Optimize grid rounding and add debug output

Author: TrueDoctor

libraries/path-bool/src/path/intersection_path_segment.rs

@@ -1,3 +1,5 @@
+use std::io::Write;
+
 use crate::aabb::{bounding_box_max_extent, bounding_boxes_overlap, Aabb};
 use crate::epsilons::Epsilons;
 use crate::line_segment::{line_segment_intersection, line_segments_intersect};
@@ -113,7 +115,15 @@ pub fn path_segment_intersection(seg0: &PathSegment, seg1: &PathSegment, endpoin
 			};
 
 			let intersections = path1.cubic_intersections_t(&path2);
+			let mut file = std::fs::File::options().append(true).create(true).open("/tmp/intersections").unwrap();
+			let format_curve = |seg0: &PathSegment| seg0.to_cubic().map(|point| format!("{} {}", point.x, point.y)).join(" ");
 			let intersections: Vec<_> = intersections.into_iter().map(|(s, t)| [s, t]).collect();
+			let intersections_fmt: Vec<_> = intersections.iter().map(|[s, t]| format!("{},{}", s, t)).collect();
+			if !intersections.is_empty() {
+				writeln!(&mut file, "{}\n{}\n{}\n", format_curve(seg0), format_curve(seg1), intersections_fmt.join(" "),).unwrap();
+				file.flush().unwrap();
+			}
+			// let intersections: Vec<_> = intersections.into_iter().map(|(s, t)| [s, t]).collect();
 			return intersections;
 		}
 		(PathSegment::Cubic(_, _, _, _), PathSegment::Line(_, _)) => {
@@ -125,6 +135,7 @@ pub fn path_segment_intersection(seg0: &PathSegment, seg1: &PathSegment, endpoin
 		_ => (),
 	};
 
+	// Fallback for quadratics and arc segments
 	// https://math.stackexchange.com/questions/20321/how-can-i-tell-when-two-cubic-b%C3%A9zier-curves-intersect
 
 	let mut pairs = vec![(

libraries/path-bool/src/util/grid.rs

@@ -4,14 +4,14 @@ use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
 
 pub(crate) struct Grid {
-	cell_size: f64,
+	cell_factor: f64,
 	cells: FxHashMap<IVec2, SmallVec<[usize; 6]>>,
 }
 
 impl Grid {
 	pub(crate) fn new(cell_size: f64, edges: usize) -> Self {
 		Grid {
-			cell_size,
+			cell_factor: cell_size.recip(),
 			cells: FxHashMap::with_capacity_and_hasher(edges, Default::default()),
 		}
 	}
@@ -45,7 +45,7 @@ impl Grid {
 	}
 
 	fn point_to_cell(&self, point: DVec2) -> IVec2 {
-		(point / self.cell_size).as_ivec2()
+		(point * self.cell_factor).as_ivec2()
 	}
 }