content: /*
   * Copyright 2002-2019 Drew Noakes and contributors
   *
   *    Licensed under the Apache License, Version 2.0 (the "License");
   *    you may not use this file except in compliance with the License.
   *    You may obtain a copy of the License at
   *
   *        https://www.apache.org/licenses/LICENSE-2.0
   *
   *    Unless required by applicable law or agreed to in writing, software
   *    distributed under the License is distributed on an "AS IS" BASIS,
   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *    See the License for the specific language governing permissions and
   *    limitations under the License.
   *
   * More information about this project is available at:
   *
   *    https://drewnoakes.com/code/exif/
   *    https://github.com/drewnoakes/metadata-extractor
   */
  package com.drew.metadata.pcx;
  
  import com.drew.imaging.ImageProcessingException;
  import com.drew.lang.SequentialReader;
  import com.drew.lang.annotations.NotNull;
  import com.drew.metadata.Metadata;
  
  /**
   * Reads PCX image file metadata.
   *
   * <ul>
   *   <li>https://courses.engr.illinois.edu/ece390/books/labmanual/graphics-pcx.html</li>
   *   <li>https://www.fileformat.info/format/pcx/egff.htm</li>
   *   <li>https://fileformats.archiveteam.org/wiki/PCX</li>
   * </ul>
   *
   * @author Drew Noakes https://drewnoakes.com
   */
  public class PcxReader
  {
      public void extract(@NotNull final SequentialReader reader, @NotNull final Metadata metadata)
      {
          reader.setMotorolaByteOrder(false);
  
          PcxDirectory directory = new PcxDirectory();
          metadata.addDirectory(directory);
  
          try {
              byte identifier = reader.getInt8();
              if (identifier != 0x0A)
                  throw new ImageProcessingException("Invalid PCX identifier byte");
  
              directory.setInt(PcxDirectory.TAG_VERSION, reader.getInt8());
  
              byte encoding = reader.getInt8();
              if (encoding != 0x01)
                  throw new ImageProcessingException("Invalid PCX encoding byte");
  
              directory.setInt(PcxDirectory.TAG_BITS_PER_PIXEL, reader.getUInt8());
              directory.setInt(PcxDirectory.TAG_XMIN,           reader.getUInt16());
              directory.setInt(PcxDirectory.TAG_YMIN,           reader.getUInt16());
              directory.setInt(PcxDirectory.TAG_XMAX,           reader.getUInt16());
              directory.setInt(PcxDirectory.TAG_YMAX,           reader.getUInt16());
              directory.setInt(PcxDirectory.TAG_HORIZONTAL_DPI, reader.getUInt16());
              directory.setInt(PcxDirectory.TAG_VERTICAL_DPI,   reader.getUInt16());
              directory.setByteArray(PcxDirectory.TAG_PALETTE,  reader.getBytes(48));
              reader.skip(1);
              directory.setInt(PcxDirectory.TAG_COLOR_PLANES,   reader.getUInt8());
              directory.setInt(PcxDirectory.TAG_BYTES_PER_LINE, reader.getUInt16());
  
              int paletteType = reader.getUInt16();
              if (paletteType != 0)
                  directory.setInt(PcxDirectory.TAG_PALETTE_TYPE, paletteType);
  
              int hScrSize = reader.getUInt16();
              if (hScrSize != 0)
                  directory.setInt(PcxDirectory.TAG_HSCR_SIZE, hScrSize);
  
              int vScrSize = reader.getUInt16();
              if (vScrSize != 0)
                  directory.setInt(PcxDirectory.TAG_VSCR_SIZE, vScrSize);
  
          } catch (Exception ex) {
              directory.addError("Exception reading PCX file metadata: " + ex.getMessage());
          }
      }
  }
  