jtBaseApp/node_modules/@cesium/engine/Source/Core/PlaneOutlineGeometry.js

import BoundingSphere from "./BoundingSphere.js";
import Cartesian3 from "./Cartesian3.js";
import Check from "./Check.js";
import ComponentDatatype from "./ComponentDatatype.js";
import defined from "./defined.js";
import Geometry from "./Geometry.js";
import GeometryAttribute from "./GeometryAttribute.js";
import GeometryAttributes from "./GeometryAttributes.js";
import PrimitiveType from "./PrimitiveType.js";

/**
 * Describes geometry representing the outline of a plane centered at the origin, with a unit width and length.
 *
 * @alias PlaneOutlineGeometry
 * @constructor
 *
 */
function PlaneOutlineGeometry() {
  this._workerName = "createPlaneOutlineGeometry";
}

/**
 * The number of elements used to pack the object into an array.
 * @type {number}
 */
PlaneOutlineGeometry.packedLength = 0;

/**
 * Stores the provided instance into the provided array.
 *
 * @param {PlaneOutlineGeometry} value The value to pack.
 * @param {number[]} array The array to pack into.
 *
 * @returns {number[]} The array that was packed into
 */
PlaneOutlineGeometry.pack = function (value, array) {
  //>>includeStart('debug', pragmas.debug);
  Check.defined("value", value);
  Check.defined("array", array);
  //>>includeEnd('debug');

  return array;
};

/**
 * Retrieves an instance from a packed array.
 *
 * @param {number[]} array The packed array.
 * @param {number} [startingIndex=0] The starting index of the element to be unpacked.
 * @param {PlaneOutlineGeometry} [result] The object into which to store the result.
 * @returns {PlaneOutlineGeometry} The modified result parameter or a new PlaneOutlineGeometry instance if one was not provided.
 */
PlaneOutlineGeometry.unpack = function (array, startingIndex, result) {
  //>>includeStart('debug', pragmas.debug);
  Check.defined("array", array);
  //>>includeEnd('debug');

  if (!defined(result)) {
    return new PlaneOutlineGeometry();
  }

  return result;
};

const min = new Cartesian3(-0.5, -0.5, 0.0);
const max = new Cartesian3(0.5, 0.5, 0.0);

/**
 * Computes the geometric representation of an outline of a plane, including its vertices, indices, and a bounding sphere.
 *
 * @returns {Geometry|undefined} The computed vertices and indices.
 */
PlaneOutlineGeometry.createGeometry = function () {
  const attributes = new GeometryAttributes();
  const indices = new Uint16Array(4 * 2);
  const positions = new Float64Array(4 * 3);

  positions[0] = min.x;
  positions[1] = min.y;
  positions[2] = min.z;
  positions[3] = max.x;
  positions[4] = min.y;
  positions[5] = min.z;
  positions[6] = max.x;
  positions[7] = max.y;
  positions[8] = min.z;
  positions[9] = min.x;
  positions[10] = max.y;
  positions[11] = min.z;

  attributes.position = new GeometryAttribute({
    componentDatatype: ComponentDatatype.DOUBLE,
    componentsPerAttribute: 3,
    values: positions,
  });

  indices[0] = 0;
  indices[1] = 1;
  indices[2] = 1;
  indices[3] = 2;
  indices[4] = 2;
  indices[5] = 3;
  indices[6] = 3;
  indices[7] = 0;

  return new Geometry({
    attributes: attributes,
    indices: indices,
    primitiveType: PrimitiveType.LINES,
    boundingSphere: new BoundingSphere(Cartesian3.ZERO, Math.sqrt(2.0)),
  });
};
export default PlaneOutlineGeometry;