How to draw a rectangle with rounded corners in Espruino

rectRnd_sample.js

g.clear();
function RectRnd(x1,y1,x2,y2,r) {
      pp = [];
      pp.push.apply(pp,g.quadraticBezier([x2-r,y1, x2,y1,x2,y1+r]));
      pp.push.apply(pp,g.quadraticBezier([x2,y2-r,x2,y2,x2-r,y2]));
      pp.push.apply(pp,g.quadraticBezier([x1+r,y2,x1,y2,x1,y2-r]));
      pp.push.apply(pp,g.quadraticBezier([x1,y1+r,x1,y1,x1+r,y1]));
      return pp;
}
function fillRectRnd(x1,y1,x2,y2,r) {
      g.fillPoly(RectRnd(x1,y1,x2,y2,r),1);
}
function drawRectRnd(x1,y1,x2,y2,r) {
      g.drawPoly(RectRnd(x1,y1,x2,y2,r),1);
}
drawRectRnd(10,10,150,50,5);
fillRectRnd(10,60,150,120,5);