cesium/Source/Workers/GeometryPipeline-a88e5bfc.js

CesiumJS is a JavaScript library for creating 3D globes and 2D maps in a web browser without a plugin.

/* This file is automatically rebuilt by the Cesium build process. */
define(['exports', './AttributeCompression-4d18cc04', './Matrix2-fc7e9822', './RuntimeError-c581ca93', './defaultValue-94c3e563', './ComponentDatatype-4a60b8d6', './Transforms-3ac41eb6', './EncodedCartesian3-d3e254ea', './GeometryAttribute-a441ff32', './IndexDatatype-db156785', './IntersectionTests-68fbc42d', './Plane-e20fba8c'], (function (exports, AttributeCompression, Matrix2, RuntimeError, defaultValue, ComponentDatatype, Transforms, EncodedCartesian3, GeometryAttribute, IndexDatatype, IntersectionTests, Plane) { 'use strict';

  const scratchCartesian1 = new Matrix2.Cartesian3();
  const scratchCartesian2$1 = new Matrix2.Cartesian3();
  const scratchCartesian3$1 = new Matrix2.Cartesian3();

  /**
   * Computes the barycentric coordinates for a point with respect to a triangle.
   *
   * @function
   *
   * @param {Cartesian2|Cartesian3} point The point to test.
   * @param {Cartesian2|Cartesian3} p0 The first point of the triangle, corresponding to the barycentric x-axis.
   * @param {Cartesian2|Cartesian3} p1 The second point of the triangle, corresponding to the barycentric y-axis.
   * @param {Cartesian2|Cartesian3} p2 The third point of the triangle, corresponding to the barycentric z-axis.
   * @param {Cartesian3} [result] The object onto which to store the result.
   * @returns {Cartesian3|undefined} The modified result parameter or a new Cartesian3 instance if one was not provided. If the triangle is degenerate the function will return undefined.
   *
   * @example
   * // Returns Cartesian3.UNIT_X
   * const p = new Cesium.Cartesian3(-1.0, 0.0, 0.0);
   * const b = Cesium.barycentricCoordinates(p,
   *   new Cesium.Cartesian3(-1.0, 0.0, 0.0),
   *   new Cesium.Cartesian3( 1.0, 0.0, 0.0),
   *   new Cesium.Cartesian3( 0.0, 1.0, 1.0));
   */
  function barycentricCoordinates(point, p0, p1, p2, result) {
    //>>includeStart('debug', pragmas.debug);
    RuntimeError.Check.defined("point", point);
    RuntimeError.Check.defined("p0", p0);
    RuntimeError.Check.defined("p1", p1);
    RuntimeError.Check.defined("p2", p2);
    //>>includeEnd('debug');

    if (!defaultValue.defined(result)) {
      result = new Matrix2.Cartesian3();
    }

    // Implementation based on http://www.blackpawn.com/texts/pointinpoly/default.html.
    let v0;
    let v1;
    let v2;
    let dot00;
    let dot01;
    let dot02;
    let dot11;
    let dot12;

    if (!defaultValue.defined(p0.z)) {
      if (Matrix2.Cartesian2.equalsEpsilon(point, p0, ComponentDatatype.CesiumMath.EPSILON14)) {
        return Matrix2.Cartesian3.clone(Matrix2.Cartesian3.UNIT_X, result);
      }
      if (Matrix2.Cartesian2.equalsEpsilon(point, p1, ComponentDatatype.CesiumMath.EPSILON14)) {
        return Matrix2.Cartesian3.clone(Matrix2.Cartesian3.UNIT_Y, result);
      }
      if (Matrix2.Cartesian2.equalsEpsilon(point, p2, ComponentDatatype.CesiumMath.EPSILON14)) {
        return Matrix2.Cartesian3.clone(Matrix2.Cartesian3.UNIT_Z, result);
      }

