/// <summary>
 /// Initializes a new instance of the <c>Polyline3dVertex</c> class.
 /// </summary>
 /// <param name="location">Polyline <see cref="Vector3f">vertex</see> coordinates.</param>
 public Polyline3dVertex(Vector3f location)
     : base(DxfObjectCode.Vertex)
 {
     this.flags = VertexTypeFlags.Polyline3dVertex;
     this.location = location;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
 }

 /// <summary>
 /// Initializes a new instance of the <c>PolylineVertex</c> class.
 /// </summary>
 /// <param name="location">Polyface mesh vertex <see cref="Vector3d">location</see>.</param>
 public PolyfaceMeshVertex(Vector3d location)
     : base(DxfObjectCode.Vertex)
 {
     this.flags = VertexTypeFlags.PolyfaceMeshVertex | VertexTypeFlags.Polygon3dMesh;
     this.location = location;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
 }

 /// <summary>
 /// Initializes a new instance of the <c>PolyfaceMeshFace</c> class.
 /// </summary>
 /// <remarks>
 /// By default the face is made up of three vertexes.
 /// </remarks>
 public PolyfaceMeshFace()
     : base(DxfObjectCode.Vertex)
 {
     this.flags = VertexTypeFlags.PolyfaceMeshVertex;
     this.vertexIndexes = new int[3];
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Point</c> class.
 /// </summary>
 public Point()
     : base(DxfObjectCode.Point)
 {
     this.location = Vector3d.Zero;
     this.thickness = 0.0f;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.normal = Vector3d.UnitZ;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Layer</c> class.
 /// </summary>
 /// <param name="name">Layer name.</param>
 public Layer(string name)
     : base(DxfObjectCode.Layer)
 {
     if (string.IsNullOrEmpty(name))
         throw (new ArgumentNullException("name"));
     this.name = name;
     this.color = AciColor.Default;
     this.lineType = LineType.Continuous;
     this.isVisible = true;
 }

 /// <summary>
 /// Initializes a new instance of the <c>PolyfaceMesh</c> class.
 /// </summary>
 public PolyfaceMesh()
     : base(DxfObjectCode.Polyline)
 {
     this.flags = PolylineTypeFlags.PolyfaceMesh;
     this.faces = new List<PolyfaceMeshFace>();
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.endSequence = new EndSequence();
 }

 /// <summary>
 /// Initializes a new instance of the <c>Polyline3d</c> class.
 /// </summary>
 /// <param name="vertexes">3d polyline <see cref="Polyline3dVertex">vertex</see> list.</param>
 public Polyline3d(List<Polyline3dVertex> vertexes)
     : base(DxfObjectCode.Polyline)
 {
     this.flags = PolylineTypeFlags.Polyline3D;
     this.vertexes = vertexes;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.endSequence = new EndSequence();
 }

 /// <summary>
 /// Initializes a new instance of the <c>HatchGradientPattern</c> class as a default linear gradient. 
 /// </summary>
 /// <param name="description">Description of the pattern (optional, this information is not saved in the dxf file). By default it will use the supplied name.</param>
 public HatchGradientPattern(string description = null)
     : base("SOLID", description)
 {
     this.color1 = AciColor.Blue;
     this.color2 = AciColor.Yellow;
     this.singleColor = false;
     this.gradientType = HatchGradientPatternType.Linear;
     this.tint = 1.0;
     this.centered = true;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Circle</c> class.
 /// </summary>
 /// <param name="center">Circle <see cref="Vector3d">center</see> in object coordinates.</param>
 /// <param name="radius">Circle radius.</param>
 /// <remarks>The center Z coordinate represents the elevation of the arc along the normal.</remarks>
 public Circle(Vector3d center, double radius)
     : base(DxfObjectCode.Circle)
 {
     this.center = center;
     this.radius = radius;
     this.thickness = 0.0f;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.normal = Vector3d.UnitZ;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Circle</c> class.
 /// </summary>
 public Circle()
     : base(DxfObjectCode.Circle)
 {
     this.center = Vector3f.Zero;
     this.radius = 1.0f;
     this.thickness = 0.0f;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.normal = Vector3f.UnitZ;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Line</c> class.
 /// </summary>
 public Line()
     : base(DxfObjectCode.Line)
 {
     this.startPoint = Vector3d.Zero;
     this.endPoint = Vector3d.Zero;
     this.thickness = 0.0f;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.normal = Vector3d.UnitZ;
 }

 /// <summary>
 /// Initializes a new instance of the <c>PolylineVertex</c> class.
 /// </summary>
 /// <param name="location">Polyline <see cref="Vector2f">vertex</see> coordinates.</param>
 public PolylineVertex(Vector2f location)
     : base(DxfObjectCode.Vertex)
 {
     this.flags = VertexTypeFlags.PolylineVertex;
     this.location = location;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.bulge = 0.0f;
     this.beginThickness = 0.0f;
     this.endThickness = 0.0f;
 }

