Allegro data file: JavaScript parsing library

Allegro library for C (mostly used for game and multimedia apps programming) used its own container file format.

In general, it allows storage of arbitrary binary data blocks bundled together with some simple key-value style metadata ("properties") for every block. Allegro also pre-defines some simple formats for bitmaps, fonts, MIDI music, sound samples and palettes. Allegro library v4.0+ also support LZSS compression.

This spec applies to Allegro data files for library versions 2.2 up to 4.4.

Application

Allegro library (v2.2-v4.4)

KS implementation details

License: CC0-1.0

This page hosts a formal specification of Allegro data file using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime library

All parsing code for JavaScript generated by Kaitai Struct depends on the JavaScript runtime library. You have to install it before you can parse data.

The JavaScript runtime library is available at npm:

npm install kaitai-struct

Code

See the usage examples in the JavaScript notes.

Parse structure from an ArrayBuffer:

var arrayBuffer = ...;
var data = new AllegroDat(new KaitaiStream(arrayBuffer));

After that, one can get various attributes from the structure by accessing fields or properties like:

data.packMagic // => get pack magic

JavaScript source code to parse Allegro data file

AllegroDat.js

// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    define(['kaitai-struct/KaitaiStream'], factory);
  } else if (typeof module === 'object' && module.exports) {
    module.exports = factory(require('kaitai-struct/KaitaiStream'));
  } else {
    root.AllegroDat = factory(root.KaitaiStream);
  }
}(this, function (KaitaiStream) {
/**
 * Allegro library for C (mostly used for game and multimedia apps
 * programming) used its own container file format.
 * 
 * In general, it allows storage of arbitrary binary data blocks
 * bundled together with some simple key-value style metadata
 * ("properties") for every block. Allegro also pre-defines some simple
 * formats for bitmaps, fonts, MIDI music, sound samples and
 * palettes. Allegro library v4.0+ also support LZSS compression.
 * 
 * This spec applies to Allegro data files for library versions 2.2 up
 * to 4.4.
 * @see {@link https://liballeg.org/stabledocs/en/datafile.html|Source}
 */

var AllegroDat = (function() {
  AllegroDat.PackEnum = Object.freeze({
    UNPACKED: 1936484398,

    1936484398: "UNPACKED",
  });

  function AllegroDat(_io, _parent, _root) {
    this._io = _io;
    this._parent = _parent;
    this._root = _root || this;

    this._read();
  }
  AllegroDat.prototype._read = function() {
    this.packMagic = this._io.readU4be();
    this.datMagic = this._io.readBytes(4);
    if (!((KaitaiStream.byteArrayCompare(this.datMagic, [65, 76, 76, 46]) == 0))) {
      throw new KaitaiStream.ValidationNotEqualError([65, 76, 76, 46], this.datMagic, this._io, "/seq/1");
    }
    this.numObjects = this._io.readU4be();
    this.objects = new Array(this.numObjects);
    for (var i = 0; i < this.numObjects; i++) {
      this.objects[i] = new DatObject(this._io, this, this._root);
    }
  }

  /**
   * Simple monochrome monospaced font, 95 characters, 8x16 px
   * characters.
   */

  var DatFont16 = AllegroDat.DatFont16 = (function() {
    function DatFont16(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    DatFont16.prototype._read = function() {
      this.chars = new Array(95);
      for (var i = 0; i < 95; i++) {
        this.chars[i] = this._io.readBytes(16);
      }
    }

    return DatFont16;
  })();

  var DatBitmap = AllegroDat.DatBitmap = (function() {
    function DatBitmap(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    DatBitmap.prototype._read = function() {
      this.bitsPerPixel = this._io.readS2be();
      this.width = this._io.readU2be();
      this.height = this._io.readU2be();
      this.image = this._io.readBytesFull();
    }

    return DatBitmap;
  })();

  var DatFont = AllegroDat.DatFont = (function() {
    function DatFont(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    DatFont.prototype._read = function() {
      this.fontSize = this._io.readS2be();
      switch (this.fontSize) {
      case 8:
        this.body = new DatFont8(this._io, this, this._root);
        break;
      case 16:
        this.body = new DatFont16(this._io, this, this._root);
        break;
      case 0:
        this.body = new DatFont39(this._io, this, this._root);
        break;
      }
    }

    return DatFont;
  })();