      v0 = Matrix2.Cartesian2.subtract(p1, p0, scratchCartesian1);
      v1 = Matrix2.Cartesian2.subtract(p2, p0, scratchCartesian2$1);
      v2 = Matrix2.Cartesian2.subtract(point, p0, scratchCartesian3$1);

      dot00 = Matrix2.Cartesian2.dot(v0, v0);
      dot01 = Matrix2.Cartesian2.dot(v0, v1);
      dot02 = Matrix2.Cartesian2.dot(v0, v2);
      dot11 = Matrix2.Cartesian2.dot(v1, v1);
      dot12 = Matrix2.Cartesian2.dot(v1, v2);
    } else {
      if (Matrix2.Cartesian3.equalsEpsilon(point, p0, ComponentDatatype.CesiumMath.EPSILON14)) {
        return Matrix2.Cartesian3.clone(Matrix2.Cartesian3.UNIT_X, result);
      }
      if (Matrix2.Cartesian3.equalsEpsilon(point, p1, ComponentDatatype.CesiumMath.EPSILON14)) {
        return Matrix2.Cartesian3.clone(Matrix2.Cartesian3.UNIT_Y, result);
      }
      if (Matrix2.Cartesian3.equalsEpsilon(point, p2, ComponentDatatype.CesiumMath.EPSILON14)) {
        return Matrix2.Cartesian3.clone(Matrix2.Cartesian3.UNIT_Z, result);
      }

      v0 = Matrix2.Cartesian3.subtract(p1, p0, scratchCartesian1);
      v1 = Matrix2.Cartesian3.subtract(p2, p0, scratchCartesian2$1);
      v2 = Matrix2.Cartesian3.subtract(point, p0, scratchCartesian3$1);

      dot00 = Matrix2.Cartesian3.dot(v0, v0);
      dot01 = Matrix2.Cartesian3.dot(v0, v1);
      dot02 = Matrix2.Cartesian3.dot(v0, v2);
      dot11 = Matrix2.Cartesian3.dot(v1, v1);
      dot12 = Matrix2.Cartesian3.dot(v1, v2);
    }

    result.y = dot11 * dot02 - dot01 * dot12;
    result.z = dot00 * dot12 - dot01 * dot02;
    const q = dot00 * dot11 - dot01 * dot01;

    // Triangle is degenerate
    if (q === 0) {
      return undefined;
    }

    result.y /= q;
    result.z /= q;
    result.x = 1.0 - result.y - result.z;
    return result;
  }

  /**
   * Encapsulates an algorithm to optimize triangles for the post
   * vertex-shader cache.  This is based on the 2007 SIGGRAPH paper
   * 'Fast Triangle Reordering for Vertex Locality and Reduced Overdraw.'
   * The runtime is linear but several passes are made.
   *
   * @namespace Tipsify
   *
   * @see <a href='http://gfx.cs.princeton.edu/pubs/Sander_2007_%3ETR/tipsy.pdf'>
   * Fast Triangle Reordering for Vertex Locality and Reduced Overdraw</a>
   * by Sander, Nehab, and Barczak
   *
   * @private
   */
  const Tipsify = {};

  /**
   * Calculates the average cache miss ratio (ACMR) for a given set of indices.
   *
   * @param {Object} options Object with the following properties:
   * @param {Number[]} options.indices Lists triads of numbers corresponding to the indices of the vertices
   *                        in the vertex buffer that define the geometry's triangles.
   * @param {Number} [options.maximumIndex] The maximum value of the elements in <code>args.indices</code>.
   *                                     If not supplied, this value will be computed.
   * @param {Number} [options.cacheSize=24] The number of vertices that can be stored in the cache at any one time.
   * @returns {Number} The average cache miss ratio (ACMR).
   *
   * @exception {DeveloperError} indices length must be a multiple of three.
   * @exception {DeveloperError} cacheSize must be greater than two.
   *
   * @example
   * const indices = [0, 1, 2, 3, 4, 5];
   * const maxIndex = 5;
   * const cacheSize = 3;
   * const acmr = Cesium.Tipsify.calculateACMR({indices : indices, maxIndex : maxIndex, cacheSize : cacheSize});
   */
  Tipsify.calculateACMR = function (options) {
    options = defaultValue.defaultValue(options, defaultValue.defaultValue.EMPTY_OBJECT);
    const indices = options.indices;
    let maximumIndex = options.maximumIndex;
    const cacheSize = defaultValue.defaultValue(options.cacheSize, 24);

