Dear ImGui with Glium and Winit: Cross Platform Desktop GUI Development (Rust)

Building desktop GUI apps that work consistently across different operating systems presents several technical challenges. Dear ImGui combined with Glium and Winit provides a technical stack for cross-platform development.

ImGui's immediate mode architecture regenerates the interface for each frame.

Glium handles OpenGL context management across Windows, macOS, and Linux. (Please note: Glium is no longer under active development as of Aug 2016. Refer to Glium post-mortem.)

Winit handles window creation, and input processing.

This post examines a basic "Hello World" implementation using ImGui, Glium and Winit on the three major desktop platforms. The application demonstrates a simple counter interface with color customization and framerate display.

Below, you'll find screenshots of the application running on Windows, macOS, and Linux. Each screenshot is paired with the corresponding OS task manager and file explorer, showing memory, CPU utilization and file size on different operating systems. These comparisons provide insight into how the same codebase performs across different desktop environments.

From a technical perspective, the combination approach of ImGui, Glium and Winit represents one of two major GUI programming paradigms: immediate mode (used by ImGui) versus retained mode (used by frameworks like GTK, Qt, and WPF).

In immediate mode, the entire UI is regenerated each frame and state is managed by the application, leading to a more direct programming model but potentially higher CPU usage. Retained mode frameworks maintain a persistent widget hierarchy and internal state, which can be more efficient for complex interfaces.

The performance metrics from the task managers reveal this tradeoff—the ImGui application uses more CPU due to constant redrawing. Developers should consider these tradeoffs when choosing between immediate mode libraries like ImGui and traditional retained mode frameworks for cross-platform desktop applications.