feat(geom): add centerOfWeight(), centroidOfBounds(), update centroid()

- update centroid() impls for complex poly & poly, moved to centerOfWeight()
- update centroid() to support more types
- update pkg exports

packages/geom/package.json

@@ -265,9 +265,15 @@
 		"./bpatch": {
 			"default": "./bpatch.js"
 		},
+		"./center-of-weight": {
+			"default": "./center-of-weight.js"
+		},
 		"./center": {
 			"default": "./center.js"
 		},
+		"./centroid-of-bounds": {
+			"default": "./centroid-of-bounds.js"
+		},
 		"./centroid": {
 			"default": "./centroid.js"
 		},

packages/geom/src/center-of-weight.ts

@@ -0,0 +1,50 @@
+import type { Maybe } from "@thi.ng/api";
+import type { MultiFn1O } from "@thi.ng/defmulti";
+import { DEFAULT, defmulti } from "@thi.ng/defmulti/defmulti";
+import {
+	centerOfWeight2,
+	complexCenterOfWeight2,
+} from "@thi.ng/geom-poly-utils/center-of-weight";
+import type { Vec } from "@thi.ng/vectors";
+import type { IShape } from "./api.js";
+import type { ComplexPolygon } from "./api/complex-polygon.js";
+import type { Polygon } from "./api/polygon.js";
+import { centroid } from "./centroid.js";
+import { __dispatch } from "./internal/dispatch.js";
+
+/**
+ * Attempts to compute the center of weight (CoW) for given `shape`, otherwise
+ * returns `undefined`.
+ *
+ * @remarks
+ * The actual CoW is only available for these types:
+ *
+ * - {@link ComplexPolygon}
+ * - {@link Polygon}
+ *
+ * For all other shapes, the normal {@link centroid} calculation will be used.
+ * Also see {@link centroidOfBounds}.
+ *
+ * @param shape
+ * @param out
+ */
+export const centerOfWeight: MultiFn1O<IShape, Vec, Maybe<Vec>> = defmulti<
+	any,
+	Maybe<Vec>,
+	Maybe<Vec>
+>(
+	__dispatch,
+	{},
+	{
+		[DEFAULT]: ($: IShape, out?: Vec) => centroid($, out),
+
+		complexpoly: ($: ComplexPolygon, out?) =>
+			complexCenterOfWeight2(
+				$.boundary.points,
+				$.children.map((c) => c.points),
+				out
+			),
+
+		poly: ($: Polygon, out) => centerOfWeight2($.points, out),
+	}
+);

packages/geom/src/center.ts

@@ -1,10 +1,10 @@
 import type { Maybe } from "@thi.ng/api";
 import type { MultiFn2 } from "@thi.ng/defmulti";
 import { DEFAULT, defmulti } from "@thi.ng/defmulti/defmulti";
-import type { IShape } from "./api.js";
 import { ZERO2, ZERO3, type ReadonlyVec } from "@thi.ng/vectors/api";
 import { set2, set3 } from "@thi.ng/vectors/set";
 import { submN } from "@thi.ng/vectors/submn";
+import type { IShape } from "./api.js";
 import { Arc } from "./api/arc.js";
 import { Circle } from "./api/circle.js";
 import { Ellipse } from "./api/ellipse.js";
@@ -23,7 +23,7 @@ export type CenterFn = {
 
 /**
  * Returns copy of given shape centered around optionally provided point `p`
- * (default: worldspace origin).
+ * (default: world space origin).
  *
  * @remarks
  * Implemented for all shape types supported by {@link centroid} and

packages/geom/src/centroid-of-bounds.ts

@@ -0,0 +1,17 @@
+import type { Vec } from "@thi.ng/vectors";
+import type { IShape } from "./api.js";
+import { bounds } from "./bounds.js";
+import { centroid } from "./centroid.js";
+
+/**
+ * Attempts to compute the bounding box of given `shape` and if available,
+ * returns its centroid (or writes it to `out`, if given). Otherwise returns
+ * `undefined`.
+ *
+ * @param shape
+ * @param out
+ */
+export const centroidOfBounds = (shape: IShape, out?: Vec) => {
+	const b = bounds(shape);
+	return b ? centroid(b, out) : undefined;
+};

packages/geom/src/centroid.ts

@@ -1,19 +1,14 @@
 import type { Maybe } from "@thi.ng/api";
 import type { MultiFn1O } from "@thi.ng/defmulti";
 import { defmulti } from "@thi.ng/defmulti/defmulti";
-import type { AABBLike, IShape, PCLike } from "./api.js";
-import {
-	centerOfWeight2,
-	complexCenterOfWeight2,
-} from "@thi.ng/geom-poly-utils/center-of-weight";
 import { centroid as _centroid } from "@thi.ng/geom-poly-utils/centroid";
 import type { Vec } from "@thi.ng/vectors";
 import { add } from "@thi.ng/vectors/add";
-import { addmN } from "@thi.ng/vectors/addmn";
+import { addmN, addmN2 } from "@thi.ng/vectors/addmn";
 import { maddN } from "@thi.ng/vectors/maddn";
-import { mixN } from "@thi.ng/vectors/mixn";
 import { mulN } from "@thi.ng/vectors/muln";
 import { set } from "@thi.ng/vectors/set";
+import type { AABBLike, IShape, PCLike } from "./api.js";
 import type { Circle } from "./api/circle.js";
 import type { ComplexPolygon } from "./api/complex-polygon.js";
 import type { Group } from "./api/group.js";
@@ -25,10 +20,13 @@ import { bounds } from "./bounds.js";
 import { __dispatch } from "./internal/dispatch.js";
 
