@thi.ng/imgui

# ![@thi.ng/imgui](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/banners/thing-imgui.svg?224bad78) [![npm version](https://img.shields.io/npm/v/@thi.ng/imgui.svg)](https://www.npmjs.com/package/@thi.ng/imgui) ![npm downloads](https://img.shields.io/npm/dm/@thi.ng/imgui.svg) [![Mastodon Follow](https://img.shields.io/mastodon/follow/109331703950160316?domain=https%3A%2F%2Fmastodon.thi.ng&style=social)](https://mastodon.thi.ng/@toxi) > [!NOTE] > This is one of 210 standalone projects, maintained as part > of the [@thi.ng/umbrella](https://github.com/thi-ng/umbrella/) monorepo > and anti-framework. > > 🚀 Please help me to work full-time on these projects by [sponsoring me on > GitHub](https://github.com/sponsors/postspectacular). Thank you! ❤️ - [About](#about) - [Current features](#current-features) - [Available components / widgets](#available-components--widgets) - [State handling](#state-handling) - [Layout support](#layout-support) - [Key controls](#key-controls) - [Current limitations](#current-limitations) - [Status](#status) - [Related packages](#related-packages) - [Installation](#installation) - [Dependencies](#dependencies) - [Usage examples](#usage-examples) - [API](#api) - [Authors](#authors) - [License](#license) ## About Immediate mode GUI with flexible state handling & data only shape output. ![screenshot](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/imgui/imgui-all.png) Currently still somewhat bare-bones, but already usable & customizable [immediate mode GUI](https://github.com/ocornut/imgui#references) implementation, primarily for [@thi.ng/hdom-canvas](https://github.com/thi-ng/umbrella/tree/develop/packages/hdom-canvas) / [@thi.ng/hiccup-canvas](https://github.com/thi-ng/umbrella/tree/develop/packages/hiccup-canvas) and [@thi.ng/webgl](https://github.com/thi-ng/umbrella/tree/develop/packages/webgl), however with no direct dependency on either and only outputting data structures. IMGUI components are largely ephemeral and expressed as simple functions, producing a visual representation of a user state value. IMGUIs are reconstructed from scratch each frame and don't exist otherwise (apart from some rudimentary input state & config). If a component's function isn't called again, it won't exist in the next frame shown to the user. Components only return a new value if an user interaction produced a change. Additionally, each component produces a number of shapes & text labels, all of which are collected internally and are, from the user's POV, a mere side effect. At the end of the update cycle IMGUI produces a tree of [@thi.ng/hiccup-canvas](https://github.com/thi-ng/umbrella/tree/develop/packages/hiccup-canvas) compatible elements, which can be easily converted into other formats (incl. SVG). *Note: The WebGL conversion still in the early stages and not yet published, pending ongoing development in other packages...* ### Current features - No direct user state mutation (unlike most other IMGUI impls) - Flexible & nestable grid layout with support for cell-spans - Theme stack for scoped theme switches / overrides - Stack for scoped disabled GUI elements & to create modals - Hashing & caching of component local state & draws shapes / resources - Hover-based mouse cursor overrides - Hover tooltips - Re-usable hover & activation behaviors (for creating new components) - Fully keyboard controllable & Tab-focus switching / highlighting - All built-in components based on [@thi.ng/geom](https://github.com/thi-ng/umbrella/tree/develop/packages/geom) shape primitives ### Available components / widgets The above screenshot shows most of the currently available components: - Push button (horizontal / vertical) - Icon button (w/ opt text label) - 2x dial types & dial groups (h / v) - Dropdown - Radial menu - Radio button group (h / v) - Ramp (keyframe-based control curve editor) - Slider & slider groups (h / v) - Text input (single line, filtered input) - Text label - Toggle button - XY pad All components are: - Skinnable (via theme) - Keyboard controllable (incl. focus switching) - Support tooltips ### State handling All built-in components only return a result value if the component was interacted with and would result