Dear ImGui Rust Bindings

Modern Rust bindings for Dear ImGui with full Dear ImGui v1.92+ support, including dynamic font system, advanced docking, and modern texture management.

Overview

This project provides comprehensive Rust bindings for Dear ImGui v1.92+, featuring:

• Dear ImGui v1.92+ Support: Full support for the latest Dear ImGui features including dynamic font loading, ImGuiBackendFlags_RendererHasTextures, and modern texture management
• Dynamic Font System: On-demand glyph loading, runtime font size adjustment, and custom font loaders (FreeType support)
• Advanced Docking: Complete window docking and layout management with DockSpace API
• Modern Backends: WGPU v26, OpenGL via glow, with automatic texture lifecycle management
• Type Safety: Memory-safe Rust wrappers with zero-cost abstractions
• Cross-Platform: Windows, Linux, macOS support

Note: Multi-viewport support is not currently implemented but may be added in future releases.

Key Features

• Complete Widget Set: All Dear ImGui widgets with type-safe Rust APIs
• Advanced Tables: Sorting, filtering, resizing, and custom rendering
• Custom Drawing: Full DrawList API for custom graphics
• Comprehensive Styling: Theme system with runtime style modifications
• Input Handling: Keyboard, mouse, gamepad with callback support

Crates

dear-imgui/
├── dear-imgui/          # High-level safe Rust bindings
├── dear-imgui-sys/      # Low-level FFI bindings to Dear ImGui C++
├── backends/
│   ├── dear-imgui-wgpu/    # WGPU renderer backend
│   ├── dear-imgui-glow/    # OpenGL renderer backend
│   └── dear-imgui-winit/   # Winit platform integration
└── extensions/
    ├── dear-imguizmo/      # 3D gizmo manipulation (Work in progress)
    └── dear-implot/        # Advanced plotting library

Quick Start

Add to your Cargo.toml:

[dependencies]
dear-imgui = "0.1"
dear-imgui-wgpu = "0.1"
dear-imgui-winit = "0.1"

Basic WGPU example:

use dear_imgui::*;
use dear_imgui_wgpu::{WgpuRenderer, WgpuInitInfo};

let mut imgui = Context::create()?;
let mut renderer = WgpuRenderer::new(init_info, &mut imgui)?;

// Main loop
let ui = imgui.frame();
ui.window("Hello World")
    .size([300.0, 100.0], Condition::FirstUseEver)
    .build(|| {
        ui.text("Hello, world!");
        if ui.button("Click me") {
            println!("Button clicked!");
        }
    });

let draw_data = imgui.render();
renderer.render(&draw_data, &render_pass);

Examples

Run the included examples to see features in action:

cargo run --bin wgpu_basic           # Basic WGPU integration
cargo run --bin glow_basic           # Basic Glow integration
cargo run --bin game_engine_docking  # Advanced docking layout
cargo run --bin implot_basic         # Plotting with dear-implot

Installation

Add this to your Cargo.toml:

[dependencies]
dear-imgui = "0.1"
dear-imgui-wgpu = "0.1"  # For WGPU backend
dear-imgui-winit = "0.1" # For Winit integration

Or for OpenGL support:

[dependencies]
dear-imgui = "0.1"
dear-imgui-glow = "0.1"  # For OpenGL backend
dear-imgui-winit = "0.1" # For Winit integration

Architecture

Modern Texture Management

This library implements Dear ImGui v1.92+'s ImGuiBackendFlags_RendererHasTextures system, enabling:

• Automatic texture lifecycle management
• Dynamic font atlas resizing
• Backend-agnostic texture operations
• Memory-efficient texture streaming

FFI Layer (dear-imgui-sys)

Direct C++ FFI bindings with MSVC ABI compatibility fixes, handling complex return types and ensuring cross-platform stability.

Safe Layer (dear-imgui)

Type-safe Rust API featuring:

• Builder patterns for complex widgets
• RAII resource management
• Zero-cost abstractions over C++ types
• Comprehensive error handling

Acknowledgments

This project builds upon the excellent work of several other projects:

• Dear ImGui by Omar Cornut - The original C++ immediate mode GUI library
• imgui-rs - Provided the API design patterns and inspiration for the Rust binding approach
• easy-imgui-rs by rodrigorc - Demonstrated solutions for C++ ABI compatibility issues and MSVC fixes that we adapted for our FFI layer
• imgui-wgpu-rs - Provided reference implementation for WGPU backend integration

License

This project is licensed under MIT OR Apache-2.0.

• Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (http://opensource.org/licenses/MIT)

Development Setup

git clone https://github.com/Latias94/dear-imgui
cd dear-imgui
git submodule update --init --recursive
cargo build
cargo test
cargo run --example wgpu_basic

Comparison with imgui-rs

Advantages:

• Dear ImGui v1.92+ support with dynamic fonts and modern texture management
• Built-in docking support
• Modern Rust ecosystem integration (wgpu v26, winit v0.30+)
• Direct C++ FFI without cimgui dependency
• Comprehensive MSVC ABI compatibility

Current Status:

• Production-ready for most use cases
• Active development with regular updates
• Growing ecosystem of extensions

Choose this library if you need the latest Dear ImGui features, docking support, or want to work with modern Rust graphics libraries.

Technical Details

MSVC ABI Compatibility

One of the key technical challenges in creating Rust bindings for C++ libraries is handling ABI (Application Binary Interface) compatibility issues. This is particularly problematic on MSVC where small C++ class return types can cause crashes.

Our solution, inspired by easy-imgui-rs, includes:

1. FFI-Safe Wrapper Types: Convert C++ types like ImVec2 to POD equivalents
2. C Wrapper Functions: Provide C-compatible interfaces for problematic functions
3. Conditional Compilation: Apply fixes only where needed (MSVC targets)
4. Selective Function Blocking: Block problematic functions during bindgen and provide manual implementations

See dear-imgui-sys/README.md for detailed technical information.