GCanvas/node/examples/gradients.js

const { createCanvas, Image } = require('../export');
const canvas = createCanvas(320, 320)
const ctx = canvas.getContext('2d')

// Create gradients
var lingrad = ctx.createLinearGradient(0, 0, 0, 150)
lingrad.addColorStop(0, '#00ABEB')
lingrad.addColorStop(0.5, '#fff')
lingrad.addColorStop(0.5, '#26C000')
lingrad.addColorStop(1, '#fff')

var lingrad2 = ctx.createLinearGradient(0, 50, 0, 95)
lingrad2.addColorStop(0.5, '#ff0000')
lingrad2.addColorStop(1, 'rgba(0,0,0,0)')

// assign gradients to fill and stroke styles
ctx.fillStyle = lingrad
ctx.fillRect(10, 10, 130, 130)
ctx.strokeStyle = lingrad2

// draw shapes

ctx.strokeRect(50, 50, 50, 50)

const fs = require('fs')
const path = require('path')
const out = fs.createWriteStream(path.join(__dirname, "..")+ '/gradients.png');
var stream = canvas.createPNGStream();
stream.pipe(out);