in a state change (i.e. a slider has been dragged or button pressed). So, unlike the traditional IMGUI pattern (esp. in languages with pointer support), none of the components here directly manipulate user state and this task is left entirely to the user. This results in somewhat *slightly* more verbose code, but offers complete freedom WRT how user state is & can be organized. Also, things like undo / redo become easier to handle this way. ```ts import { Atom, History } from "@thi.ng/atom"; import { toggle } from "@thi.ng/imgui"; // example state (see @thi.ng/atom) const STATE = new History(new Atom({ foo: true })); //...IMGUI & layout initialization omitted here // get atom snapshot const curr = STATE.deref(); // toggle component will only return result if user clicked it let res = toggle({ gui, layout, id: "foo", value: curr.foo, label: curr.foo ? "ON" : "OFF" }); // conditional immutable update (w/ automatic undo snapshot) if (res !== undefined) STATE.resetIn("foo", res); ``` ### Layout support Most component functions exist in two versions: Using a [@thi.ng/layout](https://github.com/thi-ng/umbrella/tree/develop/packages/layout)-compatible grid layout manager or not (e.g. `dial` vs. `dialRaw`). The latter versions are more "low-level" & verbose to use, but offer complete layout freedom and are re-used by other component types. The components in this package not needing a layout manager are only expecting a `ILayout` or `IGridLayout` interface, allowing for custom implementations. Furthermore / alternatively, the [@thi.ng/layout](https://github.com/thi-ng/umbrella/tree/develop/packages/layout) package also defines a [`LayoutBox` interface](https://github.com/thi-ng/umbrella/tree/develop/packages/imgui/src/api.ts), which can be passed instead and too is the type `ILayout` implementations are expected to produce when allocating space for a component. The `GridLayout` class supports infinite nesting and column/row-based space allocation, based on an initial configuration and supporting multiple column/row spans. ![screenshot](https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/layout/grid-layout.png) The code producing this structure: ```ts import { gridLayout } from "@thi.ng/layout"; // create a single column layout @ position 10,10 / 200px wide // the last values are row height and cell spacing const layout = gridLayout(10, 10, 200, 1, 16, 4); // get next layout box (1st row) // usually you don't need to call .next() manually, but merely pass // the layout instance to a component... layout.next(); // { x: 10, y: 10, w: 200, h: 16, cw: 200, ch: 16, gap: 4 } // 2nd row layout.next(); // { x: 10, y: 30, w: 200, h: 16, cw: 200, ch: 16, gap: 4 } // create nested 2-column layout (3rd row) const twoCols = layout.nest(2); twoCols.next(); // { x: 10, y: 50, w: 98, h: 16, cw: 98, ch: 16, gap: 4 } twoCols.next(); // { x: 112, y: 50, w: 98, h: 16, cw: 98, ch: 16, gap: 4 } // now nest 3-columns in the 1st column of twoCols // (i.e. now each column is 1/6th of the main layout's width) const inner = twoCols.nest(3); // allocate with col/rowspan, here 1 column x 4 rows inner.next([1, 4]) // { x: 10, y: 70, w: 30, h: 76, cw: 30, ch: 16, gap: 4 } inner.next([1, 4]) // { x: 44, y: 70, w: 30, h: 76, cw: 30, ch: 16, gap: 4 } inner.next([1, 4]) // { x: 78, y: 70, w: 30, h: 76, cw: 30, ch: 16, gap: 4 } // back to twoCols (2nd column) twoCols.next([1, 2]); // { x: 112, y: 70, w: 98, h: 36, cw: 98, ch: 16, gap: 4 } ``` ### Key controls The entire UI is fully keyboard controllable, built-in behaviors: | Keys | Scope | Description | |-----------------------------|------------------|-------------------------------| | `Tab` / `Shift+Tab` | Global | Switch focus | | `Enter` / `Space` | Global | Activate focused button | | `Up` / `Down` or drag mouse | Slider, Dial, XY | Adjust value | | `Shift+Up/Down` | Slider, Dial, XY | Adjust value (5x step) | | `Left/Right` | Radial menu | Navigate menu CW/CCW | | `Left/Right` | Textfield | Move cursor to prev/next word | | `Left/Right` | XY | Adjust X value | | `Alt+Left/Right` | Textfield | Move cursor to prev/next word | More complex behaviors can be achieved in user land. E.g. in the [demo](https://github.com/thi-ng/umbrella/tree/develop/examples/imgui/), holding