Draw gravel-lane crossings as gravel, not asphalt slabs

.github/workflows/ci.yml

@@ -84,7 +84,9 @@ jobs:
       - run: bun run games:clone
         env:
           GAMES_CLONE_TOKEN: ${{ secrets.GAMES_CLONE_TOKEN }}
-      - run: bun test packages apps/dev scripts
+      # Browser and physics suites cold-start Chromium/WASM; on a loaded runner the first test in a
+      # file can pass Bun's 5 s default and cascade through the file. Tests with their own timeout keep it.
+      - run: bun test --timeout 20000 packages apps/dev scripts
 
   web-build:
     runs-on: ubuntu-latest

changes/gravel-junctions.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- City districts (`@jgengine/shell` `CityRenderer`) draw a crossing of gravel lanes as gravel instead of a dark asphalt slab; a crossing that touches any paved street stays asphalt.

packages/shell/src/scene/CityRenderer.tsx

@@ -56,6 +56,7 @@ import { InstancedBuildings, type InstancedBuildingPlacement } from "../structur
 import { getBuildingKit } from "../structures/buildingKitRegistry";
 import { createCityWindowMaterial } from "./cityWindowMaterial";
 import { registerSceneKindRenderer, type SceneKindRenderContext } from "./sceneKindRenderers";
+import { junctionSurface } from "./cityJunctionSurface";
 
 const ASPHALT_COLOR = "#3a3b3d";
 const GRAVEL_COLOR = "#93815f";
@@ -825,7 +826,9 @@ function OneCity({ object, context }: { object: SceneKindObject; context: SceneK
       const crossIndex = trimmed.junctionIndices[j]!;
       const scuff = (hashString(`cross:${crossIndex}`) % 512) / 512;
       wearColor.setRGB(0.76 + scuff * 0.18, 0.77 + scuff * 0.17, 0.8 + scuff * 0.16);
-      patches.addMesh(trimmed.junctions[j]!, wearColor);
+      const cross = resolved.intersections[crossIndex];
+      if (cross !== undefined && junctionSurface(cross, resolved.streets) === "gravel") gravel.addMesh(trimmed.junctions[j]!);
+      else patches.addMesh(trimmed.junctions[j]!, wearColor);
     }
     for (const paint of buildIntersectionMarkings(trimmed, deckSampler, {
       mouthClearance: 1.25,

packages/shell/src/scene/cityJunctionSurface.test.ts

@@ -0,0 +1,24 @@
+import { describe, expect, test } from "bun:test";
+import { junctionSurface } from "./cityJunctionSurface";
+
+const street = (surface: "asphalt" | "gravel", points: [number, number][]) => ({ surface, width: 6, points });
+const cross = { x: 0, z: 0, radius: 4 };
+
+describe("junctionSurface", () => {
+  test("a crossing of gravel lanes stays gravel", () => {
+    expect(junctionSurface(cross, [street("gravel", [[-20, 0], [20, 0]]), street("gravel", [[0, -20], [0, 20]])])).toBe("gravel");
+  });
+
+  test("a gravel lane meeting a paved main is asphalt", () => {
+    expect(junctionSurface(cross, [street("asphalt", [[-20, 0], [20, 0]]), street("gravel", [[0, 0], [0, 20]])])).toBe("asphalt");
+  });
+
+  test("distant paved streets do not pave a gravel crossing", () => {
+    const far = street("asphalt", [[-20, 40], [20, 40]]);
+    expect(junctionSurface(cross, [street("gravel", [[-20, 0], [20, 0]]), far])).toBe("gravel");
+  });
+
+  test("a crossing no street reaches falls back to asphalt", () => {
+    expect(junctionSurface(cross, [street("gravel", [[-20, 50], [20, 50]])])).toBe("asphalt");
+  });
+});

packages/shell/src/scene/cityJunctionSurface.ts

@@ -0,0 +1,36 @@
+import type { CityIntersection, CityStreet } from "@jgengine/core/world/cityKind";
+
+/**
+ * Surface for a crossing's welded patch: gravel only when every street running through the crossing
+ * is gravel, so an unpaved hamlet's junctions stay gravel while a lane meeting a paved main stays asphalt.
+ * @internal
+ */
+export function junctionSurface(
+  cross: Pick<CityIntersection, "x" | "z" | "radius">,
+  streets: readonly Pick<CityStreet, "points" | "width" | "surface">[],
+): CityStreet["surface"] {
+  let touched = false;
+  for (const street of streets) {
+    const reach = cross.radius + street.width * 0.5 + 0.5;
+    if (distanceToPath(cross.x, cross.z, street.points) > reach) continue;
+    if (street.surface !== "gravel") return "asphalt";
+    touched = true;
+  }
+  return touched ? "gravel" : "asphalt";
+}
+
+function distanceToPath(x: number, z: number, points: CityStreet["points"]): number {
+  if (points.length === 0) return Infinity;
+  if (points.length === 1) return Math.hypot(x - points[0]![0], z - points[0]![1]);
+  let best = Infinity;
+  for (let i = 1; i < points.length; i += 1) {
+    const [ax, az] = points[i - 1]!;
+    const [bx, bz] = points[i]!;
+    const dx = bx - ax;
+    const dz = bz - az;
+    const len2 = dx * dx + dz * dz;
+    const t = len2 === 0 ? 0 : Math.max(0, Math.min(1, ((x - ax) * dx + (z - az) * dz) / len2));
+    best = Math.min(best, Math.hypot(x - (ax + dx * t), z - (az + dz * t)));
+  }
+  return best;
+}

scripts/export-manifest.json

@@ -922,6 +922,7 @@
     "./scene/StudioStage",
     "./scene/WaterRenderer",
     "./scene/builtinSceneKindRenderers",
+    "./scene/cityJunctionSurface",
     "./scene/cityWindowMaterial",
     "./scene/sceneKindRenderers",
     "./settings/QuickControls",