canvasFP.js

import md5 from 'blueimp-md5'

export default function (options) {
    options = options ? options : {};
    var result = {}
    // Very simple now, need to make it more complex (geo shapes etc)
    var canvas = document.createElement('canvas')
    canvas.width = 2000
    canvas.height = 200
    canvas.style.display = 'inline'
    var ctx = canvas.getContext('2d')
    // detect browser support of canvas winding
    // http://blogs.adobe.com/webplatform/2013/01/30/winding-rules-in-canvas/
    // https://github.com/Modernizr/Modernizr/blob/master/feature-detects/canvas/winding.js
    ctx.rect(0, 0, 10, 10)
    ctx.rect(2, 2, 6, 6)
    result.canvasWinding = ((ctx.isPointInPath(5, 5, 'evenodd') === false) ? 'yes' : 'no');


    ctx.textBaseline = 'alphabetic'
    ctx.fillStyle = '#f60'
    ctx.fillRect(125, 1, 62, 20)
    ctx.fillStyle = '#069'
    // https://github.com/Valve/fingerprintjs2/issues/66
    if (options.dontUseFakeFontInCanvas) {
        ctx.font = '11pt Arial'
    } else {
        ctx.font = '11pt no-real-font-123'
    }
    ctx.fillText('Cwm fjordbank glyphs vext quiz, \ud83d\ude03', 2, 15)
    ctx.fillStyle = 'rgba(102, 204, 0, 0.2)'
    ctx.font = '18pt Arial'
    ctx.fillText('Cwm fjordbank glyphs vext quiz, \ud83d\ude03', 4, 45)

    // canvas blending
    // http://blogs.adobe.com/webplatform/2013/01/28/blending-features-in-canvas/
    // http://jsfiddle.net/NDYV8/16/
    ctx.globalCompositeOperation = 'multiply'
    ctx.fillStyle = 'rgb(255,0,255)'
    ctx.beginPath()
    ctx.arc(50, 50, 50, 0, Math.PI * 2, true)
    ctx.closePath()
    ctx.fill()
    ctx.fillStyle = 'rgb(0,255,255)'
    ctx.beginPath()
    ctx.arc(100, 50, 50, 0, Math.PI * 2, true)
    ctx.closePath()
    ctx.fill()
    ctx.fillStyle = 'rgb(255,255,0)'
    ctx.beginPath()
    ctx.arc(75, 100, 50, 0, Math.PI * 2, true)
    ctx.closePath()
    ctx.fill()
    ctx.fillStyle = 'rgb(255,0,255)'
    // canvas winding
    // http://blogs.adobe.com/webplatform/2013/01/30/winding-rules-in-canvas/
    // http://jsfiddle.net/NDYV8/19/
    ctx.arc(75, 75, 75, 0, Math.PI * 2, true)
    ctx.arc(75, 75, 25, 0, Math.PI * 2, true)
    ctx.fill('evenodd')

    if (canvas.toDataURL) {
        result.rawData = canvas.toDataURL();
        result.hash = md5(result.rawData);
    }
    return result
};