feat(geom): add tessellation post-processing helpers

- add graphFromTessellation()
- add edgesFromTessellation()
- add edgePointsFromTessellation()
- update deps (adjacency)
- update pkg exports/meta

packages/geom/package.json

@@ -37,6 +37,7 @@
 		"tool:tangle": "../../node_modules/.bin/tangle src/**/*.ts"
 	},
 	"dependencies": {
+		"@thi.ng/adjacency": "^2.5.51",
 		"@thi.ng/api": "^8.11.2",
 		"@thi.ng/arrays": "^2.9.6",
 		"@thi.ng/associative": "^6.3.60",
@@ -73,6 +74,7 @@
 	},
 	"keywords": [
 		"2d",
+		"3d",
 		"analysis",
 		"arc",
 		"area",
@@ -83,14 +85,25 @@
 		"clipping",
 		"conversion",
 		"datastructure",
+		"edges",
+		"ellipse",
 		"geometry",
+		"graph",
 		"graphics",
+		"group",
 		"intersection",
+		"parser",
+		"path",
+		"polygon",
+		"polyline",
 		"polymorphic",
 		"sample",
 		"scatter",
 		"shape",
+		"spline",
 		"svg",
+		"triangulation",
+		"tessellation",
 		"typescript"
 	],
 	"publishConfig": {
@@ -301,6 +314,9 @@
 		"./flip": {
 			"default": "./flip.js"
 		},
+		"./from-tessellation": {
+			"default": "./from-tessellation.js"
+		},
 		"./group": {
 			"default": "./group.js"
 		},

packages/geom/src/from-tessellation.ts

@@ -0,0 +1,86 @@
+import type { Edge } from "@thi.ng/adjacency";
+import { defAdjBitMatrix } from "@thi.ng/adjacency/binary";
+import type { GroupAttribs, Tessellation } from "@thi.ng/geom-api";
+import { indexedPoints } from "@thi.ng/geom-tessellate/tessellate";
+import { map } from "@thi.ng/transducers/map";
+import { mapcat } from "@thi.ng/transducers/mapcat";
+import { partition } from "@thi.ng/transducers/partition";
+import { wrapSides } from "@thi.ng/transducers/wrap-sides";
+import { Group } from "./api/group.js";
+import { Polygon } from "./api/polygon.js";
+
+/**
+ * Creates a group of polygons from the given tessellation. If `attribs` are
+ * given, they will be used as the group's attribs.
+ *
+ * @param tess
+ * @param attribs
+ */
+export const groupFromTessellation = (
+	tess: Tessellation,
+	attribs?: GroupAttribs
+) =>
+	new Group(
+		attribs,
+		tess.indices.map((ids) => new Polygon(indexedPoints(tess.points, ids)))
+	);
+
+/**
+ * Create a directed or undirected graph from the given tessellation. The graph
+ * is stored as
+ * [`AdjacencyBitMatrix`](https://docs.thi.ng/umbrella/adjacency/classes/AdjacencyBitMatrix.html)
+ * and can be edited, queried, and analyzed further.
+ *
+ * @remarks
+ * Also see {@link edgesFromTessellation}, {@link edgePointsFromTessellation}.
+ *
+ * @param tessel
+ */
+export const graphFromTessellation = (
+	{ points, indices }: Tessellation,
+	directed = false
+) =>
+	defAdjBitMatrix(
+		points.length,
+		<Iterable<Edge>>(
+			mapcat((ids) => partition(2, 1, wrapSides(ids, 0, 1)), indices)
+		),
+		!directed
+	);
+
+/**
+ * Returns an iterable of unique edges in the given tessellation, where each
+ * edge is a 2-tuple of point indices `[a,b]`, each referring to points in the
+ * tessellation's `points` array.
+ *
+ * @remarks
+ *
+ * @example
+ * ``ts
+ * import * as g from "@thi.ng/geom";
+ *
+ * // tessellate rect into a triangle fan
+ * const tess = g.tessellate(g.rect(100), [g.TESSELLATE_TRI_FAN]);
+ *
+ * // extract unique edges (ignoring direction)
+ * console.log([...g.uniqueEdgesFromTessellation(tess)]);
+ * // [[ 3, 4 ], [ 2, 3 ], [ 2, 4 ], [ 1, 2 ],
+ * //  [ 1, 4 ], [ 0, 1 ], [ 0, 3 ], [ 0, 4 ]]
+ * ```
+ *
+ * @param tess
+ */
+export const edgesFromTessellation = (tess: Tessellation) =>
+	graphFromTessellation(tess, false).edges();
+
+/**
+ * Similar to {@link edgesFromTessellation}, but returns edges as pairs of
+ * points (instead of point IDs).
+ *
+ * @param tess
+ */
+export const edgePointsFromTessellation = (tess: Tessellation) =>
+	map(
+		(e) => indexedPoints(tess.points, e),
+		graphFromTessellation(tess, false).edges()
+	);

