Advance M8-M11 parity workflows

web/app/src/volume/nanovdb-float32.ts

@@ -2,6 +2,10 @@ import type { NanoVDBFloat32TreeLayoutIR, NanoVDBGridIR } from "../../../protoco
 
 export interface NanoVDBSampleIR { value: number; active: boolean }
 
+type NanoVDBNearestLocation =
+  | { sample: NanoVDBSampleIR }
+  | { leaf: number; voxel: number };
+
 export class NanoVDBFloat32Sampler {
   private readonly view: DataView;
   private readonly layout: NanoVDBFloat32TreeLayoutIR;
@@ -24,6 +28,20 @@ export class NanoVDBFloat32Sampler {
   }
 
   nearest(coord: readonly [number, number, number]): NanoVDBSampleIR {
+    const location = this.nearestLocation(coord);
+    if ("sample" in location) return location.sample;
+    return {
+      value: this.f32(location.leaf + this.layout.leafValuesOffset + location.voxel * 4),
+      active: this.mask(location.leaf + this.layout.leafValueMaskOffset, location.voxel),
+    };
+  }
+
+  leafByteOffset(coord: readonly [number, number, number]): number | null {
+    const location = this.nearestLocation(coord);
+    return "leaf" in location ? location.leaf : null;
+  }
+
+  private nearestLocation(coord: readonly [number, number, number]): NanoVDBNearestLocation {
     if (coord.some((value) => !Number.isSafeInteger(value) || value < -0x8000_0000 || value > 0x7fff_ffff)) throw new Error("NANOVDB_MANIFEST_INVALID: sample coordinate is outside int32");
     const tableSize = this.u32(this.root + this.layout.rootTableSizeOffset);
     const key = this.rootKey(coord);
@@ -39,20 +57,20 @@ export class NanoVDBFloat32Sampler {
       if (candidate > key) low = middle + 1;
       else high = middle - 1;
     }
-    if (tile < 0) return { value: this.view.getFloat32(this.root + 28, true), active: false };
+    if (tile < 0) return { sample: { value: this.view.getFloat32(this.root + 28, true), active: false } };
     const child = this.i64(tile + this.layout.rootTileChildOffset);
-    if (child === 0n) return { value: this.f32(tile + this.layout.rootTileValueOffset), active: this.u32(tile + this.layout.rootTileStateOffset) !== 0 };
+    if (child === 0n) return { sample: { value: this.f32(tile + this.layout.rootTileValueOffset), active: this.u32(tile + this.layout.rootTileStateOffset) !== 0 } };
     const upper = this.child(this.root, child, this.layout.upperNodeBytes);
     const upperOffset = (((coord[0] >>> 0 & 4095) >>> 7) << 10) | (((coord[1] >>> 0 & 4095) >>> 7) << 5) | ((coord[2] >>> 0 & 4095) >>> 7);
     const upperSample = this.internal(upper, upperOffset, this.layout.upperValueMaskOffset, this.layout.upperChildMaskOffset, this.layout.upperTableOffset, this.layout.lowerNodeBytes);
-    if ("sample" in upperSample) return upperSample.sample;
+    if ("sample" in upperSample) return upperSample;
     const lower = upperSample.child;
     const lowerOffset = (((coord[0] >>> 0 & 127) >>> 3) << 8) | (((coord[1] >>> 0 & 127) >>> 3) << 4) | ((coord[2] >>> 0 & 127) >>> 3);
     const lowerSample = this.internal(lower, lowerOffset, this.layout.lowerValueMaskOffset, this.layout.lowerChildMaskOffset, this.layout.lowerTableOffset, this.layout.leafNodeBytes);
-    if ("sample" in lowerSample) return lowerSample.sample;
+    if ("sample" in lowerSample) return lowerSample;
     const leaf = lowerSample.child;
     const voxel = ((coord[0] >>> 0 & 7) << 6) | ((coord[1] >>> 0 & 7) << 3) | (coord[2] >>> 0 & 7);
-    return { value: this.f32(leaf + this.layout.leafValuesOffset + voxel * 4), active: this.mask(leaf + this.layout.leafValueMaskOffset, voxel) };
+    return { leaf, voxel };
   }
 
   linear(coord: readonly [number, number, number]): NanoVDBSampleIR {