    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(indices)) {
      throw new RuntimeError.DeveloperError("indices is required.");
    }
    //>>includeEnd('debug');

    const numIndices = indices.length;

    //>>includeStart('debug', pragmas.debug);
    if (numIndices < 3 || numIndices % 3 !== 0) {
      throw new RuntimeError.DeveloperError("indices length must be a multiple of three.");
    }
    if (maximumIndex <= 0) {
      throw new RuntimeError.DeveloperError("maximumIndex must be greater than zero.");
    }
    if (cacheSize < 3) {
      throw new RuntimeError.DeveloperError("cacheSize must be greater than two.");
    }
    //>>includeEnd('debug');

    // Compute the maximumIndex if not given
    if (!defaultValue.defined(maximumIndex)) {
      maximumIndex = 0;
      let currentIndex = 0;
      let intoIndices = indices[currentIndex];
      while (currentIndex < numIndices) {
        if (intoIndices > maximumIndex) {
          maximumIndex = intoIndices;
        }
        ++currentIndex;
        intoIndices = indices[currentIndex];
      }
    }

    // Vertex time stamps
    const vertexTimeStamps = [];
    for (let i = 0; i < maximumIndex + 1; i++) {
      vertexTimeStamps[i] = 0;
    }

    // Cache processing
    let s = cacheSize + 1;
    for (let j = 0; j < numIndices; ++j) {
      if (s - vertexTimeStamps[indices[j]] > cacheSize) {
        vertexTimeStamps[indices[j]] = s;
        ++s;
      }
    }

    return (s - cacheSize + 1) / (numIndices / 3);
  };

  /**
   * Optimizes triangles for the post-vertex shader cache.
   *
   * @param {Object} options Object with the following properties:
   * @param {Number[]} options.indices Lists triads of numbers corresponding to the indices of the vertices
   *                        in the vertex buffer that define the geometry's triangles.
   * @param {Number} [options.maximumIndex] The maximum value of the elements in <code>args.indices</code>.
   *                                     If not supplied, this value will be computed.
   * @param {Number} [options.cacheSize=24] The number of vertices that can be stored in the cache at any one time.
   * @returns {Number[]} A list of the input indices in an optimized order.
   *
   * @exception {DeveloperError} indices length must be a multiple of three.
   * @exception {DeveloperError} cacheSize must be greater than two.
   *
   * @example
   * const indices = [0, 1, 2, 3, 4, 5];
   * const maxIndex = 5;
   * const cacheSize = 3;
   * const reorderedIndices = Cesium.Tipsify.tipsify({indices : indices, maxIndex : maxIndex, cacheSize : cacheSize});
   */
  Tipsify.tipsify = function (options) {
    options = defaultValue.defaultValue(options, defaultValue.defaultValue.EMPTY_OBJECT);
    const indices = options.indices;
    const maximumIndex = options.maximumIndex;
    const cacheSize = defaultValue.defaultValue(options.cacheSize, 24);

    let cursor;

    function skipDeadEnd(vertices, deadEnd, indices, maximumIndexPlusOne) {
      while (deadEnd.length >= 1) {
        // while the stack is not empty
        const d = deadEnd[deadEnd.length - 1]; // top of the stack
        deadEnd.splice(deadEnd.length - 1, 1); // pop the stack

        if (vertices[d].numLiveTriangles > 0) {
          return d;
        }
      }

      while (cursor < maximumIndexPlusOne) {
        if (vertices[cursor].numLiveTriangles > 0) {
          ++cursor;
          return cursor - 1;
        }
        ++cursor;
      }
      return -1;
    }

