Bezier-rs: Subpath offset and bezier offset improvements (#1039)

* Added subpath offset

* Enhanced offset to produce smooth curves

* Lots of outline bugfixes

* Fixed failing unit tests

* Added subpath outline

* Refactor bezier offset and outline to return Subpaths

* Fix outline bug due to smooth joining and removed reduce optimization that causes jumping approximations

* Bugfix when subpath angle is acute but doesn't intersect

* Stylistic changes per review

* Stylistic changes per review and updated doc comments

---------

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

website/other/bezier-rs-demos/src/features/subpath-features.ts

@@ -114,6 +114,32 @@ const subpathFeatures = {
 		],
 		chooseTVariant: true,
 	},
+	offset: {
+		name: "Offset",
+		callback: (subpath: WasmSubpathInstance, options: Record<string, number>): string => subpath.offset(options.distance),
+		sliderOptions: [
+			{
+				variable: "distance",
+				min: -25,
+				max: 25,
+				step: 1,
+				default: 10,
+			},
+		],
+	},
+	outline: {
+		name: "Outline",
+		callback: (subpath: WasmSubpathInstance, options: Record<string, number>): string => subpath.outline(options.distance),
+		sliderOptions: [
+			{
+				variable: "distance",
+				min: 0,
+				max: 25,
+				step: 1,
+				default: 10,
+			},
+		],
+	},
 };
 
 export type SubpathFeatureKey = keyof typeof subpathFeatures;