Drawing on moving object

Hi!

I am a newbie in unity and I am trying to do a 2D app.
The whole point is to draw on a rotating circle/square.
It can draw several lines with different colors and and the circle itself may already have some in the beginning.
How should I go about this, what would be the most efficient way of doing it?

Thanks!

One step at a time, just like you learn to walk.

Imphenzia: How Did I Learn To Make Games:

DO NOT be thinking about efficiency. Use these two steps:

  1. Get it working

  2. Get it working well.

Often times #2 will happen just as a happy byproduct of doing #1.