New to Bangle.js and Espruino. Need help with graphics

Great combination... looking good!

You can right away use fillCircle() without first using drawCircle();.

You can simplify by:

• fill red circle (with outer diameter)
  
• draw green polygon (wedge... with outer diameter where you calculate the polygon coordinates)
  
• fill black circle (with inner diameter)
  
• draw the rest inside the black circle
  
  

For filling a wedge you need only to calculate half the number of 'circle-points'.

For calculation the points on the (outer) circle, use the trigonometric functions Math.sin() (and Math.cos()). For a smooth curve but not to over do, calculate the steps by dividing pi by the diameter of the circle in pixels. To make it fast, you can have a preset array that you calculate before hand (with some JS either in an html page in the browser or a program on your BangleJS that generates the array as literal / code upfront. And as you know, ou need to calculate actually only pi/4 and the rest you 'mirror'.

Since there is no anti-aliasing, you can put rounded values into the array, which you may calculate a bit different: you take y and calc x (rounded) for half a quadrant and mirror the other three (3) quadrants.

When it comes to drawing, you calculate how much of the pre-calculated array you have to use for the polygon.

Besides @Gordon, I know that @JumJum and @MaBe have worked on circles and ellipses and stroke with.