Added action to change the index of linedefs, things, sectors, and vertices. Can be accessed through a shortcut (not bound by default) or the menu of the respective mode (#903)

Source/Core/Editing/UndoManager.cs

@@ -67,6 +67,10 @@ namespace CodeImp.DoomBuilder.Editing
 			AddThing,
 			RemThing,
 			PrpThing,
+			IndexLinedef,
+			IndexThing,
+			IndexSector,
+			IndexVertex,
 		}
 		
 		#endregion
@@ -425,6 +429,10 @@ namespace CodeImp.DoomBuilder.Editing
 						case StreamCodes.AddThing: PlayAddThing(ds); break;
 						case StreamCodes.RemThing: PlayRemThing(ds); break;
 						case StreamCodes.PrpThing: PlayPrpThing(ds); break;
+						case StreamCodes.IndexLinedef: PlayIndexLinedef(ds); break;
+						case StreamCodes.IndexThing: PlayIndexThing(ds); break;
+						case StreamCodes.IndexSector: PlayIndexSector(ds); break;
+						case StreamCodes.IndexVertex: PlayIndexVertex(ds); break;
 					}
 					
 					// Sanity check
@@ -1326,6 +1334,82 @@ namespace CodeImp.DoomBuilder.Editing
 			t.Marked = true;
 		}
 
+		internal void RecIndexLinedef(int oldindex, int newindex)
+		{
+			if (!BeginRecordData(StreamCodes.IndexLinedef)) return;
+			ss.wInt(oldindex);
+			ss.wInt(newindex);
+			EndRecordData();
+		}
+
+		private static void PlayIndexLinedef(DeserializerStream ds)
+		{
+			ds.rInt(out int oldindex);
+			ds.rInt(out int newindex);
+
+			// Record again because redo will not work otherwise (for map elements this regularly happens in BeforePropsChange
+			// oldindex and newindex are flipped here because we have to change them back
+			General.Map.UndoRedo.RecIndexLinedef(newindex, oldindex);
+			General.Map.Map.ChangeLindefIndex(newindex, oldindex);
+		}
+
+		internal void RecIndexThing(int oldindex, int newindex)
+		{
+			if (!BeginRecordData(StreamCodes.IndexThing)) return;
+			ss.wInt(oldindex);
+			ss.wInt(newindex);
+			EndRecordData();
+		}
+
+		private static void PlayIndexThing(DeserializerStream ds)
+		{
+			ds.rInt(out int oldindex);
+			ds.rInt(out int newindex);
+
+			// Record again because redo will not work otherwise (for map elements this regularly happens in BeforePropsChange
+			// oldindex and newindex are flipped here because we have to change them back
+			General.Map.UndoRedo.RecIndexThing(newindex, oldindex);
+			General.Map.Map.ChangeThingIndex(newindex, oldindex);
+		}
+
+		internal void RecIndexSector(int oldindex, int newindex)
+		{
+			if (!BeginRecordData(StreamCodes.IndexSector)) return;
+			ss.wInt(oldindex);
+			ss.wInt(newindex);
+			EndRecordData();
+		}
+
+		private static void PlayIndexSector(DeserializerStream ds)
+		{
+			ds.rInt(out int oldindex);
+			ds.rInt(out int newindex);
+
+			// Record again because redo will not work otherwise (for map elements this regularly happens in BeforePropsChange
+			// oldindex and newindex are flipped here because we have to change them back
+			General.Map.UndoRedo.RecIndexSector(newindex, oldindex);
+			General.Map.Map.ChangeSectorIndex(newindex, oldindex);
+		}
+
+		internal void RecIndexVertex(int oldindex, int newindex)
+		{
+			if (!BeginRecordData(StreamCodes.IndexVertex)) return;
+			ss.wInt(oldindex);
+			ss.wInt(newindex);
+			EndRecordData();
+		}
+
+		private static void PlayIndexVertex(DeserializerStream ds)
+		{
+			ds.rInt(out int oldindex);
+			ds.rInt(out int newindex);
+
+			// Record again because redo will not work otherwise (for map elements this regularly happens in BeforePropsChange
+			// oldindex and newindex are flipped here because we have to change them back
+			General.Map.UndoRedo.RecIndexVertex(newindex, oldindex);
+			General.Map.Map.ChangeVertexIndex(newindex, oldindex);
+		}
+
 		#endregion
 	}
 }

Source/Core/Map/Linedef.cs

@@ -1364,6 +1364,16 @@ namespace CodeImp.DoomBuilder.Map
 			colorPresetIndex = -1;
 		}
 
+		/// <summary>
+		/// Changes the linedef's index to a new index.
+		/// </summary>
+		/// <param name="newindex">The new index to set</param>
+		public void ChangeIndex(int newindex)
+		{
+			General.Map.UndoRedo.RecIndexLinedef(Index, newindex);
+			map?.ChangeLindefIndex(Index, newindex);
+		}
+
 		// String representation
 		public override string ToString()
 		{

Source/Core/Map/MapSet.cs

@@ -813,7 +813,43 @@ namespace CodeImp.DoomBuilder.Map
 		{
 			RemoveItem(ref things, index, ref numthings);
 		}		
-		
+
+		private void ChangeItemIndex<T>(ref T[] array, int oldindex, int newindex, int counter) where T : MapElement
+		{
+			if (oldindex == newindex || oldindex < 0 || newindex < 0 || oldindex >= array.Length || newindex >= array.Length)
+				return;
+
+			T item = array[oldindex];
+
+			if (oldindex > newindex) // Shift everything right
+			{
+				for (int i = oldindex; i > newindex; i--)
+				{
+					array[i] = array[i - 1];
+					array[i].Index++;
+				}
+			}
+			else // Shift everything left
+			{
+				for (int i = oldindex; i < newindex; i++)
+				{
+					array[i] = array[i + 1];
+					array[i].Index--;
+				}
+			}
+
+			array[newindex] = item;
+			array[newindex].Index = newindex;
+		}
+
+		internal void ChangeLindefIndex(int oldindex, int newindex) => ChangeItemIndex(ref linedefs, oldindex, newindex, numlinedefs);
+
+		internal void ChangeThingIndex(int oldindex, int newindex) => ChangeItemIndex(ref things, oldindex, newindex, numthings);
+
+		internal void ChangeSectorIndex(int oldindex, int newindex) => ChangeItemIndex(ref sectors, oldindex, newindex, numsectors);
+
+		internal void ChangeVertexIndex(int oldindex, int newindex) => ChangeItemIndex(ref vertices, oldindex, newindex, numvertices);
+
 		#endregion
 
