It should be possible to specify origin of the bar indicator. For example, the radial scale is going from -10 to 10. In the current implementation bar indicator always starts at the minimum of the scale. We should have an ability to change origin of the bar indicator so that it starts at 0. I.e. if the value of the bar indicator was set to 5 then the bar should start at 0 and go to 5, currently is starts at -10 and goes to 5.