Phenomenon

Phenomenon is a very small, low-level WebGL library that provides the essentials to deliver a high performance experience. Its core functionality is built around the idea of moving millions of particles around using the power of the GPU.

Features:

Small in size, no dependencies
GPU based for high performance
Low-level & highly configurable
Helper functions with options
Add & destroy instances dynamically
Dynamic attribute switching

Want to see some magic right away? Have a look here!

Install

$ npm install --save phenomenon

Usage

// Import the library
import Phenomenon from 'phenomenon';

// Create a renderer
const phenomenon = new Phenomenon(options);

// Add an instance
phenomenon.add("particles", options);

For a better understanding of how to use the library, read along or have a look at the demo!

API

Phenomenon(options)

Returns an instance of Phenomenon.

Throughout this documentation we'll refer to an instance of this as renderer.

options.canvas

Type: HTMLElement
Default: document.querySelector('canvas')

The element where the scene, with all of its instances, will be rendered to. The provided element has to be <canvas> otherwise it won't work.

options.context

Type: Object
Default: {}

Overrides that are used when getting the WebGL context from the canvas. The library overrides two settings by default.

Name	Default	Description
Alpha	`false`	Setting this property to `true` will result in the canvas having a transparent background. By default clearColor is used instead.
Antialias	`false`	Setting this property to `true` will make the edges sharper, but could negatively impact performance. See for yourself if it's worth it!

Read more about all the possible overrides on MDN.

options.contextType

Type: String
Default: webgl

The context identifier defining the drawing context associated to the canvas. For WebGL 2.0 use webgl2.

options.settings

Type: Object
Default: {}

Overrides that can be used to alter the behaviour of the experience.

Name	Value	Default	Description
devicePixelRatio	`number`	`1`	The resolution multiplier by which the scene is rendered relative to the canvas' resolution. Use `window.devicePixelRatio` for the highest possible quality, `1` for the best performance.
clearColor	`array`	`[1,1,1,1]`	The color in `rgba` that is used as the background of the scene.
clip	`array`	`[0.001, 100]`	The near and far clip plane in 3D space.
position	`number`	`{x:0,y:0,z:2}`	The distance in 3D space between the center of the scene and the camera.
shouldRender	`boolean`	`true`	A boolean indicating whether the scene should start rendering automatically.
uniforms	`object`	`{}`	Shared values between all instances that can be updated at any given moment. By default this feature is used to render all the instances with the same `uProjectionMatrix`, `uModelMatrix` and `uViewMatrix`. It's also useful for moving everything around with the same progress value; `uProgress`.
onSetup(gl)	`function`	`undefined`	A setup hook that is called before first render which can be used for gl context changes.
onRender(renderer)	`function`	`undefined`	A render hook that is invoked after every rendered frame. Use this to update `renderer.uniforms`.
debug	`boolean`	`false`	Whether or not the console should log shader compilation warnings.

.resize()

Update all values that are based on the dimensions of the canvas to make it look good on all screen sizes.

.toggle(shouldRender)

Toggle the rendering state of the scene. When shouldRender is false requestAnimationFrame is disabled so no resources are used.

shouldRender

Type: Boolean
Default: undefined

An optional boolean to set the rendering state to a specific value. Leaving this value empty will result in a regular boolean switch.

.add(key, settings)

This function is used to add instances to the renderer. These instances can be as simple or complex as you'd like them to be. There's no limit to how many of these you can add. Make sure they all have a different key!

key

Type: String
Default: undefined

Every instance should have a unique name. This name can also be used to destroy the instance specifically later.

settings

Type: Object
Default: {}

An object containing overrides for parameters that are used when getting the WebGL context from the canvas.

Name	Value	Default	Description
attributes	`array`	`[]`	Values used in the program that are stored once, directly on the GPU.
uniforms	`object`	`{}`	Values used in the program that can be updated on the fly.
vertex	`string`	-	The vertex shader is used to position the geometry in 3D space.
fragment	`string`	-	The fragment shader is used to provide the geometry with color or texture.
multiplier	`number`	`1`	The amount of duplicates that will be created for the same instance.
mode	`number`	`0`	The way the instance will be rendered. Particles = 0, triangles = 4.
geometry	`object`	`{}`	Vertices (and optional normals) of a model.
modifiers	`object`	`{}`	Modifiers to alter the attributes data on initialize.
onRender	`function`	`undefined`	A render hook that is invoked after every rendered frame.

Note: Less instances with a higher multiplier will be faster than more instances with a lower multiplier!

.remove(key)

Remove an instance from the scene (and from memory) by its key.

.destroy()

Remove all instances and the renderer itself. The canvas element will remain in the DOM.

.prepareAttribute(attribute)

Dynamically override an attribute with the same logic that is used during initial creation of the instance. The function requires an object with a name, size and data attribute.

Note: The calculation of the data function is done on the CPU. Be sure to check for dropped frames with a lot of particles.

Attributes can also be switched. In the demo this is used to continue with a new start position identical to the end position. This can be achieved with .prepareBuffer(attribute) in which the data function is replaced with the final array.

Examples

Contribute

Are you excited about this library and have interesting ideas on how to improve it? Please tell me or contribute directly! 🙌

npm install > npm start > http://localhost:8080

License

MIT © Colin van Eenige