanline;
 202          }
 203          $compressed = gzdeflate($data, 9);
 204  
 205          $data = 'IDAT' . pack('CCa' . strlen($compressed) . 'a4', 0x78, 0x01, $compressed, $this->_Adler32($data));
 206          return pack('Na' . strlen($data) . 'N', strlen($data) - 4, $data, crc32($data));
 207      }
 208  
 209      /**
 210       * Create tEXt block.
 211       */
 212      function _tEXt($keyword, $text)
 213      {
 214          $data = 'tEXt' . $keyword . "\0" . $text;
 215          return pack('Na' . strlen($data) . 'N', strlen($data) - 4, $data, crc32($data));
 216      }
 217  
 218      /**
 219       * Create last modified time block.
 220       */
 221      function _tIME($date = null)
 222      {
 223          if (is_null($date)) {
 224              $date = time();
 225          }
 226  
 227          $data = 'tIME' . pack('nCCCCC', intval(date('Y', $date)), intval(date('m', $date)), intval(date('j', $date)), intval(date('G', $date)), intval(date('i', $date)), intval(date('s', $date)));
 228          return pack('Na' . strlen($data) . 'N', strlen($data) - 4, $data, crc32($data));
 229      }
 230  
 231      /**
 232       * Calculate an Adler32 checksum for a string.
 233       */
 234      function _Adler32($input)
 235      {
 236          $s1 = 1;
 237          $s2 = 0;
 238          $iMax = strlen($input);
 239          for ($i = 0; $i < $iMax; $i++) {
 240              $s1 = ($s1 + ord($input[$i])) % 0xFFF1;
 241              $s2 = ($s2 + $s1) % 0xFFF1;
 242          }
 243          return pack('N', (($s2 << 16) | $s1));
 244      }
 245  
 246  }