docs(geom-subdiv-curve): add diagram generator tool

packages/geom-subdiv-curve/tools/visualize.ts

@@ -0,0 +1,87 @@
+import { COSINE_GRADIENTS, cosineColor } from "@thi.ng/color";
+import { writeText } from "@thi.ng/file-io";
+import { asSvg, group, points, polygon, polyline, svgDoc } from "@thi.ng/geom";
+import { iterate, mapIndexed, pairs } from "@thi.ng/transducers";
+import { ReadonlyVec, add2 } from "@thi.ng/vectors";
+import {
+	SUBDIV_CHAIKIN,
+	SUBDIV_CUBIC,
+	SUBDIV_DISPLACE,
+	SUBDIV_DLG,
+	SUBDIV_MID,
+	SUBDIV_THIRDS,
+	subdivide,
+	type SubdivKernel,
+} from "../src/index.js";
+
+const visualizeOpen = (kernel: SubdivKernel, iter = 4) =>
+	svgDoc(
+		{ __margin: 20, weight: 0.5 },
+		...mapIndexed(
+			(i, pts) => {
+				const col = cosineColor(
+					COSINE_GRADIENTS["orange-magenta-blue"],
+					1
+				);
+				pts = pts.map((p) => add2([], p, [140 * i, 0]));
+				return group({}, [
+					polyline(pts, { stroke: col }),
+					points(pts, { fill: col, stroke: "none", size: 2 }),
+				]);
+			},
+			iterate(
+				(pts) => subdivide(pts, [kernel], false),
+				<ReadonlyVec[]>[
+					[0, 0],
+					[0, 100],
+					[50, 50],
+					[100, 100],
+					[100, 0],
+				],
+				iter
+			)
+		)
+	);
+
+const visualizeClosed = (kernel: SubdivKernel, iter = 4) =>
+	svgDoc(
+		{ __margin: 20, weight: 0.5 },
+		...mapIndexed(
+			(i, pts) => {
+				const col = cosineColor(
+					COSINE_GRADIENTS["orange-magenta-blue"],
+					1
+				);
+				pts = pts.map((p) => add2([], p, [140 * i, 0]));
+				return group({}, [
+					polygon(pts, { stroke: col }),
+					points(pts, { fill: col, stroke: "none", size: 2 }),
+				]);
+			},
+			iterate(
+				(pts) => subdivide(pts, [kernel], true),
+				<ReadonlyVec[]>[
+					[0, 0],
+					[100, 0],
+					[100, 100],
+					[0, 100],
+				],
+				iter
+			)
+		)
+	);
+
+for (let [id, kernel] of pairs({
+	chaikin: SUBDIV_CHAIKIN,
+	cubic: SUBDIV_CUBIC,
+	mid: SUBDIV_MID,
+	thirds: SUBDIV_THIRDS,
+	dlc: SUBDIV_DLG,
+	displace: SUBDIV_DISPLACE([
+		[0.25, 0.05],
+		[0.75, -0.05],
+	]),
+})) {
+	writeText(`export/subdiv-${id}-open.svg`, asSvg(visualizeOpen(kernel)));
+	writeText(`export/subdiv-${id}-closed.svg`, asSvg(visualizeClosed(kernel)));
+}