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sprinkler

sprinkler.jsv0.4.3

With Sprinkler you can create an image rain on canvas. Give it a canvas element and a list of image paths and call start() to make it rain bananas or frogs or anything you can imagine!

Compatible with all the browsers that support canvas.

Examples

Usage

The following will make the canvas rain snowflakes.

var c = document.getElementById('canvas');
var s = Sprinkler.create(c);

var images = [
  'img/snowflake.png',
  'img/snowflakeb.png',
  'img/snowflakec.png'
];
s.load(images, function (err, start) {
  start();
});

Installation

Browsers

<script src="scripts/sprinkler.js"></script>

CommonJS & Node.js

$ npm install sprinkler
---
> var Sprinkler = require('sprinkler');

AMD & Require.js

define(['scripts/sprinkler'], function (Sprinkler) { ... });

API

Sprinkler.create(canvasElement)

Create a sprinkler animation on the given canvas.

#load(imagePaths, callback(err, start))

Loads image files specified by the image source paths in imagePaths and then calls the callback. Returns nothing.

imagePaths, an array of image source paths.

start(options)

Start animation. start is given via load callback.

Returns a stop function that stops the animation.

Optional options object can take following properties:

  • selectImages, an array of indices of the images to be used
  • imagesInSecond, an average number of dropped images in a second
  • zMin and zMax, range for initial scale, z, in [0, Inf]
  • rMin and rMax, range for initial __r__otation, in [0, 2*Math.PI]
  • aMin and aMax, range for initial transparency (__a__lpha), in [0, 1]
  • dxMin and dxMax, range for horizontal velocity, in [-Inf, Inf]
  • dyMin and dyMax, range for vertical velocity, in [0, Inf]
  • dzMin and dzMax, range for scale velocity, in [-Inf, Inf]
  • drMin and drMax, range for rotation velocity, in [-Inf, Inf]
  • daMin and daMax, range for transparency velocity, in [-Inf, Inf]
  • ddxMin and ddxMax, range for horizontal acceleration, in [-Inf, Inf]
  • ddyMin and ddyMax, range for vertical acceleration, in [0, Inf]
  • ddzMin and ddzMax, range for scale acceleration, in [-Inf, Inf]
  • ddrMin and ddrMax, range for rotation acceleration, in [-Inf, Inf]
  • ddaMin and ddaMax, range for transparency acceleration, in [-Inf, Inf]

Values are picked randomly but uniformly from the given ranges.

Default values are:

{
  selectImages: [all],
  imagesInSecond: 7,
  zMin: 0.38, zMax: 1,
  rMin: 0, rMax: 2 * Math.PI,
  aMin: 1, aMax: 1,
  dxMin: -1, dxMax: 1,
  dyMin: 100, dyMax: 100,
  dzMin: 0, dzMax: 0,
  drMin: -1, drMax: 1,
  daMin: 0, daMax: 0,
  ddxMin: 0, ddxMax: 0,
  ddyMin: 0, ddyMax: 0,
  ddzMin: 0, ddzMax: 0,
  ddrMin: 0, ddrMax: 0,
  ddaMin: 0, ddaMax: 0,
}

stop()

Stops the animation. stop is returned by start.

Notes for developers

Run tests with $ npm test.

Build with $ npm run build.

Serve with $ npm start.

Todo

  • improved tests

Versioning

Semantic Versioning 2.0.0

License

MIT License