Improve performance for finding path segment intersection using loose bbox

node-graph/gcore/src/vector/algorithms/intersection.rs

@@ -1,4 +1,4 @@
-use super::contants::MIN_SEPARATION_VALUE;
+use super::{contants::MIN_SEPARATION_VALUE, util::pathseg_loose_bbox};
 use kurbo::{BezPath, DEFAULT_ACCURACY, ParamCurve, PathSeg, Shape};
 
 /// Calculates the intersection points the bezpath has with a given segment and returns a list of `(usize, f64)` tuples,
@@ -63,8 +63,8 @@ pub fn subsegment_intersections(segment1: PathSeg, min_t1: f64, max_t1: f64, seg
 /// by splitting the segment recursively until the size of the subsegment's bounding box is smaller than the accuracy.
 #[allow(clippy::too_many_arguments)]
 fn segment_intersections_inner(segment1: PathSeg, min_t1: f64, max_t1: f64, segment2: PathSeg, min_t2: f64, max_t2: f64, accuracy: f64, intersections: &mut Vec<(f64, f64)>) {
-	let bbox1 = segment1.subsegment(min_t1..max_t1).bounding_box();
-	let bbox2 = segment2.subsegment(min_t2..max_t2).bounding_box();
+	let bbox1 = pathseg_loose_bbox(segment1.subsegment(min_t1..max_t1));
+	let bbox2 = pathseg_loose_bbox(segment2.subsegment(min_t2..max_t2));
 
 	let mid_t1 = (min_t1 + max_t1) / 2.;
 	let mid_t2 = (min_t2 + max_t2) / 2.;

node-graph/gcore/src/vector/algorithms/util.rs

@@ -1,5 +1,20 @@
 use glam::DVec2;
-use kurbo::{ParamCurve, ParamCurveDeriv, PathSeg};
+use kurbo::{ParamCurve, ParamCurveDeriv, PathSeg, Rect};
+
+use crate::vector::misc::pathseg_points_vec;
+
+pub fn pathseg_loose_bbox(segment: PathSeg) -> Rect {
+	pathseg_points_vec(segment)
+		.iter()
+		.fold(None, |bbox: Option<Rect>, point| {
+			if let Some(bbox) = bbox {
+				Some(Rect::new(bbox.x0.min(point.x), bbox.y0.min(point.y), bbox.x1.max(point.x), bbox.y1.max(point.y)))
+			} else {
+				Some(Rect::new(point.x, point.y, point.x, point.y))
+			}
+		})
+		.unwrap()
+}
 
 pub fn pathseg_tangent(segment: PathSeg, t: f64) -> DVec2 {
 	// NOTE: .deriv() method gives inaccurate result when it is 1.