MicroUI – A tiny, portable, immediate-mode UI library written in ANSI C

https://github.com/rxi/microui

by peter_d_sherman • 1 month ago

257 87 1 month ago

github.com

peter_d_sherman• 1 month ago

"Features

o Tiny: around 1100 sloc of ANSI C

o Works within a fixed-sized memory region: no additional memory is allocated

o Built-in controls: window, scrollable panel, button, slider, textbox, label, checkbox, wordwrapped text

o Works with any rendering system that can draw rectangles and text

o Designed to allow the user to easily add custom controls

o Simple layout system"

Littice• 1 month ago

Immediate-mode in pure C is a nice constraint. how does it handle text rendering, do you bring your own atlas or is there something built in? Thats usually the part that balloons the dependency footprint.

dvhh• 1 month ago

it does not, it basically delegate that part to lower level library for which you have to write the glue code for, there is an example for SDL.

flohofwoe7• 1 month ago

The demo uses a simple prebuilt fixed-size font atlas texture and renders the entire UI (including character quads) via batched glDrawElements calls (one draw call per clip-rect).

But the way how text rendering is delegated to the user is quite flexible, microui basically calls these three user-provided functions:

    int r_get_text_height(void)
    int r_get_text_width(const char* text, int len);
    void r_draw_text(const char* text, mu_Vec2 pos, mu_Color color);

...how r_draw_text() is implemented is then entirely up to you.

krapp• 1 month ago

If anyone wants it here is an old fork of mine that uses SDL3 - https://codeberg.org/krapp/microui_sdl3_demo

ur-whale• 1 month ago

Nice, except the hard part seems to be missing: interfacing with an actual window system (X11, TUI, WIN32, whatever ...)

foul• 1 month ago

In demo/ someone can "steal" the renderer part which, being based on SDL, is to some extent cross-platform.

exDM69• 1 month ago

That's the whole point!

You plug it into your project and it can be rendered on anything that can push pixels and/or triangles to the screen. Events from windowing system go in, list of triangles comes out.

This is intended to be used with OpenGL, Vulkan, D3D and other graphics environment and used in cases where integrating a "real" GUI toolkit would be more trouble than it's worth.

Other popular libs like Dear Imgui or Egui work the same way.

flohofwoe7• 1 month ago

It's a "bring your own renderer" UI framework, just like Dear ImGui or Nuklear. In some situation (e.g. when adding debugging UIs to a game) this is actually a big advantage compared to the renderer being baked into the library, since the game already has a renderer subsystem which the UI can easily hook into.

pkolchanov• 1 month ago

I've worked on a minimal application layer (Cocoa, X11, win32) that you might find interesting. It includes a microui example.

https://github.com/pkolchanov/brr

abtinf• 1 month ago

The first thing I look for in any UI library is accessibility support. Makes it trivial to filter out toy projects.

spwa4• 1 month ago

Then just save yourself some time. Immediate mode and accessibility are mutually exclusive.

whizzter• 1 month ago

This is a library in similar vein to "Dear imgui", minimal requirements for integration (rectangle and text rendering) so that it's easy to embed into game-engines,etc for debug UI's and similar things.

monocasa2• 1 month ago

Or, not every UI library is intended for use cases where a13y even makes sense.

Like a debug UI in a game engine, or in an embedded device that doesn't even have input for a13y.

fwip• 1 month ago

Being accessible to the intended users always matters. If you think it doesn't, that probably means it's currently accessible to those users (or that those who are it is inaccessible to have filtered themselves out, and are no longer users).

For example - in your debug UI, colorblind-friendly colors don't matter, until you hire your twelfth member of the team, who struggles to tell red and green apart.

xyzzy_plugh• 1 month ago

No. As much as I would like it to be the case, that is most certainly a poor criteria to evaluate a UI library.

Dear ImGui [0] is without a doubt the most prevalent immediate mode UI library. It does not have native accessibility features, but that hasn't stopped companies such as Intel, Meta, IKEA and Google from shipping products built upon it. It's also used in a ton of games.

Calling Dear ImGui a toy project at this point would be like calling Unreal Engine a toy project.

It's a shame accessibility support is not more widespread, and furthermore it's a shame that it is so laborious to add it.

0: https://github.com/ocornut/imgui/

SwellJoe3• 1 month ago

OK, if "toy project" isn't the right word, then perhaps, "unethical" or "exclusionary" would be better words to use.

I judge software harshly that could be useful to folks with accessibility needs that don't try to address it (within bounds of their resources and capabilities, obviously lots of OSS just doesn't have the ability to deliver an accessible experience for tiny little throwaway apps). I definitely choose technologies to use based on whether they can be accessible with a little extra effort on my part. I'm not necessarily good at it, it's a complicated topic, but when I get bug reports about an accessibility issue I tend to drop everything else and try to fix it.