    function getNextVertex(
      indices,
      cacheSize,
      oneRing,
      vertices,
      s,
      deadEnd,
      maximumIndexPlusOne
    ) {
      let n = -1;
      let p;
      let m = -1;
      let itOneRing = 0;
      while (itOneRing < oneRing.length) {
        const index = oneRing[itOneRing];
        if (vertices[index].numLiveTriangles) {
          p = 0;
          if (
            s -
              vertices[index].timeStamp +
              2 * vertices[index].numLiveTriangles <=
            cacheSize
          ) {
            p = s - vertices[index].timeStamp;
          }
          if (p > m || m === -1) {
            m = p;
            n = index;
          }
        }
        ++itOneRing;
      }
      if (n === -1) {
        return skipDeadEnd(vertices, deadEnd, indices, maximumIndexPlusOne);
      }
      return n;
    }

    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(indices)) {
      throw new RuntimeError.DeveloperError("indices is required.");
    }
    //>>includeEnd('debug');

    const numIndices = indices.length;

    //>>includeStart('debug', pragmas.debug);
    if (numIndices < 3 || numIndices % 3 !== 0) {
      throw new RuntimeError.DeveloperError("indices length must be a multiple of three.");
    }
    if (maximumIndex <= 0) {
      throw new RuntimeError.DeveloperError("maximumIndex must be greater than zero.");
    }
    if (cacheSize < 3) {
      throw new RuntimeError.DeveloperError("cacheSize must be greater than two.");
    }
    //>>includeEnd('debug');

    // Determine maximum index
    let maximumIndexPlusOne = 0;
    let currentIndex = 0;
    let intoIndices = indices[currentIndex];
    const endIndex = numIndices;
    if (defaultValue.defined(maximumIndex)) {
      maximumIndexPlusOne = maximumIndex + 1;
    } else {
      while (currentIndex < endIndex) {
        if (intoIndices > maximumIndexPlusOne) {
          maximumIndexPlusOne = intoIndices;
        }
        ++currentIndex;
        intoIndices = indices[currentIndex];
      }
      if (maximumIndexPlusOne === -1) {
        return 0;
      }
      ++maximumIndexPlusOne;
    }

    // Vertices
    const vertices = [];
    let i;
    for (i = 0; i < maximumIndexPlusOne; i++) {
      vertices[i] = {
        numLiveTriangles: 0,
        timeStamp: 0,
        vertexTriangles: [],
      };
    }
    currentIndex = 0;
    let triangle = 0;
    while (currentIndex < endIndex) {
      vertices[indices[currentIndex]].vertexTriangles.push(triangle);
      ++vertices[indices[currentIndex]].numLiveTriangles;
      vertices[indices[currentIndex + 1]].vertexTriangles.push(triangle);
      ++vertices[indices[currentIndex + 1]].numLiveTriangles;
      vertices[indices[currentIndex + 2]].vertexTriangles.push(triangle);
      ++vertices[indices[currentIndex + 2]].numLiveTriangles;
      ++triangle;
      currentIndex += 3;
    }

    // Starting index
    let f = 0;

    // Time Stamp
    let s = cacheSize + 1;
    cursor = 1;

    // Process
    let oneRing = [];
    const deadEnd = []; //Stack
    let vertex;
    let intoVertices;
    let currentOutputIndex = 0;
    const outputIndices = [];
    const numTriangles = numIndices / 3;
    const triangleEmitted = [];
    for (i = 0; i < numTriangles; i++) {
      triangleEmitted[i] = false;
    }
    let index;
    let limit;
    while (f !== -1) {
      oneRing = [];
      intoVertices = vertices[f];
      limit = intoVertices.vertexTriangles.length;
      for (let k = 0; k < limit; ++k) {
        triangle = intoVertices.vertexTriangles[k];
        if (!triangleEmitted[triangle]) {
          triangleEmitted[triangle] = true;
          currentIndex = triangle + triangle + triangle;
          for (let j = 0; j < 3; ++j) {
            // Set this index as a possible next index
            index = indices[currentIndex];
            oneRing.push(index);
            deadEnd.push(index);

