* Massive UI change from WinForms to WPF.

* Now requires C# 7.2, .NET 4.6.2, most likely needs to be built with Visual Studio 2017.
* Utilizes PostSharp, primarily for INotifyPropertyChanged support and some required contracts. (You do not need a license to build unless you change something yourself.)
* Included Roboto Mono font for the text boxes.
* Rebuilt wall images.
* Nicer About dialog box.
* More caching being done.
* Utilized asynchronous methods, which allowed for a "throbber" of sorts to be used.
* Added a loading overlay for the above.
* Split a few objects into their own files.
* Added a display of the selected color to the Color to Wall controls.
* Used DebuggerDisplay over ToString in many places.
* Partially fixed the issue with the way walls were being rendered, rand.Next(0, 2) would only get a 0 or a 1, 2 was never picked. Still seems off from the actual game, though.
* Switched to PackageReference over packages.config.
* Made it so the process to regenerate the wall images edits the project file directly, as resources were changed to comply with WPF's way of embedding resources.
* Updated README to include updates and listing what 3rd-party resources I used.
* Updated copyright year.
* Included a program icon (it is just Terraria's actual icon).
* Included a nice unhandled exception window, as WPF doesn't have one like WinForms does.

.gitignore

@@ -1,13 +1,9 @@
-.vs/
+# User-specific files
+*.user
+
+# Build results
 [Bb]in/
 [Oo]bj/
 
-# NuGet Packages
-*.nupkg
-# The packages folder can be ignored because of Package Restore
-**/packages/*
-# except build/, which is used as an MSBuild target.
-!**/packages/build/
-# NuGet v3's project.json files produces more ignorable files
-*.nuget.props
-*.nuget.targets
+# Visual Studio 2015/2017 cache/options directory
+.vs/

About.xaml

@@ -0,0 +1,75 @@
+<Window x:Class="TerrariaPixelArtHelper.About"
+		xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+		xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:local="clr-namespace:TerrariaPixelArtHelper"
+		xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+		Title="About"
+		FocusManager.FocusedElement="{Binding ElementName=okButton, Mode=OneTime}"
+		ResizeMode="NoResize" ShowInTaskbar="False"
+		SizeToContent="WidthAndHeight" WindowStartupLocation="CenterOwner"
+		WindowStyle="ThreeDBorderWindow"
+		mc:Ignorable="d">
+	<Window.Background>
+		<SolidColorBrush Color="{StaticResource {x:Static SystemColors.ControlColorKey}}" />
+	</Window.Background>
+	<StackPanel Margin="10">
+		<Label Padding="0"
+			   Content="{x:Static local:About.Version}"
+			   ContentStringFormat="Terraria Pixel Art Helper v{0} by: Naram Qashat (CyberBotX)" />
+		<TextBlock>
+			<Hyperlink NavigateUri="https://github.com/CyberBotX/TerrariaPixelArtHelper" RequestNavigate="Hyperlink_RequestNavigate">https://github.com/CyberBotX/TerrariaPixelArtHelper</Hyperlink>
+		</TextBlock>
+		<ContentControl Content="{StaticResource Lines}" />
+		<TextBlock>
+			<Run>Terraria is copyright to</Run>
+			<Hyperlink NavigateUri="https://re-logic.com/" RequestNavigate="Hyperlink_RequestNavigate">Re-Logic</Hyperlink>
+		</TextBlock>
+		<TextBlock Text="Program icon comes from Terraria" />
+		<ContentControl Content="{StaticResource Lines}" />
+		<TextBlock Text="Uses the font Roboto Mono by: Christian Robertson" />
+		<TextBlock>
+			<Hyperlink NavigateUri="https://fonts.google.com/specimen/Roboto+Mono" RequestNavigate="Hyperlink_RequestNavigate">https://fonts.google.com/specimen/Roboto+Mono</Hyperlink>
+		</TextBlock>
+		<ContentControl Content="{StaticResource Lines}" />
+		<GroupBox>
+			<GroupBox.BorderBrush>
+				<SolidColorBrush Color="{StaticResource {x:Static SystemColors.ControlDarkDarkColorKey}}" />
+			</GroupBox.BorderBrush>
+			<GroupBox.Header>
+				<TextBlock Height="17" Text="Utilizes the following libraries:" />
+			</GroupBox.Header>
+			<!-- Idea for AlternationCount and DataTemplate.Triggers comes from https://stackoverflow.com/a/34138980 -->
+			<ItemsControl Margin="2"
+						  AlternationCount="{Binding Items.Count, RelativeSource={RelativeSource Self}, Mode=OneWay}"
+						  ItemsSource="{Binding Source={x:Static local:About.Libraries}, Mode=OneWay}">
+				<ItemsControl.ItemTemplate>
+					<DataTemplate>
+						<StackPanel>
+							<ContentControl x:Name="Separator" Content="{StaticResource Lines}" />
+							<StackPanel Orientation="Horizontal">
+								<TextBlock Text="{Binding Library, Mode=OneWay}" />
+								<TextBlock Text=" v" />
+								<TextBlock Text="{Binding Version, Mode=OneWay}" />
+								<TextBlock Text=" by: " />
+								<TextBlock Text="{Binding Author, Mode=OneWay}" />
+							</StackPanel>
+							<TextBlock>
+								<Hyperlink NavigateUri="{Binding Url, Mode=OneWay}" RequestNavigate="Hyperlink_RequestNavigate">
+									<Run Text="{Binding Url, Mode=OneWay}" />
+								</Hyperlink>
+							</TextBlock>
+						</StackPanel>
+						<DataTemplate.Triggers>
+							<Trigger Property="ItemsControl.AlternationIndex" Value="0">
+								<Setter TargetName="Separator" Property="Visibility" Value="Collapsed" />
+							</Trigger>
+						</DataTemplate.Triggers>
+					</DataTemplate>
+				</ItemsControl.ItemTemplate>
+			</ItemsControl>
+		</GroupBox>
+		<Button x:Name="okButton"
+				Width="50"
+				Margin="0,5,0,0"
+				Click="OK_Click" Content="OK" />
+	</StackPanel>
+</Window>

