three.js/examples/js/loaders/AWDLoader.js

/**
 * Author: Pierre Lepers
 * Date: 09/12/2013 17:21
 */

THREE.AWDLoader = (function () {



  var UNCOMPRESSED  = 0,
      DEFLATE       = 1,
      LZMA          = 2,

      AWD_FIELD_INT8      = 1,
      AWD_FIELD_INT16     = 2,
      AWD_FIELD_INT32     = 3,
      AWD_FIELD_UINT8     = 4,
      AWD_FIELD_UINT16    = 5,
      AWD_FIELD_UINT32    = 6,
      AWD_FIELD_FLOAT32   = 7,
      AWD_FIELD_FLOAT64   = 8,
      AWD_FIELD_BOOL      = 21,
      AWD_FIELD_COLOR     = 22,
      AWD_FIELD_BADDR     = 23,
      AWD_FIELD_STRING    = 31,
      AWD_FIELD_BYTEARRAY = 32,
      AWD_FIELD_VECTOR2x1 = 41,
      AWD_FIELD_VECTOR3x1 = 42,
      AWD_FIELD_VECTOR4x1 = 43,
      AWD_FIELD_MTX3x2    = 44,
      AWD_FIELD_MTX3x3    = 45,
      AWD_FIELD_MTX4x3    = 46,
      AWD_FIELD_MTX4x4    = 47,

      BOOL       = 21,
      COLOR      = 22,
      BADDR      = 23,

      INT8    = 1,
      INT16   = 2,
      INT32   = 3,
      UINT8   = 4,
      UINT16  = 5,
      UINT32  = 6,
      FLOAT32 = 7,
      FLOAT64 = 8;


  var littleEndian = true;

  // ResourcesLoader
  // =============
  // handle loading for external resources
  function ResourcesLoader( awdUrl ) {

    this._baseDir = awdUrl.substr( 0, awdUrl.lastIndexOf( '/' ) + 1 );

    this._loadingManager = new THREE.LoadingManager();

  }

  ResourcesLoader.prototype = {

    loadTexture : function( path ) {
      var tex = new THREE.Texture();

      var loader = new THREE.ImageLoader( this._loadingManager );

      loader.load( this._baseDir + path, function( image ) {
        tex.image = image;
        tex.needsUpdate = true;
      });

      return tex;

    }
  }



  function Block() {
    this.id = 0;
    this.data = null;
  }



  function AWDLoader( showStatus ) {

    THREE.Loader.call( this, showStatus );

    this.trunk = new THREE.Object3D();

    this.materialFactory = undefined;

    this._resourceLoader = null;
    this._url = '';

    this._data;
    this._ptr = 0;

    this._version =  [];
    this._streaming = false;
    this._optimized_for_accuracy = false;
    this._compression = 0;
    this._bodylen = 0xFFFFFFFF;


    this._blocks = [ new Block() ];

    this._accuracyMatrix  = false;
    this._accuracyGeo     = false;
    this._accuracyProps   = false;


  };


  AWDLoader.prototype = Object.create( THREE.Loader.prototype );
  AWDLoader.prototype.constructor = AWDLoader;

  AWDLoader.prototype.load = function ( url, callback ) {

    var that = this;
    this._url = url;
    var xhr = new XMLHttpRequest();
    xhr.open( "GET", url, true );
    xhr.responseType = 'arraybuffer';

    xhr.onreadystatechange = function () {

      if ( xhr.readyState == 4 ) {

        if ( xhr.status == 200 || xhr.status == 0 ) {
          that.parse( xhr.response );
          callback( that.trunk );

        } else {

          console.error( 'AWDLoader: Couldn\'t load ' + url + ' (' + xhr.status + ')' );

        }

      }

    };

    xhr.send( null );

  };

  AWDLoader.prototype.parse = function ( data ) {

    var blen = data.byteLength;

    this._ptr = 0;
    this._data = new DataView( data );

    this._parseHeader( );

    if ( this._compression != 0  ) {
      console.error( 'compressed AWD not supported' );
    }

    if (!this._streaming && this._bodylen != data.byteLength - this._ptr ) {
      console.error('AWDLoader: body len does not match file length', this._bodylen,  blen - this._ptr);
    }

    while ( this._ptr < blen ) {
      this.parseNextBlock();
    }

    return this.trunk;

