From eb494752195b2dcb2c8773e17b9efec8b7e9b8eb Mon Sep 17 00:00:00 2001
From: Thomas Neil James Shadwell <thomas@shadwell.im>
Date: Wed, 25 Dec 2024 16:24:07 +0000
Subject: [PATCH] zemn.me: 3d scene renderer

---
 .../zemn.me/app/experiments/3d/BUILD.bazel    |  26 ++++
 project/zemn.me/app/experiments/3d/client.tsx | 142 ++++++++++++++++++
 project/zemn.me/app/experiments/3d/page.tsx   |  15 ++
 project/zemn.me/app/experiments/BUILD.bazel   |   1 +
 ts/math/cartesian.ts                          |   4 +
 ts/math/mesh/mesh.ts                          |   4 +-
 6 files changed, 190 insertions(+), 2 deletions(-)
 create mode 100644 project/zemn.me/app/experiments/3d/BUILD.bazel
 create mode 100644 project/zemn.me/app/experiments/3d/client.tsx
 create mode 100644 project/zemn.me/app/experiments/3d/page.tsx

diff --git a/project/zemn.me/app/experiments/3d/BUILD.bazel b/project/zemn.me/app/experiments/3d/BUILD.bazel
new file mode 100644
index 0000000000..72a97bc495
--- /dev/null
+++ b/project/zemn.me/app/experiments/3d/BUILD.bazel
@@ -0,0 +1,26 @@
+load("//bzl:rules.bzl", "bazel_lint")
+load("//ts:rules.bzl", "ts_project")
+
+ts_project(
+    name = "3d",
+    srcs = [
+        "client.tsx",
+        "page.tsx",
+    ],
+    visibility = ["//project/zemn.me/app/experiments:__subpackages__"],
+    deps = [
+        "//:node_modules/@types/react",
+        "//:node_modules/@types/react-dom",
+        "//:node_modules/d3-array",
+        "//:node_modules/next",
+        "//:node_modules/react",
+        "//:node_modules/react-dom",
+        "//ts/math",
+        "//ts/math/mesh",
+    ],
+)
+
+bazel_lint(
+    name = "bazel_lint",
+    srcs = ["BUILD.bazel"],
+)
diff --git a/project/zemn.me/app/experiments/3d/client.tsx b/project/zemn.me/app/experiments/3d/client.tsx
new file mode 100644
index 0000000000..176ca4a05a
--- /dev/null
+++ b/project/zemn.me/app/experiments/3d/client.tsx
@@ -0,0 +1,142 @@
+"use client";
+import { extent } from "d3-array";
+import React, { Fragment, useId, useState } from "react";
+
+import { Iterable } from "#root/ts/iter/index.js";
+import { camera } from "#root/ts/math/camera.js";
+import { clamp3DTo2D, Line2D, Line3D, point, Point3D, x, y } from "#root/ts/math/cartesian.js";
+import { Centre, cube, Mesh, mesh2Edges } from "#root/ts/math/mesh/mesh.js";
+
+interface Camera {
+	position: Point3D
+	lookAt: Point3D
+}
+
+interface EdgesRendererProps {
+	readonly edges: Line2D<2>[]
+}
+
+function EdgesRenderer(props: EdgesRendererProps) {
+	const { edges } = props;
+
+	// Compute the viewBox from the extents of the edges
+	const [xmin, xmax] = extent(edges.map(l => l.map(pt => x(pt))).flat(2))!;
+	const [ymin, ymax] = extent(edges.map(l => l.map(pt => y(pt))).flat(2))!;
+
+	return (
+		<>
+			{Object.entries({ xmin, xmax, ymin, ymax }).map(([k, v]) => <>
+				{k}: {v}{" "}</>)}
+			<svg height={200} viewBox={[xmin, ymin, xmax, ymax].join(" ")} width={200}>
+				{edges.map((edge, i) => {
+					const [start, end] = edge;
+					return (
+						<line
+							key={i}
+							stroke="black" strokeWidth={(xmax! - xmin!) / 100}
+							x1={x(start)} x2={x(end)}
+							y1={y(start)}
+							y2={y(end)}
+						/>
+					);
+				})}
+			</svg>
+		</>
+	);
+}
+
+interface Scene<Object> {
+	readonly objects: Object[]
+	readonly edges: (v: Object) => globalThis.Iterable<Line3D<2>>
+	readonly camera: Camera
+}
+
+interface MapProps<Object> {
+	className?: string
+	scene: Scene<Object>
+}
+
+function Map<Object>(p: MapProps<Object>) {
+	const cameraViewLine: Line3D<2> = [
+		p.scene.camera.position,
+		p.scene.camera.lookAt
+	];
+
+	const meshesEdges =
+		Iterable(p.scene.objects)