packages/geom/src/index.ts

@@ -89,6 +89,7 @@ export * from "./convolve.js";
 export * from "./edges.js";
 export * from "./fit-into-bounds.js";
 export * from "./flip.js";
+export * from "./from-tessellation.js";
 export * from "./intersects.js";
 export * from "./map-point.js";
 export * from "./offset.js";

packages/geom/src/tessellate.ts

@@ -1,12 +1,7 @@
 import type { Maybe } from "@thi.ng/api";
 import { ensureArray } from "@thi.ng/arrays/ensure-array";
 import { DEFAULT, defmulti } from "@thi.ng/defmulti/defmulti";
-import type {
-	GroupAttribs,
-	IShape,
-	Tessellation,
-	Tessellator,
-} from "@thi.ng/geom-api";
+import type { IShape, Tessellation, Tessellator } from "@thi.ng/geom-api";
 import { earCut } from "@thi.ng/geom-tessellate/earcut";
 import {
 	earCutComplex,
@@ -18,15 +13,13 @@ import { quadFan } from "@thi.ng/geom-tessellate/quad-fan";
 import { rimTris } from "@thi.ng/geom-tessellate/rim-tris";
 import {
 	tessellate as _tessellate,
-	indexedPoints,
 	tessellateQueue,
 } from "@thi.ng/geom-tessellate/tessellate";
 import { triFan } from "@thi.ng/geom-tessellate/tri-fan";
 import { triFanSplit } from "@thi.ng/geom-tessellate/tri-fan-split";
 import { range } from "@thi.ng/transducers/range";
 import type { ComplexPolygon } from "./api/complex-polygon.js";
 import { Group } from "./api/group.js";
-import { Polygon } from "./api/polygon.js";
 import { __dispatch } from "./internal/dispatch.js";
 import { vertices } from "./vertices.js";
 
@@ -104,15 +97,6 @@ export const tessellate = defmulti<IShape, Iterable<Tessellator>, Tessellation>(
 	}
 );
 
-export const groupFromTessellation = (
-	tess: Tessellation,
-	attribs?: GroupAttribs
-) =>
-	new Group(
-		attribs,
-		tess.indices.map((ids) => new Polygon(indexedPoints(tess.points, ids)))
-	);
-
 /**
  * Alias for thi.ng/geom-tessellate
  * [`earCut`](https://docs.thi.ng/umbrella/geom-tessellate/functions/earCut.html)

yarn.lock

@@ -3669,7 +3669,7 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@thi.ng/adjacency@workspace:^, @thi.ng/adjacency@workspace:packages/adjacency":
+"@thi.ng/adjacency@npm:^2.5.51, @thi.ng/adjacency@workspace:^, @thi.ng/adjacency@workspace:packages/adjacency":
   version: 0.0.0-use.local
   resolution: "@thi.ng/adjacency@workspace:packages/adjacency"
   dependencies:
@@ -4869,6 +4869,7 @@ __metadata:
   resolution: "@thi.ng/geom@workspace:packages/geom"
   dependencies:
     "@microsoft/api-extractor": "npm:^7.45.0"
+    "@thi.ng/adjacency": "npm:^2.5.51"
     "@thi.ng/api": "npm:^8.11.2"
     "@thi.ng/arrays": "npm:^2.9.6"
     "@thi.ng/associative": "npm:^6.3.60"