  }



  AWDLoader.prototype.parseNextBlock = function ( ) {

    var assetData,
        ns, type, len, block,
        blockId = this.readU32(),
        ns      = this.readU8(),
        type    = this.readU8(),
        flags   = this.readU8(),
        len     = this.readU32();


    switch (type) {
      case 1:
        assetData = this.parseMeshData(len);
        break;
      case 22:
        assetData = this.parseContainer(len);
        break;
      case 23:
        assetData = this.parseMeshInstance(len);
        break;
      case 81:
        assetData = this.parseMaterial(len);
        break;
      case 82:
        assetData = this.parseTexture(len);
        break;
      case 101:
        assetData = this.parseSkeleton(len);
        break;

//      case 111:
//        assetData = this.parseMeshPoseAnimation(len, true);
//        break;
      case 112:
        assetData = this.parseMeshPoseAnimation(len, false);
        break;
      case 113:
        assetData = this.parseVertexAnimationSet(len);
        break;
      case 102:
      	assetData = this.parseSkeletonPose(len);
      	break;
      case 103:
      	assetData = this.parseSkeletonAnimation(len);
      	break;
      case 122:
        assetData = this.parseAnimatorSet(len);
        break;
      // case 121:
      // 	assetData = parseUVAnimation(len);
      // 	break;
      default:
        //debug('Ignoring block!',type, len);
        this._ptr += len;
        break;
    }


    // Store block reference for later use
    this._blocks[blockId] = block = new Block();
    block.data = assetData;
    block.id = blockId;

  }


  AWDLoader.prototype._parseHeader = function () {

    var version = this._version,
        awdmagic =
            ( this.readU8()<<16)
        |   ( this.readU8()<<8 )
        |     this.readU8();

    if ( awdmagic != 4282180 )
      throw new Error( "AWDLoader - bad magic" );

    version[0] = this.readU8();
    version[1] = this.readU8();

    var flags = this.readU16();

    this._streaming = (flags & 0x1) == 0x1;

    if ((version[0] === 2) && (version[1] === 1)) {
      this._accuracyMatrix =  (flags & 0x2) === 0x2;
      this._accuracyGeo =     (flags & 0x4) === 0x4;
      this._accuracyProps =   (flags & 0x8) === 0x8;
    }

    this._geoNrType     = this._accuracyGeo     ? FLOAT64 : FLOAT32;
    this._matrixNrType  = this._accuracyMatrix  ? FLOAT64 : FLOAT32;
    this._propsNrType   = this._accuracyProps   ? FLOAT64 : FLOAT32;

    this._optimized_for_accuracy 	= (flags & 0x2) === 0x2;

    this._compression = this.readU8();
    this._bodylen = this.readU32();


  }


  AWDLoader.prototype.parseContainer = function ( len ) {
    var parent,
        ctr     = new THREE.Object3D(),
        par_id  = this.readU32(),
        mtx     = this.parseMatrix4();

    ctr.name = this.readUTF();
    ctr.applyMatrix( mtx );

    parent = this._blocks[par_id].data || this.trunk;
    parent.add(ctr);

    this.parseProperties({
      1:this._matrixNrType,
      2:this._matrixNrType,
      3:this._matrixNrType,
      4:UINT8
    });

    ctr.extra = this.parseUserAttributes();

    return ctr;
  }



  AWDLoader.prototype.parseMeshInstance = function ( len ) {
    var name,
        mesh, geometries, meshLen, meshes,
        par_id, data_id,
        mtx,
        materials, mat, mat_id,
        num_materials,
        materials_parsed,
        parent,
        i;

    par_id        = this.readU32();
    mtx           = this.parseMatrix4();
    name          = this.readUTF();
    data_id       = this.readU32();
    num_materials = this.readU16();

    geometries = this.getBlock( data_id );

    materials = [];
    materials_parsed = 0;

    for ( i = 0; i < num_materials; i ++) {
      mat_id = this.readU32();
      mat = this.getBlock( mat_id );
      materials.push( mat );
    }



    meshLen = geometries.length
    meshes = [];

