dwg following dxf structure

src/ACadSharp/DxfSubclassMarker.cs

@@ -89,6 +89,7 @@ public static class DxfSubclassMarker
 		public const string EvalGraphExpr = "AcDbEvalExpr";
 		public const string BlockElement = "AcDbBlockElement";
 		public const string BlockParameter = "AcDbBlockParameter";
+		public const string Block1PtParameter = "AcDbBlock1PtParameter";
 		public const string Block2PtParameter = "AcDbBlock2PtParameter";
 		public const string BlockLinearParameter = "AcDbBlockLinearParameter";
 

src/ACadSharp/IO/DWG/DwgStreamReaders/DwgObjectReader.cs

@@ -17,6 +17,7 @@
 using System.Globalization;
 using ACadSharp.Objects.Evaluations;
 using ACadSharp.XData;
+using System.Diagnostics;
 
 namespace ACadSharp.IO.DWG
 {
@@ -1121,52 +1122,80 @@ private CadTemplate readEvaluationGraph()
 			return template;
 		}
 
+		private void readEvaluationExpression(CadEvaluationExpressionTemplate template)
+		{
+			this.readCommonNonEntityData(template);
+
+			//AcDbEvalExpr
+			//90
+			template.CadObject.Value90 = _objectReader.ReadBitLong();
+			//98
+			template.CadObject.Value98 = _objectReader.ReadBitLong();
+			//99
+			template.CadObject.Value99 = _objectReader.ReadBitLong();
+
+			//-9999 always the same value
+			short n9999 = this._mergedReaders.ReadBitShort();
+			Debug.Assert(n9999 == -9999);
+		}
+
+		private void readBlockElement(CadBlockElementTemplate template)
+		{
+			this.readEvaluationExpression(template);
+
+			//300 name
+			template.BlockElement.ElementName = this._mergedReaders.ReadVariableText();
+			//98
+			template.BlockElement.Value98 = this._mergedReaders.ReadBitLong();
+			//99
+			template.BlockElement.Value99 = this._mergedReaders.ReadBitLong();
+			//1071
+			template.BlockElement.Value1071 = this._mergedReaders.ReadBitLong();
+		}
+
+		private void readBlockParameter(CadBlockParameterTemplate template)
+		{
+			this.readBlockElement(template);
+
+			//280
+			template.BlockParameter.Value280 = this._mergedReaders.ReadBit();
+			//281
+			template.BlockParameter.Value281 = this._mergedReaders.ReadBit();
+		}
+
+		private void readBlock1PtParameter(CadBlock1PtParameterTemplate template)
+		{
+			this.readBlockParameter(template);
+
+			//1010 1020 1030
+			template.Block1PtParameter.Location = this._mergedReaders.Read3BitDouble();
+
+			//170
+			template.Block1PtParameter.Value170 = this._mergedReaders.ReadBitShort();
+			//171
+			template.Block1PtParameter.Value171 = this._mergedReaders.ReadBitShort();
+			//93
+			template.Block1PtParameter.Value93 = this._mergedReaders.ReadBitLong();
+		}
+
 		private CadTemplate readBlockVisibilityParameter()
 		{
 			BlockVisibilityParameter blockVisibilityParameter = new BlockVisibilityParameter();
-			BlockVisibilityParameterTemplate template = new BlockVisibilityParameterTemplate(blockVisibilityParameter);
+			CadBlockVisibilityParameterTemplate template = new CadBlockVisibilityParameterTemplate(blockVisibilityParameter);
 
-			this.readCommonNonEntityData(template);
+			this.readBlock1PtParameter(template);
 
-			var l1 = _objectReader.ReadBitLong();
-			var s2 = _objectReader.ReadBitShort();  //	can also be L
-			var s3 = _objectReader.ReadBitShort();  //	can also be L
-			var b4 = _objectReader.ReadBit();
-			var s5 = _objectReader.ReadBitShort();  //	can also be L
-			var b6 = _objectReader.ReadBit();
-			var s7 = _objectReader.ReadBitShort();  //	can also be L
-
-			var b_8 = _objectReader.ReadBit();
-			var b_9 = _objectReader.ReadBit();
-			var b_10 = _objectReader.ReadBit();
-			var b_11 = _objectReader.ReadBit();
-			var b_12 = _objectReader.ReadBit();
-			var b_13 = _objectReader.ReadBit();
-			var S_14 = _objectReader.ReadBitShort();  //	can also be L
-
-			var s_15 = _objectReader.ReadBitShort();
-			var b_16 = _objectReader.ReadBit();
-			var b_17 = _objectReader.ReadBit();
-			var s_18 = _objectReader.ReadBitShort();
-
-			//	300	Parameter Type
-			blockVisibilityParameter.ParameterType = _textReader.ReadVariableText();
-
-			//	1010, 1020, 1030	Menu position
-			blockVisibilityParameter.BasePosition = _objectReader.Read3BitDouble();
-			//	2x0 <- 
-			var s170 = _objectReader.ReadBitShort();
-			var s171 = _objectReader.ReadBitShort();
-			var l93 = _objectReader.ReadBitLong();
-
-			//	301
+			//281
 			blockVisibilityParameter.Name = _textReader.ReadVariableText();
-			//	302
+			//301
+			blockVisibilityParameter.Name = _textReader.ReadVariableText();
+			//302
 			blockVisibilityParameter.Description = _textReader.ReadVariableText();
-			//	DXF 91
-			blockVisibilityParameter.L91 = _objectReader.ReadBitLong();
+			//DXF 91
+			blockVisibilityParameter.Value91 = _objectReader.ReadBitLong();
+
 			//DwgAnalyseTools.resetPosition(214293, 0);
-			//  DXF 93 Total entities count (no property)
+			//DXF 93 Total entities count (no property)
 			var totalEntitiesCount = _objectReader.ReadBitLong();
 			for (int i = 0; i < totalEntitiesCount; i++)
 			{

