@gush/candybar

Candybar 🍫

A simple <canvas> rendering engine and collection of classes and utils. And by "engine" I mean about as advanced as a broken scooter 🛴 on fire 🔥

🚨 This is an alpha release

Really, don't use this thing for anything yet.

Getting started

First, install it

yarn add @gush/candybar

then create a canvas

import { Canvas } from '@gush/candybar';

const canvas = new Canvas({
    canvas: document.getElementById('canvas'),
});

which will leave you with a beautiful blank canvas. 🙌🏻

Canvas options

Canvas classes can be created with a few options:

• canvas
• container
• hasPointer
• entities
• pauseInBackground
• dpr

new Canvas({
    // This is the required HTML element that the Canvas class will render to.
    canvas: document.getElementById('canvas'),
    // Container is the element that the canvas should be fit within,
    // if this is not provided it's assumed this is a full screen canvas
    container: document.getElementById('container'),
    // Indicates if the canvas should capture mouse/touch pointer events.
    hasPointer: true,
    // Indicates if the engine should pause when the window is not in focus
    pauseInBackground: true,
    // Entities are objects that will be renedered by the Canvas engine.
    entities: [...things],
    // Override Device Pixel Ratio. Defaults based on device and falls back to 1.
    dpr: 1,
});

Entities

The engine will loop through each entity and call a couple methods to "render" the entity. First a draw() method is called where you should do any drawing using the HTML canvas API. Then an update() method is called which should be used to update any properties based on the engine.

class MyThing {
    constructor() {
        this.x = 0;
        this.y = 0;
    }

    setup = ({ canvas }) => {
        // setup will be called once before the first draw and is provided the class context
        this.w = canvas.width / 10;
        window.addEventListener('resize', handleResize);
    };

    destroy = () => {
        // called when destroy is called on the Canvas
        window.removeEventListener('resize', handleResize);
    };

    draw = ({ ctx }) => {
        // draw with canvas API through the provided context
        ctx.fillRect(this.x, this.y, 100, 100);
    };

    update = ({ pointer }) => {
        // update the rect position based on pointer position
        const { x, y } = this.pointer.position;
        this.x = x;
        this.y = y;
    };

    resize = (context, event) => {
        // handle resize events.
        this.w = context.canvas.width / 10;
    };
}