Export the interleaved and columnar Morton sorts, add a stride option

src/lib/index.ts

@@ -12,7 +12,7 @@ export type {
 } from './chunk';
 
 // Structural combinators (lazy views over sources)
-export { bakeTransform, concatSource, selectLod, stackLods } from './ops';
+export { bakeTransform, concatSource, selectLod, stackLods, sortMortonColumns, sortMortonInterleaved } from './ops';
 
 // How a scene was trained (carried on `ChunkSourceMetadata.model`). The per-format
 // spellings of the tag live with their reader/writer.

src/lib/ops/index.ts

@@ -1,7 +1,7 @@
 // Tier-1 ops over a ChunkSource (views & passes).
 export { mapSource } from './map-source';
 export { bakeTransform } from './bake-transform';
-export { mortonOrder, sortMortonColumns } from './morton-order';
+export { mortonOrder, sortMortonColumns, sortMortonInterleaved } from './morton-order';
 export { permuteSource } from './permute-source';
 export { stackLods } from './stack-lods';
 export { selectLod, resolveLodLevels } from './select-lod';

src/lib/ops/morton-order.ts

@@ -124,11 +124,16 @@ const sortMortonStrided = (
  * Sort `indices` in place into morton (Z-order) using interleaved positions
  * `[x, y, z, x, y, z, ...]` — the natural packing of the `position` layer.
  *
- * @param positions - Interleaved xyz; gaussian `g` is at `positions[g*3 + {0,1,2}]`.
+ * `stride` lets the same call sort a wider record whose first three words are
+ * xyz, e.g. a packed `[x, y, z, w]` GPU texture row viewed as floats, without
+ * copying the positions out first.
+ *
+ * @param positions - Interleaved xyz; gaussian `g` is at `positions[g*stride + {0,1,2}]`.
  * @param indices - Indices to sort in place.
+ * @param stride - Words per gaussian in `positions` (default 3).
  */
-const sortMortonInterleaved = (positions: ArrayLike<number>, indices: Uint32Array): void => {
-    sortMortonStrided(indices, positions, positions, positions, 3, 0, 1, 2);
+const sortMortonInterleaved = (positions: ArrayLike<number>, indices: Uint32Array, stride = 3): void => {
+    sortMortonStrided(indices, positions, positions, positions, stride, 0, 1, 2);
 };
 
 /**