Refactor the 'Scatter Points' node to use Kurbo instead of Bezier-rs (#2634)

* it works!

* clean up

* Code review

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

Author: indierusty

demo-artwork/red-dress.graphite

@@ -1,8 +1,7 @@
 use super::poisson_disk::poisson_disk_sample;
-use crate::vector::PointId;
-use bezier_rs::Subpath;
-use glam::{DAffine2, DVec2};
-use kurbo::{BezPath, ParamCurve, ParamCurveDeriv, PathSeg, Point, Shape};
+use crate::vector::misc::dvec2_to_point;
+use glam::DVec2;
+use kurbo::{Affine, BezPath, Line, ParamCurve, ParamCurveDeriv, PathSeg, Point, Rect, Shape};
 
 /// Accuracy to find the position on [kurbo::Bezpath].
 const POSITION_ACCURACY: f64 = 1e-5;
@@ -199,26 +198,29 @@ fn bezpath_t_value_to_parametric(bezpath: &kurbo::BezPath, t: BezPathTValue, pre
 ///
 /// While the conceptual process described above asymptotically slows down and is never guaranteed to produce a maximal set in finite time,
 /// this is implemented with an algorithm that produces a maximal set in O(n) time. The slowest part is actually checking if points are inside the subpath shape.
-pub fn poisson_disk_points(this: &Subpath<PointId>, separation_disk_diameter: f64, rng: impl FnMut() -> f64, subpaths: &[(Subpath<PointId>, [DVec2; 2])], subpath_index: usize) -> Vec<DVec2> {
-	let Some(bounding_box) = this.bounding_box() else { return Vec::new() };
-	let (offset_x, offset_y) = bounding_box[0].into();
-	let (width, height) = (bounding_box[1] - bounding_box[0]).into();
+pub fn poisson_disk_points(bezpath: &BezPath, separation_disk_diameter: f64, rng: impl FnMut() -> f64, subpaths: &[(BezPath, Rect)], subpath_index: usize) -> Vec<DVec2> {
+	if bezpath.elements().is_empty() {
+		return Vec::new();
+	}
+	let bbox = bezpath.bounding_box();
+	let (offset_x, offset_y) = (bbox.x0, bbox.y0);
+	let (width, height) = (bbox.x1 - bbox.x0, bbox.y1 - bbox.y0);
 
 	// TODO: Optimize the following code and make it more robust
 
-	let mut shape = this.clone();
-	shape.set_closed(true);
-	shape.apply_transform(DAffine2::from_translation((-offset_x, -offset_y).into()));
+	let mut shape = bezpath.clone();
+	shape.close_path();
+	shape.apply_affine(Affine::translate((-offset_x, -offset_y)));
 
 	let point_in_shape_checker = |point: DVec2| {
 		// Check against all paths the point is contained in to compute the correct winding number
 		let mut number = 0;
-		for (i, (shape, bb)) in subpaths.iter().enumerate() {
-			let point = point + bounding_box[0];
-			if bb[0].x > point.x || bb[0].y > point.y || bb[1].x < point.x || bb[1].y < point.y {
+		for (i, (shape, bbox)) in subpaths.iter().enumerate() {
+			let point = point + DVec2::new(bbox.x0, bbox.y0);
+			if bbox.x0 > point.x || bbox.y0 > point.y || bbox.x1 < point.x || bbox.y1 < point.y {
 				continue;
 			}
-			let winding = shape.winding_order(point);
+			let winding = shape.winding(dvec2_to_point(point));
 
 			if i == subpath_index && winding == 0 {
 				return false;
@@ -228,9 +230,9 @@ pub fn poisson_disk_points(this: &Subpath<PointId>, separation_disk_diameter: f6
 		number != 0
 	};
 
-	let square_edges_intersect_shape_checker = |corner1: DVec2, size: f64| {
-		let corner2 = corner1 + DVec2::splat(size);
-		this.rectangle_intersections_exist(corner1, corner2)
+	let square_edges_intersect_shape_checker = |position: DVec2, size: f64| {
+		let rect = Rect::new(position.x, position.y, position.x + size, position.y + size);
+		bezpath_rectangle_intersections_exist(bezpath, rect)
 	};
 
