Bezier-rs: Add parametric evaluate and line intersect to subpath (#852)

* add slider to subpath component + change evaluate to take an enum

Co-authored-by: Rob Nadal <RobNadal@users.noreply.github.com>

wip - add intersect to subpath, TODO fix bug

Co-authored-by: Rob Nadal <RobNadal@users.noreply.github.com>

add unit tests to subpath intersections

stress, testing

Co-authored-by: Hannah Li <hannahli2010@gmail.com>

* add parametric eval impl to subpath

* add line intersection to subpath

* Uncomment and #[ignore] disabled tests

* Reorder a few imports

* change subpath:eval slider to radio button

* fixed bug with solve_cubic, fixed unit tests, improved intersection accuracy

* fix failing test

Co-authored-by: Hannah Li <hannahli2010@gmail.com>
Co-authored-by: Keavon Chambers <keavon@keavon.com>

website/other/bezier-rs-demos/wasm/src/subpath.rs

@@ -1,9 +1,10 @@
-use bezier_rs::{ManipulatorGroup, Subpath};
+use crate::svg_drawing::*;
+
+use bezier_rs::{Bezier, ComputeType, ManipulatorGroup, Subpath};
+
 use glam::DVec2;
 use wasm_bindgen::prelude::*;
 
-use crate::svg_drawing::*;
-
 /// Wrapper of the `Subpath` struct to be used in JS.
 #[wasm_bindgen]
 pub struct WasmSubpath(Subpath);
@@ -54,6 +55,103 @@ impl WasmSubpath {
 
 	pub fn length(&self) -> String {
 		let length_text = draw_text(format!("Length: {:.2}", self.0.length(None)), 5., 193., BLACK);
-		format!("{}{}{}{}", SVG_OPEN_TAG, self.to_default_svg(), length_text, SVG_CLOSE_TAG)
+		wrap_svg_tag(format!("{}{}", self.to_default_svg(), length_text))
+	}
+
+	pub fn evaluate(&self, t: f64, compute_type: String) -> String {
+		let point = match compute_type.as_str() {
+			"Euclidean" => self.0.evaluate(ComputeType::Euclidean(t)),
+			"Parametric" => self.0.evaluate(ComputeType::Parametric(t)),
+			_ => panic!("Unexpected ComputeType string: '{}'", compute_type),
+		};
+		let point_text = draw_circle(point, 4., RED, 1.5, WHITE);
+		wrap_svg_tag(format!("{}{}", self.to_default_svg(), point_text))
+	}
+
+	pub fn intersect_line_segment(&self, js_points: &JsValue) -> String {
+		let points: [DVec2; 2] = js_points.into_serde().unwrap();
+		let line = Bezier::from_linear_dvec2(points[0], points[1]);
+
+		let subpath_svg = self.to_default_svg();
+
+		let empty_string = String::new();
+		let mut line_svg = String::new();
+		line.to_svg(
+			&mut line_svg,
+			CURVE_ATTRIBUTES.to_string().replace(BLACK, RED),
+			empty_string.clone(),
+			empty_string.clone(),
+			empty_string,
+		);
+
+		let intersections_svg = self
+			.0
+			.intersections(&line, None, None)
+			.iter()
+			.map(|intersection_t| {
+				let point = self.0.evaluate(ComputeType::Parametric(*intersection_t));
+				draw_circle(point, 4., RED, 1.5, WHITE)
+			})
+			.fold(String::new(), |acc, item| format!("{acc}{item}"));
+
+		wrap_svg_tag(format!("{subpath_svg}{line_svg}{intersections_svg}"))
+	}
+
+	pub fn intersect_quadratic_segment(&self, js_points: &JsValue) -> String {
+		let points: [DVec2; 3] = js_points.into_serde().unwrap();
+		let line = Bezier::from_quadratic_dvec2(points[0], points[1], points[2]);
+
+		let subpath_svg = self.to_default_svg();
+
+		let empty_string = String::new();
+		let mut line_svg = String::new();
+		line.to_svg(
+			&mut line_svg,
+			CURVE_ATTRIBUTES.to_string().replace(BLACK, RED),
+			empty_string.clone(),
+			empty_string.clone(),
+			empty_string,
+		);
+
+		let intersections_svg = self
+			.0
+			.intersections(&line, None, None)
+			.iter()
+			.map(|intersection_t| {
+				let point = self.0.evaluate(ComputeType::Parametric(*intersection_t));
+				draw_circle(point, 4., RED, 1.5, WHITE)
+			})
+			.fold(String::new(), |acc, item| format!("{acc}{item}"));
+
+		wrap_svg_tag(format!("{subpath_svg}{line_svg}{intersections_svg}"))
+	}
+
+	pub fn intersect_cubic_segment(&self, js_points: &JsValue) -> String {
+		let points: [DVec2; 4] = js_points.into_serde().unwrap();
+		let line = Bezier::from_cubic_dvec2(points[0], points[1], points[2], points[3]);
+
+		let subpath_svg = self.to_default_svg();
+
+		let empty_string = String::new();
+		let mut line_svg = String::new();
+		line.to_svg(
+			&mut line_svg,
+			CURVE_ATTRIBUTES.to_string().replace(BLACK, RED),
+			empty_string.clone(),
+			empty_string.clone(),
+			empty_string,
+		);
+
+		let intersections_svg = self
+			.0
+			.intersections(&line, None, None)
+			.iter()
+			.map(|intersection_t| {
+				let point = self.0.evaluate(ComputeType::Parametric(*intersection_t));
+				draw_circle(point, 4., RED, 1.5, WHITE)
+			})
+			.fold(String::new(), |acc, item| format!("{acc}{item}"));
+
+		wrap_svg_tag(format!("{subpath_svg}{line_svg}{intersections_svg}"))
 	}
 }