I guess a lot of folks consider games exclusively for folks without those accessibility needs, so maybe that's why something like Dear ImGui can live for years in thousands of projects without anyone complaining about accessibility. But, I wouldn't consider it for anything that isn't specifically about graphics and I don't think anyone else should either. (No one has to listen to me, but I think less of them.)

14u2c• 1 month ago

You've cherry picked a very specific example that is designed to run in 3d engines. For anything rendering at standard OS api level level (the vast majority libs), accessibility is fine as evaluation criteria.

RodgerTheGreat• 1 month ago

"Accessibility" is an open-ended set of functionality, not a checkbox; it is never "complete", there is always room for improvement. Colorblind support (which ones)? High-Contrast mode? Adjustable text size? Screenreader integration? Localization? IME support? Keyboard navigation? Keyboard remapping? Functional entirely without a keyboard? Touch support? Pen support? Dyslexia-aiding typefaces? The list goes on and on.

jazzypants2• 1 month ago

This is one of the reasons why web technology is so popular and persistent. You get almost all of that for free as long as you use semantic HTML.

Dwedit• 1 month ago

One clearly defined starting point is exposing any custom controls to accessibility APIs that are used to enumerate and interact (simulated mouse actions, reading the text, etc) with controls on the screen. Both scripting tools and screen readers make use of these. Built-in controls already have the enumeration and interaction feature and don't need additional code, but custom controls may not have that.

In the MicroUI example here, there are buttons and text labels and other kinds of controls, but no ability for an outside process to enumerate or interact with the controls. Any program will just set a single giant window with no text and no controls inside. Accessibility software can still hook text output APIs, but not if it also uses custom font rendering.

Anyway, the Windows accessibility API is just implementing a few COM objects, and COM (other than the specific ABI used for storing the vtable and function call convention) is not necessarily specific to Win32.

jdmoreira• 1 month ago

What? On a micro immediate mode UI?

Really insane comment TBH

dwb• 1 month ago

The point of a UI library is to interface with users. If it totally fails to interface with a subset of users then it is obviously deficient to some degree. It is callous and foolish to dismiss offhand users who rely on assistive technologies. You probably have a poor idea of who they are and how many people we’re talking about. You never know when you or someone you care about will become one of them, even temporarily. You never know how far your software will reach when you write it.

qsera2• 1 month ago

Not very smart. I would go further and say that even full unicode support could be avoided and a software can still be massively useful.

It is sad that the world is so hung up on unicode and things like accessibility that we all have to submit to the tyranny of browser layers!

anonymous908213• 1 month ago

sad that the world is so hung up on unicode

It is sad that the world is hung up on enabling 2/3rds of the world population to read and write text! If only the entire world catered to America. Nobody should ever speak anything other than English, honestly.

SeasonalEnnui• 1 month ago

I agree, and the lack of empathy around this area is sad. If you're developing an app, it is better to fall into the pit of success by using a UI framework that already has accessibility baked in. Any project that uses Dear Imgui for end-user applications has already made a bad design choice. AccessKit (https://accesskit.dev/) seems to be a positive step forward, with some UI frameworks implemented (including immediate mode egui).

einpoklum2• 1 month ago

It's supposed to be a _tiny_ library. Naturally its capabilities will tend towards being minimal. I don't expect decent RTL language support, for example, although it's quite important if those are the languages where you live.

As for linking to something written in Rust with bindings etc. - that is the opposite of tiny when you consider the dependencies, and it would not be portable to weaker or older systems.

Intralexical7• 1 month ago

Any project that uses Dear Imgui for end-user applications has already made a bad design choice.

Note that any project using Dear ImGui will presumably have read the README for it, the second paragraph of which starts:

Dear ImGui is designed to enable fast iterations and to empower programmers to create content creation tools and visualization / debug tools (as opposed to UI for the average end-user).

ricardobeat• 1 month ago

Is there any game engine out there with good accessibility support for their UI?

nkrisc• 1 month ago

I can’t say how it compares to others, but Godot added screen reader support in 4.5 a year or so ago.

functionmouse• 1 month ago

Windows XP has better accessibility than anything since, by virtue of staying entirely out of the way of accessibility tools. Time to downgrade!

HumblyTossed3• 1 month ago

Everything is an engineering decision. Leaving out something doesn't mean it's a "toy". So, I don't really get your criticism here.

synergy20• 1 month ago

how is this different from lvgl? is this immediate mode or retained mode?

flohofwoe7• 1 month ago

Very different, starting at the line count:

Lvgl is 440kloc across 1134 files (in the src directory), while microui is 1121 lines of code in one .c and one .h file.

