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const CanvasKitInit = require('./bin/canvaskit.js');
const fs = require('fs');
const path = require('path');
CanvasKitInit({
locateFile: (file) => __dirname + '/bin/'+file,
}).then((CanvasKit) => {
let canvas = CanvasKit.MakeCanvas(300, 300);
let img = fs.readFileSync(path.join(__dirname, 'test.png'));
img = canvas.decodeImage(img);
let fontData = fs.readFileSync(path.join(__dirname, './Roboto-Regular.woff'));
canvas.loadFont(fontData, {
'family': 'Roboto',
'style': 'normal',
'weight': '400',
});
let ctx = canvas.getContext('2d');
ctx.font = '30px Roboto';
ctx.rotate(.1);
ctx.fillText('Awesome ', 50, 100);
ctx.strokeText('Groovy!', 250, 100);
// Draw line under Awesome
ctx.strokeStyle = 'rgba(125,0,0,0.5)';
ctx.beginPath();
ctx.lineWidth = 6;
ctx.lineTo(50, 102);
ctx.lineTo(250, 102);
ctx.stroke();
// squished vertically
ctx.globalAlpha = 0.7
ctx.imageSmoothingQuality = 'medium';
ctx.drawImage(img, 150, 150, 150, 100);
ctx.rotate(-.2);
ctx.imageSmoothingEnabled = false;
ctx.drawImage(img, 100, 150, 400, 350, 10, 200, 150, 100);
console.log('<img src="' + canvas.toDataURL() + '" />');
fancyAPI(CanvasKit);
});
function fancyAPI(CanvasKit) {
let surface = CanvasKit.MakeSurface(300, 300);
const canvas = surface.getCanvas();
const paint = new CanvasKit.Paint();
const fontMgr = CanvasKit.FontMgr.RefDefault();
let robotoData = fs.readFileSync(path.join(__dirname, './Roboto-Regular.woff'));
const roboto = fontMgr.MakeTypefaceFromData(robotoData);
const textPaint = new CanvasKit.Paint();
textPaint.setColor(CanvasKit.Color(40, 0, 0));
textPaint.setAntiAlias(true);
const textFont = new CanvasKit.Font(roboto, 30);
const skpath = starPath(CanvasKit);
const dpe = CanvasKit.PathEffect.MakeDash([15, 5, 5, 10], 1);
paint.setPathEffect(dpe);
paint.setStyle(CanvasKit.PaintStyle.Stroke);
paint.setStrokeWidth(5.0);
paint.setAntiAlias(true);
paint.setColor(CanvasKit.Color(66, 129, 164, 1.0));
canvas.clear(CanvasKit.Color(255, 255, 255, 1.0));
canvas.drawPath(skpath, paint);
canvas.drawText('Try Clicking!', 10, 280, textPaint, textFont);
surface.flush();
const img = surface.makeImageSnapshot();
if (!img) {
console.error('no snapshot');
return;
}
const pngBytes = img.encodeToBytes();
if (!pngBytes) {
console.error('encoding failure');
return
}
// See https://stackoverflow.com/a/12713326
let b64encoded = Buffer.from(pngBytes).toString('base64');
console.log(`<img src="data:image/png;base64,${b64encoded}" />`);
// These delete calls free up memeory in the C++ WASM memory block.
dpe.delete();
skpath.delete();
textPaint.delete();
paint.delete();
roboto.delete();
textFont.delete();
surface.dispose();
}
function starPath(CanvasKit, X=128, Y=128, R=116) {
let p = new CanvasKit.Path();
p.moveTo(X + R, Y);
for (let i = 1; i < 8; i++) {
let a = 2.6927937 * i;
p.lineTo(X + R * Math.cos(a), Y + R * Math.sin(a));
}
return p;
}