Class SelectionState

src/plot_state.rs:1324–1330

                Some(axis_ranges.1),
            )?;
            let y1 = data_value_to_plot_with_axis_range(
                hline1.y,
                widget.y_axis_scale,
                hline1.transform.as_ref(),
                Some(axis_ranges.1),
            )?;
            push_quad_as_triangles(&mut vertices, [x0, y0], [x0, y1], [x1, y0], [x1, y1]);
        }
        (FillEndpoint::VLine(vline0), FillEndpoint::VLine(vline1)) => {
            let (y0, y1) = y_domain?;