source: OniSplit/Objects/ObjectBase.cs@ 1114

using System;
using System.Xml;
using Oni.Xml;

namespace Oni.Objects
{
    internal abstract class ObjectBase
    {
        private ObjectType typeId;
        private int objectId;
        private ObjectFlags objectFlags;
        private Vector3 position;
        private Vector3 rotation;
        private Matrix? transform;

        public ObjectType TypeId
        {
            get { return typeId; }
            protected set { typeId = value; }
        }

        public int ObjectId
        {
            get { return objectId; }
            set { objectId = value; }
        }

        public Matrix Transform
        {
            get
            {
                if (transform == null)
                {
                    transform = Matrix.CreateRotationX(MathHelper.ToRadians(rotation.X))
                        * Matrix.CreateRotationY(MathHelper.ToRadians(rotation.Y))
                        * Matrix.CreateRotationZ(MathHelper.ToRadians(rotation.Z))
                        * Matrix.CreateTranslation(position);
                }

                return transform.Value;
            }
        }

        public void Write(BinaryWriter writer)
        {
            writer.Write(objectId);
            writer.Write((int)objectFlags);
            writer.Write(position);
            writer.Write(rotation);
            WriteOsd(writer);
        }

        protected abstract void WriteOsd(BinaryWriter writer);

        public void Read(BinaryReader reader)
        {
            objectId = reader.ReadInt32();
            objectFlags = (ObjectFlags)reader.ReadInt32();
            position = reader.ReadVector3();
            rotation = reader.ReadVector3();
            ReadOsd(reader);
        }

        protected abstract void ReadOsd(BinaryReader reader);

        public void Write(XmlWriter xml)
        {
            xml.WriteStartElement("Header");
            xml.WriteEndElement();
            xml.WriteStartElement("OSD");
            xml.WriteEndElement();
            xml.WriteEndElement();
        }

        protected abstract void WriteOsd(XmlWriter xml);

        public void Read(XmlReader xml, ObjectLoadContext context)
        {
            xml.ReadStartElement();
            xml.ReadStartElement("Header");

            while (xml.IsStartElement())
            {
                switch (xml.LocalName)
                {
                    case "Flags":
                        objectFlags = Oni.Metadata.MetaEnum.Parse<ObjectFlags>(xml.ReadElementContentAsString("Flags", ""));
                        break;
                    case "Position":
                        position = xml.ReadElementContentAsVector3("Position");
                        break;
                    case "Rotation":
                        rotation = xml.ReadElementContentAsVector3("Rotation");
                        break;
                    default:
                        xml.Skip();
                        break;
                }
            }

            xml.ReadEndElement();

            xml.ReadStartElement("OSD");
            ReadOsd(xml, context);
            xml.ReadEndElement();

            xml.ReadEndElement();
        }

        protected abstract void ReadOsd(XmlReader xml, ObjectLoadContext context);
    }
}