# regl-component

> element wrapper to manage multiple regl contexts

Latest version **3.0.1** (published 2018-02-26) · BSD license · 0 weekly downloads

## Install

```sh
npm install regl-component
pnpm add regl-component
yarn add regl-component
bun add regl-component
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 3.0.1 |
| Published | 2018-02-26 |
| First published | 2017-05-31 |
| Weekly downloads | 0 |
| License | BSD |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 2 |
| Unpacked size | 18.3 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Maintainers | substack |

## Links

- npm: https://www.npmjs.com/package/regl-component
- npm.io page: https://npm.io/package/regl-component

## Dependencies (2)

- [nanobus](https://npm.io/package/nanobus.md) ^4.3.3
- [nanocomponent](https://npm.io/package/nanocomponent.md) ^6.5.0

## Recent versions

- 3.0.1 (latest) — 2018-02-26
- 3.0.0 — 2018-02-25
- 2.0.0 — 2018-01-08
- 1.2.8 — 2017-12-29
- 1.2.7 — 2017-12-28
- 1.2.6 — 2017-07-26
- 1.2.5 — 2017-07-26
- 1.2.4 — 2017-07-06
- 1.2.3 — 2017-07-06
- 1.2.2 — 2017-07-05
- 1.2.1 — 2017-07-04
- 1.2.0 — 2017-07-04
- 1.1.2 — 2017-07-04
- 1.1.1 — 2017-07-03
- 1.1.0 — 2017-06-01
- … 3 more at https://npm.io/package/regl-component/versions

## README

# regl-component

element wrapper to manage multiple [regl][] contexts

This module uses [nanocomponent][] to provide a vanilla DOM wrapper on top of a
modified version of [multi-regl][], which shares a single webgl element among
all components.

[regl]: http://regl.party
[nanocomponent]: https://npmjs.com/package/nanocomponent
[multi-regl]: https://npmjs.com/package/multi-regl

# example

[view this demo](https://substack.neocities.org/example/regl-component.html)

``` js
var app = require('choo')()
var html = require('choo/html')
var rcom = require('regl-component')(require('regl'))
var anormals = require('angle-normals')

var chart = require('conway-hart')
var demos = [
  fromMesh(rcom.create(), chart('mI')),
  fromMesh(rcom.create(), chart('jT')),
  fromMesh(rcom.create(), chart('djmeD')),
  fromMesh(rcom.create(), chart('pO'))
]

app.route('/', function (state, emit) {
  return html`<body>
    ${rcom.render()}
    ${demos.map(function (demo) {
      return html`<div>
        ${demo.render({ width: 400, height: 150 })}
        <hr>
      </div>`
    })}
  </body>`
})
app.mount('body')

function fromMesh (rc, mesh) {
  rc.on('regl', function (regl) {
    var draw = regl({
      frag: `
        precision highp float;
        varying vec3 vnorm;
        void main () {
          gl_FragColor = vec4(vnorm*0.5+0.5,1);
        }
      `,
      vert: `
        precision highp float;
        attribute vec3 position, normal;
        varying vec3 vnorm;
        uniform float aspect;
        void main () {
          vnorm = normal;
          gl_Position = vec4(position.xy*vec2(1,aspect)*0.3,position.z*0.1+0.1,1);
        }
      `,
      uniforms: {
        aspect: function (context) {
          return context.viewportWidth / context.viewportHeight
        }
      },
      attributes: {
        position: mesh.positions,
        normal: anormals(mesh.cells, mesh.positions)
      },
      elements: mesh.cells
    })
    regl.clear({ color: [0,0,0,1], depth: true })
    draw()
  })
  return rc
}
```

# api

``` js
var reglComponent = require('regl-component')
```

## var rcom = reglComponent(createRegl, opts)

Create an `rcom` component given a `createRegl` constructor function.

Any `opts` are passed to the regl constructor.

## var rootElem = rcom.render()

Generate the root element `rootElem` that takes care of the full-screen canvas
overlay.

## var rc = rcom.create()

Create a component wrapper `rc`.

## var elem = rc.render(props)

Return a cached element `elem` given:

* `props.width` - element width
* `props.height` - element height

## rc.on('regl', function (regl) {})

Listen for the regl event to get a handle on a regl instance when a webgl
context is available. This event many fire multiple times if a context is lost
and re-initialized.

# install

npm install regl-component

# license

BSD

---
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