            // Output index
            outputIndices[currentOutputIndex] = index;
            ++currentOutputIndex;

            // Cache processing
            vertex = vertices[index];
            --vertex.numLiveTriangles;
            if (s - vertex.timeStamp > cacheSize) {
              vertex.timeStamp = s;
              ++s;
            }
            ++currentIndex;
          }
        }
      }
      f = getNextVertex(
        indices,
        cacheSize,
        oneRing,
        vertices,
        s,
        deadEnd,
        maximumIndexPlusOne
      );
    }

    return outputIndices;
  };

  /**
   * Content pipeline functions for geometries.
   *
   * @namespace GeometryPipeline
   *
   * @see Geometry
   */
  const GeometryPipeline = {};

  function addTriangle(lines, index, i0, i1, i2) {
    lines[index++] = i0;
    lines[index++] = i1;

    lines[index++] = i1;
    lines[index++] = i2;

    lines[index++] = i2;
    lines[index] = i0;
  }

  function trianglesToLines(triangles) {
    const count = triangles.length;
    const size = (count / 3) * 6;
    const lines = IndexDatatype.IndexDatatype.createTypedArray(count, size);

    let index = 0;
    for (let i = 0; i < count; i += 3, index += 6) {
      addTriangle(lines, index, triangles[i], triangles[i + 1], triangles[i + 2]);
    }

    return lines;
  }

  function triangleStripToLines(triangles) {
    const count = triangles.length;
    if (count >= 3) {
      const size = (count - 2) * 6;
      const lines = IndexDatatype.IndexDatatype.createTypedArray(count, size);

      addTriangle(lines, 0, triangles[0], triangles[1], triangles[2]);
      let index = 6;

      for (let i = 3; i < count; ++i, index += 6) {
        addTriangle(
          lines,
          index,
          triangles[i - 1],
          triangles[i],
          triangles[i - 2]
        );
      }

      return lines;
    }

    return new Uint16Array();
  }

  function triangleFanToLines(triangles) {
    if (triangles.length > 0) {
      const count = triangles.length - 1;
      const size = (count - 1) * 6;
      const lines = IndexDatatype.IndexDatatype.createTypedArray(count, size);

      const base = triangles[0];
      let index = 0;
      for (let i = 1; i < count; ++i, index += 6) {
        addTriangle(lines, index, base, triangles[i], triangles[i + 1]);
      }

      return lines;
    }

    return new Uint16Array();
  }

  /**
   * Converts a geometry's triangle indices to line indices.  If the geometry has an <code>indices</code>
   * and its <code>primitiveType</code> is <code>TRIANGLES</code>, <code>TRIANGLE_STRIP</code>,
   * <code>TRIANGLE_FAN</code>, it is converted to <code>LINES</code>; otherwise, the geometry is not changed.
   * <p>
   * This is commonly used to create a wireframe geometry for visual debugging.
   * </p>
   *
   * @param {Geometry} geometry The geometry to modify.
   * @returns {Geometry} The modified <code>geometry</code> argument, with its triangle indices converted to lines.
   *
   * @exception {DeveloperError} geometry.primitiveType must be TRIANGLES, TRIANGLE_STRIP, or TRIANGLE_FAN.
   *
   * @example
   * geometry = Cesium.GeometryPipeline.toWireframe(geometry);
   */
  GeometryPipeline.toWireframe = function (geometry) {
    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(geometry)) {
      throw new RuntimeError.DeveloperError("geometry is required.");
    }
    //>>includeEnd('debug');

