- /**
- * Paints a zero axis across the viewport.
- * @param p the QPainter to paint into.
- * @param y the y-offset of the axis.
- * @param left the x-coordinate of the left edge of the view.
- * @param right the x-coordinate of the right edge of the view.
- */
- void paint_axis(QPainter &p, int y, int left, int right);