 		#region ================== Serialization

Source/Core/Map/Sector.cs

@@ -819,6 +819,16 @@ namespace CodeImp.DoomBuilder.Map
 			return new Geometry.Plane(new Vector3D(0, 0, -1), s.CeilHeight);
 		}
 
+		/// <summary>
+		/// Changes the sector's index to a new index.
+		/// </summary>
+		/// <param name="newindex">The new index to set</param>
+		public void ChangeIndex(int newindex)
+		{
+			General.Map.UndoRedo.RecIndexSector(Index, newindex);
+			map?.ChangeSectorIndex(Index, newindex);
+		}
+
 		// String representation
 		public override string ToString()
 		{

Source/Core/Map/Thing.cs

@@ -740,6 +740,16 @@ namespace CodeImp.DoomBuilder.Map
 			return Vector2D.Distance(p, pos);
 		}
 
+		/// <summary>
+		/// Changes the thing's index to a new index.
+		/// </summary>
+		/// <param name="newindex">The new index to set</param>
+		public void ChangeIndex(int newindex)
+		{
+			General.Map.UndoRedo.RecIndexThing(Index, newindex);
+			map?.ChangeThingIndex(Index, newindex);
+		}
+
 		#endregion
 	}
 }

Source/Core/Map/Vertex.cs

@@ -338,6 +338,16 @@ namespace CodeImp.DoomBuilder.Map
 			General.Map.IsChanged = true;
 		}
 
+		/// <summary>
+		/// Changes the thing's index to a new index.
+		/// </summary>
+		/// <param name="newindex">The new index to set</param>
+		public void ChangeIndex(int newindex)
+		{
+			General.Map.UndoRedo.RecIndexVertex(Index, newindex);
+			map?.ChangeVertexIndex(Index, newindex);
+		}
+
 		// String representation
 		public override string ToString()
 		{

Source/Plugins/BuilderModes/BuilderModes.csproj

@@ -165,6 +165,12 @@
     <Compile Include="General\Association.cs" />
     <Compile Include="General\BuilderPlug.cs" />
     <Compile Include="General\CopyStructures.cs" />
+    <Compile Include="Interface\ChangeMapElementIndexForm.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="Interface\ChangeMapElementIndexForm.Designer.cs">
+      <DependentUpon>ChangeMapElementIndexForm.cs</DependentUpon>
+    </Compile>
     <Compile Include="Interface\ErrorCheckForm.cs">
       <SubType>Form</SubType>
     </Compile>
@@ -223,6 +229,9 @@
     <Compile Include="ClassicModes\VerticesMode.cs" />
   </ItemGroup>
   <ItemGroup>
+    <EmbeddedResource Include="Interface\ChangeMapElementIndexForm.resx">
+      <DependentUpon>ChangeMapElementIndexForm.cs</DependentUpon>
+    </EmbeddedResource>
     <EmbeddedResource Include="Interface\ImageExportSettingsForm.resx">
       <DependentUpon>ImageExportSettingsForm.cs</DependentUpon>
     </EmbeddedResource>

Source/Plugins/BuilderModes/BuilderModesMono.csproj

@@ -163,6 +163,12 @@
     <Compile Include="General\Association.cs" />
     <Compile Include="General\BuilderPlug.cs" />
     <Compile Include="General\CopyStructures.cs" />
+    <Compile Include="Interface\ChangeMapElementIndexForm.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="Interface\ChangeMapElementIndexForm.Designer.cs">
+      <DependentUpon>ChangeMapElementIndexForm.cs</DependentUpon>
+    </Compile>
     <Compile Include="Interface\ErrorCheckForm.cs">
       <SubType>Form</SubType>
     </Compile>
@@ -221,6 +227,9 @@
     <Compile Include="ClassicModes\VerticesMode.cs" />
   </ItemGroup>
   <ItemGroup>
+    <EmbeddedResource Include="Interface\ChangeMapElementIndexForm.resx">
+      <DependentUpon>ChangeMapElementIndexForm.cs</DependentUpon>
+    </EmbeddedResource>
     <EmbeddedResource Include="Interface\ImageExportSettingsForm.resx">
       <DependentUpon>ImageExportSettingsForm.cs</DependentUpon>
     </EmbeddedResource>

Source/Plugins/BuilderModes/ClassicModes/LinedefsMode.cs

@@ -2158,6 +2158,31 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			General.Interface.DisplayStatus(StatusType.Action, "Added 'lightfog' flag to " + addedcout + " sidedefs, removed it from " + removedcount + " sidedefs.");
 		}
 
+		[BeginAction("changemapelementindex")]
+		private void ChangeMapElementIndex()
+		{
+			// Make list of selected linedefs
+			List<Linedef> selected = General.Map.Map.GetSelectedLinedefs(true).ToList();
+			if ((selected.Count == 0) && (highlighted != null) && !highlighted.IsDisposed) selected.Add(highlighted);
+			if (selected.Count != 1)
+			{
+				General.ToastManager.ShowToast(ToastMessages.CHANGEMAPELEMENTINDEX, ToastType.WARNING, "Changing linedef index failed", "You need to select or highlight exactly 1 linedef.");
+				return;
+			}
+
+			ChangeMapElementIndexForm f = new ChangeMapElementIndexForm("linedef", selected[0].Index, General.Map.Map.Linedefs.Count - 1);
+			if (f.ShowDialog() == DialogResult.OK)
+			{
+				int newindex = f.GetNewIndex();
+				int oldindex = selected[0].Index;
+				General.Map.UndoRedo.CreateUndo("Change linedef index");
+
+				selected[0].ChangeIndex(newindex);
+
+				General.ToastManager.ShowToast(ToastMessages.CHANGEMAPELEMENTINDEX, ToastType.INFO, "Successfully change linedef index", $"Changed index of linedef {oldindex} to {newindex}.");
+			}
+		}
+
 		#endregion
 	}
 }

Source/Plugins/BuilderModes/ClassicModes/SectorsMode.cs

@@ -20,6 +20,7 @@ using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Diagnostics;
+using System.Linq;
 using System.Threading.Tasks;
 using System.Windows.Forms;
 using System.Collections.Concurrent;
@@ -2838,6 +2839,31 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			General.Interface.RedrawDisplay();
 		}
 
