garageCube

It doesn't paint an arc like a pie chart.
It paints a circle partly occluded by a line from the edge of the circle.
Drawing an arc from 0 to 90 degrees should result in a quarter circle, with a right angle at the center.
Instead it results in tiny slice of the edge of a circle.
Sweeping the endAngle from 0 to 360 should fill it in like the hand of a clock sweeping from the center.
Instead it reveals a circle as if sweeping from the 3 o'clock position on the edge of the circle.

See attached for what results from

radius = 20
startAngle = 0
endAngle = 90
module.paintArc('deckAView', 20, 20, radius, 0, 360, 1, 0, 0, 1)
module.paintArc('deckAView', 20, 20, radius, startAngle, endAngle, 1, 1, 1, 1)