pixijs / storybook

Storybook for PixiJS

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Storybook for PixiJS is a UI development environment for your PixiJS Components. With it, you can visualize different states of your Components and develop them interactively.

Storybook runs outside of your app. So you can develop UI components in isolation without worrying about app specific dependencies and requirements.

Getting Started

We don't currently have a init script for PixiJS storybook. Currently the easiest way is to initialize with the html framework and manually edit the configuration:

cd my-app
npx storybook@"~7.0.0-beta" init -t html

Remove HTML framework/renderer and install PixiJS framework/renderer:

npm remove @storybook/html @storybook/html-webpack5 --save-dev
npm install @pixi/storybook-renderer @pixi/storybook-webpack5 --save-dev

Replace .storybook/main.js with the below, setting up the correct paths as necessary.

module.exports = {
  // use glob matching, eg: ../src/stories/**/*.stories.@(ts|tsx|js|jsx|mdx)
  stories: ['RELATIVE_PATH_TO_STORIES'],
  staticDirs: ['RELATIVE_PATH_TO_ASSETS'],
  logLevel: 'debug',
  addons: [
    '@storybook/addon-actions',
    '@storybook/addon-backgrounds',
    '@storybook/addon-controls',
    '@storybook/addon-viewport',
    '@storybook/addon-links',
    '@storybook/addon-highlight',
  ],
  core: {
    channelOptions: { allowFunction: false, maxDepth: 10 },
    disableTelemetry: true,
  },
  features: {
    buildStoriesJson: true,
    breakingChangesV7: true,
  },
  framework: '@pixi/storybook-webpack5',
};

Replace .storybook/preview.js with:

export const parameters = { 
  layout: 'fullscreen', 
  pixi: {
    // these are passed as options to `PIXI.Application` when instantiated by the 
    // renderer
    applicationOptions: {
      backgroundColor: 0x1099bb,
      resolution: 1,
    },
    // optional, if you want to provide custom resize logic, pass a function here,
    // if nothing is provided, the default resize function is used, which looks like
    // this, where w and h will be the width and height of the storybook canvas.
    resizeFn: (w, h) => {
      return {
        rendererWidth: w,
        rendererHeight: h,
        canvasWidth: w,
        canvasHeight: h,
      };
    },
  },
};

Depending on where you want to keep your story source, either delete src/stories folder if you plan to keep your stories co-located with their components, or empty src/stories of the example HTML stories and replace with your own. See below for instructions on how to write PixiJS Stories in the correct format.

PixiJS Stories

Unlike reactive web UI frameworks, PixiJS requires a more imperative code style to interact with the HTML5 Canvas API. Components are added to a display list, most commonly via a top level Application instance, and often need to respond to application-level events and callbacks. This Pixi renderer, handles setting up an Application and Renderer for you and handles adding and removing your Story's DisplayObject from the Stage, but in order to accommodate this, PixiJS stories must return a JS object with a fixed API:

type StoryFnPixiReturnType = {
  view: DisplayObject; 
  // optionally respond to requestAnimationFrame tick
  update?: (delta: number) => void;
  // optionally respond to application level resizing
  resize?: (rendererWidth: number, rendererHeight: number) => void;
  // optionally clean up things when story is rerendered / removed - this happens a lot, so do it!
  destroy?: () => void;
}

If your component already matches this particular interface, then you can just return an instance of it.

You can see an example story here

Decorators

PixiJS Storybook Framework is compatible with Storybook Decorators, these just need to return stories in the above API, for example you could add margin to a Story's component like so:

import { Container } from 'pixi.js';

const MARGIN = 10;
const DOUBLE_MARGIN = MARGIN * 2;

export const backgroundDecorator = (story) => {
  // The extra Container isn't really necessary just to add margin, but it shows how it's
  // possible to wrap with other PIXI objects
  const root = new Container();
  
  // storyResult is the value returned from your Story function
  const storyResult = story();
  
  root.addChild(storyResult.view);
  
  // Decorate the storyResult with other graphics / functionality:
  return {
    view: root,
    update: (delta) => storyResult.update?.(delta),
    resize: (screenWidth, screenHeight) => {
      root.x = MARGIN;
      root.y = MARGIN;
      
      storyResult.resize?.(screenWidth - DOUBLE_MARGIN, screenHeight - DOUBLE_MARGIN);
    },
    destroy: () => storyResult.destroy?.(),
  };
};

Then add the decorator to ./storybook/preview.js:

import { backgroundDecorator } from 'decorators/backgroundDecorator';

// ...

export const decorators = [backgroundDecorator];

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Storybook also comes with a lot of addons and a great API to customize as you wish. You can also build a static version of your Storybook and deploy it anywhere you want.