down `Alt` whilst adjusting a slider or dial group will set all values uniformly... ### Current limitations Some of the most obvious missing features: - [ ] variable width font support (currently monospace only) - [ ] more granular theme options - [ ] theme-aware layouting (font size, padding etc.) - [ ] image / texture support (Tex ID abstraction) - [ ] windows / element containers - [ ] menu / tree components - [ ] scrolling / clipping - [ ] drag & drop ## Status **STABLE** - used in production [Search or submit any issues for this package](https://github.com/thi-ng/umbrella/issues?q=%5Bimgui%5D+in%3Atitle) ## Related packages - [@thi.ng/hdom-canvas](https://github.com/thi-ng/umbrella/tree/develop/packages/hdom-canvas) - [@thi.ng/hdom](https://github.com/thi-ng/umbrella/tree/develop/packages/hdom) component wrapper for declarative canvas scenegraphs - [@thi.ng/hiccup-canvas](https://github.com/thi-ng/umbrella/tree/develop/packages/hiccup-canvas) - Hiccup shape tree renderer for vanilla Canvas 2D contexts - [@thi.ng/rdom-canvas](https://github.com/thi-ng/umbrella/tree/develop/packages/rdom-canvas) - [@thi.ng/rdom](https://github.com/thi-ng/umbrella/tree/develop/packages/rdom) component wrapper for [@thi.ng/hiccup-canvas](https://github.com/thi-ng/umbrella/tree/develop/packages/hiccup-canvas) and declarative canvas drawing ## Installation ```bash yarn add @thi.ng/imgui ``` ESM import: ```ts import * as imgui from "@thi.ng/imgui"; ``` Browser ESM import: ```html <script type="module" src="https://esm.run/@thi.ng/imgui"></script> ``` [JSDelivr documentation](https://www.jsdelivr.com/) Package sizes (brotli'd, pre-treeshake): ESM: 7.48 KB ## Dependencies - [@thi.ng/api](https://github.com/thi-ng/umbrella/tree/develop/packages/api) - [@thi.ng/checks](https://github.com/thi-ng/umbrella/tree/develop/packages/checks) - [@thi.ng/geom](https://github.com/thi-ng/umbrella/tree/develop/packages/geom) - [@thi.ng/geom-isec](https://github.com/thi-ng/umbrella/tree/develop/packages/geom-isec) - [@thi.ng/layout](https://github.com/thi-ng/umbrella/tree/develop/packages/layout) - [@thi.ng/math](https://github.com/thi-ng/umbrella/tree/develop/packages/math) - [@thi.ng/ramp](https://github.com/thi-ng/umbrella/tree/develop/packages/ramp) - [@thi.ng/transducers](https://github.com/thi-ng/umbrella/tree/develop/packages/transducers) - [@thi.ng/vectors](https://github.com/thi-ng/umbrella/tree/develop/packages/vectors) Note: @thi.ng/api is in _most_ cases a type-only import (not used at runtime) ## Usage examples Three projects in this repo's [/examples](https://github.com/thi-ng/umbrella/tree/develop/examples) directory are using this package: | Screenshot | Description | Live demo | Source | |:--------------------------------------------------------------------------------------------------------------------|:-------------------------------------------|:---------------------------------------------------|:--------------------------------------------------------------------------------| | <img src="https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/examples/fft-synth.png" width="240"/> | Interactive inverse FFT toy synth | [Demo](https://demo.thi.ng/umbrella/fft-synth/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/fft-synth) | | <img src="https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/imgui/imgui-all.png" width="240"/> | Canvas based Immediate Mode GUI components | [Demo](https://demo.thi.ng/umbrella/imgui/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/imgui) | | <img src="https://raw.githubusercontent.com/thi-ng/umbrella/develop/assets/examples/imgui-basics.png" width="240"/> | Minimal IMGUI usage example | [Demo](https://demo.thi.ng/umbrella/imgui-basics/) | [Source](https://github.com/thi-ng/umbrella/tree/develop/examples/imgui-basics) | ## API [Generated API docs](https://docs.thi.ng/umbrella/imgui/) TODO ## Authors - [Karsten Schmidt](https://thi.ng) If this project contributes to an academic publication, please cite it as: ```bibtex @misc{thing-imgui, title = "@thi.ng/imgui", author = "Karsten Schmidt", note = "https://thi.ng/imgui", year = 2019 } ``` ## License © 2019 - 2025 Karsten Schmidt // Apache License 2.0