  /**
   * Simple monochrome monospaced font, 95 characters, 8x8 px
   * characters.
   */

  var DatFont8 = AllegroDat.DatFont8 = (function() {
    function DatFont8(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    DatFont8.prototype._read = function() {
      this.chars = new Array(95);
      for (var i = 0; i < 95; i++) {
        this.chars[i] = this._io.readBytes(8);
      }
    }

    return DatFont8;
  })();

  var DatObject = AllegroDat.DatObject = (function() {
    function DatObject(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    DatObject.prototype._read = function() {
      this.properties = []
      var i = 0;
      do {
        var _ = new Property(this._io, this, this._root);
        this.properties.push(_);
        i++;
      } while (!(!(_.isValid)));
      this.lenCompressed = this._io.readS4be();
      this.lenUncompressed = this._io.readS4be();
      switch (this.type) {
      case "BMP ":
        this._raw_body = this._io.readBytes(this.lenCompressed);
        var _io__raw_body = new KaitaiStream(this._raw_body);
        this.body = new DatBitmap(_io__raw_body, this, this._root);
        break;
      case "RLE ":
        this._raw_body = this._io.readBytes(this.lenCompressed);
        var _io__raw_body = new KaitaiStream(this._raw_body);
        this.body = new DatRleSprite(_io__raw_body, this, this._root);
        break;
      case "FONT":
        this._raw_body = this._io.readBytes(this.lenCompressed);
        var _io__raw_body = new KaitaiStream(this._raw_body);
        this.body = new DatFont(_io__raw_body, this, this._root);
        break;
      default:
        this.body = this._io.readBytes(this.lenCompressed);
        break;
      }
    }
    Object.defineProperty(DatObject.prototype, 'type', {
      get: function() {
        if (this._m_type !== undefined)
          return this._m_type;
        this._m_type = this.properties[this.properties.length - 1].magic;
        return this._m_type;
      }
    });

    return DatObject;
  })();

  /**
   * New bitmap font format introduced since Allegro 3.9: allows
   * flexible designation of character ranges, 8-bit colored
   * characters, etc.
   */

  var DatFont39 = AllegroDat.DatFont39 = (function() {
    function DatFont39(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    DatFont39.prototype._read = function() {
      this.numRanges = this._io.readS2be();
      this.ranges = new Array(this.numRanges);
      for (var i = 0; i < this.numRanges; i++) {
        this.ranges[i] = new Range(this._io, this, this._root);
      }
    }

    var Range = DatFont39.Range = (function() {
      function Range(_io, _parent, _root) {
        this._io = _io;
        this._parent = _parent;
        this._root = _root || this;

        this._read();
      }
      Range.prototype._read = function() {
        this.mono = this._io.readU1();
        this.startChar = this._io.readU4be();
        this.endChar = this._io.readU4be();
        this.chars = new Array(((this.endChar - this.startChar) + 1));
        for (var i = 0; i < ((this.endChar - this.startChar) + 1); i++) {
          this.chars[i] = new FontChar(this._io, this, this._root);
        }
      }

      /**
       * First character in range
       */

      /**
       * Last character in range (inclusive)
       */

      return Range;
    })();

    var FontChar = DatFont39.FontChar = (function() {
      function FontChar(_io, _parent, _root) {
        this._io = _io;
        this._parent = _parent;
        this._root = _root || this;

        this._read();
      }
      FontChar.prototype._read = function() {
        this.width = this._io.readU2be();
        this.height = this._io.readU2be();
        this.body = this._io.readBytes((this.width * this.height));
      }

      return FontChar;
    })();

    return DatFont39;
  })();

  var Property = AllegroDat.Property = (function() {
    function Property(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    Property.prototype._read = function() {
      this.magic = KaitaiStream.bytesToStr(this._io.readBytes(4), "UTF-8");
      if (this.isValid) {
        this.type = KaitaiStream.bytesToStr(this._io.readBytes(4), "UTF-8");
      }
      if (this.isValid) {
        this.lenBody = this._io.readU4be();
      }
      if (this.isValid) {
        this.body = KaitaiStream.bytesToStr(this._io.readBytes(this.lenBody), "UTF-8");
      }
    }
    Object.defineProperty(Property.prototype, 'isValid', {
      get: function() {
        if (this._m_isValid !== undefined)
          return this._m_isValid;
        this._m_isValid = this.magic == "prop";
        return this._m_isValid;
      }
    });

    return Property;
  })();

  var DatRleSprite = AllegroDat.DatRleSprite = (function() {
    function DatRleSprite(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    DatRleSprite.prototype._read = function() {
      this.bitsPerPixel = this._io.readS2be();
      this.width = this._io.readU2be();
      this.height = this._io.readU2be();
      this.lenImage = this._io.readU4be();
      this.image = this._io.readBytesFull();
    }

    return DatRleSprite;
  })();

  return AllegroDat;
})();
return AllegroDat;
}));