feat(geom): update asPath(), add AsPathOpts

BREAKING CHANGE: update asPath() args, add AsPathOpts as 2nd arg

- add option for using only linear path segments (no cubics)
- update impls for complexpoly & other polygon types

Author: postspectacular

packages/geom/src/as-path.ts

@@ -1,81 +1,121 @@
-import type { MultiFn1O } from "@thi.ng/defmulti";
+import type { MultiFn2O } from "@thi.ng/defmulti";
 import { DEFAULT, defmulti } from "@thi.ng/defmulti/defmulti";
-import type { Attribs, IShape, PathSegment } from "@thi.ng/geom-api";
+import type { Attribs, CubicOpts, IShape, PathSegment } from "@thi.ng/geom-api";
 import type { ReadonlyVec } from "@thi.ng/vectors";
 import { copy } from "@thi.ng/vectors/copy";
+import type { Arc } from "./api/arc.js";
 import type { ComplexPolygon } from "./api/complex-polygon.js";
 import { Line } from "./api/line.js";
 import { Path } from "./api/path.js";
 import type { Polygon } from "./api/polygon.js";
 import type { Polyline } from "./api/polyline.js";
-import type { Rect } from "./api/rect.js";
 import { asCubic } from "./as-cubic.js";
+import { asPolygon } from "./as-polygon.js";
+import { asPolyline } from "./as-polyline.js";
 import { __copyAttribs } from "./internal/copy.js";
 import { __dispatch } from "./internal/dispatch.js";
 import { pathFromCubics } from "./path.js";
 
+export interface AsPathOpts extends CubicOpts {
+	/**
+	 * If true (default: false), creates path consisting of linear segments
+	 * only.
+	 */
+	linear: boolean;
+}
+
 /**
  * Converts given shape into a {@link Path} (by default via {@link asCubic} and
  * {@link pathFromCubics}).
  *
  * @remarks
- * The following shape types will be converted into paths consisting only of linear segments (NOT cubic beziers):
- *
- * - {@link ComplexPolygon}
- * - {@link Polygon}
- * - {@link Polyline}
- * - {@link Quad}
- * - {@link Rect}
- * - {@link Triangle}
+ * If {@link AsPathOpts.linear} is enabled the shape will be converted into a
+ * path consisting only of linear segments (NOT cubic beziers). As an interim
+ * step this will involve a conversion via {@link asPolygon} or
+ * {@link asPolyline} with default opts.
  *
  * @param src
  * @param attribs
  */
-export const asPath: MultiFn1O<IShape, Attribs, IShape> = defmulti<
-	any,
-	Attribs | undefined,
-	IShape
->(
-	__dispatch,
-	{ quad: "poly", tri: "poly" },
-	{
-		[DEFAULT]: (src: IShape, attribs?: Attribs) =>
-			pathFromCubics(asCubic(src), attribs || __copyAttribs(src)),
+export const asPath: ((
+	shape: IShape,
+	opts?: Partial<AsPathOpts>,
+	attribs?: Attribs
+) => Path) &
+	MultiFn2O<IShape, Partial<AsPathOpts> | undefined, Attribs, Path> =
+	defmulti<any, Partial<AsPathOpts> | undefined, Attribs | undefined, Path>(
+		__dispatch,
+		{
+			line: "polyline",
+			quad: "poly",
+			tri: "poly",
+		},
+		{
+			[DEFAULT]: (
+				src: IShape,
+				opts?: Partial<AsPathOpts>,
+				attribs?: Attribs
+			) =>
+				opts?.linear
+					? asPath(
+							asPolygon(src)[0],
+							opts,
+							attribs || __copyAttribs(src)
+					  )
+					: __defaultImpl(src, opts, attribs),
 
-		complexpoly: ($: ComplexPolygon, attribs) =>
-			new Path(
-				__lineSegments($.boundary.points, true),
-				$.children.map((c) => __lineSegments(c.points, true)),
-				attribs || __copyAttribs($)
-			),
+			arc: ($: Arc, opts, attribs) =>
+				opts?.linear
+					? asPath(
+							asPolyline($)[0],
+							opts,
+							attribs || __copyAttribs($)
+					  )
+					: __defaultImpl($, opts, attribs),
 
-		poly: ($: Polygon, attribs) =>
-			new Path(
-				__lineSegments($.points, true),
-				[],
-				attribs || __copyAttribs($)
-			),
+			complexpoly: ($: ComplexPolygon, opts, attribs) => {
+				attribs = attribs || __copyAttribs($);
+				if (opts?.linear) {
+					return new Path(
+						__lineSegments($.boundary.points, true),
+						$.children.map((c) => __lineSegments(c.points, true)),
+						attribs
+					);
+				}
+				const res = pathFromCubics(asCubic($.boundary, opts), attribs);
+				for (let child of $.children) {
+					res.addSubPaths(
+						pathFromCubics(asCubic(child, opts)).segments
+					);
+				}
+				return res;
+			},
 
-		polyline: ($: Polyline, attribs) =>
-			new Path(
-				__lineSegments($.points, false),
-				[],
-				attribs || __copyAttribs($)
-			),
+			poly: ($: Polygon, opts, attribs) =>
+				opts?.linear
+					? new Path(
+							__lineSegments($.points, true),
+							[],
+							attribs || __copyAttribs($)
+					  )
+					: __defaultImpl($, opts, attribs),
 
-		rect: ($: Rect, attribs) => {
-			const max = $.max();
-			return new Path(
-				__lineSegments(
-					[$.pos, [max[0], $.pos[1]], max, [$.pos[0], max[1]]],
-					false
-				),
-				[],
-				attribs || __copyAttribs($)
-			);
-		},
-	}
-);
+			polyline: ($: Polyline, opts, attribs) =>
+				opts?.linear
+					? new Path(
+							__lineSegments($.points, false),
+							[],
+							attribs || __copyAttribs($)
+					  )
+					: __defaultImpl($, opts, attribs),
+		}
+	);
+
+const __defaultImpl = (
+	src: IShape,
+	opts?: Partial<CubicOpts>,
+	attribs?: Attribs
+) => pathFromCubics(asCubic(src, opts), attribs || __copyAttribs(src));
 
 const __lineSegments = (points: ReadonlyVec[], closed: boolean) => {
 	if (!points.length) return [];