making the gif for bigclicker

gif.js

var Canvas = require('canvas'),
    fs = require('fs'),
    pad = require('pad'),
    canvas = new Canvas(200,200),
    ctx = canvas.getContext('2d');

ctx.antialias = 'none';

function line(x) {
    ctx.globalCompositeOperation = 'source-over';
    ctx.beginPath();
    ctx.lineTo(x, 0);
    ctx.lineTo(x + (100 * (Math.sqrt(2)/3)), 100);
    ctx.lineTo(x, 200);

    ctx.strokeStyle = '#fff';
    ctx.lineWidth = 2;
    ctx.stroke();
}

function mask() {

    radius = 100;
    ctx.fillStyle = '#000';
    ctx.globalCompositeOperation = 'destination-atop';
    ctx.beginPath();
    ctx.arc(radius, radius, radius * 0.95, 0, Math.PI*2, true);
    ctx.closePath();
    ctx.fill();

}

var i = 0;
for (var x = -60; x < -20; x++) {
    canvas.width = 200;
    for (var z = x; z < 200; z += 20) {
        line(z);
    }
     mask();
    fs.writeFileSync('frames/' + pad(15, (i++) + 'frame.png', '0'), canvas.toBuffer());
}