Analog Clocks - programming hint

The time to draw the dial on a Bangle2 (with radius 88 rather that 120) with the code above took 376ms. The time using a version of drawRotRect that does not use transformVertices was 490ms - or 114ms slower. Timed using:

 var tt = Date.now(); 
dial(); 
console.log("Time: "+Math.ceil(Date.now()-tt)+"ms");