Bezier-rs: Add trim for Subpath (#1006)

* Move compare.rs

* Update traits for Subpath and ManipulatorGroup

* Implement trim

* UI adjustments and more tests

* Add reverse, refactor code, rename variables

* Improve comments

* Comment nits

* Address comments

* Update trim behavior

* Update doc comment for trim

---------

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

libraries/bezier-rs/src/compare.rs

@@ -0,0 +1,43 @@
+/// Comparison functions used for tests in the bezier module
+use super::{Bezier, CircleArc, Subpath};
+use crate::consts::MAX_ABSOLUTE_DIFFERENCE;
+use crate::utils::f64_compare;
+
+use glam::DVec2;
+
+// Compare two f64s with some maximum absolute difference to account for floating point errors
+pub fn compare_f64s(f1: f64, f2: f64) -> bool {
+	f64_compare(f1, f2, MAX_ABSOLUTE_DIFFERENCE)
+}
+
+/// Compare points by allowing some maximum absolute difference to account for floating point errors
+pub fn compare_points(p1: DVec2, p2: DVec2) -> bool {
+	p1.abs_diff_eq(p2, MAX_ABSOLUTE_DIFFERENCE)
+}
+
+/// Compare vectors of points by allowing some maximum absolute difference to account for floating point errors
+pub fn compare_vec_of_points(a: Vec<DVec2>, b: Vec<DVec2>, max_absolute_difference: f64) -> bool {
+	a.len() == b.len() && a.into_iter().zip(b.into_iter()).all(|(p1, p2)| p1.abs_diff_eq(p2, max_absolute_difference))
+}
+
+/// Compare vectors of beziers by allowing some maximum absolute difference between points to account for floating point errors
+pub fn compare_vector_of_beziers(beziers: &[Bezier], expected_bezier_points: Vec<Vec<DVec2>>) -> bool {
+	beziers
+		.iter()
+		.zip(expected_bezier_points.iter())
+		.all(|(&a, b)| compare_vec_of_points(a.get_points().collect::<Vec<DVec2>>(), b.to_vec(), MAX_ABSOLUTE_DIFFERENCE))
+}
+
+/// Compare circle arcs by allowing some maximum absolute difference between values to account for floating point errors
+pub fn compare_arcs(arc1: CircleArc, arc2: CircleArc) -> bool {
+	compare_points(arc1.center, arc2.center)
+		&& f64_compare(arc1.radius, arc1.radius, MAX_ABSOLUTE_DIFFERENCE)
+		&& f64_compare(arc1.start_angle, arc2.start_angle, MAX_ABSOLUTE_DIFFERENCE)
+		&& f64_compare(arc1.end_angle, arc2.end_angle, MAX_ABSOLUTE_DIFFERENCE)
+}
+
+/// Compare Subpath by verifying that their bezier segments match.
+/// In this way, matching quadratic segments where the handles are on opposite manipulator groups will be considered equal.
+pub fn compare_subpaths<ManipulatorGroupId: crate::Identifier>(subpath1: &Subpath<ManipulatorGroupId>, subpath2: &Subpath<ManipulatorGroupId>) -> bool {
+	subpath1.len() == subpath2.len() && subpath1.closed() == subpath2.closed() && subpath1.iter().eq(subpath2.iter())
+}