    const indices = geometry.indices;
    if (defaultValue.defined(indices)) {
      switch (geometry.primitiveType) {
        case GeometryAttribute.PrimitiveType.TRIANGLES:
          geometry.indices = trianglesToLines(indices);
          break;
        case GeometryAttribute.PrimitiveType.TRIANGLE_STRIP:
          geometry.indices = triangleStripToLines(indices);
          break;
        case GeometryAttribute.PrimitiveType.TRIANGLE_FAN:
          geometry.indices = triangleFanToLines(indices);
          break;
        //>>includeStart('debug', pragmas.debug);
        default:
          throw new RuntimeError.DeveloperError(
            "geometry.primitiveType must be TRIANGLES, TRIANGLE_STRIP, or TRIANGLE_FAN."
          );
        //>>includeEnd('debug');
      }

      geometry.primitiveType = GeometryAttribute.PrimitiveType.LINES;
    }

    return geometry;
  };

  /**
   * Creates a new {@link Geometry} with <code>LINES</code> representing the provided
   * attribute (<code>attributeName</code>) for the provided geometry.  This is used to
   * visualize vector attributes like normals, tangents, and bitangents.
   *
   * @param {Geometry} geometry The <code>Geometry</code> instance with the attribute.
   * @param {String} [attributeName='normal'] The name of the attribute.
   * @param {Number} [length=10000.0] The length of each line segment in meters.  This can be negative to point the vector in the opposite direction.
   * @returns {Geometry} A new <code>Geometry</code> instance with line segments for the vector.
   *
   * @exception {DeveloperError} geometry.attributes must have an attribute with the same name as the attributeName parameter.
   *
   * @example
   * const geometry = Cesium.GeometryPipeline.createLineSegmentsForVectors(instance.geometry, 'bitangent', 100000.0);
   */
  GeometryPipeline.createLineSegmentsForVectors = function (
    geometry,
    attributeName,
    length
  ) {
    attributeName = defaultValue.defaultValue(attributeName, "normal");

    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(geometry)) {
      throw new RuntimeError.DeveloperError("geometry is required.");
    }
    if (!defaultValue.defined(geometry.attributes.position)) {
      throw new RuntimeError.DeveloperError("geometry.attributes.position is required.");
    }
    if (!defaultValue.defined(geometry.attributes[attributeName])) {
      throw new RuntimeError.DeveloperError(
        `geometry.attributes must have an attribute with the same name as the attributeName parameter, ${attributeName}.`
      );
    }
    //>>includeEnd('debug');

    length = defaultValue.defaultValue(length, 10000.0);

    const positions = geometry.attributes.position.values;
    const vectors = geometry.attributes[attributeName].values;
    const positionsLength = positions.length;

    const newPositions = new Float64Array(2 * positionsLength);

    let j = 0;
    for (let i = 0; i < positionsLength; i += 3) {
      newPositions[j++] = positions[i];
      newPositions[j++] = positions[i + 1];
      newPositions[j++] = positions[i + 2];

      newPositions[j++] = positions[i] + vectors[i] * length;
      newPositions[j++] = positions[i + 1] + vectors[i + 1] * length;
      newPositions[j++] = positions[i + 2] + vectors[i + 2] * length;
    }

    let newBoundingSphere;
    const bs = geometry.boundingSphere;
    if (defaultValue.defined(bs)) {
      newBoundingSphere = new Transforms.BoundingSphere(bs.center, bs.radius + length);
    }

    return new GeometryAttribute.Geometry({
      attributes: {
        position: new GeometryAttribute.GeometryAttribute({
          componentDatatype: ComponentDatatype.ComponentDatatype.DOUBLE,
          componentsPerAttribute: 3,
          values: newPositions,
        }),
      },
      primitiveType: GeometryAttribute.PrimitiveType.LINES,
      boundingSphere: newBoundingSphere,
    });
  };

