@thi.ng/geom-accel/spatial-grid3.js

n-D spatial indexing data structures with a shared ES6 Map/Set-like API

import { isNumber } from "@thi.ng/checks/is-number";
import { Heap } from "@thi.ng/heaps/heap";
import { clamp } from "@thi.ng/math/interval";
import { addN3 } from "@thi.ng/vectors/addn";
import { distSq3 } from "@thi.ng/vectors/distsq";
import { subN3 } from "@thi.ng/vectors/subn";
import { ASpatialGrid } from "./aspatial-grid.js";
import { __addResults, CMP } from "./utils.js";
const TMP = [];
class SpatialGrid3 extends ASpatialGrid {
  _stride;
  constructor(min, size, res) {
    super(min, size, isNumber(res) ? [res, res, res] : res);
    this._cells = new Array(this._res[0] * this._res[1] * this._res[2]);
    this._stride = [this._res[0], this._res[0] * this._res[1]];
  }
  copy() {
    return super.copy();
  }
  empty() {
    return new SpatialGrid3(this._min, this._size, this._res);
  }
  doQuery(fn, k, r, limit = Infinity, acc = []) {
    const id1 = this.findIndex(subN3(TMP, k, r));
    const id2 = this.findIndex(addN3(TMP, k, r));
    const [width, slice] = this._stride;
    const x1 = id1 % width;
    const x2 = id2 % width;
    const y1 = (id1 / width | 0) * width;
    const y2 = (id2 / width | 0) * width;
    const z1 = (id1 / slice | 0) * slice;
    const z2 = (id2 / slice | 0) * slice;
    const cells = this._cells;
    let c;
    let x, y, z;
    r *= r;
    const heap = new Heap([[r]], {
      compare: CMP
    });
    const sel = heap.values;
    for (z = z1; z <= z2; z += slice) {
      for (y = y1; y <= y2; y += width) {
        for (x = x1; x <= x2; x++) {
          c = cells[z + y + x];
          c?.length && this.queryCell(distSq3, heap, c, k, limit);
        }
      }
    }
    return __addResults(fn, sel, acc);
  }
  findIndex(k) {
    const { _min: min, _res1: res1, _invSize: invSize } = this;
    const kx = clamp((k[0] - min[0]) * invSize[0], 0, res1[0]);
    const ky = clamp((k[1] - min[1]) * invSize[1], 0, res1[1]);
    const kz = clamp((k[2] - min[2]) * invSize[2], 0, res1[2]);
    return (kx | 0) + (ky | 0) * this._stride[0] + (kz | 0) * this._stride[1];
  }
}
export {
  SpatialGrid3
};