Crate imgui_winit_support

This crate provides support functions to simplify integrating imgui-rs with winit.

Using the library

In your initialization code call configure_keys:

use imgui::ImGui;

let mut imgui = ImGui::init();
imgui_winit_support::configure_keys(&mut imgui);

In your main loop you should already be retrieving events from winit and handling them. All you need to do is pass each event to imgui_winit_support as well:

events_loop.poll_events(|event| {
    // do application-specific stuff with event

    imgui_winit_support::handle_event(
        &mut imgui,
        &event,
        window_hidpi_factor,
        app_hidpi_factor
    );
});

Advanced use cases

In more advanced use cases you might want to handle and filter events yourself and call some of the various smaller helper functions exported by the library.

For example, you might want to customize mouse wheel line scrolling amount:

events_loop.poll_events(|event| {
    // do application-specific stuff with event

    // default handling for events
    imgui_winit_support::handle_event(
        &mut imgui,
        &event,
        window_hidpi_factor,
        app_hidpi_factor
    );

    // Scroll 10 times the pixels per line by handling LineDelta events again and
    // overriding the mouse wheel value
    if let Event::WindowEvent { event, .. } = event {
        match event {
            WindowEvent::MouseWheel {
                delta: MouseScrollDelta::LineDelta(_, lines),
                phase: TouchPhase::Moved,
                ..
            } => {
                imgui.set_mouse_wheel(lines * 10.0);
            }
            _ => ()
        }
    }
});

Functions

configure_keys	Configure imgui key map with winit VirtualKeyCode values
get_frame_size	Get the current frame size for imgui frame rendering.
handle_event	Update imgui state from winit event
handle_keyboard_input	Update imgui keyboard state
handle_modifiers	Update imgui keyboard modifier state
handle_mouse_button_state	Update imgui mouse button state
handle_mouse_scroll_delta	Update imgui mouse wheel position
handle_window_event	Update imgui state from winit window event
update_mouse_cursor	Update winit window mouse cursor state