+		[BeginAction("changemapelementindex")]
+		private void ChangeMapElementIndex()
+		{
+			// Make list of selected linedefs
+			List<Sector> selected = General.Map.Map.GetSelectedSectors(true).ToList();
+			if ((selected.Count == 0) && (highlighted != null) && !highlighted.IsDisposed) selected.Add(highlighted);
+			if (selected.Count != 1)
+			{
+				General.ToastManager.ShowToast(ToastMessages.CHANGEMAPELEMENTINDEX, ToastType.WARNING, "Changing sector index failed", "You need to select or highlight exactly 1 sector.");
+				return;
+			}
+
+			ChangeMapElementIndexForm f = new ChangeMapElementIndexForm("sector", selected[0].Index, General.Map.Map.Sectors.Count - 1);
+			if (f.ShowDialog() == DialogResult.OK)
+			{
+				int newindex = f.GetNewIndex();
+				int oldindex = selected[0].Index;
+				General.Map.UndoRedo.CreateUndo("Change sector index");
+
+				selected[0].ChangeIndex(newindex);
+
+				General.ToastManager.ShowToast(ToastMessages.CHANGEMAPELEMENTINDEX, ToastType.INFO, "Successfully change sector index", $"Changed index of sector {oldindex} to {newindex}.");
+			}
+		}
+
 		#endregion
 	}
 }

Source/Plugins/BuilderModes/ClassicModes/ThingsMode.cs

@@ -1607,6 +1607,31 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			}
 		}
 
+		[BeginAction("changemapelementindex")]
+		private void ChangeMapElementIndex()
+		{
+			// Make list of selected linedefs
+			List<Thing> selected = General.Map.Map.GetSelectedThings(true).ToList();
+			if ((selected.Count == 0) && (highlighted != null) && !highlighted.IsDisposed) selected.Add(highlighted);
+			if (selected.Count != 1)
+			{
+				General.ToastManager.ShowToast(ToastMessages.CHANGEMAPELEMENTINDEX, ToastType.WARNING, "Changing thing index failed", "You need to select or highlight exactly 1 thing.");
+				return;
+			}
+
+			ChangeMapElementIndexForm f = new ChangeMapElementIndexForm("thing", selected[0].Index, General.Map.Map.Things.Count - 1);
+			if (f.ShowDialog() == DialogResult.OK)
+			{
+				int newindex = f.GetNewIndex();
+				int oldindex = selected[0].Index;
+				General.Map.UndoRedo.CreateUndo("Change thing index");
+
+				selected[0].ChangeIndex(newindex);
+
+				General.ToastManager.ShowToast(ToastMessages.CHANGEMAPELEMENTINDEX, ToastType.INFO, "Successfully change thing index", $"Changed index of thing {oldindex} to {newindex}.");
+			}
+		}
+
 		#endregion
 	}
 }

Source/Plugins/BuilderModes/ClassicModes/VerticesMode.cs

@@ -1219,11 +1219,36 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			}
 		}
 
+		[BeginAction("changemapelementindex")]
+		private void ChangeMapElementIndex()
+		{
+			// Make list of selected linedefs
+			List<Vertex> selected = General.Map.Map.GetSelectedVertices(true).ToList();
+			if ((selected.Count == 0) && (highlighted != null) && !highlighted.IsDisposed) selected.Add(highlighted);
+			if (selected.Count != 1)
+			{
+				General.ToastManager.ShowToast(ToastMessages.CHANGEMAPELEMENTINDEX, ToastType.WARNING, "Changing vertex index failed", "You need to select or highlight exactly 1 vertex.");
+				return;
+			}
+
+			ChangeMapElementIndexForm f = new ChangeMapElementIndexForm("vertex", selected[0].Index, General.Map.Map.Vertices.Count - 1);
+			if (f.ShowDialog() == DialogResult.OK)
+			{
+				int newindex = f.GetNewIndex();
+				int oldindex = selected[0].Index;
+				General.Map.UndoRedo.CreateUndo("Change vertex index");
+
+				selected[0].ChangeIndex(newindex);
+
+				General.ToastManager.ShowToast(ToastMessages.CHANGEMAPELEMENTINDEX, ToastType.INFO, "Successfully change vertex index", $"Changed index of vertex {oldindex} to {newindex}.");
+			}
+		}
+
 		#endregion
 
 		#region ================== Action assist (mxd)
 
-			//mxd
+		//mxd
 		private static void MergeLines(ICollection<Vertex> selected, Linedef ld1, Linedef ld2, Vertex v) 
 		{
 			Vertex v1 = (ld1.Start == v) ? ld1.End : ld1.Start;

Source/Plugins/BuilderModes/General/BuilderPlug.cs

@@ -45,6 +45,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 	internal class ToastMessages
 	{
 		public static readonly string VISUALSLOPING = "visualsloping";
+		public static readonly string CHANGEMAPELEMENTINDEX = "changemapelementindex";
 	}
 
 	public class BuilderPlug : Plug
@@ -257,6 +258,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 
 			// Register toasts
 			General.ToastManager.RegisterToast(ToastMessages.VISUALSLOPING, "Visual sloping", "Toasts related to visual sloping");
+			General.ToastManager.RegisterToast(ToastMessages.CHANGEMAPELEMENTINDEX, "Change map element index", "Toasts related to changing the index of map elements");
 		}
 
