High speed Cassowary constraint solver in JavaScript.
npm install @lume/kiwiLUME Kiwi is a fast TypeScript implementation of the Cassowary constraint
solving algorithm>), based on the seminal Cassowary paper. Originally created by
Chris Colbert, it was redesigned from the ground up to be lightweight, fast and
easy to maintain. View the benchmarks to see how it compares to
Cassowary.js.
Soon it will be compiled to
WebAssembly with
AssemblyScript (TypeScript to WebAssembly
compiler).
- Demo
- Install
- Usage
- Documentation
- Benchmarks
- Tests
Install using NPM:
``sh`
npm install @lume/kiwi
If you have a plain web app with no build, or a non-browser JS runtime that also
supports import maps like Deno, you'll need to add @lume/kiwi to yourimportmap script so that the browser or JS runtime knows where to import kiwi from. F.e.
something like this:
`html`
Note, if using importmaps and native ES Modules in a browser, or in a JS runtime like Deno, you can get Kiwi directly from the UNPKG CDN without installing it locally (just as the live CodePen demo does):
`html`
After installing, import kiwi into your project:
`js
import * as kiwi from '@lume/kiwi'
console.log(kiwi)
// ...use kiwi...
`
The following example creates a solver which automatically calculates a width based on some constraints:
`js
// Create a solver
var solver = new kiwi.Solver()
// Create edit variables
var left = new kiwi.Variable()
var width = new kiwi.Variable()
solver.addEditVariable(left, kiwi.Strength.strong)
solver.addEditVariable(width, kiwi.Strength.strong)
solver.suggestValue(left, 100)
solver.suggestValue(width, 400)
// Create and add a constraint
var right = new kiwi.Variable()
solver.addConstraint(new kiwi.Constraint(new kiwi.Expression([-1, right], left, width), kiwi.Operator.Eq))
// Solve the constraints
solver.updateVariables()
console.assert(right.value() === 500)
// later, update the constraints and re-calculate
setTimeout(() => {
solver.suggestValue(left, 200)
solver.suggestValue(width, 600)
solver.updateVariables() // update
console.assert(right.value() === 800)
}, 2000)
`
To run the benchmark in the browser, just visit this page.
To run the benchmark locally using nodejs, _clone or download this repository_ and execute the following steps:
npm install
npm run bench
Statically serve the project, f.e. npx five-server . which opens a new browser/bench/index.html
tab, then visit to verify that the benchmark also runs in a
browser.
Sample result output:
`
----- Running creation benchmark...
Cassowary.js x 2,597 ops/sec ±1.56% (93 runs sampled)
kiwi x 26,243 ops/sec ±1.34% (91 runs sampled)
kiwi new API x 20,840 ops/sec ±7.19% (80 runs sampled)
Fastest is kiwi (± 10.11x faster)
----- Running solving benchmark...
Cassowary.js x 260,002 ops/sec ±2.62% (89 runs sampled)
kiwi x 595,455 ops/sec ±1.74% (89 runs sampled)
Fastest is kiwi (± 2.29x faster)
To run the tests in the browser, just visit this page.
To run the tests locally using nodejs, _clone or download this repository_ and execute the following steps:
npm install
npm run build && npm run test
Start a static server, f.e. npx five-server . which opens a new browser tab,/test/index.html` to verify that tests also pass in a browser.
and visit
If you like this project and want to support it, show some love and give it a
star, try it and report any bugs, write new feature ideas, or even
open a pull request!
© 2013 Nucleic Development Team
© 2021 Joseph Orbegoso Pea (http://github.com/trusktr)
© 2021 Lume
