A modern C# wrapper library that simplifies creating ImGui applications with OpenGL rendering and GLFW window management.

About

C.ImGuiGLFW is a C# class library that simplifies the creation of ImGui-rendered windows. It uses OpenGL 4.6 core for rendering, GLFW for window management system, and Hexa.NET.ImGui for ImGui integration.

Requirements

• .NET 9.0 or higher
• Windows (tested), macOS and Linux (untested)
• OpenGL 4.6 compatible graphics driver

Installation

Get C.ImGuiGLFW from NuGet using one of the following methods:

.NET CLI (Recommended)

dotnet add package C.ImGuiGLFW

Use this command in terminal/command prompt. Works on Windows, macOS, and Linux.

Package Manager Console

Install-Package C.ImGuiGLFW

Use this command in Visual Studio's Package Manager Console (Windows only).

NuGet Package Manager GUI

Alternatively, you can install via the graphical interface in Visual Studio or your preferred IDE by searching for "C.ImGuiGLFW".

Basic Setup

Initialize the ImGuiController in the Main() method of your program:

ImGuiController.Initialize("MyApplication", modules: Module.All);

The Initialize method has multiple overloads to accommodate different initialization scenarios:

// Basic initialization with default settings ImGuiController.Initialize(); // Initialize with modules ImGuiController.Initialize(modules: Module.All); // Initialize with window title ImGuiController.Initialize("MyApp"); // Initialize with title and modules ImGuiController.Initialize("MyApp", Module.All); // Initialize with title and dimensions ImGuiController.Initialize("MyApp", 800, 600); // Initialize with title, dimensions, and modules ImGuiController.Initialize("MyApp", 800, 600, Module.All); // Initialize with dimensions only ImGuiController.Initialize(800, 600); // Initialize with dimensions and modules ImGuiController.Initialize(800, 600, Module.All); // Initialize with dimensions and position ImGuiController.Initialize(800, 600, new Vector2(100, 100)); // Initialize with dimensions, position, and modules ImGuiController.Initialize(800, 600, new Vector2(100, 100), Module.Guizmo); // Initialize with dimensions, position, and resizable flag ImGuiController.Initialize(800, 600, new Vector2(100, 100), true); // Initialize with dimensions, position, resizable flag, and modules ImGuiController.Initialize(800, 600, new Vector2(100, 100), true, Module.Nodes, Module Plot); // Initialize with dimensions and position coordinates ImGuiController.Initialize(800, 600, 100, 100); // Initialize with dimensions, position coordinates, and modules ImGuiController.Initialize(800, 600, 100, 100, Module.Plot); // Initialize with custom WindowSettings ImGuiController.Initialize(windowSettings); // Initialize with custom WindowSettings and modules ImGuiController.Initialize(windowSettings, Module.All);

Parameters:

• windowSettings: Custom window settings (optional, reads from file if null)
• title: Window title
• width/height: Window dimensions in pixels
• position: Window position as Vector2 or separate X/Y coordinates
• resizable: Whether the window should be resizable
• modules: ImGui modules to initialize (optional params array)

Event Handling

Subscribe to various events to handle user input and UI rendering:

// Handle main menu bar rendering ImGuiController.OnMainMenuBarRender += MainMenuBar; // Handle character input events ImGuiController.OnChar += OnCharInput;

Custom Font Loading

Important: All custom font loading must be completed before calling ImGuiController.Run(). Font additions are not accepted after the application starts running.

If you want to load custom fonts with priority over the built-in fonts, use the FontBuilder before calling ImGuiController.Run():

// Initialize first (optional - can be done before or after font setup) ImGuiController.Initialize("MyApplication"); // Add fonts from TTF files ImGuiController.FontBuilder.AddFontFromFileTTF("path/to/font.ttf", 16.0f); ImGuiController.FontBuilder.AddFontFromFileTTF("path/to/font.ttf", 16.0f, glyphRanges); // Add fonts from embedded resources ImGuiController.FontBuilder.AddFontFromEmbeddedResource(assembly, "Fonts.MyFont.ttf", 16.0f); ImGuiController.FontBuilder.AddFontFromEmbeddedResource(assembly, "Fonts.MyFont.ttf", 16.0f, glyphRanges); // Add fonts from memory ImGuiController.FontBuilder.AddFontFromMemoryTTF(fontData, 16.0f, glyphRanges); // Run - no more default font additions possible after this point ImGuiController.Run();

Available Font Loading Methods

The FontBuilder provides several methods to load custom fonts:

From File System:

• AddFontFromFileTTF(string filePath, float fontSize) - Load TTF font from disk
• AddFontFromFileTTF(string filePath, float fontSize, ReadOnlySpan<uint> glyphRanges) - Load TTF font with custom glyph ranges

From Embedded Resources:

• AddFontFromEmbeddedResource(Assembly assembly, string path, float size) - Load font from assembly resource
• AddFontFromEmbeddedResource(Assembly assembly, string path, float size, ReadOnlySpan<uint> glyphRanges) - Load with custom glyph ranges

From Memory:

• AddFontFromMemoryTTF(ReadOnlySpan<byte> fontData, float size, ReadOnlySpan<uint> glyphRanges) - Load font directly from memory

Note: Specifying custom glyph ranges can reduce memory usage by loading only the required characters.