    // TODO : BufferGeometry don't support "geometryGroups" for now.
    // so we create sub meshes for each groups
    if ( meshLen  > 1 ) {
      mesh = new THREE.Object3D()
      for ( i = 0; i < meshLen; i ++) {
        var sm = new THREE.Mesh( geometries[i] );
        meshes.push( sm );
        mesh.add( sm );
      }
    }
    else {
      mesh = new THREE.Mesh( geometries[0] );
      meshes.push( mesh );
    }

    mesh.applyMatrix( mtx );
    mesh.name = name;


    parent = this.getBlock( par_id ) || this.trunk;
    parent.add( mesh );


    var matLen = materials.length;
    var maxLen = Math.max( meshLen, matLen);
    for ( i = 0; i < maxLen; i ++ )
      meshes[ i%meshLen ].material = materials[ i % matLen ];


    // Ignore for now
    this.parseProperties( null );
    mesh.extra = this.parseUserAttributes();

    return mesh;
  }



  AWDLoader.prototype.parseMaterial = function ( len ) {
    var name,
        type,
        props,
        mat,
        attributes,
        finalize,
        num_methods,
        methods_parsed;

    name        = this.readUTF();
    type        = this.readU8();
    num_methods = this.readU8();

    //log( "AWDLoader parseMaterial ",name )

    // Read material numerical properties
    // (1=color, 2=bitmap url, 11=alpha_blending, 12=alpha_threshold, 13=repeat)
    props = this.parseProperties({
      1:  AWD_FIELD_INT32,
      2:  AWD_FIELD_BADDR,
      11: AWD_FIELD_BOOL,
      12: AWD_FIELD_FLOAT32,
      13: AWD_FIELD_BOOL
    });

    methods_parsed = 0;

    while ( methods_parsed < num_methods ) {
      var method_type = this.readU16();
      this.parseProperties( null );
      this.parseUserAttributes();
    }

    attributes = this.parseUserAttributes();

    if ( this.materialFactory !== undefined ) {
      mat = this.materialFactory( name );
      if ( mat ) return mat;
    }

    mat = new THREE.MeshPhongMaterial();

    if (type === 1) { // Color material
      mat.color.setHex( props.get(1, 0xcccccc) );
    }
    else if (type === 2) { // Bitmap material
      var tex_addr = props.get(2, 0);
      mat.map = this.getBlock( tex_addr );
    }

    mat.extra = attributes;
    mat.alphaThreshold = props.get(12, 0.0);
    mat.repeat = props.get(13, false);


    return mat;
  }




  AWDLoader.prototype.parseTexture = function( len ) {


    var name = this.readUTF(),
        type = this.readU8(),
        asset,
        data_len;

    // External
    if (type === 0) {
      data_len = this.readU32();
      var url = this.readUTFBytes(data_len);
      console.log( url );

      asset = this.loadTexture( url );
    } else {
      // embed texture not supported
    }
    // Ignore for now
    this.parseProperties( null );

    this.parseUserAttributes();
    return asset;
  }

  AWDLoader.prototype.loadTexture = function( url ) {

    if ( null === this._resourceLoader )
      this._resourceLoader = new ResourcesLoader( this._url );

    return this._resourceLoader.loadTexture( url );
  }

  // broken : skeleton pose format is different than threejs one
  AWDLoader.prototype.parseSkeleton = function(len) // Array<Bone>
  {
    var name          = this.readUTF(),
        num_joints    = this.readU16(),
        skeleton      = [],
        joints_parsed = 0;

    this.parseProperties( null );

    while (joints_parsed < num_joints) {
      var joint, ibp;

      // Ignore joint id
      this.readU16();

      joint = new THREE.Bone();
      joint.parent = this.readU16() - 1; // 0=null in AWD
      joint.name = this.readUTF();

      ibp = this.parseMatrix4();
      joint.skinMatrix = ibp;

      // Ignore joint props/attributes for now
      this.parseProperties(null);
      this.parseUserAttributes();

      skeleton.push(joint);
      joints_parsed ++;
    }

    // Discard attributes for now
    this.parseUserAttributes();


    return skeleton;
  }



  AWDLoader.prototype.parseSkeletonPose = function(blockID)
  {
    var name = this.readUTF();


    var num_joints = this.readU16();
    this.parseProperties(null);

