From 468605fbf82ee654144320fa71c7ee979e5de4f4 Mon Sep 17 00:00:00 2001
From: DomCR <DomCR@users.noreply.github.com>
Date: Tue, 1 Oct 2024 13:02:40 +0200
Subject: [PATCH 1/2] refactor

---
 src/ACadSharp/Entities/Viewport.cs            | 32 ++++++++++++++++---
 .../DWG/DwgStreamReaders/DwgObjectReader.cs   |  2 +-
 .../DwgObjectWriter.Entities.cs               |  2 +-
 3 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/src/ACadSharp/Entities/Viewport.cs b/src/ACadSharp/Entities/Viewport.cs
index 42ec53a5..6536e4d8 100644
--- a/src/ACadSharp/Entities/Viewport.cs
+++ b/src/ACadSharp/Entities/Viewport.cs
@@ -17,6 +17,11 @@ namespace ACadSharp.Entities
 	[DxfSubClass(DxfSubclassMarker.Viewport)]
 	public class Viewport : Entity
 	{
+		/// <summary>
+		/// Paper view Id, it indicates that the viewport acts as a paper size.
+		/// </summary>
+		public const int PaperViewId = 1;
+
 		/// <inheritdoc/>
 		public override ObjectType ObjectType => ObjectType.VIEWPORT;
 
@@ -48,7 +53,26 @@ public class Viewport : Entity
 		/// Viewport ID
 		/// </summary>
 		[DxfCodeValue(69)]
-		public short Id { get; set; } = 1;
+		public short Id
+		{
+			get
+			{
+				if (this.Owner is BlockRecord record)
+				{
+					short id = 0;
+					foreach (Viewport viewport in record.Viewports)
+					{
+						id += 1;
+						if (viewport == this)
+						{
+							return id;
+						}
+					}
+				}
+
+				return 0;
+			}
+		}
 
 		/// <summary>
 		/// View center point(in DCS)
@@ -274,7 +298,7 @@ public double ViewWidth
 		/// View contrast
 		/// </summary>
 		[DxfCodeValue(142)]
-		public double Constrast { get; set; }
+		public double Contrast { get; set; }
 
 		/// <summary>
 		/// Ambient light color.Write only if not black color.
@@ -310,8 +334,8 @@ public override CadObject Clone()
 		/// <inheritdoc/>
 		public override BoundingBox GetBoundingBox()
 		{
-			XYZ min = new XYZ(Center.X - this.Width, Center.Y - this.Height, Center.Z);
-			XYZ max = new XYZ(Center.X + this.Width, Center.Y + this.Height, Center.Z);
+			XYZ min = new XYZ(this.Center.X - this.Width / 2, this.Center.Y - this.Height / 2, this.Center.Z);
+			XYZ max = new XYZ(this.Center.X + this.Width / 2, this.Center.Y + this.Height / 2, this.Center.Z);
 
 			return new BoundingBox(min, max);
 		}
diff --git a/src/ACadSharp/IO/DWG/DwgStreamReaders/DwgObjectReader.cs b/src/ACadSharp/IO/DWG/DwgStreamReaders/DwgObjectReader.cs
index dac09e25..7d98092a 100644
--- a/src/ACadSharp/IO/DWG/DwgStreamReaders/DwgObjectReader.cs
+++ b/src/ACadSharp/IO/DWG/DwgStreamReaders/DwgObjectReader.cs
@@ -2305,7 +2305,7 @@ private CadTemplate readViewport()
 				//Brightness BD 141
 				viewport.Brightness = this._objectReader.ReadBitDouble();
 				//Contrast BD 142
-				viewport.Constrast = this._objectReader.ReadBitDouble();
+				viewport.Contrast = this._objectReader.ReadBitDouble();
 				//Ambient light color CMC 63
 				viewport.AmbientLightColor = this._objectReader.ReadCmColor();
 			}
diff --git a/src/ACadSharp/IO/DWG/DwgStreamWriters/DwgObjectWriter.Entities.cs b/src/ACadSharp/IO/DWG/DwgStreamWriters/DwgObjectWriter.Entities.cs
index 2fd799a6..7cab5414 100644
--- a/src/ACadSharp/IO/DWG/DwgStreamWriters/DwgObjectWriter.Entities.cs
+++ b/src/ACadSharp/IO/DWG/DwgStreamWriters/DwgObjectWriter.Entities.cs
@@ -2346,7 +2346,7 @@ private void writeViewport(Viewport viewport)
 				//Brightness BD 141
 				this._writer.WriteBitDouble(viewport.Brightness);
 				//Contrast BD 142
-				this._writer.WriteBitDouble(viewport.Constrast);
+				this._writer.WriteBitDouble(viewport.Contrast);
 				//Ambient light color CMC 63
 				this._writer.WriteCmColor(viewport.AmbientLightColor);
 			}

From 752c2695d77aa3339e2a46fc09c4f20da3260955 Mon Sep 17 00:00:00 2001
From: DomCR <DomCR@users.noreply.github.com>
Date: Tue, 1 Oct 2024 13:03:26 +0200
Subject: [PATCH 2/2] minor layer fix

---
 src/ACadSharp/Tables/Layer.cs | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/ACadSharp/Tables/Layer.cs b/src/ACadSharp/Tables/Layer.cs
index 354bcd1a..dd756bea 100644
--- a/src/ACadSharp/Tables/Layer.cs
+++ b/src/ACadSharp/Tables/Layer.cs
@@ -46,10 +46,22 @@ public class Layer : TableEntry
 		/// if the index is negative, layer is off
 		/// </remarks>
 		[DxfCodeValue(62, 420, 430)]
-		public Color Color { get; set; } = new Color(7);
+		public Color Color
+		{
+			get { return this._color; }
+			set
+			{
+				if (value.IsByLayer || value.IsByBlock)
+				{
+					throw new ArgumentException("The layer color cannot be ByLayer or ByBlock", nameof(value));
+				}
+
+				this._color = value;
+			}
+		}
 
 		/// <summary>
-		/// The linetype of an object. The default linetype is the linetype of the layer (ByLayer).
+		/// The line type of an object. The default line type is the line type of the layer (ByLayer).
 		/// </summary>
 		[DxfCodeValue(DxfReferenceType.Name, 6)]
 		public LineType LineType
@@ -80,7 +92,7 @@ public LineType LineType
 		public bool PlotFlag { get; set; } = true;
 
 		/// <summary>
-		/// Specifies the lineweight of an individual object or the default lineweight for the drawing.
+		/// Specifies the line weight of an individual object or the default line weight for the drawing.
 		/// </summary>
 		[DxfCodeValue(370)]
 		public LineweightType LineWeight { get; set; } = LineweightType.Default;
@@ -104,6 +116,8 @@ public LineType LineType
 
 		private LineType _lineType = LineType.Continuous;
 
+		private Color _color = new Color(7);
+
 		internal Layer() : base() { }
 
 		public Layer(string name) : base(name) { }