 /// <summary>
 /// Initializes a new instance of the <c>NurbsCurve</c> class.
 /// </summary>
 public NurbsCurve()
 {
     this.controlPoints = new List<NurbsVertex>();
     this.normal = Vector3d.UnitZ;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.order = 0;
     this.curvePoints = 30;
     this.elevation = 0.0;
     this.thickness = 0.0f;
     this.normal = Vector3d.UnitZ;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Solid</c> class.
 /// </summary>
 /// <param name="firstVertex">Solid <see cref="Vector3d">first vertex</see>.</param>
 /// <param name="secondVertex">Solid <see cref="Vector3d">second vertex</see>.</param>
 /// <param name="thirdVertex">Solid <see cref="Vector3d">third vertex</see>.</param>
 /// <param name="fourthVertex">Solid <see cref="Vector3d">fourth vertex</see>.</param>
 public Solid(Vector3d firstVertex, Vector3d secondVertex, Vector3d thirdVertex, Vector3d fourthVertex)
     : base(DxfObjectCode.Solid)
 {
     this.firstVertex = firstVertex;
     this.secondVertex = secondVertex;
     this.thirdVertex = thirdVertex;
     this.fourthVertex = fourthVertex;
     this.thickness = 0.0f;
     this.normal = Vector3d.UnitZ;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Arc</c> class.
 /// </summary>
 /// <param name="center">Arc <see cref="SharpDxf.Vector3f">center</see> in object coordinates.</param>
 /// <param name="radius">Arc radius.</param>
 /// <param name="startAngle">Arc start angle in degrees.</param>
 /// <param name="endAngle">Arc end angle in degrees.</param>
 /// <remarks>The center Z coordinate represents the elevation of the arc along the normal.</remarks>
 public Arc(Vector3f center, float radius, float startAngle, float endAngle)
     : base(DxfObjectCode.Arc)
 {
     this.center = center;
     this.radius = radius;
     this.startAngle = startAngle;
     this.endAngle = endAngle;
     this.thickness = 0.0f;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.normal = Vector3f.UnitZ;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Polyline</c> class.
 /// </summary>
 /// <param name="vertexes">Polyline <see cref="LightWeightPolylineVertex">vertex</see> list in object coordinates.</param>
 /// <param name="isClosed">Sets if the polyline is closed</param>
 public LightWeightPolyline(List<LightWeightPolylineVertex> vertexes, bool isClosed)
     : base(DxfObjectCode.LightWeightPolyline)
 {
     this.vertexes = vertexes;
     this.isClosed = isClosed;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.normal = Vector3d.UnitZ;
     this.elevation = 0.0;
     this.thickness = 0.0f;
     this.flags = isClosed ? PolylineTypeFlags.ClosedPolylineOrClosedPolygonMeshInM : PolylineTypeFlags.OpenPolyline;
 }

        internal Layer(string name, bool checkName)
            : base(name, DxfObjectCode.Layer, checkName)
        {
            if (string.IsNullOrEmpty(name))
                throw new ArgumentNullException(nameof(name), "The layer name should be at least one character long.");

            this.IsReserved = name.Equals(DefaultName, StringComparison.OrdinalIgnoreCase);
            this.color = AciColor.Default;
            this.linetype = Linetype.Continuous;
            this.isVisible = true;
            this.plot = true;
            this.lineweight = Lineweight.Default;
            this.transparency = new Transparency(0);
        }

 /// <summary>
 /// Initializes a new instance of the <c>Ellipse</c> class.
 /// </summary>
 /// <param name="center">Ellipse <see cref="Vector3f">center</see> in object coordinates.</param>
 /// <param name="majorAxis">Ellipse major axis.</param>
 /// <param name="minorAxis">Ellipse minor axis.</param>
 /// <remarks>The center Z coordinate represents the elevation of the arc along the normal.</remarks>
 public Ellipse(Vector3f center, float majorAxis, float minorAxis)
     : base(DxfObjectCode.Ellipse)
 {
     this.center = center;
     this.majorAxis = majorAxis;
     this.minorAxis = minorAxis;
     this.startAngle = 0.0f;
     this.endAngle = 360.0f;
     this.rotation = 0.0f;
     this.curvePoints = 30;
     this.thickness = 0.0f;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.normal = Vector3f.UnitZ;
 }

 /// <summary>
 /// Initializes a new instance of the <c>Text</c> class.
 /// </summary>
 public Text()
     : base(DxfObjectCode.Text)
 {
     this.value = string.Empty;
     this.basePoint = Vector3d.Zero;
     this.alignment = TextAlignment.BaselineLeft;
     this.layer = Layer.Default;
     this.color = AciColor.ByLayer;
     this.lineType = LineType.ByLayer;
     this.normal = Vector3d.UnitZ;
     this.style = TextStyle.Default;
     this.rotation = 0.0f;
     this.height = 0.0f;
     this.widthFactor = 1.0f;
     this.obliqueAngle = 0.0f;
 }

 protected EntityObject(EntityType type, string dxfCode)
     : base(dxfCode)
 {
     this.type = type;
     this.color = AciColor.ByLayer;
     this.layer = Layer.Default;
     this.lineType = LineType.ByLayer;
     this.lineweight = Lineweight.ByLayer;
     this.transparency = Transparency.ByLayer;
     this.lineTypeScale = 1.0;
     this.isVisible = true;
     this.normal = Vector3.UnitZ;
     this.reactors = new List<DxfObject>();
     this.xData = new XDataDictionary();
     this.xData.AddAppReg += this.XData_AddAppReg;
     this.xData.RemoveAppReg += this.XData_RemoveAppReg;
 }