 		// Disposer

Source/Plugins/BuilderModes/Interface/ChangeMapElementIndexForm.Designer.cs

@@ -0,0 +1,181 @@
+
+namespace CodeImp.DoomBuilder.BuilderModes.Interface
+{
+	partial class ChangeMapElementIndexForm
+	{
+		/// <summary>
+		/// Required designer variable.
+		/// </summary>
+		private System.ComponentModel.IContainer components = null;
+
+		/// <summary>
+		/// Clean up any resources being used.
+		/// </summary>
+		/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+		protected override void Dispose(bool disposing)
+		{
+			if (disposing && (components != null))
+			{
+				components.Dispose();
+			}
+			base.Dispose(disposing);
+		}
+
+		#region Windows Form Designer generated code
+
+		/// <summary>
+		/// Required method for Designer support - do not modify
+		/// the contents of this method with the code editor.
+		/// </summary>
+		private void InitializeComponent()
+		{
+			this.components = new System.ComponentModel.Container();
+			this.label1 = new System.Windows.Forms.Label();
+			this.label2 = new System.Windows.Forms.Label();
+			this.label3 = new System.Windows.Forms.Label();
+			this.bntNewIndex = new CodeImp.DoomBuilder.Controls.ButtonsNumericTextbox();
+			this.lbCurrentIndex = new System.Windows.Forms.Label();
+			this.lbMaximumIndex = new System.Windows.Forms.Label();
+			this.btnOk = new System.Windows.Forms.Button();
+			this.btnCancel = new System.Windows.Forms.Button();
+			this.pbWarning = new System.Windows.Forms.PictureBox();
+			this.toolTip = new System.Windows.Forms.ToolTip(this.components);
+			((System.ComponentModel.ISupportInitialize)(this.pbWarning)).BeginInit();
+			this.SuspendLayout();
+			// 
+			// label1
+			// 
+			this.label1.AutoSize = true;
+			this.label1.Location = new System.Drawing.Point(22, 22);
+			this.label1.Name = "label1";
+			this.label1.Size = new System.Drawing.Size(72, 13);
+			this.label1.TabIndex = 0;
+			this.label1.Text = "Current index:";
+			// 
+			// label2
+			// 
+			this.label2.AutoSize = true;
+			this.label2.Location = new System.Drawing.Point(22, 55);
+			this.label2.Name = "label2";
+			this.label2.Size = new System.Drawing.Size(82, 13);
+			this.label2.TabIndex = 1;
+			this.label2.Text = "Maximum index:";
+			// 
+			// label3
+			// 
+			this.label3.AutoSize = true;
+			this.label3.Location = new System.Drawing.Point(22, 88);
+			this.label3.Name = "label3";
+			this.label3.Size = new System.Drawing.Size(60, 13);
+			this.label3.TabIndex = 2;
+			this.label3.Text = "New index:";
+			// 
+			// bntNewIndex
+			// 
+			this.bntNewIndex.AllowDecimal = false;
+			this.bntNewIndex.AllowExpressions = false;
+			this.bntNewIndex.AllowNegative = false;
+			this.bntNewIndex.AllowRelative = false;
+			this.bntNewIndex.ButtonStep = 1;
+			this.bntNewIndex.ButtonStepBig = 10F;
+			this.bntNewIndex.ButtonStepFloat = 1F;
+			this.bntNewIndex.ButtonStepSmall = 0.1F;
+			this.bntNewIndex.ButtonStepsUseModifierKeys = false;
+			this.bntNewIndex.ButtonStepsWrapAround = false;
+			this.bntNewIndex.Location = new System.Drawing.Point(111, 83);
+			this.bntNewIndex.Name = "bntNewIndex";
+			this.bntNewIndex.Size = new System.Drawing.Size(100, 24);
+			this.bntNewIndex.StepValues = null;
+			this.bntNewIndex.TabIndex = 3;
+			this.bntNewIndex.WhenTextChanged += new System.EventHandler(this.bntNewIndex_WhenTextChanged);
+			// 
+			// lbCurrentIndex
+			// 
+			this.lbCurrentIndex.AutoSize = true;
+			this.lbCurrentIndex.Location = new System.Drawing.Point(110, 22);
+			this.lbCurrentIndex.Name = "lbCurrentIndex";
+			this.lbCurrentIndex.Size = new System.Drawing.Size(25, 13);
+			this.lbCurrentIndex.TabIndex = 4;
+			this.lbCurrentIndex.Text = "123";
+			// 
+			// lbMaximumIndex
+			// 
+			this.lbMaximumIndex.AutoSize = true;
+			this.lbMaximumIndex.Location = new System.Drawing.Point(110, 55);
+			this.lbMaximumIndex.Name = "lbMaximumIndex";
+			this.lbMaximumIndex.Size = new System.Drawing.Size(37, 13);
+			this.lbMaximumIndex.TabIndex = 5;
+			this.lbMaximumIndex.Text = "65535";
+			// 
+			// btnOk
+			// 
+			this.btnOk.DialogResult = System.Windows.Forms.DialogResult.OK;
+			this.btnOk.Location = new System.Drawing.Point(55, 133);
+			this.btnOk.Name = "btnOk";
+			this.btnOk.Size = new System.Drawing.Size(75, 23);
+			this.btnOk.TabIndex = 6;
+			this.btnOk.Text = "OK";
+			this.btnOk.UseVisualStyleBackColor = true;
+			// 
+			// btnCancel
+			// 
+			this.btnCancel.DialogResult = System.Windows.Forms.DialogResult.Cancel;
+			this.btnCancel.Location = new System.Drawing.Point(136, 133);
+			this.btnCancel.Name = "btnCancel";
+			this.btnCancel.Size = new System.Drawing.Size(75, 23);
+			this.btnCancel.TabIndex = 7;
+			this.btnCancel.Text = "Cancel";
+			this.btnCancel.UseVisualStyleBackColor = true;
+			// 
+			// pbWarning
+			// 
+			this.pbWarning.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.Warning;
+			this.pbWarning.Location = new System.Drawing.Point(217, 87);
+			this.pbWarning.Name = "pbWarning";
+			this.pbWarning.Size = new System.Drawing.Size(16, 16);
+			this.pbWarning.TabIndex = 8;
+			this.pbWarning.TabStop = false;
+			this.toolTip.SetToolTip(this.pbWarning, "The new index is too high");
+			this.pbWarning.Visible = false;
+			// 
+			// ChangeMapElementIndexForm
+			// 
+			this.AcceptButton = this.btnOk;
+			this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
+			this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+			this.CancelButton = this.btnCancel;
+			this.ClientSize = new System.Drawing.Size(264, 168);
+			this.Controls.Add(this.pbWarning);
+			this.Controls.Add(this.btnCancel);
+			this.Controls.Add(this.btnOk);
+			this.Controls.Add(this.lbMaximumIndex);
+			this.Controls.Add(this.lbCurrentIndex);
+			this.Controls.Add(this.bntNewIndex);
+			this.Controls.Add(this.label3);
+			this.Controls.Add(this.label2);
+			this.Controls.Add(this.label1);
+			this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
+			this.MaximizeBox = false;
+			this.MinimizeBox = false;
+			this.Name = "ChangeMapElementIndexForm";
+			this.Text = "ChangeMapElementIndexForm";
+			((System.ComponentModel.ISupportInitialize)(this.pbWarning)).EndInit();
+			this.ResumeLayout(false);
+			this.PerformLayout();
+
+		}
+
+		#endregion
+
+		private System.Windows.Forms.Label label1;
+		private System.Windows.Forms.Label label2;
+		private System.Windows.Forms.Label label3;
+		private Controls.ButtonsNumericTextbox bntNewIndex;
+		private System.Windows.Forms.Label lbCurrentIndex;
+		private System.Windows.Forms.Label lbMaximumIndex;
+		private System.Windows.Forms.Button btnOk;
+		private System.Windows.Forms.Button btnCancel;
+		private System.Windows.Forms.PictureBox pbWarning;
+		private System.Windows.Forms.ToolTip toolTip;
+	}
+}