    // debug( 'parse Skeleton Pose. joints : ' + num_joints);

    var pose = [];

    var joints_parsed = 0;

    while (joints_parsed < num_joints) {

      var joint_pose;

      var has_transform; //:uint;
      var mtx_data;

      has_transform = this.readU8();

      if (has_transform === 1) {
        mtx_data = this.parseMatrix4();
      } else
      {
        mtx_data = new THREE.Matrix4();
      }
      pose[joints_parsed] = mtx_data;
      joints_parsed ++;
    }
    // Skip attributes for now
    this.parseUserAttributes();

    return pose
  }

  AWDLoader.prototype.parseSkeletonAnimation = function(blockID)
  {
    var frame_dur;
    var pose_addr;
    var pose;

    var name = this.readUTF();

    var clip = [];

    var num_frames = this.readU16();
    this.parseProperties(null);

    var frames_parsed = 0;
    var returnedArray;


    // debug( 'parse Skeleton Animation. frames : ' + num_frames);

    while (frames_parsed < num_frames) {
      pose_addr = this.readU32();
      frame_dur = this.readU16();

      pose = this._blocks[pose_addr].data
      // debug( 'pose address ',pose[2].elements[12],pose[2].elements[13],pose[2].elements[14] );
      clip.push( {
        pose : pose,
        duration : frame_dur
      } );

      frames_parsed ++;
    }
    if (clip.length == 0) {
      // debug("Could not this SkeletonClipNode, because no Frames where set.");
      return;
    }
    // Ignore attributes for now
    this.parseUserAttributes();
    return clip;
  }



  AWDLoader.prototype.parseVertexAnimationSet = function(len)
  {
    var poseBlockAdress,
        name           = this.readUTF(),
        num_frames     = this.readU16(),
        props          = this.parseProperties({ 1:UINT16 }),
        frames_parsed  = 0,
        skeletonFrames = [];

    while (frames_parsed < num_frames) {
      poseBlockAdress = this.readU32();
      skeletonFrames.push(this._blocks[poseBlockAdress].data);
      frames_parsed ++;
    }

    this.parseUserAttributes();


    return skeletonFrames;
  }


  AWDLoader.prototype.parseAnimatorSet = function(len)
  {
    var targetMesh;

    var animSetBlockAdress; //:int

    var targetAnimationSet; //:AnimationSetBase;
    var outputString = ""; //:String = "";
    var name = this.readUTF();
    var type = this.readU16();

    var props = this.parseProperties({ 1:BADDR });

    animSetBlockAdress = this.readU32();
    var targetMeshLength = this.readU16();

    var meshAdresses = []; //:Vector.<uint> = new Vector.<uint>;

    for (var i = 0; i < targetMeshLength; i ++)
      meshAdresses.push( this.readU32() );

    var activeState = this.readU16();
    var autoplay = Boolean(this.readU8());
    this.parseUserAttributes();
    this.parseUserAttributes();

    var returnedArray;
    var targetMeshes = []; //:Vector.<Mesh> = new Vector.<Mesh>;

    for (i = 0; i < meshAdresses.length; i ++) {
//      returnedArray = getAssetByID(meshAdresses[i], [AssetType.MESH]);
//      if (returnedArray[0])
        targetMeshes.push(this._blocks[meshAdresses[i]].data);
    }

    targetAnimationSet = this._blocks[animSetBlockAdress].data
    var thisAnimator;

    if (type == 1) {


      thisAnimator = {
        animationSet : targetAnimationSet,
        skeleton : this._blocks[props.get(1, 0)].data
      };

    } else if (type == 2) {
      // debug( "vertex Anim???");
    }


    for (i = 0; i < targetMeshes.length; i ++) {
        targetMeshes[i].animator = thisAnimator;
    }
    // debug("Parsed a Animator: Name = " + name);

    return thisAnimator;
  }







  AWDLoader.prototype.parseMeshData = function ( len ) {

    var name      = this.readUTF(),
        num_subs  = this.readU16(),
        geom,
        subs_parsed = 0,
        props,
        buffer,
        skinW, skinI,
        geometries = [];




    props = this.parseProperties({
      1: this._geoNrType,
      2: this._geoNrType
    });