  /**
   * Creates an object that maps attribute names to unique locations (indices)
   * for matching vertex attributes and shader programs.
   *
   * @param {Geometry} geometry The geometry, which is not modified, to create the object for.
   * @returns {Object} An object with attribute name / index pairs.
   *
   * @example
   * const attributeLocations = Cesium.GeometryPipeline.createAttributeLocations(geometry);
   * // Example output
   * // {
   * //   'position' : 0,
   * //   'normal' : 1
   * // }
   */
  GeometryPipeline.createAttributeLocations = function (geometry) {
    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(geometry)) {
      throw new RuntimeError.DeveloperError("geometry is required.");
    }
    //>>includeEnd('debug')

    // There can be a WebGL performance hit when attribute 0 is disabled, so
    // assign attribute locations to well-known attributes.
    const semantics = [
      "position",
      "positionHigh",
      "positionLow",

      // From VertexFormat.position - after 2D projection and high-precision encoding
      "position3DHigh",
      "position3DLow",
      "position2DHigh",
      "position2DLow",

      // From Primitive
      "pickColor",

      // From VertexFormat
      "normal",
      "st",
      "tangent",
      "bitangent",

      // For shadow volumes
      "extrudeDirection",

      // From compressing texture coordinates and normals
      "compressedAttributes",
    ];

    const attributes = geometry.attributes;
    const indices = {};
    let j = 0;
    let i;
    const len = semantics.length;

    // Attribute locations for well-known attributes
    for (i = 0; i < len; ++i) {
      const semantic = semantics[i];

      if (defaultValue.defined(attributes[semantic])) {
        indices[semantic] = j++;
      }
    }

    // Locations for custom attributes
    for (const name in attributes) {
      if (attributes.hasOwnProperty(name) && !defaultValue.defined(indices[name])) {
        indices[name] = j++;
      }
    }

    return indices;
  };

  /**
   * Reorders a geometry's attributes and <code>indices</code> to achieve better performance from the GPU's pre-vertex-shader cache.
   *
   * @param {Geometry} geometry The geometry to modify.
   * @returns {Geometry} The modified <code>geometry</code> argument, with its attributes and indices reordered for the GPU's pre-vertex-shader cache.
   *
   * @exception {DeveloperError} Each attribute array in geometry.attributes must have the same number of attributes.
   *
   *
   * @example
   * geometry = Cesium.GeometryPipeline.reorderForPreVertexCache(geometry);
   *
   * @see GeometryPipeline.reorderForPostVertexCache
   */
  GeometryPipeline.reorderForPreVertexCache = function (geometry) {
    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(geometry)) {
      throw new RuntimeError.DeveloperError("geometry is required.");
    }
    //>>includeEnd('debug');

    const numVertices = GeometryAttribute.Geometry.computeNumberOfVertices(geometry);

    const indices = geometry.indices;
    if (defaultValue.defined(indices)) {
      const indexCrossReferenceOldToNew = new Int32Array(numVertices);
      for (let i = 0; i < numVertices; i++) {
        indexCrossReferenceOldToNew[i] = -1;
      }

      // Construct cross reference and reorder indices
      const indicesIn = indices;
      const numIndices = indicesIn.length;
      const indicesOut = IndexDatatype.IndexDatatype.createTypedArray(numVertices, numIndices);

      let intoIndicesIn = 0;
      let intoIndicesOut = 0;
      let nextIndex = 0;
      let tempIndex;
      while (intoIndicesIn < numIndices) {
        tempIndex = indexCrossReferenceOldToNew[indicesIn[intoIndicesIn]];
        if (tempIndex !== -1) {
          indicesOut[intoIndicesOut] = tempIndex;
        } else {
          tempIndex = indicesIn[intoIndicesIn];
          indexCrossReferenceOldToNew[tempIndex] = nextIndex;

          indicesOut[intoIndicesOut] = nextIndex;
          ++nextIndex;
        }
        ++intoIndicesIn;
        ++intoIndicesOut;
      }
      geometry.indices = indicesOut;