Source/Plugins/BuilderModes/Interface/ChangeMapElementIndexForm.cs

@@ -0,0 +1,84 @@
+#region ================== Copyright (c) 2023 Boris Iwanski
+
+/*
+ * This program is free software: you can redistribute it and/or modify
+ *
+ * it under the terms of the GNU General Public License as published by
+ * 
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * 
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * 
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.If not, see<http://www.gnu.org/licenses/>.
+ */
+
+#endregion
+
+using CodeImp.DoomBuilder.Windows;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace CodeImp.DoomBuilder.BuilderModes.Interface
+{
+	public partial class ChangeMapElementIndexForm : DelayedForm
+	{
+		private int currentindex;
+		private int maxindex;
+
+		public ChangeMapElementIndexForm(string typetitle, int currentindex, int maxindex)
+		{
+			InitializeComponent();
+
+			Text = $"Change {typetitle} index";
+
+			this.currentindex = currentindex;
+			this.maxindex = maxindex;
+
+			lbCurrentIndex.Text = currentindex.ToString();
+			lbMaximumIndex.Text = maxindex.ToString();
+			bntNewIndex.Text = "0";
+		}
+
+		public int GetNewIndex()
+		{
+			return bntNewIndex.GetResult(0);
+		}
+
+		private void bntNewIndex_WhenTextChanged(object sender, EventArgs e)
+		{
+			int targetindex = bntNewIndex.GetResult(0);
+
+			if(targetindex > maxindex)
+			{
+				toolTip.SetToolTip(pbWarning, "The new index is too high");
+				btnOk.Enabled = false;
+				pbWarning.Visible = true;
+			}
+			else if(targetindex == currentindex)
+			{
+				toolTip.SetToolTip(pbWarning, "The new and old indices are the same");
+				btnOk.Enabled = false;
+				pbWarning.Visible = true;
+			}
+			else
+			{
+				btnOk.Enabled = true;
+				pbWarning.Visible = false;
+			}
+		}
+	}
+}

Source/Plugins/BuilderModes/Interface/ChangeMapElementIndexForm.resx

@@ -0,0 +1,126 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <metadata name="toolTip.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+    <value>17, 17</value>
+  </metadata>
+  <metadata name="toolTip.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+    <value>17, 17</value>
+  </metadata>
+</root>