src/ACadSharp/IO/Templates/CadBlockVisibilityParameterTemplate.cs

@@ -0,0 +1,92 @@
+using System.Collections.Generic;
+
+using ACadSharp.Entities;
+using ACadSharp.Objects.Evaluations;
+
+namespace ACadSharp.IO.Templates
+{
+
+	internal class CadEvaluationExpressionTemplate : CadTemplate<EvaluationExpression>
+	{
+		public CadEvaluationExpressionTemplate(EvaluationExpression cadObject)
+			: base(cadObject)
+		{
+		}
+	}
+
+	internal class CadBlockElementTemplate : CadEvaluationExpressionTemplate
+	{
+		public BlockElement BlockElement { get { return this.CadObject as BlockElement; } }
+
+		public CadBlockElementTemplate(BlockElement cadObject)
+			: base(cadObject)
+		{
+		}
+	}
+
+	internal class CadBlockParameterTemplate : CadBlockElementTemplate
+	{
+		public BlockParameter BlockParameter { get { return this.CadObject as BlockParameter; } }
+
+		public CadBlockParameterTemplate(BlockParameter cadObject)
+			: base(cadObject)
+		{
+		}
+	}
+
+	internal class CadBlock1PtParameterTemplate : CadBlockParameterTemplate
+	{
+		public Block1PtParameter Block1PtParameter { get { return this.CadObject as Block1PtParameter; } }
+
+		public CadBlock1PtParameterTemplate(Block1PtParameter cadObject)
+			: base(cadObject)
+		{
+		}
+	}
+
+	internal class CadBlockVisibilityParameterTemplate : CadBlock1PtParameterTemplate
+	{
+		public IDictionary<ulong, Entity> TotalEntityHandles { get; } = new Dictionary<ulong, Entity>();
+
+		public IDictionary<BlockVisibilityParameter.SubBlock, IList<ulong>> SubBlockHandles { get; } = new Dictionary<BlockVisibilityParameter.SubBlock, IList<ulong>>();
+
+		public CadBlockVisibilityParameterTemplate(BlockVisibilityParameter cadObject)
+			: base(cadObject)
+		{
+		}
+
+		public override void Build(CadDocumentBuilder builder)
+		{
+			base.Build(builder);
+
+			BlockVisibilityParameter bvp = this.CadObject as BlockVisibilityParameter;
+
+			foreach (var cadObjectHandle in this.TotalEntityHandles)
+			{
+				ulong handle = cadObjectHandle.Key;
+				if (builder.TryGetCadObject(handle, out Entity entity))
+				{
+					this.TotalEntityHandles[handle] = entity;
+					bvp.Entities.Add(entity);
+				}
+			}
+
+			foreach (var subGroup in bvp.SubBlocks)
+			{
+				if (this.SubBlockHandles.TryGetValue(subGroup, out IList<ulong> subBlockHandles))
+				{
+					foreach (ulong handle in subBlockHandles)
+					{
+						if (this.TotalEntityHandles.TryGetValue(handle, out Entity entity))
+						{
+							subGroup.Entities.Add(entity);
+						}
+						else if (builder.TryGetCadObject(handle, out Entity entityX))
+						{
+						}
+					}
+				}
+			}
+		}
+	}
+}

src/ACadSharp/Objects/Evaluations/BlockVisibilityParameter.cs

@@ -6,23 +6,24 @@
 
 namespace ACadSharp.Objects.Evaluations
 {
+	//BLOCKVISIBILITYPARAMETER
+	//AcDbEvalExpr
+	//AcDbBlockElement
+	//AcDbBlock1PtParameter
+	//AcDbBlockVisibilityParameter
+
 	/// <summary>
 	/// Represents a BLOCKVISIBILITYPARAMETER object, in AutoCAD used to
 	/// control the visibility state of entities in a dynamic block.
 	/// </summary>
-	public class BlockVisibilityParameter : CadObject
+	public class BlockVisibilityParameter : Block1PtParameter
 	{
-
-		/// <inheritdoc/>
-		public override ObjectType ObjectType => ObjectType.UNLISTED;
-
 		/// <inheritdoc/>
 		public override string ObjectName => DxfFileToken.ObjectBlockVisibilityParameter;
 
 		/// <inheritdoc/>
 		public override string SubclassMarker => DxfSubclassMarker.BlockVisibilityParameter;
 
-
 		/// <summary>
 		/// Gets the list of all <see cref="Entity"/> objects of the dynamic block
 		/// this <see cref="BlockVisibilityParameter"/> is associated with.
@@ -54,19 +55,19 @@ public class BlockVisibilityParameter : CadObject
 		/// Gets a title for the dialog to select the subblock that is to be set visible.
 		/// </summary>
 		[DxfCodeValue(301)]
-		public string Name { get; internal set; }
+		public string Name { get; set; }
 
 		/// <summary>
 		/// Gets a description presumably for the dialog to select the subblock that is to be set visible.
 		/// </summary>
 		[DxfCodeValue(302)]
-		public string Description { get; internal set; }
+		public string Description { get; set; }
 
 		/// <summary>
 		/// Unknown
 		/// </summary>
 		[DxfCodeValue(91)]
-		public int L91 { get; internal set; }
+		internal int Value91 { get; set; }
 
 		/// <summary>
 		/// Represents a named subblock containing <see cref="Entity"/> objects.