canvas

A lightweight wrapper around the <canvas> element to ease context and ratio handling.

Install

npm install watsondg/canvas -S

Usage

var Canvas = require('canvas');

var canvas = new Canvas({
    ratio: 1 // force to a specific deviceRatio
});
canvas.resize(200, 200);
var ctx = canvas.context;
var r = canvas.ratio;

ctx.lineTo(20 * r, 10 * r);
ctx.lineTo(25 * r, 70 * r);
ctx.stroke();

Static Methods

Canvas.getDPI()

Defines how the DPI (simple, retina, ...) is calculated. Useful to override if you want to defaults to some processed value based on performance and device. Defaults to window.devicePixelRatio.

Instance Methods

new Canvas([options])

Create a new instance of Canvas.

• options - (OPTIONAL) - configuration parameters:

• ratio: force a devicePixelRatio. Defaults to window.devicePixelRatio or 1.
• parent: a DOM element to automatically append to. If not provided, appending canvas.el is up to you.

resize(width, height)

Resize the canvas while maintaining ratio.

• width - the width to set the canvas to.
• height - the height to set the canvas to.

clear()

Clear the canvas.

snapshot(type, quality)

• shortcut to canvas.toDataURL.

destroy()

Destroy the instance.

License

MIT.