Source/Plugins/BuilderModes/Interface/MenusForm.Designer.cs

@@ -44,6 +44,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			this.curvelinedefsitem = new System.Windows.Forms.ToolStripMenuItem();
 			this.toolStripMenuItem3 = new System.Windows.Forms.ToolStripSeparator();
 			this.splitlinedefsitem = new System.Windows.Forms.ToolStripMenuItem();
+			this.changeLindefIndexToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
 			this.updatelightfogitem = new System.Windows.Forms.ToolStripMenuItem();
 			this.aligntexturesitem = new System.Windows.Forms.ToolStripMenuItem();
 			this.alignFloorToFrontItem = new System.Windows.Forms.ToolStripMenuItem();
@@ -79,27 +80,15 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			this.selectSimilarVertsItem = new System.Windows.Forms.ToolStripMenuItem();
 			this.globalstrip = new System.Windows.Forms.ToolStrip();
 			this.manualstrip = new System.Windows.Forms.ToolStrip();
-			this.buttoncopyproperties = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
-			this.buttonpasteproperties = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
-			this.buttonpastepropertiesoptions = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
 			this.seperatorcopypaste = new System.Windows.Forms.ToolStripSeparator();
 			this.buttonselectionnumbers = new System.Windows.Forms.ToolStripButton();
 			this.buttonselectioneffects = new System.Windows.Forms.ToolStripButton();
 			this.separatorsectors1 = new System.Windows.Forms.ToolStripSeparator();
-			this.buttonMakeDoor = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
 			this.separatorsectors2 = new System.Windows.Forms.ToolStripSeparator();
-			this.buttonbrightnessgradient = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
-			this.buttonfloorgradient = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
-			this.buttonceilinggradient = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
-			this.buttonflipselectionh = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
-			this.buttonflipselectionv = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
-			this.buttoncurvelinedefs = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
 			this.gradientModeMenu = new System.Windows.Forms.ToolStripComboBox();
 			this.gradientInterpolationMenu = new System.Windows.Forms.ToolStripComboBox();
 			this.separatorsectors3 = new System.Windows.Forms.ToolStripSeparator();
 			this.buttonMarqueSelectTouching = new System.Windows.Forms.ToolStripButton();
-			this.syncthingteditbutton = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
-			this.buttonAlignThingsToWall = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
 			this.buttonTextureOffsetLock = new System.Windows.Forms.ToolStripButton();
 			this.buttonTextureOffset3DFloorLock = new System.Windows.Forms.ToolStripButton();
 			this.buttonlightradii = new System.Windows.Forms.ToolStripButton();
@@ -116,6 +105,21 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			this.viewmenuitem = new System.Windows.Forms.ToolStripMenuItem();
 			this.itemlightradii = new System.Windows.Forms.ToolStripMenuItem();
 			this.itemsoundradii = new System.Windows.Forms.ToolStripMenuItem();
+			this.changeThingIndexToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
+			this.changeSectorIndexToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
+			this.buttoncopyproperties = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonpasteproperties = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonpastepropertiesoptions = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonMakeDoor = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonbrightnessgradient = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonfloorgradient = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonceilinggradient = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonflipselectionh = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonflipselectionv = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttoncurvelinedefs = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.syncthingteditbutton = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.buttonAlignThingsToWall = new CodeImp.DoomBuilder.Controls.ToolStripActionButton();
+			this.changeVertexIndexToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
 			this.menustrip.SuspendLayout();
 			this.manualstrip.SuspendLayout();
 			this.fileMenuStrip.SuspendLayout();
@@ -150,6 +154,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
             this.curvelinedefsitem,
             this.toolStripMenuItem3,
             this.splitlinedefsitem,
+            this.changeLindefIndexToolStripMenuItem,
             this.updatelightfogitem,
             this.aligntexturesitem,
             this.toolStripSeparator5,
@@ -261,6 +266,14 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			this.splitlinedefsitem.Text = "S&plit Linedefs";
 			this.splitlinedefsitem.Click += new System.EventHandler(this.InvokeTaggedAction);
 			// 
+			// changeLindefIndexToolStripMenuItem
+			// 
+			this.changeLindefIndexToolStripMenuItem.Name = "changeLindefIndexToolStripMenuItem";
+			this.changeLindefIndexToolStripMenuItem.Size = new System.Drawing.Size(223, 22);
+			this.changeLindefIndexToolStripMenuItem.Tag = "changemapelementindex";
+			this.changeLindefIndexToolStripMenuItem.Text = "Change Lindef Index";
+			this.changeLindefIndexToolStripMenuItem.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
 			// updatelightfogitem
 			// 
 			this.updatelightfogitem.Name = "updatelightfogitem";
@@ -339,6 +352,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
             this.alignsectorlinedefsitem,
             this.toolStripSeparator8,
             this.makedooritem,
+            this.changeSectorIndexToolStripMenuItem,
             this.toolStripSeparator4,
             this.selectSimilarSectors});
 			this.sectorsmenu.Name = "sectorsmenu";
@@ -449,6 +463,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
             this.toolStripSeparator3,
             this.alignToWallItem,
             this.pointAtCursorItem,
+            this.changeThingIndexToolStripMenuItem,
             this.toolStripSeparator6,
             this.selectSimilarThingsItem});
 			this.thingsmenu.Name = "thingsmenu";
@@ -515,6 +530,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			// 
 			this.vertsmenu.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
             this.placethingsv,
+            this.changeVertexIndexToolStripMenuItem,
             this.toolStripSeparator7,
             this.selectSimilarVertsItem});
 			this.vertsmenu.Name = "vertsmenu";
@@ -526,7 +542,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			// 
 			this.placethingsv.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.PlaceThings;
 			this.placethingsv.Name = "placethingsv";
-			this.placethingsv.Size = new System.Drawing.Size(153, 22);
+			this.placethingsv.Size = new System.Drawing.Size(182, 22);
 			this.placethingsv.Tag = "placethings";
 			this.placethingsv.Text = "&Place Things...";
 			this.placethingsv.Click += new System.EventHandler(this.InvokeTaggedAction);
@@ -534,13 +550,13 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			// toolStripSeparator7
 			// 
 			this.toolStripSeparator7.Name = "toolStripSeparator7";
-			this.toolStripSeparator7.Size = new System.Drawing.Size(150, 6);
+			this.toolStripSeparator7.Size = new System.Drawing.Size(179, 6);
 			// 
 			// selectSimilarVertsItem
 			// 
 			this.selectSimilarVertsItem.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.Similar;
 			this.selectSimilarVertsItem.Name = "selectSimilarVertsItem";
-			this.selectSimilarVertsItem.Size = new System.Drawing.Size(153, 22);
+			this.selectSimilarVertsItem.Size = new System.Drawing.Size(182, 22);
 			this.selectSimilarVertsItem.Tag = "selectsimilar";
 			this.selectSimilarVertsItem.Text = "Select Similar...";
 			this.selectSimilarVertsItem.Click += new System.EventHandler(this.InvokeTaggedAction);
@@ -587,40 +603,6 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			this.manualstrip.TabIndex = 2;
 			this.manualstrip.Text = "toolStrip1";
 			// 
-			// buttoncopyproperties
-			// 
-			this.buttoncopyproperties.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttoncopyproperties.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.CopyProperties;
-			this.buttoncopyproperties.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttoncopyproperties.Name = "buttoncopyproperties";
-			this.buttoncopyproperties.Size = new System.Drawing.Size(23, 22);
-			this.buttoncopyproperties.Tag = "classiccopyproperties";
-			this.buttoncopyproperties.Text = "Copy Properties";
-			this.buttoncopyproperties.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
-			// buttonpasteproperties
-			// 
-			this.buttonpasteproperties.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonpasteproperties.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.PasteProperties;
-			this.buttonpasteproperties.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonpasteproperties.Name = "buttonpasteproperties";