 	let mut points = poisson_disk_sample(width, height, separation_disk_diameter, point_in_shape_checker, square_edges_intersect_shape_checker, rng);
@@ -240,3 +242,33 @@ pub fn poisson_disk_points(this: &Subpath<PointId>, separation_disk_diameter: f6
 	}
 	points
 }
+
+fn bezpath_rectangle_intersections_exist(bezpath: &BezPath, rect: Rect) -> bool {
+	if !bezpath.bounding_box().overlaps(rect) {
+		return false;
+	}
+
+	// Top left
+	let p1 = Point::new(rect.x0, rect.y0);
+	// Top right
+	let p2 = Point::new(rect.x1, rect.y0);
+	// Bottom right
+	let p3 = Point::new(rect.x1, rect.y1);
+	// Bottom left
+	let p4 = Point::new(rect.x0, rect.y1);
+
+	let top_line = Line::new((p1.x, p1.y), (p2.x, p2.y));
+	let right_line = Line::new((p2.x, p2.y), (p3.x, p3.y));
+	let bottom_line = Line::new((p3.x, p3.y), (p4.x, p4.y));
+	let left_line = Line::new((p4.x, p4.y), (p1.x, p1.y));
+
+	for segment in bezpath.segments() {
+		for line in [top_line, right_line, bottom_line, left_line] {
+			if !segment.intersect_line(line).is_empty() {
+				return true;
+			}
+		}
+	}
+
+	false
+}

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

@@ -1,4 +1,4 @@
-use super::algorithms::bezpath_algorithms::{PERIMETER_ACCURACY, position_on_bezpath, sample_points_on_bezpath, tangent_on_bezpath};
+use super::algorithms::bezpath_algorithms::{self, PERIMETER_ACCURACY, position_on_bezpath, sample_points_on_bezpath, tangent_on_bezpath};
 use super::algorithms::offset_subpath::offset_subpath;
 use super::misc::{CentroidType, point_to_dvec2};
 use super::style::{Fill, Gradient, GradientStops, Stroke};
@@ -9,13 +9,14 @@ use crate::registry::types::{Angle, Fraction, IntegerCount, Length, Multiplier,
 use crate::renderer::GraphicElementRendered;
 use crate::transform::{Footprint, ReferencePoint, Transform, TransformMut};
 use crate::vector::PointDomain;
+use crate::vector::misc::dvec2_to_point;
 use crate::vector::style::{LineCap, LineJoin};
 use crate::{CloneVarArgs, Color, Context, Ctx, ExtractAll, GraphicElement, GraphicGroupTable, OwnedContextImpl};
 use bezier_rs::{Join, ManipulatorGroup, Subpath, SubpathTValue};
 use core::f64::consts::PI;
 use core::hash::{Hash, Hasher};
 use glam::{DAffine2, DVec2};
-use kurbo::{Affine, Shape};
+use kurbo::{Affine, BezPath, Shape};
 use rand::{Rng, SeedableRng};
 use std::collections::hash_map::DefaultHasher;
 
@@ -1364,36 +1365,30 @@ async fn poisson_disk_points(
 		return VectorDataTable::new(result);
 	}
 	let path_with_bounding_boxes: Vec<_> = vector_data
-		.stroke_bezier_paths()
-		.filter_map(|mut subpath| {
+		.stroke_bezpath_iter()
+		.map(|mut subpath| {
 			// TODO: apply transform to points instead of modifying the paths
-			subpath.apply_transform(vector_data_transform);
-			subpath.loose_bounding_box().map(|bb| (subpath, bb))
+			subpath.apply_affine(Affine::new(vector_data_transform.to_cols_array()));
+			let bbox = subpath.bounding_box();
+			(subpath, bbox)
 		})
 		.collect();
 
 	for (i, (subpath, _)) in path_with_bounding_boxes.iter().enumerate() {
-		if subpath.manipulator_groups().len() < 3 {
+		if subpath.segments().count() < 2 {
 			continue;
 		}
 
-		let mut previous_point_index: Option<usize> = None;
-
-		for point in subpath.poisson_disk_points(separation_disk_diameter, || rng.random::<f64>(), &path_with_bounding_boxes, i) {
-			let point_id = PointId::generate();
-			result.point_domain.push(point_id, point);
+		let mut poisson_disk_bezpath = BezPath::new();
 
-			// Get the index of the newly added point.
-			let point_index = result.point_domain.ids().len() - 1;
-
-			// If there is a previous point, connect it with the current point by adding a segment.
-			if let Some(prev_point_index) = previous_point_index {
-				let segment_id = SegmentId::generate();
-				result.segment_domain.push(segment_id, prev_point_index, point_index, bezier_rs::BezierHandles::Linear, StrokeId::ZERO);
+		for point in bezpath_algorithms::poisson_disk_points(subpath, separation_disk_diameter, || rng.random::<f64>(), &path_with_bounding_boxes, i) {
+			if poisson_disk_bezpath.elements().is_empty() {
+				poisson_disk_bezpath.move_to(dvec2_to_point(point));
+			} else {
+				poisson_disk_bezpath.line_to(dvec2_to_point(point));
 			}
-
-			previous_point_index = Some(point_index);
 		}
+		result.append_bezpath(poisson_disk_bezpath);
 	}
 
 	// Transfer the style from the input vector data to the result.