Function fill_polygon

std/src/console/drawing.rs:322–356

Fills the poligon defined by `points` using a scanline intersection algorithm.

(rasops: &mut R, points: &[PixelsXY])

/// Fills the poligon defined by `points` using a scanline intersection algorithm.
fn fill_polygon<R>(rasops: &mut R, points: &[PixelsXY]) -> io::Result<()>
where
    R: RasterOps + ?Sized,
{
    if points.is_empty() {
        return Ok(());
    }

    let min_y = points.iter().map(|p| i32::from(p.y)).min().expect("Points are not empty");
    let max_y = points.iter().map(|p| i32::from(p.y)).max().expect("Points are not empty");

    for y in min_y..=max_y {
        let mut xs = vec![];
        for i in 0..points.len() {
            let next = (i + 1) % points.len();
            if let Some(x) = edge_intersection(y, points[i], points[next]) {
                xs.push(x);
            }
        }

        if xs.len() < 2 {
            continue;
        }

        xs.sort_unstable();
        for pair in xs.chunks_exact(2) {
            rasops.draw_line(
                PixelsXY::new(pair[0].clamped_into(), y.clamped_into()),
                PixelsXY::new(pair[1].clamped_into(), y.clamped_into()),
            )?;
        }
    }

    Ok(())
}

/// Draws a filled polygon via `rasops`.
pub fn draw_poly_filled<R>(rasops: &mut R, points: &[PixelsXY]) -> io::Result<()>