-			this.buttonpasteproperties.Size = new System.Drawing.Size(23, 22);
-			this.buttonpasteproperties.Tag = "classicpasteproperties";
-			this.buttonpasteproperties.Text = "Paste Properties";
-			this.buttonpasteproperties.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
-			// buttonpastepropertiesoptions
-			// 
-			this.buttonpastepropertiesoptions.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonpastepropertiesoptions.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.PastePropertiesOptions;
-			this.buttonpastepropertiesoptions.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonpastepropertiesoptions.Name = "buttonpastepropertiesoptions";
-			this.buttonpastepropertiesoptions.Size = new System.Drawing.Size(23, 22);
-			this.buttonpastepropertiesoptions.Tag = "classicpastepropertieswithoptions";
-			this.buttonpastepropertiesoptions.Text = "Paste Properties Special...";
-			this.buttonpastepropertiesoptions.TextAlign = System.Drawing.ContentAlignment.TopRight;
-			this.buttonpastepropertiesoptions.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
 			// seperatorcopypaste
 			// 
 			this.seperatorcopypaste.Margin = new System.Windows.Forms.Padding(6, 0, 6, 0);
@@ -655,89 +637,12 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			this.separatorsectors1.Name = "separatorsectors1";
 			this.separatorsectors1.Size = new System.Drawing.Size(6, 25);
 			// 
-			// buttonMakeDoor
-			// 
-			this.buttonMakeDoor.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonMakeDoor.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.Door;
-			this.buttonMakeDoor.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonMakeDoor.Name = "buttonMakeDoor";
-			this.buttonMakeDoor.Size = new System.Drawing.Size(23, 22);
-			this.buttonMakeDoor.Tag = "makedoor";
-			this.buttonMakeDoor.Text = "Make Door From Selection";
-			this.buttonMakeDoor.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
 			// separatorsectors2
 			// 
 			this.separatorsectors2.Margin = new System.Windows.Forms.Padding(6, 0, 6, 0);
 			this.separatorsectors2.Name = "separatorsectors2";
 			this.separatorsectors2.Size = new System.Drawing.Size(6, 25);
 			// 
-			// buttonbrightnessgradient
-			// 
-			this.buttonbrightnessgradient.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonbrightnessgradient.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.BrightnessGradient;
-			this.buttonbrightnessgradient.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonbrightnessgradient.Name = "buttonbrightnessgradient";
-			this.buttonbrightnessgradient.Size = new System.Drawing.Size(23, 22);
-			this.buttonbrightnessgradient.Tag = "gradientbrightness";
-			this.buttonbrightnessgradient.Text = "Make Brightness Gradient";
-			this.buttonbrightnessgradient.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
-			// buttonfloorgradient
-			// 
-			this.buttonfloorgradient.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonfloorgradient.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.FloorsGradient;
-			this.buttonfloorgradient.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonfloorgradient.Name = "buttonfloorgradient";
-			this.buttonfloorgradient.Size = new System.Drawing.Size(23, 22);
-			this.buttonfloorgradient.Tag = "gradientfloors";
-			this.buttonfloorgradient.Text = "Make Floor Heights Gradient";
-			this.buttonfloorgradient.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
-			// buttonceilinggradient
-			// 
-			this.buttonceilinggradient.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonceilinggradient.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.CeilsGradient;
-			this.buttonceilinggradient.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonceilinggradient.Name = "buttonceilinggradient";
-			this.buttonceilinggradient.Size = new System.Drawing.Size(23, 22);
-			this.buttonceilinggradient.Tag = "gradientceilings";
-			this.buttonceilinggradient.Text = "Make Ceiling Heights Gradient";
-			this.buttonceilinggradient.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
-			// buttonflipselectionh
-			// 
-			this.buttonflipselectionh.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonflipselectionh.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.FlipSelectionH;
-			this.buttonflipselectionh.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonflipselectionh.Name = "buttonflipselectionh";
-			this.buttonflipselectionh.Size = new System.Drawing.Size(23, 22);
-			this.buttonflipselectionh.Tag = "flipselectionh";
-			this.buttonflipselectionh.Text = "Flip Selection Horizontally";
-			this.buttonflipselectionh.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
-			// buttonflipselectionv
-			// 
-			this.buttonflipselectionv.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonflipselectionv.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.FlipSelectionV;
-			this.buttonflipselectionv.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonflipselectionv.Name = "buttonflipselectionv";
-			this.buttonflipselectionv.Size = new System.Drawing.Size(23, 22);
-			this.buttonflipselectionv.Tag = "flipselectionv";
-			this.buttonflipselectionv.Text = "Flip Selection Vertically";
-			this.buttonflipselectionv.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
-			// buttoncurvelinedefs
-			// 
-			this.buttoncurvelinedefs.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttoncurvelinedefs.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.CurveLines;
-			this.buttoncurvelinedefs.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttoncurvelinedefs.Name = "buttoncurvelinedefs";
-			this.buttoncurvelinedefs.Size = new System.Drawing.Size(23, 22);
-			this.buttoncurvelinedefs.Tag = "curvelinesmode";
-			this.buttoncurvelinedefs.Text = "Curve Linedefs";
-			this.buttoncurvelinedefs.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
 			// gradientModeMenu
 			// 
 			this.gradientModeMenu.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
@@ -773,29 +678,6 @@ namespace CodeImp.DoomBuilder.BuilderModes
     "";
 			this.buttonMarqueSelectTouching.Click += new System.EventHandler(this.buttonMarqueSelectTouching_Click);
 			// 
-			// syncthingteditbutton
-			// 
-			this.syncthingteditbutton.CheckOnClick = true;
-			this.syncthingteditbutton.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.syncthingteditbutton.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.SelectThingsInSectors;
-			this.syncthingteditbutton.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.syncthingteditbutton.Name = "syncthingteditbutton";
-			this.syncthingteditbutton.Size = new System.Drawing.Size(23, 22);
-			this.syncthingteditbutton.Tag = "syncedthingedit";
-			this.syncthingteditbutton.Text = "Synchronized Things Editing";
-			this.syncthingteditbutton.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
-			// buttonAlignThingsToWall
-			// 
-			this.buttonAlignThingsToWall.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
-			this.buttonAlignThingsToWall.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.AlignThings;
-			this.buttonAlignThingsToWall.ImageTransparentColor = System.Drawing.Color.Magenta;
-			this.buttonAlignThingsToWall.Name = "buttonAlignThingsToWall";
-			this.buttonAlignThingsToWall.Size = new System.Drawing.Size(23, 22);
-			this.buttonAlignThingsToWall.Tag = "thingaligntowall";
-			this.buttonAlignThingsToWall.ToolTipText = "Align Things to Nearest Linedef";
-			this.buttonAlignThingsToWall.Click += new System.EventHandler(this.InvokeTaggedAction);
-			// 
 			// buttonTextureOffsetLock
 			// 
 			this.buttonTextureOffsetLock.CheckOnClick = true;
@@ -949,6 +831,164 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			this.itemsoundradii.Text = "Show Ambient Sound Radii";
 			this.itemsoundradii.Click += new System.EventHandler(this.buttonsoundradii_Click);
 			// 
+			// changeThingIndexToolStripMenuItem
+			// 
+			this.changeThingIndexToolStripMenuItem.Name = "changeThingIndexToolStripMenuItem";
+			this.changeThingIndexToolStripMenuItem.Size = new System.Drawing.Size(244, 22);
+			this.changeThingIndexToolStripMenuItem.Tag = "changemapelementindex";
+			this.changeThingIndexToolStripMenuItem.Text = "Change Thing Index";
+			this.changeThingIndexToolStripMenuItem.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// changeSectorIndexToolStripMenuItem
+			// 
+			this.changeSectorIndexToolStripMenuItem.Name = "changeSectorIndexToolStripMenuItem";
+			this.changeSectorIndexToolStripMenuItem.Size = new System.Drawing.Size(223, 22);
+			this.changeSectorIndexToolStripMenuItem.Tag = "changemapelementindex";
+			this.changeSectorIndexToolStripMenuItem.Text = "Change Sector Index";
+			this.changeSectorIndexToolStripMenuItem.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttoncopyproperties
+			// 
+			this.buttoncopyproperties.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttoncopyproperties.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.CopyProperties;