Controlling Built-in Font Loading

If you don't want to load the built-in fonts, you can disable them by setting the following properties to false (default is true):

// Disable specific built-in fonts ImGuiController.FontBuilder.AddNotoSansFont = false; ImGuiController.FontBuilder.AddFontAwesomeFont = false; ImGuiController.FontBuilder.AddEmojiFont = false; ImGuiController.FontBuilder.AddDefaultFont = false; // ImGui's default font

Note: Built-in fonts are automatically added after all custom fonts have been loaded, but only if their respective properties are set to true.

Font Loading Order

1. Custom fonts added via:
   • AddFontFromFileTTF()
   • AddFontFromEmbeddedResource()
   • AddFontFromMemoryTTF()
2. Built-in fonts (if enabled):
   • Noto Sans Font
   • Font Awesome Font
   • Emoji Font
   • ImGui Default Font

Adding Windows

Create and add your custom ImGui windows:

var demoWindow = new DemoWindow(); ImGuiController.AddWindow(demoWindow);

Running the Application

Start the main application loop:

ImGuiController.Run();

Example

Here's a minimal example:

using System; using C.ImGuiGLFW; class Program { static void Main() { // Initialize ImGuiController ImGuiController.Initialize("TESTWINDOW"); // Set up event handlers ImGuiController.OnMainMenuBarRender += MainMenuBar; ImGuiController.OnChar += OnCharInput; // Create and add windows var demoWindow = new DemoWindow(); ImGuiController.AddWindow(demoWindow); // Start the application ImGuiController.Run(); } private static void MainMenuBar() { // Your main menu bar implementation } private static void OnCharInput(uint codepoint) { // Handle character input } }

Creating Custom Windows

To create custom windows, implement the appropriate window interface or base class:

public class DemoWIndow : Window { protected override void Draw() { ImGui.Text("Hello, World!"); } }

Available Modules

The Module enum allows you to specify which ImGui modules to initialize:

• Module.All: Load all available modules
• Module.Guizmo: ImGuizmo for 3D gizmo manipulation
• Module.Nodes: ImNodes for node-based graph editing
• Module.Plot: ImPlot for data plotting and visualization

Multiple modules can be specified:

// Load specific modules ImGuiController.Initialize("MyApp", Module.Guizmo, Module.Plot); // Load all modules (equivalent to Module.All) ImGuiController.Initialize("MyApp", Module.Guizmo, Module.Nodes, Module.Plot);

More Examples

For more detailed examples and advanced usage patterns, please visit the here.

Feedback and Contributions

I welcome your feedback and contributions to make C.ImGuiGLFW even better! If you have:

Feature requests - Ideas for new functionality or improvements Bug reports - Issues you've encountered while using the library Method suggestions - Additional methods or overloads you'd find useful

Please feel free to submit an issue or pull request on the GitHub repository.

Your contributions help improve the library for everyone who uses it. I appreciate bug reports, feature suggestions, code improvements, and documentation enhancements.

Dependencies

This project depends on several NuGet packages. Run dotnet list package to see current versions, or check THIRD-PARTY-NOTICES for license details.

Acknowledgments

This project builds upon the excellent work of many open source contributors:

Core Technologies

• Dear ImGui by Omar Cornut - The amazing immediate mode GUI library that makes this all possible
• GLFW - Multi-platform library for OpenGL, Vulkan, window and input
• OpenGL - The cross-platform graphics API

.NET Bindings & Utilities

• Hexa.NET Libraries by Juna Meinhold - Comprehensive .NET bindings for ImGui, GLFW, OpenGL and related libraries
  • Hexa.NET.ImGui - C# bindings for Dear ImGui
  • Hexa.NET.GLFW - C# bindings for GLFW
  • Hexa.NET.OpenGL - C# bindings for OpenGL
  • Hexa.NET.ImGuizmo - C# bindings for ImGuizmo
  • Hexa.NET.ImNodes - C# bindings for ImNodes
  • Hexa.NET.ImPlot - C# bindings for ImPlot

Web Browser Integration

• CefSharp - .NET bindings for the Chromium Embedded Framework (CEF)
  • Enables embedding modern web browser functionality within .NET applications
  • Provides headless browser capabilities for web content rendering

Additional Libraries

• ImGuizmo by Cédric Guillemet - 3D gizmo for scene editing
• ImNodes by Nelarius - Node editor for Dear ImGui
• ImPlot by Evan Pezent - Advanced plotting library for ImGui
• Serilog - Flexible logging library for .NET
• SixLabors.ImageSharp - Cross-platform image processing library

Microsoft Technologies

• .NET - The platform this library runs on
• Microsoft.CodeAnalysis - The .NET Compiler Platform ("Roslyn")

Special thanks to all the maintainers and contributors of these projects for making modern cross-platform GUI development in C# possible.