Microui is immediate mode, very minimal and 'bring your own renderer'. Probably most useful for adding a small debugging UI to a 3D game/app.

kartoffelsaft• 1 month ago

This has been my goto for personal toy projects for a while now. Trivial to slot in to basically anything that can display text and takes mouse input.

I will mention, however, it's kinda abandonware at this point. There is some bug with the draw call iterator which does a misaligned pointer access, which, if your environment is set up to catch that, can get annoying (Zig for example panics on it). There's a github issue that some have used as reason to fork it but all the forks I tried were subtly wrong, for what that's worth.

packetlost• 1 month ago

it's kinda abandonware at this point

That's sad. I'm a fan of rxi's work, including this one.

pstuart• 1 month ago

It's MIT and these days handing it off to Claude to tart it up as needed should be viable.

leecommamichael• 1 month ago

Genuine question; abandonware or complete? Something of this size serves as a nice substrate or starting-point regardless.

HumblyTossed3• 1 month ago

Exactly. Software can be _done_.

And that's okay(tm).

Intralexical7• 1 month ago

The whole thing's less than 2kLoCs. If it needs ongoing maintenance, something's gone wrong IMO.

I think it's reasonable to just patch it yourself if it doesn't work with your other tools (Zig). Though thank you for sharing the heads up.

afavour• 1 month ago

Cool to see a demo in there that you can run in a browser, presumably compiled to WebAssembly. The kind of thing that was unimaginable years ago.

OvervCW• 1 month ago

What is the advantage of this compared to Dear Imgui?

ranger_danger• 1 month ago

it's lighter weight and written in C

kettlez• 1 month ago

This is included in the Odin vendor libraries, it's fantastic for Raylib debug menus

dsego• 1 month ago

Raylib also has Raygui

https://github.com/raysan5/raygui

But I found it pretty straightforward (and satisfying) to just build my own gui functions/widgets with raylib (inspired by raygui).

https://github.com/dsego/strobe-tuner/blob/main/app/gui.odin

flohofwoe7• 1 month ago

I wrote a little demo to run microui on top of the sokol headers here, it's really interesting in how minimal it is.

WASM demo: https://floooh.github.io/sokol-html5/sgl-microui-sapp.html

Source code: https://github.com/floooh/sokol-samples/blob/master/sapp/sgl...

The renderer backend is just a bunch of C functions you need to provide:

https://github.com/floooh/sokol-samples/blob/3f4185a8578cd2b...

It's also interesting to compare the binary sizes:

microui sample (https://floooh.github.io/sokol-html5/sgl-microui-sapp.html): 79.6 KBytes compressed download

Nuklear sample (https://floooh.github.io/sokol-html5/nuklear-sapp.html): 155 kb compressed download

Dear ImGui sample (https://floooh.github.io/sokol-html5/imgui-sapp.html): 491 KB compressed download

zuzululu• 1 month ago

pretty nifty but im trying to figure out what the use case for this is when its aimed at hobbyists ?

I use pygtk and dont have to fiddle with lower level stuff

flohofwoe7• 1 month ago

Minimal debugging/controller overlays for games would be the most obvious use case (e.g. similar to dat.gui for web).

Levitating• 1 month ago

pygtk requires GTK, this library works with any rendering library that can draw rectangles and text

onsclom2• 1 month ago

I made my own WASM demo @ https://microui-wasm.vercel.app/ and it's only 14.6 kB compressed!

Will share source code if someone is interested, but key bits:

- had a small JS glue layer using CanvasRenderingContext2D to render

- made a `wasm32-freestanding` build to lower the wasm bundle size, which meant shimming the bits of the libc microui uses

Narishma3• 1 month ago

Your demo seems to constantly consume 100% CPU at all times.

starik36• 1 month ago

Why is the WASM demo so fuzzy? I am on Windows/Firefox.

https://imgur.com/uy78t52

Intralexical7• 1 month ago

Looks like the rendering functions used in the demo are doing antialiasing without font hinting?

flohofwoe7• 1 month ago

TL;DR: it can be all sorts of things, from 'half-pixel' positioning problems, to upscaling issues, to poor source data. I didn't put too much effort into getting the text rendering look good (and text rendering is hard).

More details:

The demo is using half-resolution on high-dpi displays (currently that's sokol-app's default setting, but not sure if that still makes sense in this day and age tbh), this half resolution amplifies all sorts of text rendering issues, and it gets especially bad when there's a fractional system-dpi-scale like 125% or 150%.

PS: another problem (maybe the main problem, even if everything else is correct) is that the demo's pre-baked font atlas texture isn't all that great since it has 'anti-aliasing' baked into the glyph pixels, and the font atlas texture has a very low resolution (glyph height is 10 pixels, which would be ok for a 'crisp' hand-drawn bitmap font, but not when the font atlas has been created from a regular TTF font, which this one seems to be).

