33c85bd62a
Same fixes as the previous commits (run no egui pass at all when
nothing will be shown), but the mechanisms are shared instead of
duplicated:
* `Context::run_frame(input, show_ui, f)` is the one entry point for
integrations: one `FramePhase::Logic` (always, outside any pass),
then one `FramePhase::Ui` per pass (none when `show_ui` is false).
`Context::run_logic` is now a thin wrapper around it, and the
logic-outside-of-pass sequencing lives in egui, not in each backend.
* egui itself buffers the input of pass-less frames
(`ViewportState::pending_raw_input`) and prepends it to the next
pass. This replaces `EpiIntegration::pending_raw_input` and the web
backend's `input.raw.append`, so an integration cannot lose input.
* `FullOutput` is now `{ platform_output, viewport_commands,
pass_output: Option<PassOutput> }`, and `LogicOutput` is gone.
One-shot viewport commands (imperative) are separated from
`ViewportOutput` (which viewports should exist - declarative), so
each backend has exactly one command-handling path, shared by frames
with and without a pass. `pass_output: None` encodes "no pass ran:
paint nothing, leave the viewports alone" in the type.
* The glow/wgpu `!show_ui` early-return blocks are gone: a hidden root
viewport flows through the same tail as a visible one, with the
paint and viewport-structure steps gated on `pass_output`.
Behavioral fixes that fall out:
* `App::logic` now sees the current window state in visible frames
too (it was one frame stale outside the hidden path).
* Auto-save keeps working while a window is minimized or occluded.
* Commands sent to a freshly created viewport apply in the same frame.
* The Wayland resize workaround now also covers commands from
pass-less frames.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
eframe: the egui framework
eframe is the official framework library for writing apps using egui. The app can be compiled both to run natively (for Linux, Mac, Windows, and Android) or as a web app (using Wasm).
To get started, see the examples.
To learn how to set up eframe for web and native, go to https://github.com/emilk/eframe_template/ and follow the instructions there!
There is also a tutorial video at https://www.youtube.com/watch?v=NtUkr_z7l84.
For how to use egui, see the egui docs.
eframe defaults to using wgpu for rendering (with an option to change to glow), and on native it uses egui-winit.
To use on Linux, first run:
sudo apt-get install libxcb-render0-dev libxcb-shape0-dev libxcb-xfixes0-dev libxkbcommon-dev libssl-dev
You need to either use edition = "2024", or set resolver = "2" in the [workspace] section of your to-level Cargo.toml. See this link for more info.
You can opt-in to the using egui_glow for rendering by enabling the glow feature and setting NativeOptions::renderer to Renderer::Glow.
Alternatives
eframe is not the only way to write an app using egui! You can also try egui-miniquad, bevy_egui, egui_sdl2_gl, and others.
You can also use egui_glow and winit to build your own app as demonstrated in https://github.com/emilk/egui/blob/main/crates/egui_glow/examples/pure_glow.rs.
Limitations when running egui on the web
eframe and egui compiles to Wasm using either WebGPU (when available) or WebGL2 for rendering, and almost nothing else from the web tech stack. This has some benefits, but also produces some challenges and serious downsides.
- Rendering: Getting pixel-perfect rendering right on the web is very difficult.
- Search: you cannot search an egui web page like you would a normal web page.
- Bringing up an on-screen keyboard on mobile: there is no JS function to do this, so
eframefakes it by adding some invisible DOM elements. It doesn't always work. - Mobile text editing is not as good as for a normal web app.
- No integration with browser settings for colors and fonts.
- Accessibility: There is an experimental screen reader for
eframe, but it has to be enabled explicitly. There is no JS function to ask "Does the user want a screen reader?" (and there should probably not be such a function, due to user tracking/integrity concerns).eguisupports AccessKit, but as of early 2024, AccessKit lacks a Web backend.
In many ways, eframe is trying to make the browser do something it wasn't designed to do (though there are many things browser vendors could do to improve how well libraries like egui work).
The suggested use for eframe are for web apps where performance and responsiveness are more important than accessibility and mobile text editing.
Companion crates
Not all rust crates work when compiled to Wasm, but here are some useful crates have been designed to work well both natively and as Wasm:
Name
The frame in eframe stands both for the frame in which your egui app resides and also for "framework" (eframe is a framework, egui is a library).