diff --git a/crates/engine/src/vectoredit/ops.rs b/crates/engine/src/vectoredit/ops.rs index 093d0854..cce23d15 100644 --- a/crates/engine/src/vectoredit/ops.rs +++ b/crates/engine/src/vectoredit/ops.rs @@ -3,7 +3,7 @@ //! `vectoredit.rs` re-fit the node afterwards. use figcraft_doc::*; -use figcraft_geom::kurbo::{CubicBez, ParamCurve}; +use figcraft_geom::kurbo::{CubicBez, ParamCurve, ParamCurveNearest}; use figcraft_geom::{Affine, Point, Vec2}; fn tvec(t: (f64, f64)) -> Vec2 { @@ -766,6 +766,19 @@ fn inside_ranges(net: &VectorNetwork, seg: usize, c: Point, r: f64) -> Vec<(f64, if ia { b } else { a } }; let n = 64; + // Upper bound on the curve's speed: no point of a sample interval is farther than the whole + // interval length from either end, so only intervals that come that close need a closer look. + let speed = 3.0 * [(cb.p1 - cb.p0).hypot(), (cb.p2 - cb.p1).hypot(), (cb.p3 - cb.p2).hypot()].into_iter().fold(0.0, f64::max); + let reach = speed / f64::from(n); + // A crossing narrower than an interval whose ends are both outside: the closest point. + let dip = |a: f64, b: f64| -> Option { + if (cb.eval(a) - c).hypot().min((cb.eval(b) - c).hypot()) > r + reach { + return None; + } + let near = cb.subsegment(a..b).nearest(c, 1e-12); + let m = a + (b - a) * near.t; + (m > a && m < b && inside(m)).then_some(m) + }; let mut out = Vec::new(); let mut start: Option = if inside(0.0) { Some(0.0) } else { None }; let mut prev = 0.0; @@ -773,6 +786,11 @@ fn inside_ranges(net: &VectorNetwork, seg: usize, c: Point, r: f64) -> Vec<(f64, let t = f64::from(i) / f64::from(n); match (start, inside(t)) { (None, true) => start = Some(edge(prev, t)), + (None, false) => { + if let Some(m) = dip(prev, t) { + out.push((edge(prev, m), edge(m, t))); + } + } (Some(s0), false) => { out.push((s0, edge(prev, t))); start = None; @@ -999,4 +1017,38 @@ mod tests { assert!(!erase(&mut m, Point::new(f64::NAN, 0.0), 5.0)); assert!(!erase(&mut m, Point::new(0.0, 0.0), -1.0)); } + + #[test] + fn eraser_catches_narrow_crossing_between_samples() { + // A radius-1 brush on a long line: the crossing fits between the sampled parameters. + let mut n = VectorNetwork::from_points(&[Point::new(0.0, 0.0), Point::new(6400.0, 0.0)], false); + assert!(erase(&mut n, Point::new(5050.0, 0.0), 1.0)); + assert_eq!(n.segments.len(), 2); + let ends: Vec = n.vertices.iter().map(|v| v.x).collect(); + assert!(ends.iter().any(|x| (x - 5049.0).abs() < 0.01) && ends.iter().any(|x| (x - 5051.0).abs() < 0.01), "{ends:?}"); + assert!(ends.iter().any(|x| x.abs() < 1e-9) && ends.iter().any(|x| (x - 6400.0).abs() < 1e-9), "{ends:?}"); + // A curved segment that only grazes the brush between samples. + let mut c = VectorNetwork::from_points(&[Point::new(0.0, 0.0), Point::new(6400.0, 0.0)], false); + c.segments[0].ta = (0.0, 3000.0); + c.segments[0].tb = (0.0, 3000.0); + let cb = c.cubic(0).unwrap(); + let t = 0.7039; + let p = cb.eval(t); + let d = figcraft_geom::kurbo::ParamCurveDeriv::deriv(&cb).eval(t).to_vec2().normalize(); + let normal = Vec2::new(-d.y, d.x); + assert!(erase(&mut c, p + normal * 0.5, 1.0)); + assert_eq!(c.segments.len(), 2); + } + + #[test] + fn eraser_catches_crossing_at_full_speed_between_samples() { + // The line moves fastest at t = 0.5; centre a tiny brush halfway between two samples there. + let mut n = VectorNetwork::from_points(&[Point::new(0.0, 0.0), Point::new(6400.0, 0.0)], false); + let centre = n.cubic(0).unwrap().eval(32.5 / 64.0); + assert!(erase(&mut n, centre, 0.5)); + assert_eq!(n.segments.len(), 2); + let ends: Vec = n.vertices.iter().map(|v| v.x).collect(); + assert!(ends.iter().any(|x| (x - (centre.x - 0.5)).abs() < 0.01), "{ends:?}"); + assert!(ends.iter().any(|x| (x - (centre.x + 0.5)).abs() < 0.01), "{ends:?}"); + } }