wilhelm_renderer_imgui

Dear ImGui integration for the wilhelm_renderer stack.

Bundles Dear ImGui v1.91.8 with the GLFW and OpenGL3 backends, compiled as a static library with C FFI wrappers for Rust.

Architecture

wilhelm_renderer_imgui is a sibling of wilhelm_renderer — neither depends on the other. Both depend on wilhelm_renderer_sys, which bundles GLFW and provides the shared window/OpenGL context. Your application combines them: it asks wilhelm_renderer for a window, then hands the GLFW window pointer to ImGui::new.

┌─────────────────────────────────────────────────────────────┐
│                    Application                              │
├──────────────────────────┬──────────────────────────────────┤
│   wilhelm_renderer       │   wilhelm_renderer_imgui         │
│   (App, Window,          │   (Dear ImGui + GLFW/GL3         │
│    Renderer, Color,      │    backends)                     │
│    graphics2d)           │                                  │
├──────────────────────────┴──────────────────────────────────┤
│   wilhelm_renderer_sys (FFI + bundled GLFW/FreeType/glad)   │
├─────────────────────────────────────────────────────────────┤
│   OpenGL (system)                                           │
└─────────────────────────────────────────────────────────────┘

Installation

Add both sibling crates to your Cargo.toml:

[dependencies]
wilhelm_renderer = "0.12"
wilhelm_renderer_imgui = "0.9"

The two crates must agree on the underlying wilhelm_renderer_sys version (they share one statically-linked libglfw3.a). The published versions above are pinned to compatible sys versions; if you override either dependency, ensure both transitively pull in the same wilhelm_renderer_sys.

Build Requirements

• C++ compiler and CMake
• Linux: libgl1-mesa-dev
• Dear ImGui is bundled — no external ImGui dependency needed
• GLFW is supplied by wilhelm_renderer_sys — no system GLFW required

Usage

use std::cell::RefCell;
use std::rc::Rc;

use wilhelm_renderer::core::{App, Color, Window};
use wilhelm_renderer::graphics2d::shapes::{ShapeKind, ShapeRenderable, ShapeStyle, Triangle};
use wilhelm_renderer_imgui::ImGui;

fn main() {
    let window = Window::new("Demo", 800, 600, Color::from_rgb(0.1, 0.1, 0.15));
    let mut app = App::new(window);

    // Add a triangle
    let mut triangle = ShapeRenderable::from_shape(
        ShapeKind::Triangle(Triangle::new([
            (-100.0, 50.0), (100.0, 50.0), (0.0, -100.0),
        ])),
        ShapeStyle::fill(Color::from_rgb(0.2, 0.6, 0.9)),
    );
    triangle.set_position(400.0, 300.0);
    app.add_shape(triangle);

    // Initialize ImGui
    let imgui = ImGui::new(app.window.glfw_window_ptr(), true);

    // Shared state (modified by ImGui, read by pre_render)
    let pos_x = Rc::new(RefCell::new(400.0f32));
    let pos_y = Rc::new(RefCell::new(300.0f32));
    let scale = Rc::new(RefCell::new(1.0f32));

    let (pos_x_update, pos_y_update, scale_update) =
        (Rc::clone(&pos_x), Rc::clone(&pos_y), Rc::clone(&scale));

    // Update shape properties before rendering
    app.on_pre_render(move |shapes, _| {
        if let Some(shape) = shapes.first_mut() {
            shape.set_position(*pos_x_update.borrow(), *pos_y_update.borrow());
            shape.set_scale(*scale_update.borrow());
        }
    });

    // ImGui controls
    app.on_render(move |_renderer, _camera| {
        imgui.new_frame();

        imgui.begin("Shape Controls", None, 0);
        imgui.text("Position");
        imgui.slider_float("X", &mut pos_x.borrow_mut(), 0.0, 800.0);
        imgui.slider_float("Y", &mut pos_y.borrow_mut(), 0.0, 600.0);
        imgui.separator();
        imgui.text("Transform");
        imgui.slider_float("Scale", &mut scale.borrow_mut(), 0.1, 3.0);
        imgui.end();

        imgui.render();
    });

    app.run();
}

Available Widgets

• Windows: begin, end, set_next_window_pos/size
• Text/Buttons: text, button, checkbox
• Sliders/Input: slider_float/int, input_float/int
• Color: color_edit3/4
• Layout: same_line, separator, spacing, indent
• Tree: tree_node, tree_pop
• Combo: begin_combo, end_combo, selectable
• Menu: begin_main_menu_bar, begin_menu, menu_item
• Tables: begin_table, table_next_row/column, table_setup_column
• Popups: begin_popup, open_popup, close_current_popup
• Demo: show_demo_window

Example

Run the interactive demo:

cargo run --example demo

License

MIT