Pressure sensitivity

[blurymind]

Web api's allow to get pressure sensitivity data from the PointerEvent (event.pressure). That can be used to drive line thickness, which makes a huge difference when you use a samsung galaxy note device for example.
My findings were that one must enable pointer events first

See Fabricjs got this a while back in 3.0.0
Canvas.enablePointerEvents

someone also wrote a brush that uses it,since the ordinary one doesnt have varied thickness it seems
fabricjs/fabric.js#4885
https://research.archinc.jp/fabricjs-psbrush/

fabric also has a pencilbrush, although not sure if it has point thickness/opacity which pressure can use
http://fabricjs.com/docs/fabric.PencilBrush.html

outside of fabricjs there are a few examples of this such as
https://github.com/amoshydra/draw