About.xaml.cs

@@ -0,0 +1,82 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Windows;
+using System.Windows.Navigation;
+
+/// <remarks>
+/// See Program.cs for license.
+/// </remarks>
+namespace TerrariaPixelArtHelper
+{
+	/// <summary>
+	/// Interaction logic for About.xaml
+	/// </summary>
+	public partial class About : Window
+	{
+		public static List<LibraryData> Libraries = new List<LibraryData>()
+		{
+			new LibraryData()
+			{
+				Library = "CalcBinding",
+				Version = typeof(CalcBinding.Binding).Assembly.GetName().Version,
+				Author = "Alexander Zinchenko",
+				Url = "https://github.com/Alex141/CalcBinding"
+			},
+			new LibraryData()
+			{
+				Library = "FontAwesome5",
+				Version = typeof(FontAwesome5.WPF.FontAwesome).Assembly.GetName().Version,
+				Author = "Codinion",
+				Url = "https://github.com/MartinTopfstedt/FontAwesome5"
+			},
+			new LibraryData()
+			{
+				Library = "JeremyAnsel.ColorQuant",
+				Version = typeof(JeremyAnsel.ColorQuant.WuColorQuantizer).Assembly.GetName().Version,
+				Author = "Jérémy Ansel",
+				Url = "https://github.com/JeremyAnsel/JeremyAnsel.ColorQuant"
+			},
+			new LibraryData()
+			{
+				Library = "Math.NET Numerics",
+				Version = typeof(MathNet.Numerics.Constants).Assembly.GetName().Version,
+				Author = "Christoph Ruegg, Marcus Cuda, Jurgen Van Gael",
+				Url = "https://numerics.mathdotnet.com/"
+			},
+			new LibraryData()
+			{
+				Library = "PostSharp",
+				Version = typeof(PostSharp.Post).Assembly.GetName().Version,
+				Author = "PostSharp Technologies",
+				Url = "https://www.postsharp.net/"
+			},
+			new LibraryData()
+			{
+				Library = "WriteableBitmapEx",
+				Version = typeof(System.Windows.Media.Imaging.BitmapFactory).Assembly.GetName().Version,
+				Author = "Schulte Software Development",
+				Url = "https://github.com/teichgraf/WriteableBitmapEx"
+			}
+		};
+
+		public static Version Version = typeof(About).Assembly.GetName().Version;
+
+		public About() => this.InitializeComponent();
+
+		void OK_Click(object sender, RoutedEventArgs e) => this.Close();
+
+		void Hyperlink_RequestNavigate(object sender, RequestNavigateEventArgs e) => Process.Start(e.Uri.ToString());
+	}
+
+	public class LibraryData
+	{
+		public string Author { get; set; }
+
+		public string Library { get; set; }
+
+		public Version Version { get; set; }
+
+		public string Url { get; set; }
+	}
+}

App.xaml

@@ -0,0 +1,22 @@
+<Application x:Class="TerrariaPixelArtHelper.App"
+			 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+			 DispatcherUnhandledException="Application_DispatcherUnhandledException" StartupUri="MainWindow.xaml">
+	<Application.Resources>
+		<FontFamily x:Key="RobotoMono">pack://application:,,,/Fonts/RobotoMono/#Roboto Mono</FontFamily>
+		<StackPanel x:Key="Lines"
+					Margin="0,5"
+					x:Shared="False">
+			<Line Height="1"
+				  Stroke="White"
+				  X2="{Binding ActualWidth, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type StackPanel}}}" />
+			<Line Height="1" X2="{Binding ActualWidth, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type StackPanel}}}">
+				<Line.Stroke>
+					<SolidColorBrush Color="{StaticResource {x:Static SystemColors.ControlDarkDarkColorKey}}" />
+				</Line.Stroke>
+			</Line>
+			<Line Height="1"
+				  Stroke="White"
+				  X2="{Binding ActualWidth, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type StackPanel}}}" />
+		</StackPanel>
+	</Application.Resources>
+</Application>