Add local glTF viewer and visual coverage

Amp-Thread-ID: https://ampcode.com/threads/T-01a02d1c-27fc-7761-9f51-ed97b2dd4e3e
Co-authored-by: Heaust Azure <heaust.azure@gmail.com>

addons/handles/test/scene-helpers.ts

@@ -0,0 +1,53 @@
+import { Mesh } from "../src/Mesh";
+import { Scene } from "../src/Scene";
+import type { PBRMaterial } from "../src/materials/PBRMaterial";
+import type { YawnCore } from "./core-mock";
+
+export const triangle = {
+  positions: [-1, -1, 0, 1, -1, 0, 0, 1, 0],
+  normals: [0, 0, 1, 0, 0, 1, 0, 0, 1],
+  tangents: [1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1],
+  uvs: [0, 0, 1, 0, 0.5, 1],
+  uvs2: [0.1, 0.1, 0.9, 0.1, 0.5, 0.9],
+  colors: [1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1],
+  indices: [0, 1, 2],
+};
+
+export async function createScene() {
+  const scene = new Scene({} as HTMLCanvasElement);
+  await scene.ready;
+  return scene;
+}
+
+export function testCore(scene: Scene) {
+  return scene.core as unknown as YawnCore;
+}
+
+export function latestGraph(scene: Scene): any {
+  return testCore(scene).graphs.at(-1);
+}
+
+export function renderPipeline(graph: any, id: string) {
+  return graph.pipelines.render.find((pipeline: any) => pipeline.id === id);
+}
+
+export function pbrPipelines(graph: any) {
+  return graph.pipelines.render.filter((pipeline: any) =>
+    pipeline.id.startsWith("forward-pbr-"),
+  );
+}
+
+export function forwardPasses(graph: any) {
+  return graph.passes.filter(
+    (pass: any) =>
+      pass.type === "render" && pass.pipeline.startsWith("forward-"),
+  );
+}
+
+export function detailedMesh(
+  scene: Scene,
+  material: PBRMaterial,
+  vertexData: Record<string, ArrayLike<number>> = triangle,
+) {
+  return new Mesh(scene, { material, vertexData });
+}