@ -37,11 +37,11 @@ If you have questions, use [Discussions](https://github.com/emilk/egui/discussio
## Demo
[Click to run egui web demo](https://emilk.github.io/egui/index.html) (works in any browser with WASM and WebGL support).
[Click to run egui web demo](https://emilk.github.io/egui/index.html) (works in any browser with WASM and WebGL support). Uses [`egui_web`](https://github.com/emilk/egui/tree/master/egui_web).
To test the demo app locally, run `cargo run --release -p egui_demo_app`.
The native backend is currently using [`glium`](https://github.com/glium/glium) ([though there are plans to change that](https://github.com/emilk/egui/issues/93)) and should work out-of-the-box on Mac and Windows, but on Linux you need to first run:
The native backend is [`egui_glium`](https://github.com/emilk/egui/tree/master/egui_glium) (using [`glium`](https://github.com/glium/glium)) and should work out-of-the-box on Mac and Windows, but on Linux you need to first run:
egui is *not* a framework. egui is a library you call into, not an environment you program for.
@ -101,11 +101,11 @@ But if you are writing something interactive in Rust that needs a simple GUI, eg
### egui vs Dear ImGui
The obvious alternative to egui is [`imgui-rs`](https://github.com/Gekkio/imgui-rs), the Rust wrapper around the C++ library [Dear ImGui](https://github.com/ocornut/imgui). Dear ImGui is a great library, which a lot more features and polish compared to egui. However, egui provides some benefits for Rust users:
The obvious alternative to egui is [`imgui-rs`](https://github.com/Gekkio/imgui-rs), the Rust wrapper around the C++ library [Dear ImGui](https://github.com/ocornut/imgui). Dear ImGui is a great library (and the main inspiration for egui), with a lot more features and polish. However, egui provides some benefits for Rust users:
* egui is pure Rust
* egui is easily compiled to WASM
* egui lets you use native Rust String types (`imgui-rs` forces you to use annoying macros and wrappers for zero-terminated strings)
* egui lets you use native Rust string types (`imgui-rs` forces you to use annoying macros and wrappers for zero-terminated strings)
* [Writing your own widgets in egui is simple](https://github.com/emilk/egui/blob/master/egui_demo_lib/src/apps/demo/toggle_switch.rs)
egui also tries to improve your experience in other small ways:
@ -162,8 +162,8 @@ The integration needs to do two things:
I maintain two official egui integrations made for apps:
* [`egui_web`](https://crates.io/crates/egui_web) for making a web app. Compiles to WASM, renders with WebGL. [Click to run the egui demo](https://emilk.github.io/egui/index.html).
* [`egui_glium`](https://crates.io/crates/egui_glium) for compiling native apps with [Glium](https://github.com/glium/glium).
* [`egui_web`](https://github.com/emilk/egui/tree/master/egui_web) for making a web app. Compiles to WASM, renders with WebGL. [Click to run the egui demo](https://emilk.github.io/egui/index.html).
* [`egui_glium`](https://github.com/emilk/egui/tree/master/egui_glium) for compiling native apps with [Glium](https://github.com/glium/glium).
If you making an app, consider using [`eframe`](https://github.com/emilk/egui/tree/master/eframe), a framework which allows you to write code that works on both the web (`egui_web`) and native (using `egui_glium`).
This crates allows you to compile GUI code written with [egui](https://crates.io/crates/egui) to [WASM](https://en.wikipedia.org/wiki/WebAssembly) to run on a web page.
[Run the web demo](https://emilk.github.io/egui/index.html) to try it now.
Check out [egui_template](https://github.com/emilk/egui_template) for an example of how to set it up.
## Downsides with using egui on the web
`egui_web` uses WebGL and WASM, and almost nothing else from the web tech stack. This has some benefits, but also produces some challanges and serious downsides.
* Rendering: Getting pixel-perfect rendering right on the web is very difficult, leading to text that is hard to read on low-DPI screens (https://github.com/emilk/egui/issues/516). Additonally, WebGL does not support linear framebuffer blending.
* Search: you cannot search a 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 `egui_web` fakes 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.
* Accessibility: There is an experimental screen reader for `egui_web`, 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 conserns).
* No integration with browser settings for colors and fonts.
* On Linux and Mac, Firefox will copy the WebGL render target from GPU, to CPU and then back again (https://bugzilla.mozilla.org/show_bug.cgi?id=1010527#c0), slowing down egui.
The suggested use for `egui_web` is for experiments, personal projects and web games. Using egui for a serious web page is probably a bad idea.
In many ways, `egui_web` 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).
Emil Ernerfeldt
3 years ago