[codex] fix adapter mesh bounds overflow

packages/adapter-mesh/src/index.ts

@@ -53,6 +53,20 @@ function parseObj(source: string): Triangle[] {
   return triangles;
 }
 
+function computeMeshBounds(triangles: Triangle[]): { min: Point3; max: Point3 } {
+  const min: Point3 = [Infinity, Infinity, Infinity];
+  const max: Point3 = [-Infinity, -Infinity, -Infinity];
+  for (const triangle of triangles) {
+    for (const vertex of triangle) {
+      for (let axis = 0; axis < 3; axis += 1) {
+        min[axis] = Math.min(min[axis], vertex[axis]);
+        max[axis] = Math.max(max[axis], vertex[axis]);
+      }
+    }
+  }
+  return { min, max };
+}
+
 function cross(a: Point3, b: Point3): Point3 {
   return [a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0]];
 }
@@ -114,9 +128,7 @@ export function objToVoxelPlan(source: string, options: ObjToVoxelPlanOptions =
   if (mode !== "surface" && mode !== "solid") fail("voxelMode must be surface or solid");
   const block = validateBlock(options.defaultBlock ?? "minecraft:stone");
   const parsed = parseObj(source);
-  const rawVertices = parsed.flat();
-  const min: Point3 = [0, 1, 2].map((axis) => Math.min(...rawVertices.map((v) => v[axis]))) as Point3;
-  const max: Point3 = [0, 1, 2].map((axis) => Math.max(...rawVertices.map((v) => v[axis]))) as Point3;
+  const { min, max } = computeMeshBounds(parsed);
   const extents = subtract(max, min);
   if (extents.some((extent) => extent <= EPSILON)) fail("mesh bounds must have non-zero width, height and depth");
   const scale = targetHeight / extents[1];

packages/adapter-mesh/test/adapter-mesh.test.ts

@@ -54,4 +54,21 @@ describe("OBJ to VoxelPlan", () => {
     expect(solid.blocks.length).toBe(64);
     expect(() => objToVoxelPlan(source("gabled-cabin"), { targetHeight: 64, maxBlocks: 100 })).toThrow(/exceed maxBlocks/);
   });
+
+  it("computes bounds for large repeated face references without argument overflow", () => {
+    const repeatedFaceCount = 50_000;
+    const input = [
+      "v 0 0 0",
+      "v 1 0 0",
+      "v 0 1 1",
+      ...Array.from({ length: repeatedFaceCount }, () => "f 1 2 3"),
+    ].join("\n");
+
+    const plan = objToVoxelPlan(input, { targetHeight: 1, maxBlocks: 1, voxelMode: "surface" });
+
+    expect(plan.size).toEqual([1, 1, 1]);
+    expect(plan.blocks).toHaveLength(1);
+    expect(plan.blocks[0].pos).toEqual([0, 0, 0]);
+    expect(plan.blocks.every(({ pos }) => pos.every((value, axis) => value >= 0 && value < plan.size[axis]))).toBe(true);
+  });
 });