+			this.buttoncopyproperties.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttoncopyproperties.Name = "buttoncopyproperties";
+			this.buttoncopyproperties.Size = new System.Drawing.Size(23, 22);
+			this.buttoncopyproperties.Tag = "classiccopyproperties";
+			this.buttoncopyproperties.Text = "Copy Properties";
+			this.buttoncopyproperties.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonpasteproperties
+			// 
+			this.buttonpasteproperties.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonpasteproperties.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.PasteProperties;
+			this.buttonpasteproperties.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonpasteproperties.Name = "buttonpasteproperties";
+			this.buttonpasteproperties.Size = new System.Drawing.Size(23, 22);
+			this.buttonpasteproperties.Tag = "classicpasteproperties";
+			this.buttonpasteproperties.Text = "Paste Properties";
+			this.buttonpasteproperties.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonpastepropertiesoptions
+			// 
+			this.buttonpastepropertiesoptions.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonpastepropertiesoptions.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.PastePropertiesOptions;
+			this.buttonpastepropertiesoptions.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonpastepropertiesoptions.Name = "buttonpastepropertiesoptions";
+			this.buttonpastepropertiesoptions.Size = new System.Drawing.Size(23, 22);
+			this.buttonpastepropertiesoptions.Tag = "classicpastepropertieswithoptions";
+			this.buttonpastepropertiesoptions.Text = "Paste Properties Special...";
+			this.buttonpastepropertiesoptions.TextAlign = System.Drawing.ContentAlignment.TopRight;
+			this.buttonpastepropertiesoptions.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonMakeDoor
+			// 
+			this.buttonMakeDoor.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonMakeDoor.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.Door;
+			this.buttonMakeDoor.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonMakeDoor.Name = "buttonMakeDoor";
+			this.buttonMakeDoor.Size = new System.Drawing.Size(23, 22);
+			this.buttonMakeDoor.Tag = "makedoor";
+			this.buttonMakeDoor.Text = "Make Door From Selection";
+			this.buttonMakeDoor.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonbrightnessgradient
+			// 
+			this.buttonbrightnessgradient.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonbrightnessgradient.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.BrightnessGradient;
+			this.buttonbrightnessgradient.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonbrightnessgradient.Name = "buttonbrightnessgradient";
+			this.buttonbrightnessgradient.Size = new System.Drawing.Size(23, 22);
+			this.buttonbrightnessgradient.Tag = "gradientbrightness";
+			this.buttonbrightnessgradient.Text = "Make Brightness Gradient";
+			this.buttonbrightnessgradient.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonfloorgradient
+			// 
+			this.buttonfloorgradient.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonfloorgradient.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.FloorsGradient;
+			this.buttonfloorgradient.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonfloorgradient.Name = "buttonfloorgradient";
+			this.buttonfloorgradient.Size = new System.Drawing.Size(23, 22);
+			this.buttonfloorgradient.Tag = "gradientfloors";
+			this.buttonfloorgradient.Text = "Make Floor Heights Gradient";
+			this.buttonfloorgradient.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonceilinggradient
+			// 
+			this.buttonceilinggradient.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonceilinggradient.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.CeilsGradient;
+			this.buttonceilinggradient.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonceilinggradient.Name = "buttonceilinggradient";
+			this.buttonceilinggradient.Size = new System.Drawing.Size(23, 22);
+			this.buttonceilinggradient.Tag = "gradientceilings";
+			this.buttonceilinggradient.Text = "Make Ceiling Heights Gradient";
+			this.buttonceilinggradient.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonflipselectionh
+			// 
+			this.buttonflipselectionh.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonflipselectionh.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.FlipSelectionH;
+			this.buttonflipselectionh.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonflipselectionh.Name = "buttonflipselectionh";
+			this.buttonflipselectionh.Size = new System.Drawing.Size(23, 22);
+			this.buttonflipselectionh.Tag = "flipselectionh";
+			this.buttonflipselectionh.Text = "Flip Selection Horizontally";
+			this.buttonflipselectionh.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonflipselectionv
+			// 
+			this.buttonflipselectionv.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonflipselectionv.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.FlipSelectionV;
+			this.buttonflipselectionv.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonflipselectionv.Name = "buttonflipselectionv";
+			this.buttonflipselectionv.Size = new System.Drawing.Size(23, 22);
+			this.buttonflipselectionv.Tag = "flipselectionv";
+			this.buttonflipselectionv.Text = "Flip Selection Vertically";
+			this.buttonflipselectionv.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttoncurvelinedefs
+			// 
+			this.buttoncurvelinedefs.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttoncurvelinedefs.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.CurveLines;
+			this.buttoncurvelinedefs.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttoncurvelinedefs.Name = "buttoncurvelinedefs";
+			this.buttoncurvelinedefs.Size = new System.Drawing.Size(23, 22);
+			this.buttoncurvelinedefs.Tag = "curvelinesmode";
+			this.buttoncurvelinedefs.Text = "Curve Linedefs";
+			this.buttoncurvelinedefs.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// syncthingteditbutton
+			// 
+			this.syncthingteditbutton.CheckOnClick = true;
+			this.syncthingteditbutton.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.syncthingteditbutton.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.SelectThingsInSectors;
+			this.syncthingteditbutton.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.syncthingteditbutton.Name = "syncthingteditbutton";
+			this.syncthingteditbutton.Size = new System.Drawing.Size(23, 22);
+			this.syncthingteditbutton.Tag = "syncedthingedit";
+			this.syncthingteditbutton.Text = "Synchronized Things Editing";
+			this.syncthingteditbutton.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// buttonAlignThingsToWall
+			// 
+			this.buttonAlignThingsToWall.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+			this.buttonAlignThingsToWall.Image = global::CodeImp.DoomBuilder.BuilderModes.Properties.Resources.AlignThings;
+			this.buttonAlignThingsToWall.ImageTransparentColor = System.Drawing.Color.Magenta;
+			this.buttonAlignThingsToWall.Name = "buttonAlignThingsToWall";
+			this.buttonAlignThingsToWall.Size = new System.Drawing.Size(23, 22);
+			this.buttonAlignThingsToWall.Tag = "thingaligntowall";
+			this.buttonAlignThingsToWall.ToolTipText = "Align Things to Nearest Linedef";
+			this.buttonAlignThingsToWall.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
+			// changeVertexIndexToolStripMenuItem
+			// 
+			this.changeVertexIndexToolStripMenuItem.Name = "changeVertexIndexToolStripMenuItem";
+			this.changeVertexIndexToolStripMenuItem.Size = new System.Drawing.Size(182, 22);
+			this.changeVertexIndexToolStripMenuItem.Tag = "changemapelementindex";
+			this.changeVertexIndexToolStripMenuItem.Text = "Change Vertex Index";
+			this.changeVertexIndexToolStripMenuItem.Click += new System.EventHandler(this.InvokeTaggedAction);
+			// 
 			// MenusForm
 			// 
 			this.AutoScaleDimensions = new System.Drawing.SizeF(96F, 96F);
@@ -1066,5 +1106,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		private System.Windows.Forms.ToolStripMenuItem itemsoundradii;
 		private System.Windows.Forms.ToolStripButton buttonTextureOffset3DFloorLock;
 		private System.Windows.Forms.ToolStripMenuItem selectionToImageToolStripMenuItem;
+		private System.Windows.Forms.ToolStripMenuItem changeLindefIndexToolStripMenuItem;
+		private System.Windows.Forms.ToolStripMenuItem changeThingIndexToolStripMenuItem;
+		private System.Windows.Forms.ToolStripMenuItem changeSectorIndexToolStripMenuItem;
+		private System.Windows.Forms.ToolStripMenuItem changeVertexIndexToolStripMenuItem;
 	}
 }

Source/Plugins/BuilderModes/Resources/Actions.cfg

@@ -1551,4 +1551,14 @@ applycamerarotationtothings
 	allowkeys =  true;
 	allowmouse = true;
 	allowscroll = false;
+}
+
+changemapelementindex
+{
+	title = "Change Map Element Index";
+	category = "linedefs";
+	description = "Changes the index of the highlighted or selected vertex, linedef, sector, or thing. Only works on a single map element. It will shift all indices between the old and new index.";
+	allowkeys = true;
+	allowmouse = true;
+	allowscroll = false;
 }