public int getLeftRightPadding( Component c ) {
		// Subtract lineWidth from radius because radius is given for the outside
		// of the painted line, but insets from super already include lineWidth.
		// Reduce padding by 10% to make padding slightly smaller because it is not recognizable
		// when the view is minimally painted over the beginning of the border curve.
		int arc = getArc( c );
		return (arc > 0)
			? Math.max( Math.round( UIScale.scale( ((arc / 2f) - getLineWidth( c )) * 0.9f ) ), 0 )
			: 0;
	}
Returns the scaled left/right padding used when arc is larger than zero.
<p>
This is the distance from the inside of the left border to the left side of the view component.
On the right side, this is the distance between the right side of the view component and
the vertical scrollbar. Or the inside of the right border if the scrollbar is hidden.
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatScrollPaneBorder.java