MicroUI – A tiny, portable, immediate-mode UI library written in ANSI C
120 points - today at 12:04 PM
Sourcekartoffelsaft
today at 2:04 PM
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
today at 3:15 PM
> it's kinda abandonware at this point
That's sad. I'm a fan of rxi's work, including this one.
This is included in the Odin vendor libraries, it's fantastic for Raylib debug menus
The first thing I look for in any UI library is accessibility support. Makes it trivial to filter out toy projects.
RodgerTheGreat
today at 1:42 PM
"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.
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.
jazzypants
today at 1:54 PM
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.
xyzzy_plugh
today at 1:26 PM
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/
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.
SeasonalEnnui
today at 4:26 PM
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).
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
today at 5:35 PM
> 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.
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.
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.
This library's default is greyscale anyway, so it's by default colorblind friendly.
jdmoreira
today at 2:23 PM
What? On a micro immediate mode UI?
Really insane comment TBH
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.
Then just save yourself some time. Immediate mode and accessibility are mutually exclusive.
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.
What is the advantage of this compared to Dear Imgui?
ranger_danger
today at 2:29 PM
it's lighter weight and written in C
synergy20
today at 1:50 PM
how is this different from lvgl? is this immediate mode or retained mode?
flohofwoe
today at 4:14 PM
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.
Nice, except the hard part seems to be missing: interfacing with an actual window system (X11, TUI, WIN32, whatever ...)
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.
flohofwoe
today at 4:18 PM
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.
In demo/ someone can "steal" the renderer part which, being based on SDL, is to some extent cross-platform.
peter_d_sherman
today at 12:06 PM
>"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"
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.
flohofwoe
today at 4:26 PM
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.
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.