Function ncdirect_vline_interp 

pub fn ncdirect_vline_interp(
    ncd: &mut NcDirect,
    egc: &str,
    len: u32,
    h1: impl Into<NcChannels_u64>,
    h2: impl Into<NcChannels_u64>,
) -> NcResult_i32

Draws horizontal lines using the specified NcChannels_u64s, interpolating between them as we go.

The string at egc may not use more than one column.

All lines start at the current cursor position.

For a vertical line, len may be as long as you’d like; the screen will scroll as necessary.

Method: NcDirect.vline_interp().