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   1  <?php
   2  
   3  /**
   4   * Joomla! Content Management System
   5   *
   6   * @copyright   (C) 2005 Open Source Matters, Inc. <https://www.joomla.org>
   7   * @license     GNU General Public License version 2 or later; see LICENSE
   8   */
   9  
  10  namespace Joomla\CMS\Image\Filter;
  11  
  12  use Joomla\CMS\Image\ImageFilter;
  13  
  14  // phpcs:disable PSR1.Files.SideEffects
  15  \defined('JPATH_PLATFORM') or die;
  16  // phpcs:enable PSR1.Files.SideEffects
  17  
  18  /**
  19   * Image Filter class fill background with color;
  20   *
  21   * @since       3.4
  22   */
  23  class Backgroundfill extends ImageFilter
  24  {
  25      /**
  26       * Method to apply a background color to an image resource.
  27       *
  28       * @param   array  $options  An array of options for the filter.
  29       *                           color  Background matte color
  30       *
  31       * @return  void
  32       *
  33       * @since   3.4
  34       * @throws  \InvalidArgumentException
  35       */
  36      public function execute(array $options = [])
  37      {
  38          // Validate that the color value exists and is an integer.
  39          if (!isset($options['color'])) {
  40              throw new \InvalidArgumentException('No color value was given. Expected string or array.');
  41          }
  42  
  43          $colorCode = $options['color'] ?? null;
  44  
  45          // Get resource dimensions
  46          $width  = imagesx($this->handle);
  47          $height = imagesy($this->handle);
  48  
  49          // Sanitize color
  50          $rgba = $this->sanitizeColor($colorCode);
  51  
  52          // Enforce alpha on source image
  53          if (imageistruecolor($this->handle)) {
  54              imagealphablending($this->handle, false);
  55              imagesavealpha($this->handle, true);
  56          }
  57  
  58          // Create background
  59          $bg = imagecreatetruecolor($width, $height);
  60          imagesavealpha($bg, empty($rgba['alpha']));
  61  
  62          // Allocate background color.
  63          $color = imagecolorallocatealpha($bg, $rgba['red'], $rgba['green'], $rgba['blue'], $rgba['alpha']);
  64  
  65          // Fill background
  66          imagefill($bg, 0, 0, $color);
  67  
  68          // Apply image over background
  69          imagecopy($bg, $this->handle, 0, 0, 0, 0, $width, $height);
  70  
  71          // Move flattened result onto current handle.
  72          // If handle was palette-based, it'll stay like that.
  73          imagecopy($this->handle, $bg, 0, 0, 0, 0, $width, $height);
  74  
  75          // Free up memory
  76          imagedestroy($bg);
  77      }
  78  
  79      /**
  80       * Method to sanitize color values and/or convert to an array
  81       *
  82       * @param   mixed  $input  Associative array of colors and alpha, or hex RGBA string when alpha FF is opaque. Defaults to black and opaque alpha.
  83       *
  84       * @return  array  Associative array of red, green, blue and alpha
  85       *
  86       * @since   3.4
  87       *
  88       * @note    '#FF0000FF' returns an array with alpha of 0 (opaque)
  89       */
  90      protected function sanitizeColor($input)
  91      {
  92          // Construct default values
  93          $colors = ['red' => 0, 'green' => 0, 'blue' => 0, 'alpha' => 0];
  94  
  95          // Make sure all values are in
  96          if (\is_array($input)) {
  97              $colors = array_merge($colors, $input);
  98          } elseif (\is_string($input)) {
  99              // Convert RGBA 6-9 char string
 100              $hex = ltrim($input, '#');
 101  
 102              $hexValues = [
 103                  'red'   => substr($hex, 0, 2),
 104                  'green' => substr($hex, 2, 2),
 105                  'blue'  => substr($hex, 4, 2),
 106                  'alpha' => substr($hex, 6, 2),
 107              ];
 108  
 109              $colors = array_map('hexdec', $hexValues);
 110  
 111              // Convert Alpha to 0..127 when provided
 112              if (\strlen($hex) > 6) {
 113                  $colors['alpha'] = floor((255 - $colors['alpha']) / 2);
 114              }
 115          } else {
 116              // Cannot sanitize such type
 117              return $colors;
 118          }
 119  
 120          // Make sure each value is within the allowed range
 121          foreach ($colors as &$value) {
 122              $value = max(0, min(255, (int) $value));
 123          }
 124  
 125          $colors['alpha'] = min(127, $colors['alpha']);
 126  
 127          return $colors;
 128      }
 129  }