expo / expo-pixi

Tools for using pixi.js in Expo
MIT License
304 stars 118 forks source link
cross-platform expo pixi signature webgl

expo-pixi

Tools to use Pixi.js in Expo!

To get started: yarn add expo-pixi in your Expo project and import it with import ExpoPixi from 'expo-pixi';.

Side-Effects

To use Pixi.js with Expo & React Native you will want to import a modified version of Pixi.js like so:


// ✅
import { PIXI } from 'expo-pixi';

// ❌
import * as PIXI from 'pixi.js';

Now you can create a new Application the way you would on the web, but be sure to pass in a WebGLRenderingContext.


// ✅
const app = new PIXI.Application({ context });

// ❌
const app = ExpoPIXI.application({ context });

Finally, because of the way React Native currently works you must load in assets asynchronously.


/*
 * Accepts: 
 * - Expo.Asset: import { Asset } from 'expo-asset'; Asset.fromModule( ... );
 * - URL (with file extension): 'http://i.imgur.com/uwrbErh.png'
 * - Static Resource: require('./icon.png')
 */

// ✅
const sprite = await PIXI.Sprite.fromExpoAsync('http://i.imgur.com/uwrbErh.png');

// OR 

const texture = await PIXI.Texture.fromExpoAsync('http://i.imgur.com/uwrbErh.png');

// ❌
const sprite = await ExpoPIXI.spriteAsync('http://i.imgur.com/uwrbErh.png');

// OR 

const texture = await ExpoPIXI.textureAsync('http://i.imgur.com/uwrbErh.png');

Using web syntax will return a Promise, and throw a warning. It's bad practice, but if the asset is loaded already, this will work without throwing a warning.

const sprite = await PIXI.Sprite.from(require('./icon.png'));

// > console.warning(PIXI.Sprite.from(asset: ${typeof asset}) is not supported. Returning a Promise!);

// OR 

const texture = await PIXI.Texture.from(require('./icon.png'));

// > console.warning(PIXI.Texture.from(asset: ${typeof asset}) is not supported. Returning a Promise!);

Functions

ExpoPixi.application(props): PIXI.Application

Deprecated: Use new PIXI.Application({ context });

A helper function to create a PIXI.Application from a WebGL context. EXGL knows to end a frame when the function: endFrameEXP is called on the GL context.

context is the only required prop.

Learn more about PIXI.Application props

ExpoPixi.textureAsync(resource: any): Promise

Deprecated: Use PIXI.Texture.fromExpoAsync(resource);

ExpoPixi.spriteAsync(resource: any): Promise

Deprecated: Use PIXI.Sprite.fromExpoAsync(resource);

a helper function to resolve the asset passed in. textureAsync accepts:

You cannot send in relative string paths as Metro Bundler looks for static resources.


ExpoPixi.sprite({ localUri: string, width: number, height: number }): PIXI.Sprite

Deprecated: Use PIXI.Sprite.from(resource);

ExpoPixi.texture({ localUri: string, width: number, height: number }): PIXI.Texture

Deprecated: Use PIXI.Texture.from(resource);

Pixi.js does a type check so we wrap our asset in a HTMLImageElement shim.

ExpoPixi.Sketch

A component used for drawing smooth signatures and sketches.

See the sketch example on how to save the images!

Notice: the edges and ends are not rounded as this is not supported in PIXI yet: Issue

Props

Property Type Default Description
strokeColor number 0x000000 Color of the lines
strokeWidth number 10 Weight of the lines
strokeAlpha number 1 Opacity of the lines
onChange () => PIXI.Renderer null Invoked whenever a user is done drawing a line
onReady () => WebGLRenderingContext null Invoked when the GL context is ready to be used

ExpoPixi.FilterImage

A Image component that uses PIXI.Filter

Props

Property Type Default Description
resizeMode string null Currently only supports cover, and contain
filters Array null Array of filters to apply to the image
source number, string, Expo.Asset null Source can be a static resource, image url (not {uri}), or an Expo.Asset

Example

Snack

import React from 'react';
import Expo from 'expo';
import { PIXI } from 'expo-pixi';

export default () => (
  <Expo.GLView
    style={{ flex: 1 }}
    onContextCreate={async context => {
      const app = new PIXI.Application({ context });
      const sprite = await PIXI.Sprite.fromExpoAsync(
        'http://i.imgur.com/uwrbErh.png',
      );
      app.stage.addChild(sprite);
    }}
  />
);

NPM