    // Loop through sub meshes
    while (subs_parsed < num_subs) {

      var sm_len, sm_end, attrib;

      geom = new THREE.BufferGeometry();
      geom.name = name;
      geometries.push( geom );


      sm_len = this.readU32();
      sm_end = this._ptr + sm_len;


      // Ignore for now
      this.parseProperties({ 1:this._geoNrType, 2:this._geoNrType });

      // Loop through data streams
      while ( this._ptr < sm_end ) {


        var idx = 0,
            str_type  = this.readU8(),
            str_ftype = this.readU8(),
            str_len   = this.readU32(),
            str_end   = str_len + this._ptr;





        // VERTICES
        // ------------------
        if ( str_type === 1 ) {

          buffer = new Float32Array( ( str_len / 12 ) * 3 );
          attrib = new THREE.BufferAttribute( buffer, 3 );

          geom.addAttribute( 'position', attrib );
          idx = 0;

          while (this._ptr < str_end) {
            buffer[idx]   = -this.readF32();
            buffer[idx + 1] = this.readF32();
            buffer[idx + 2] = this.readF32();
            idx+=3;
          }
        }


        // INDICES
        // -----------------
        else if (str_type === 2) {

          buffer = new Uint16Array( str_len / 2 );
          attrib = new THREE.BufferAttribute( buffer, 1 );
          geom.addAttribute( 'index', attrib );

          geom.offsets.push({
            start: 0,
            index: 0,
            count: str_len / 2
          });

          idx = 0;

          while (this._ptr < str_end) {
            buffer[idx + 1]   = this.readU16();
            buffer[idx]     = this.readU16();
            buffer[idx + 2]   = this.readU16();
            idx+=3;
          }
        }

        // UVS
        // -------------------
        else if (str_type === 3) {

          buffer = new Float32Array( ( str_len / 8 ) * 2 );
          attrib = new THREE.BufferAttribute( buffer, 2 );

          geom.addAttribute( 'uv', attrib );
          idx = 0;

          while (this._ptr < str_end) {
            buffer[idx]   = this.readF32();
            buffer[idx + 1] = 1.0 - this.readF32();
            idx+=2;
          }
        }

        // NORMALS
        else if (str_type === 4) {

          buffer = new Float32Array( ( str_len / 12 ) * 3 );
          attrib = new THREE.BufferAttribute( buffer, 3 );
          geom.addAttribute( 'normal', attrib );
          idx = 0;

          while (this._ptr < str_end) {
            buffer[idx]   = -this.readF32();
            buffer[idx + 1] = this.readF32();
            buffer[idx + 2] = this.readF32();
            idx+=3;
          }

        }

        // else if (str_type == 6) {
        //   skinI = new Float32Array( str_len>>1 );
        //   idx = 0

        //   while (this._ptr < str_end) {
        //     skinI[idx]   = this.readU16();
        //     idx++;
        //   }

        // }
        // else if (str_type == 7) {
        //   skinW = new Float32Array( str_len>>2 );
        //   idx = 0;

        //   while (this._ptr < str_end) {
        //     skinW[idx]   = this.readF32();
        //     idx++;
        //   }
        // }
        else {
          this._ptr = str_end;
        }



      }

      this.parseUserAttributes();


      geom.computeBoundingSphere();
      subs_parsed ++;
    }


    //geom.computeFaceNormals();


    this.parseUserAttributes();
    //finalizeAsset(geom, name);

    return geometries;
  }

  AWDLoader.prototype.parseMeshPoseAnimation = function(len, poseOnly)
  {
    var num_frames = 1,
        num_submeshes,
        frames_parsed,
        subMeshParsed,
        frame_dur,
        x, y, z,

        str_len,
        str_end,
        geom,
        subGeom,
        idx = 0,
        clip = {},
        indices,
        verts,
        num_Streams,
        streamsParsed,
        streamtypes = [],

        props,
        thisGeo,
        name = this.readUTF(),
        geoAdress = this.readU32();


    var mesh = this.getBlock( geoAdress );

    if (mesh == null) {
      console.log( "parseMeshPoseAnimation target mesh not found at:", geoAdress );
      return;
    }

    geom = mesh.geometry;
    geom.morphTargets = [];

    if (!poseOnly)
      num_frames = this.readU16();

    num_submeshes = this.readU16();
    num_Streams = this.readU16();