Does this Dear ImGui demo look better on your setup? This is using the native display DPI and uses a TTF font instead of a bitmap font:

https://floooh.github.io/sokol-html5/imgui-highdpi-sapp.html

socalgal2• 1 month ago

I asked Claude to write one from scratch. A few minutes later it was done with exactly the features I needed. I started with some existing one, but when it couldn't handle multiple pointers (2 hands in VR/AR each with a pointer) without major mods I end up asking Claude if it could replace it with a custom one.

It first said "that's a ton of work" to which I said, "Really? A basic IMGUI needs a texture with glyphs. The abiltiy to draw textured rectangles with vertex colors. Scissor support for clipping. Some hit testing." and it was like, "yea, you're right", and a few mins later it wrote what I needed.

I'm not saying you shouldn't use this library.

jacereda• 1 month ago

I used this one in 2022 to make a proof of concept for a build once / run anywhere graphical app and IIRC the library was quite nice, even if a bit limited. The resulting kludge is at https://github.com/jacereda/cosmogfx and there's a prebuilt binary that should run on Linux, Windows and some BSDs. https://github.com/jacereda/cosmogfx/releases/download/v0.0....

Cosmopolitan Libc has since integrated the bits to make OpenGL work in cross-platform binaries and it's awesome.

jmiskovic• 1 month ago

Also see: https://rxi.github.io/microui_v2_an_implementation_overview....

em-bee• 1 month ago

anyone working on bindings to other languages? (go, python, ruby, etc)

HumblyTossed3• 1 month ago

I was just thinking this would be great with go. If it would work.

shideneyu• 1 month ago

love the web assembly demo. By the way, I hope this kind of interface for the web becomes more mainstream in the future, I start to hate html / css cuz everything looks the same because of it (even in the train stations they use it for scheduling)

einpoklum2• 1 month ago

How can such a library be both tiny and portable, when the C standard library has no graphics facilities? Don't you need to lay down a lot of basis for different platforms and graphics backends, to be portable? And if you do that, how can you be tiny?

b3orn• 1 month ago

Almost all of these immediate mode UI libraries for C/C++ come without a rendering backend. Usually there are "example" implementations for libraries like SDL that you can use, or you implement your own backend. A lot of these libraries are popular for debug UIs in games and you probably need a custom backend for whatever graphics engine you use in your game.

hparadiz2• 1 month ago

I need something like this but with a few more bells and whistles.

amelius• 1 month ago

The problem is always: you don't know beforehand what bells and whistles you will need. That's why Qt is probably the only safe bet (or Web/Electron if you don't mind the slower performance).

hparadiz2• 1 month ago

I know exactly what I need. I just built a task manager in C with GTK+. It uses the theming built into GTK to allow users to change themes while the program is running but it's too memory heavy for my taste. I also have a background in web dev and understand how to build for accessibility. Currently the memory allocated for every single process on my computer is <3 MB but the interface displaying that information uses almost 55MB total when rendering. I need the ability to set fonts, colors, and sizes and the ability draw text as desktop manager understandable standard copy/pastable text. I want the font rendering to support basic anti aliasing. The API also needs to expose draw surfaces for me to draw OpenGL/Vulkan as needed. It needs to support both X and Waylandisms for window decorations. I specifically need the API to support animated icons for window decorations as that is currently unsupported by anyone at all in this space. https://github.com/hparadiz/evemon

You're right though I'm already thinking of scaling and hidpi as another thing I need.

0x02032• 1 month ago

For a slightly larger, cross-platform, retained mode GUI written in C, there's libagar [0]. Different use case than MicroUI, but still a neat project.

[0] https://libagar.org/

Narishma3• 1 month ago

If that's your project, the Arabic text rendering is broken in this screenshot:

https://libagar.org/screenshots/agar171.png

0x02032• 1 month ago

It's not mine; just a project I've toyed with a few times in my search for GUI toolkits over the years. Issues and/or PRs can be filed on the github page though.

wefw3434• 1 month ago

this is easy

question is how produce sms-message like text widget, with alligment like iphone

ioma8• 1 month ago

I just ported it to rust 1:1 (https://github.com/ioma8/microui-rs) Yes with assistance of AI, not ashamed of that.

skrellm• 1 month ago

I've created a similar (minimal, lightweight, ANSI C) UI library, which is even easier to use.

https://gitlab.com/bztsrc/smgui

I don't like immediate-mode, because you must handle everything in the same thread, so mine is a state-mode GUI.

For immediate-mode and ANSI C, there's also Nuklear:

https://github.com/Immediate-Mode-UI/Nuklear

This latter has all the bells and whistles.

MicroUI – A tiny, portable, immediate-mode UI library written in ANSI C

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