+			.map(p.scene.edges)
+			.flatten();
+
+	const lines: Line3D<2>[] = [
+		cameraViewLine,
+		...meshesEdges.to_array()
+	];
+
+	// Convert 3D lines to 2D
+	const edges2D: EdgesRendererProps["edges"] = lines.map(([s, e]) => [
+		clamp3DTo2D(s), clamp3DTo2D(e)
+	]) as Line2D<2>[];
+
+	return <EdgesRenderer edges={edges2D} />;
+}
+
+function Projection<Object>(p: MapProps<Object>) {
+	return <EdgesRenderer edges={
+		Iterable(p.scene.objects)
+			.map(p.scene.edges)
+			.flatten()
+			.map(([start, end]): Line2D<2> =>
+				[
+					camera(
+						p.scene.camera.position,
+						p.scene.camera.lookAt,
+						start,
+						4,
+					),
+					camera(
+						p.scene.camera.position,
+						p.scene.camera.lookAt,
+						end,
+						4,
+					),
+				]).to_array()
+	} />
+
+}
+
+
+export function SceneRenderer<Object>(props: Scene<Object>) {
+	return <div style={{ grid: "" }}>
+		{/* top down map */}
+		<Map scene={props} />
+		{/* projection */}
+		<Projection scene={props} />
+	</div>
+}
+
+export function ThreeDClient() {
+	const subject = cube(point<3>(0, 0, 0), 1);
+	const xyz = [1, 5, 2].map(v => useState<number>(v));
+
+	return <>
+		{xyz.map(([g, s], i) => <Fragment key={`axis${i}`}>
+
+			<input
+			id={useId()} key={`axis${i}`}
+			max="50" min="-50" onChange={t => s(+t.target.value)}
+				type="range" value={g} />
+
+			{g}
+
+		</Fragment>)}
+		<SceneRenderer
+			camera={{
+				lookAt: subject[Centre],
+				position: point<3>(
+					...xyz.map(([g]) => g) as [number, number, number]
+				)
+			}}
+			edges={(v: Mesh<8>) => mesh2Edges(v)}
+			objects={[subject]}
+		/></>;
+}
diff --git a/project/zemn.me/app/experiments/3d/page.tsx b/project/zemn.me/app/experiments/3d/page.tsx
new file mode 100644
index 0000000000..97e49cda43
--- /dev/null
+++ b/project/zemn.me/app/experiments/3d/page.tsx
@@ -0,0 +1,15 @@
+import { Metadata } from 'next/types';
+
+import { ThreeDClient } from '#root/project/zemn.me/app/experiments/3d/client.js';
+
+
+
+export default function Page() {
+	return <ThreeDClient/>
+}
+
+export const metadata: Metadata = {
+	title: "test 3d renderer"
+}
+
+
diff --git a/project/zemn.me/app/experiments/BUILD.bazel b/project/zemn.me/app/experiments/BUILD.bazel
index 5031d787a4..bf2f171b80 100644
--- a/project/zemn.me/app/experiments/BUILD.bazel
+++ b/project/zemn.me/app/experiments/BUILD.bazel
@@ -15,6 +15,7 @@ ts_project(
         "//:node_modules/nuqs",
         "//:node_modules/react",
         "//:node_modules/seedrandom",
+        "//project/zemn.me/app/experiments/3d",
         "//project/zemn.me/app/experiments/article",
         "//project/zemn.me/app/experiments/cultist",
         "//project/zemn.me/app/experiments/factorio",
diff --git a/ts/math/cartesian.ts b/ts/math/cartesian.ts
index fab36236f2..fd7cdf090b 100644
--- a/ts/math/cartesian.ts
+++ b/ts/math/cartesian.ts
@@ -64,6 +64,10 @@ export function length(l: Line2D<2>): number {
 	return magnitude(Matrix.sub<1, 2>(l[1], l[0]));
 }
 
+export function clamp3DTo2D(pt: Point<3>): Point<2> {
+	return point<2>(x(pt), y(pt))
+}
+
 export function magnitude(l: Point): number {
 	return vecMag(l.map(([v]) => v))
 }
diff --git a/ts/math/mesh/mesh.ts b/ts/math/mesh/mesh.ts
index 0da5f2a925..edc9833a58 100644
--- a/ts/math/mesh/mesh.ts
+++ b/ts/math/mesh/mesh.ts
@@ -29,8 +29,8 @@ export interface Mesh<N extends number = number> {
 }
 
 export function mesh2Edges<N extends number>(m: Mesh<N>) {
-	return map(m[Edges], ([start, end]) =>
-		[m[Verticies][start], m[Verticies][end]] as const
+	return map(m[Edges], ([start, end]): Cartesian.Line3D<2> =>
+		[m[Verticies][start]!, m[Verticies][end]!]
 	)
 }