    // debug("VA num_frames : ", num_frames );
    // debug("VA num_submeshes : ", num_submeshes );
    // debug("VA numstreams : ", num_Streams );

    streamsParsed = 0;
    while (streamsParsed < num_Streams) {
      streamtypes.push(this.readU16());
      streamsParsed ++;
    }
    props = this.parseProperties({ 1:BOOL, 2:BOOL });

    clip.looping = props.get(1, true);
    clip.stitchFinalFrame = props.get(2, false);

    frames_parsed = 0;

    while (frames_parsed < num_frames) {

      frame_dur = this.readU16();
      subMeshParsed = 0;

      while (subMeshParsed < num_submeshes) {

        streamsParsed = 0;
        str_len = this.readU32();
        str_end = this._ptr + str_len;

        while (streamsParsed < num_Streams) {

          if (streamtypes[streamsParsed] == 1) {

            //geom.addAttribute( 'morphTarget'+frames_parsed, Float32Array, str_len/12, 3 );
            var buffer = new Float32Array(str_len / 4);
            geom.morphTargets.push( {
              array : buffer
            });

            //buffer = geom.attributes['morphTarget'+frames_parsed].array
            idx = 0;

            while ( this._ptr < str_end ) {
              buffer[idx]     = this.readF32();
              buffer[idx + 1]   = this.readF32();
              buffer[idx + 2]   = this.readF32();
              idx += 3;
            }


            subMeshParsed ++;
          } else
            this._ptr = str_end;
          streamsParsed ++;
        }
      }


      frames_parsed ++;
    }
    this.parseUserAttributes();

    return null;
  }









  AWDLoader.prototype.getBlock = function ( id ) {
    return this._blocks[id].data;
  },


  AWDLoader.prototype.parseMatrix4 = function ( ) {
    var mtx = new THREE.Matrix4();
    var e = mtx.elements;

    e[0] = this.readF32();
    e[1] = this.readF32();
    e[2] = this.readF32();
    e[3] = 0.0;
    //e[3] = 0.0;

    e[4] = this.readF32();
    e[5] = this.readF32();
    e[6] = this.readF32();
    //e[7] = this.readF32();
    e[7] = 0.0;

    e[8] = this.readF32();
    e[9] = this.readF32();
    e[10] = this.readF32();
    //e[11] = this.readF32();
    e[11] = 0.0;

    e[12] = -this.readF32();
    e[13] = this.readF32();
    e[14] = this.readF32();
    //e[15] = this.readF32();
    e[15] = 1.0;
    return mtx;
  }


  AWDLoader.prototype.parseProperties = function ( expected ) {
    var list_len = this.readU32();
    var list_end = this._ptr + list_len;

    var props = new AWDProperties();

    if ( expected ) {

      while ( this._ptr < list_end ) {

        var key = this.readU16();
        var len = this.readU32();
        var type;

        if ( expected.hasOwnProperty( key ) ) {
          type = expected[ key ];
          props.set( key, this.parseAttrValue( type, len ) );
        } else {
          this._ptr += len;
        }
      }

    }

    return props;

  };


  AWDLoader.prototype.parseUserAttributes = function ( ) {
    // skip for now
    this._ptr = this.readU32() + this._ptr;
    return null;
  };


  AWDLoader.prototype.parseAttrValue = function ( type, len ) {

    var elem_len;
    var read_func;

