itowns/lib/Provider/PointCloudProvider.js

A JS/WebGL framework for 3D geospatial data visualization

import * as THREE from 'three';
import { Extent } from '@itowns/geographic';
let nextuuid = 1;
function addPickingAttribute(points) {
  // generate unique id for picking
  const numPoints = points.geometry.attributes.position.count;
  const ids = new Uint8Array(4 * numPoints);
  const baseId = nextuuid++;
  if (numPoints > 0xffff || baseId > 0xffff) {
    // TODO: fixme
    console.warn('Currently picking is limited to Points with less than 65535 elements and less than 65535 Points instances');
    return points;
  }
  for (let i = 0; i < numPoints; i++) {
    // todo numpoints > 16bits
    const v = baseId << 16 | i;
    ids[4 * i + 0] = (v & 0xff000000) >> 24;
    ids[4 * i + 1] = (v & 0x00ff0000) >> 16;
    ids[4 * i + 2] = (v & 0x0000ff00) >> 8;
    ids[4 * i + 3] = (v & 0x000000ff) >> 0;
  }
  points.baseId = baseId;
  points.geometry.setAttribute('unique_id', new THREE.BufferAttribute(ids, 4, true));
  return points;
}
export default {
  executeCommand(command) {
    const layer = command.layer;
    const node = command.requester;
    return node.load().then(geometry => {
      const points = new THREE.Points(geometry, layer.material);
      addPickingAttribute(points);
      points.frustumCulled = false;
      points.matrixAutoUpdate = false;
      points.position.copy(geometry.userData.origin || node.bbox.min);
      points.scale.copy(layer.scale);
      points.updateMatrix();
      points.tightbbox = geometry.boundingBox.applyMatrix4(points.matrix);
      points.layer = layer;
      points.extent = Extent.fromBox3(command.view.referenceCrs, node.bbox);
      points.userData.node = node;
      return points;
    });
  }
};