 /**
- * Computes (possibly weighted) centroid of given shape, writes result in
- * optionally provided output vector (or creates new one if omitted).
+ * Computes the unweighted centroid of given shape, writes result in optionally
+ * provided output vector (or creates new one if omitted).
  *
  * @remarks
+ * For vertex based shapes, this computes the simple mean position of the
+ * vertices. Also see {@link centroidOfBounds}, {@link centerOfWeight}.
+ *
  * Currently implemented for:
  *
  * - {@link AABB}
@@ -43,12 +41,18 @@ import { __dispatch } from "./internal/dispatch.js";
  * - {@link Line}
  * - {@link Path}
  * - {@link Polygon}
+ * - {@link Polygon3}
  * - {@link Polyline}
+ * - {@link Polyline3}
  * - {@link Points}
  * - {@link Points3}
  * - {@link Quad}
+ * - {@link Quad3}
  * - {@link Quadratic}
- * - {@link Text} - (no way to compute size, only position & any margin)
+ * - {@link Quadratic3}
+ * - {@link Text} (returns position, not considering body or alignment)
+ * - {@link Triangle}
+ * - {@link Triangle3}
  *
  * @param shape
  * @param out
@@ -61,27 +65,33 @@ export const centroid: MultiFn1O<IShape, Vec, Maybe<Vec>> = defmulti<
 	__dispatch,
 	{
 		arc: "circle",
-		aabb: "rect",
 		bpatch: "points",
 		ellipse: "circle",
+		cubic: "points",
+		cubic3: "points",
 		line3: "line",
 		path: "group",
 		points3: "points",
+		poly: "points",
+		poly3: "points",
 		polyline: "points",
-		quad: "poly",
+		polyline3: "points",
+		quad: "points",
+		quad3: "points",
+		quadratic: "points",
+		quadratic3: "points",
+		rect: "aabb",
 		sphere: "circle",
 		text: "circle",
 		tri3: "tri",
 	},
 	{
+		abbb: ($: AABBLike, out?) => maddN(out || [], $.size, 0.5, $.pos),
+
 		circle: ($: Circle, out?) => set(out || [], $.pos),
 
 		complexpoly: ($: ComplexPolygon, out?) =>
-			complexCenterOfWeight2(
-				$.boundary.points,
-				$.children.map((c) => c.points),
-				out
-			),
+			_centroid($.boundary.points, out),
 
 		extra: () => undefined,
 
@@ -91,17 +101,13 @@ export const centroid: MultiFn1O<IShape, Vec, Maybe<Vec>> = defmulti<
 		},
 
 		line: ({ points }: Line, out?) =>
-			mixN(out || [], points[0], points[1], 0.5),
+			addmN2(out || [], points[0], points[1], 0.5),
 
 		points: ($: PCLike, out?) => _centroid($.points, out),
 
 		plane: ($: Plane, out?) => mulN(out || [], $.normal, $.w),
 
-		poly: ($: Polygon, out?) => centerOfWeight2($.points, out),
-
-		rect: ($: AABBLike, out?) => maddN(out || [], $.size, 0.5, $.pos),
-
-		tri: ({ points }: Triangle, out?) =>
-			addmN(null, add(out || [], points[0], points[1]), points[2], 1 / 3),
+		tri: ({ points: [a, b, c] }: Triangle, out?) =>
+			addmN(null, add(out || [], a, b), c, 1 / 3),
 	}
 );

packages/geom/src/fit-into-bounds.ts

@@ -1,13 +1,13 @@
 import type { Maybe } from "@thi.ng/api";
-import type { IShape, IShape2, IShape3 } from "./api.js";
 import { minNonZero2, minNonZero3 } from "@thi.ng/math/interval";
 import { safeDiv } from "@thi.ng/math/safe-div";
 import type { MatOpNV, MatOpV } from "@thi.ng/matrices";
 import { concat } from "@thi.ng/matrices/concat";
 import { scale23, scale44 } from "@thi.ng/matrices/scale";
 import { translation23, translation44 } from "@thi.ng/matrices/translation";
 import type { ReadonlyVec, Vec } from "@thi.ng/vectors";
-import { neg } from "@thi.ng/vectors/neg";
+import { mulN2, mulN3 } from "@thi.ng/vectors/muln";
+import type { IShape, IShape2, IShape3 } from "./api.js";
 import type { AABB } from "./api/aabb.js";
 import type { Arc } from "./api/arc.js";
 import type { Circle } from "./api/circle.js";
@@ -61,7 +61,7 @@ export function fitIntoBounds2(shape: IShape2, dest: Rect) {
 		translation23,
 		scale23,
 		shape,
-		neg(null, c),
+		mulN2(null, c, -1),
 		centroid(dest)!,
 		minNonZero2(
 			safeDiv(dest.size[0], src.size[0]),
@@ -80,7 +80,7 @@ export const fitIntoBounds3 = <T extends IShape3>(
 	shape: T,
 	dest: AABB
 ): Maybe<T> => {
-	const src = <AABB>bounds(shape);
+	const src = bounds(shape);
 	if (!src) return;
 	const c = centroid(src);
 	if (!c) return;
@@ -89,7 +89,7 @@ export const fitIntoBounds3 = <T extends IShape3>(
 			translation44,
 			scale44,
 			shape,
-			neg(null, c),
+			mulN3(null, c, -1),
 			centroid(dest)!,
 			minNonZero3(
 				safeDiv(dest.size[0], src.size[0]),
@@ -128,7 +128,7 @@ export const fitAllIntoBounds2 = (shapes: IShape2[], dest: Rect) => {
 					translation23,
 					scale23,
 					s,
-					neg(null, c1),
+					mulN2(null, c1, -1),
 					c2,
 					smat
 				)