Features

106class Features {107  public $has_primary_item = false; // True if "pitm" was parsed.108  public $has_alpha = false; // True if an alpha "auxC" was parsed.109  public $primary_item_id;110  public $primary_item_features = array( // Deduced from the data below.111    'width'        => UNDEFINED, // In number of pixels.112    'height'       => UNDEFINED, // Ignores crop and rotation.113    'bit_depth'    => UNDEFINED, // Likely 8, 10 or 12 bits per channel per pixel.114    'num_channels' => UNDEFINED  // Likely 1, 2, 3 or 4 channels:115                                          //   (1 monochrome or 3 colors) + (0 or 1 alpha)116  );117 118  public $tiles = array(); // Tile[]119  public $props = array(); // Prop[]120  public $dim_props = array(); // Dim_Prop[]121  public $chan_props = array(); // Chan_Prop[]122 123  /**124   * Binds the width, height, bit depth and number of channels from stored internal features.125   *126   * @param int     $target_item_id Id of the item whose features will be bound.127   * @param int     $tile_depth     Maximum recursion to search within tile-parent relations.128   * @return Status                 FOUND on success or NOT_FOUND on failure.129   */130  private function get_item_features( $target_item_id, $tile_depth ) {131    foreach ( $this->props as $prop ) {132      if ( $prop->item_id != $target_item_id ) {133        continue;134      }135 136      // Retrieve the width and height of the primary item if not already done.137      if ( $target_item_id == $this->primary_item_id &&138           ( $this->primary_item_features['width'] == UNDEFINED ||139             $this->primary_item_features['height'] == UNDEFINED ) ) {140        foreach ( $this->dim_props as $dim_prop ) {141          if ( $dim_prop->property_index != $prop->property_index ) {142            continue;143          }144          $this->primary_item_features['width']  = $dim_prop->width;145          $this->primary_item_features['height'] = $dim_prop->height;146          if ( $this->primary_item_features['bit_depth'] != UNDEFINED &&147               $this->primary_item_features['num_channels'] != UNDEFINED ) {148            return FOUND;149          }150          break;151        }152      }153      // Retrieve the bit depth and number of channels of the target item if not154      // already done.155      if ( $this->primary_item_features['bit_depth'] == UNDEFINED ||156           $this->primary_item_features['num_channels'] == UNDEFINED ) {157        foreach ( $this->chan_props as $chan_prop ) {158          if ( $chan_prop->property_index != $prop->property_index ) {159            continue;160          }161          $this->primary_item_features['bit_depth']    = $chan_prop->bit_depth;162          $this->primary_item_features['num_channels'] = $chan_prop->num_channels;163          if ( $this->primary_item_features['width'] != UNDEFINED &&164              $this->primary_item_features['height'] != UNDEFINED ) {165            return FOUND;166          }167          break;168        }169      }170    }171 172    // Check for the bit_depth and num_channels in a tile if not yet found.173    if ( $tile_depth < 3 ) {174      foreach ( $this->tiles as $tile ) {175        if ( $tile->parent_item_id != $target_item_id ) {176          continue;177        }178        $status = $this->get_item_features( $tile->tile_item_id, $tile_depth + 1 );179        if ( $status != NOT_FOUND ) {180          return $status;181        }182      }183    }184    return NOT_FOUND;185  }