/// <summary>
/// Writes a new viewport to the table section.
/// </summary>
/// <param name="vp">viewport.</param>
private void WriteVPort(VPort vp)
{
Debug.Assert(this.activeTable == DxfObjectCode.VportTable);
this.chunk.Write(0, vp.CodeName);
this.chunk.Write(5, vp.Handle);
this.chunk.Write(330, vp.Owner.Handle);
this.chunk.Write(100, SubclassMarker.TableRecord);
this.chunk.Write(100, SubclassMarker.VPort);
this.chunk.Write(2, this.EncodeNonAsciiCharacters(vp.Name));
this.chunk.Write(70, (short)0);
this.chunk.Write(10, 0.0);
this.chunk.Write(20, 0.0);
this.chunk.Write(11, 1.0);
this.chunk.Write(21, 1.0);
this.chunk.Write(12, vp.ViewCenter.X);
this.chunk.Write(22, vp.ViewCenter.Y);
this.chunk.Write(13, vp.SnapBasePoint.X);
this.chunk.Write(23, vp.SnapBasePoint.Y);
this.chunk.Write(14, vp.SnapSpacing.X);
this.chunk.Write(24, vp.SnapSpacing.Y);
this.chunk.Write(15, vp.GridSpacing.X);
this.chunk.Write(25, vp.GridSpacing.Y);
this.chunk.Write(16, vp.ViewDirection.X);
this.chunk.Write(26, vp.ViewDirection.Y);
this.chunk.Write(36, vp.ViewDirection.Z);
this.chunk.Write(17, vp.ViewTarget.X);
this.chunk.Write(27, vp.ViewTarget.Y);
this.chunk.Write(37, vp.ViewTarget.Z);
this.chunk.Write(40, vp.ViewHeight);
this.chunk.Write(41, vp.ViewAspectRatio);
this.chunk.Write(75, vp.SnapMode ? (short)1 : (short)0);
this.chunk.Write(76, vp.ShowGrid ? (short)1 : (short)0);
}