    switch (type) {
      case AWD_FIELD_INT8:
        elem_len = 1;
        read_func = this.readI8;
        break;
      case AWD_FIELD_INT16:
        elem_len = 2;
        read_func = this.readI16;
        break;
      case AWD_FIELD_INT32:
        elem_len = 4;
        read_func = this.readI32;
        break;
      case AWD_FIELD_BOOL:
      case AWD_FIELD_UINT8:
        elem_len = 1;
        read_func = this.readU8;
        break;
      case AWD_FIELD_UINT16:
        elem_len = 2;
        read_func = this.readU16;
        break;
      case AWD_FIELD_UINT32:
      case AWD_FIELD_BADDR:
        elem_len = 4;
        read_func = this.readU32;
        break;
      case AWD_FIELD_FLOAT32:
        elem_len = 4;
        read_func = this.readF32;
        break;
      case AWD_FIELD_FLOAT64:
        elem_len = 8;
        read_func = this.readF64;
        break;
      case AWD_FIELD_VECTOR2x1:
      case AWD_FIELD_VECTOR3x1:
      case AWD_FIELD_VECTOR4x1:
      case AWD_FIELD_MTX3x2:
      case AWD_FIELD_MTX3x3:
      case AWD_FIELD_MTX4x3:
      case AWD_FIELD_MTX4x4:
        elem_len = 8;
        read_func = this.readF64;
        break;
    }

    if (elem_len < len) {
      var list;
      var num_read;
      var num_elems;

      list = [];
      num_read = 0;
      num_elems = len / elem_len;

      while (num_read < num_elems) {
        list.push(read_func.call( this ) );
        num_read ++;
      }

      return list;
    }
    else {
      return read_func.call( this );
    }

  }


  AWDLoader.prototype.readU8 = function () {
    return this._data.getUint8( this._ptr ++ );
  }
  AWDLoader.prototype.readI8 = function () {
    return this._data.getInt8( this._ptr ++ );
  }

  AWDLoader.prototype.readU16 = function () {
    var a = this._data.getUint16( this._ptr, littleEndian );
    this._ptr += 2;
    return a;
  }
  AWDLoader.prototype.readI16 = function () {
    var a = this._data.getInt16( this._ptr, littleEndian );
    this._ptr += 2;
    return a;
  }

  AWDLoader.prototype.readU32 = function () {
    var a = this._data.getUint32( this._ptr, littleEndian );
    this._ptr += 4;
    return a;
  }
  AWDLoader.prototype.readI32 = function () {
    var a = this._data.getInt32( this._ptr, littleEndian );
    this._ptr += 4;
    return a;
  }
  AWDLoader.prototype.readF32 = function () {
    var a = this._data.getFloat32( this._ptr, littleEndian );
    this._ptr += 4;
    return a;
  }
  AWDLoader.prototype.readF64 = function () {
    var a = this._data.getFloat64( this._ptr, littleEndian );
    this._ptr += 8;
    return a;
  }


  /**
   * Converts a UTF-8 byte array to JavaScript's 16-bit Unicode.
   * @param {Array.<number>} bytes UTF-8 byte array.
   * @return {string} 16-bit Unicode string.
   */
  AWDLoader.prototype.readUTF = function () {
    var len = this.readU16();

    return this.readUTFBytes( len );
  };

  /**
   * Converts a UTF-8 byte array to JavaScript's 16-bit Unicode.
   * @param {Array.<number>} bytes UTF-8 byte array.
   * @return {string} 16-bit Unicode string.
   */
  AWDLoader.prototype.readUTFBytes = function ( len ) {


    // TODO(user): Use native implementations if/when available

    var out = [], c = 0;

    while ( out.length < len ) {
      var c1 = this._data.getUint8( this._ptr ++, littleEndian );
      if (c1 < 128) {
        out[c ++] = String.fromCharCode(c1);
      } else if (c1 > 191 && c1 < 224) {
        var c2 = this._data.getUint8( this._ptr ++, littleEndian );
        out[c ++] = String.fromCharCode((c1 & 31) << 6 | c2 & 63);
      } else {
        var c2 = this._data.getUint8( this._ptr ++, littleEndian );
        var c3 = this._data.getUint8( this._ptr ++, littleEndian );
        out[c ++] = String.fromCharCode(
            (c1 & 15) << 12 | (c2 & 63) << 6 | c3 & 63
        );
      }
    }
    return out.join('');
  };









  AWDProperties = function() {}

  AWDProperties.prototype = {


    set : function(key, value)
    {
      this[key] = value;
    },

    get : function(key, fallback)
    {
      if ( this.hasOwnProperty(key) )
        return this[key];
      else return fallback;
    }
  }

  return AWDLoader;

})();