README.md

This is a simple example using imgui 1.80 with rust. It is copied from somewhere (sorry!) and fixed such that it would work. The dependency mess is also needed beause... not sure why it is so broken without it.

Cargo.toml

[package]
name = "imgui_test"
version = "0.1.0"
edition = "2021"

[dependencies]

imgui = "0.7.0"
#imgui-winit = { version = "0.1.2"}
imgui-winit-support = { version = "0.7.0" }
#winit = { version = "0.27.2", features = ["x11"] }

winit = { version = "0.24.0" }

imgui-glium-renderer = "0.7.0"
glium = { version = "0.29.1", default-features = true }

main.rs

use glium::glutin::event::{Event, WindowEvent};
use glium::glutin::event_loop::{ControlFlow, EventLoop};
use glium::Surface;

const TITLE: &str = "Hello, imgui-rs!";

fn main() {
    // Common setup for creating a winit window and imgui context, not specifc
    // to this renderer at all except that glutin is used to create the window
    // since it will give us access to a GL context
    let (event_loop, display) = create_window();
    let (mut winit_platform, mut imgui_context) = imgui_init(&display);

    // Create renderer from this crate
    let mut renderer = imgui_glium_renderer::Renderer::init(&mut imgui_context, &display)
        .expect("Failed to initialize renderer");

    // Timer for FPS calculation
    let mut last_frame = std::time::Instant::now();

    // Standard winit event loop
    event_loop.run(move |event, _, control_flow| match event {
        Event::NewEvents(_) => {
            let now = std::time::Instant::now();
            imgui_context.io_mut().update_delta_time(now - last_frame);
            last_frame = now;
        }
        Event::MainEventsCleared => {
            let gl_window = display.gl_window();
            winit_platform
                .prepare_frame(imgui_context.io_mut(), gl_window.window())
                .expect("Failed to prepare frame");
            gl_window.window().request_redraw();
        }
        Event::RedrawRequested(_) => {
            // Create frame for the all important `&imgui::Ui`
            let ui = imgui_context.frame();

            // Draw our example content
            ui.show_demo_window(&mut true);

            // Setup for drawing
            let gl_window = display.gl_window();
            let mut target = display.draw();

            // Renderer doesn't automatically clear window
            target.clear_color_srgb(1.0, 1.0, 1.0, 1.0);

            // Perform rendering
            winit_platform.prepare_render(&ui, gl_window.window());
            let draw_data = ui.render();
            renderer
                .render(&mut target, draw_data)
                .expect("Rendering failed");
            target.finish().expect("Failed to swap buffers");
        }
        Event::WindowEvent {
            event: WindowEvent::CloseRequested,
            ..
        } => *control_flow = ControlFlow::Exit,
        event => {
            let gl_window = display.gl_window();
            winit_platform.handle_event(imgui_context.io_mut(), gl_window.window(), &event);
        }
    });
}

fn create_window() -> (EventLoop<()>, glium::Display) {
    let event_loop = EventLoop::new();
    let context = glium::glutin::ContextBuilder::new().with_vsync(true);
    let builder = glium::glutin::window::WindowBuilder::new()
        .with_title(TITLE.to_owned())
        .with_inner_size(glium::glutin::dpi::LogicalSize::new(1024f64, 768f64));
    let display =
        glium::Display::new(builder, context, &event_loop).expect("Failed to initialize display");

    (event_loop, display)
}

fn imgui_init(display: &glium::Display) -> (imgui_winit_support::WinitPlatform, imgui::Context) {
    let mut imgui_context = imgui::Context::create();
    imgui_context.set_ini_filename(None);

    let mut winit_platform = imgui_winit_support::WinitPlatform::init(&mut imgui_context);

    let gl_window = display.gl_window();
    let window = gl_window.window();

    let dpi_mode = imgui_winit_support::HiDpiMode::Default;

    winit_platform.attach_window(imgui_context.io_mut(), window, dpi_mode);

    imgui_context
        .fonts()
        .add_font(&[imgui::FontSource::DefaultFontData { config: None }]);

    (winit_platform, imgui_context)
}