Bezier-rs: Insert function for subpath (#876)

* Add manipulator

* Add manipulator group

* Add UI

* Address comments and rebase

* Renamed add_manipulator_group to insert

Co-authored-by: Rob Nadal <robnadal44@gmail.com>

libraries/bezier-rs/src/subpath/manipulators.rs

@@ -0,0 +1,149 @@
+use super::*;
+use crate::consts::MAX_ABSOLUTE_DIFFERENCE;
+use crate::utils::f64_compare;
+use crate::ComputeType;
+
+impl Subpath {
+	/// Inserts a `ManipulatorGroup` at a certain point along the subpath based on the parametric `t`-value provided.
+	/// Expects `t` to be within the inclusive range `[0, 1]`.
+	pub fn insert(&mut self, t: ComputeType) {
+		match t {
+			ComputeType::Parametric(t) => {
+				assert!((0.0..=1.).contains(&t));
+
+				let number_of_curves = self.len_segments() as f64;
+				let scaled_t = t * number_of_curves;
+
+				let target_curve_index = scaled_t.floor() as i32;
+				let target_curve_t = scaled_t % 1.;
+
+				if f64_compare(target_curve_t, 0., MAX_ABSOLUTE_DIFFERENCE) || f64_compare(target_curve_t, 1., MAX_ABSOLUTE_DIFFERENCE) {
+					return;
+				}
+
+				// The only case where `curve` would be `None` is if the provided argument was 1
+				// But the above if case would catch that, since `target_curve_t` would be 0.
+				let curve = self.iter().nth(target_curve_index as usize).unwrap();
+
+				let [first, second] = curve.split(target_curve_t);
+				let new_group = ManipulatorGroup {
+					anchor: first.end(),
+					in_handle: first.handle_end(),
+					out_handle: second.handle_start(),
+				};
+				let number_of_groups = self.manipulator_groups.len() + 1;
+				self.manipulator_groups.insert((target_curve_index as usize) + 1, new_group);
+				self.manipulator_groups[(target_curve_index as usize) % number_of_groups].out_handle = first.handle_start();
+				self.manipulator_groups[((target_curve_index as usize) + 2) % number_of_groups].in_handle = second.handle_end();
+			}
+			// TODO: change this implementation to Euclidean compute
+			ComputeType::Euclidean(_t) => {}
+			ComputeType::EuclideanWithinError { t: _, epsilon: _ } => todo!(),
+		}
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use glam::DVec2;
+
+	fn set_up_open_subpath() -> Subpath {
+		let start = DVec2::new(20., 30.);
+		let middle1 = DVec2::new(80., 90.);
+		let middle2 = DVec2::new(100., 100.);
+		let end = DVec2::new(60., 45.);
+
+		let handle1 = DVec2::new(75., 85.);
+		let handle2 = DVec2::new(40., 30.);
+		let handle3 = DVec2::new(10., 10.);
+
+		return Subpath::new(
+			vec![
+				ManipulatorGroup {
+					anchor: start,
+					in_handle: None,
+					out_handle: Some(handle1),
+				},
+				ManipulatorGroup {
+					anchor: middle1,
+					in_handle: None,
+					out_handle: Some(handle2),
+				},
+				ManipulatorGroup {
+					anchor: middle2,
+					in_handle: None,
+					out_handle: None,
+				},
+				ManipulatorGroup {
+					anchor: end,
+					in_handle: None,
+					out_handle: Some(handle3),
+				},
+			],
+			false,
+		);
+	}
+
+	fn set_up_closed_subpath() -> Subpath {
+		let mut subpath = set_up_open_subpath();
+		subpath.closed = true;
+		subpath
+	}
+
+	#[test]
+	fn insert_in_first_segment_of_open_subpath() {
+		let mut subpath = set_up_open_subpath();
+		let location = subpath.evaluate(ComputeType::Parametric(0.2));
+		let split_pair = subpath.iter().next().unwrap().split((0.2 * 3.) % 1.);
+		subpath.insert(ComputeType::Parametric(0.2));
+		assert_eq!(subpath.manipulator_groups[1].anchor, location);
+		assert_eq!(split_pair[0], subpath.iter().next().unwrap());
+		assert_eq!(split_pair[1], subpath.iter().nth(1).unwrap());
+	}
+
+	#[test]
+	fn insert_in_last_segment_of_open_subpath() {
+		let mut subpath = set_up_open_subpath();
+		let location = subpath.evaluate(ComputeType::Parametric(0.9));
+		let split_pair = subpath.iter().nth(2).unwrap().split((0.9 * 3.) % 1.);
+		subpath.insert(ComputeType::Parametric(0.9));
+		assert_eq!(subpath.manipulator_groups[3].anchor, location);
+		assert_eq!(split_pair[0], subpath.iter().nth(2).unwrap());
+		assert_eq!(split_pair[1], subpath.iter().nth(3).unwrap());
+	}
+
+	#[test]
+	fn insert_at_exisiting_manipulator_group_of_open_subpath() {
+		// This will do nothing to the subpath
+		let mut subpath = set_up_open_subpath();
+		let location = subpath.evaluate(ComputeType::Parametric(0.75));
+		subpath.insert(ComputeType::Parametric(0.75));
+		assert_eq!(subpath.manipulator_groups[3].anchor, location);
+		assert_eq!(subpath.manipulator_groups.len(), 5);
+		assert_eq!(subpath.len_segments(), 4);
+	}
+
+	#[test]
+	fn insert_at_last_segment_of_closed_subpath() {
+		let mut subpath = set_up_closed_subpath();
+		let location = subpath.evaluate(ComputeType::Parametric(0.9));
+		let split_pair = subpath.iter().nth(3).unwrap().split((0.9 * 4.) % 1.);
+		subpath.insert(ComputeType::Parametric(0.9));
+		assert_eq!(subpath.manipulator_groups[4].anchor, location);
+		assert_eq!(split_pair[0], subpath.iter().nth(3).unwrap());
+		assert_eq!(split_pair[1], subpath.iter().nth(4).unwrap());
+		assert!(subpath.closed);
+	}
+
+	#[test]
+	fn insert_at_last_manipulator_group_of_closed_subpath() {
+		// This will do nothing to the subpath
+		let mut subpath = set_up_closed_subpath();
+		let location = subpath.evaluate(ComputeType::Parametric(1.));
+		subpath.insert(ComputeType::Parametric(1.));
+		assert_eq!(subpath.manipulator_groups[0].anchor, location);
+		assert_eq!(subpath.manipulator_groups.len(), 4);
+		assert!(subpath.closed);
+	}
+}

