Why context2d.backingStorePixelRatio deprecated?

Question

According to Paul Lewis's article, High DPI Canvas: You need to take into account the context.backingStorePixelRatio to solve blurring issues.

If this property was deprecated, will dart take care of the blur issue on high definition device?

Answer 1

I thought the exact same thing and as far as the Issue Tracker tells:

Yes, so the article was written back when Safari had a backing store ratio of 2. It's always been 1 in Chrome.

As you say the approach for dealing with this is:

canvas.width = width * window.devicePixelRatio;
canvas.height = height * window.devicePixelRatio;

canvas.style.width = width + 'px';
canvas.style.height = height + 'px';

Where width and height are however you want them (probably window.innerWidth & innerHeight for full viewport shenanigans.)

Then you just need to adjust for the fact that you upscaled the canvas with:

ctx.scale(window.devicePixelRatio, window.devicePixelRatio);

So there you have your solution.