libraries/bezier-rs/src/subpath/mod.rs

@@ -1,5 +1,6 @@
 mod core;
 mod lookup;
+mod manipulators;
 mod solvers;
 mod structs;
 pub use structs::*;
@@ -9,6 +10,7 @@ use crate::Bezier;
 use std::ops::{Index, IndexMut};
 
 /// Structure used to represent a path composed of [Bezier] curves.
+#[derive(Clone, PartialEq)]
 pub struct Subpath {
 	manipulator_groups: Vec<ManipulatorGroup>,
 	closed: bool,

libraries/bezier-rs/src/subpath/structs.rs

@@ -1,8 +1,24 @@
 use glam::DVec2;
+use std::fmt::{Debug, Formatter, Result};
 
 /// Structure used to represent a single anchor with up to two optional associated handles along a `Subpath`
+#[derive(Copy, Clone, PartialEq)]
 pub struct ManipulatorGroup {
 	pub anchor: DVec2,
 	pub in_handle: Option<DVec2>,
 	pub out_handle: Option<DVec2>,
 }
+
+impl Debug for ManipulatorGroup {
+	fn fmt(&self, f: &mut Formatter<'_>) -> Result {
+		if self.in_handle.is_some() && self.out_handle.is_some() {
+			write!(f, "anchor: {}, in: {}, out: {}", self.anchor, self.in_handle.unwrap(), self.out_handle.unwrap())
+		} else if self.in_handle.is_some() {
+			write!(f, "anchor: {}, in: {}, out: n/a", self.anchor, self.in_handle.unwrap())
+		} else if self.out_handle.is_some() {
+			write!(f, "anchor: {}, in: n/a, out: {}", self.anchor, self.out_handle.unwrap())
+		} else {
+			write!(f, "anchor: {}, in: n/a, out: n/a", self.anchor)
+		}
+	}
+}