      // Reorder attributes
      const attributes = geometry.attributes;
      for (const property in attributes) {
        if (
          attributes.hasOwnProperty(property) &&
          defaultValue.defined(attributes[property]) &&
          defaultValue.defined(attributes[property].values)
        ) {
          const attribute = attributes[property];
          const elementsIn = attribute.values;
          let intoElementsIn = 0;
          const numComponents = attribute.componentsPerAttribute;
          const elementsOut = ComponentDatatype.ComponentDatatype.createTypedArray(
            attribute.componentDatatype,
            nextIndex * numComponents
          );
          while (intoElementsIn < numVertices) {
            const temp = indexCrossReferenceOldToNew[intoElementsIn];
            if (temp !== -1) {
              for (let j = 0; j < numComponents; j++) {
                elementsOut[numComponents * temp + j] =
                  elementsIn[numComponents * intoElementsIn + j];
              }
            }
            ++intoElementsIn;
          }
          attribute.values = elementsOut;
        }
      }
    }

    return geometry;
  };

  /**
   * Reorders a geometry's <code>indices</code> to achieve better performance from the GPU's
   * post vertex-shader cache by using the Tipsify algorithm.  If the geometry <code>primitiveType</code>
   * is not <code>TRIANGLES</code> or the geometry does not have an <code>indices</code>, this function has no effect.
   *
   * @param {Geometry} geometry The geometry to modify.
   * @param {Number} [cacheCapacity=24] The number of vertices that can be held in the GPU's vertex cache.
   * @returns {Geometry} The modified <code>geometry</code> argument, with its indices reordered for the post-vertex-shader cache.
   *
   * @exception {DeveloperError} cacheCapacity must be greater than two.
   *
   *
   * @example
   * geometry = Cesium.GeometryPipeline.reorderForPostVertexCache(geometry);
   *
   * @see GeometryPipeline.reorderForPreVertexCache
   * @see {@link http://gfx.cs.princ0eton.edu/pubs/Sander_2007_%3ETR/tipsy.pdf|Fast Triangle Reordering for Vertex Locality and Reduced Overdraw}
   * by Sander, Nehab, and Barczak
   */
  GeometryPipeline.reorderForPostVertexCache = function (
    geometry,
    cacheCapacity
  ) {
    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(geometry)) {
      throw new RuntimeError.DeveloperError("geometry is required.");
    }
    //>>includeEnd('debug');

    const indices = geometry.indices;
    if (geometry.primitiveType === GeometryAttribute.PrimitiveType.TRIANGLES && defaultValue.defined(indices)) {
      const numIndices = indices.length;
      let maximumIndex = 0;
      for (let j = 0; j < numIndices; j++) {
        if (indices[j] > maximumIndex) {
          maximumIndex = indices[j];
        }
      }
      geometry.indices = Tipsify.tipsify({
        indices: indices,
        maximumIndex: maximumIndex,
        cacheSize: cacheCapacity,
      });
    }

    return geometry;
  };

  function copyAttributesDescriptions(attributes) {
    const newAttributes = {};

    for (const attribute in attributes) {
      if (
        attributes.hasOwnProperty(attribute) &&
        defaultValue.defined(attributes[attribute]) &&
        defaultValue.defined(attributes[attribute].values)
      ) {
        const attr = attributes[attribute];
        newAttributes[attribute] = new GeometryAttribute.GeometryAttribute({
          componentDatatype: attr.componentDatatype,
          componentsPerAttribute: attr.componentsPerAttribute,
          normalize: attr.normalize,
          values: [],
        });
      }
    }

    return newAttributes;
  }

  function copyVertex(destinationAttributes, sourceAttributes, index) {
    for (const attribute in sourceAttributes) {
      if (
        sourceAttributes.hasOwnProperty(attribute) &&
        defaultValue.defined(sourceAttributes[attribute]) &&
        defaultValue.defined(sourceAttributes[attribute].values)
      ) {
        const attr = sourceAttributes[attribute];

        for (let k = 0; k < attr.componentsPerAttribute; ++k) {
          destinationAttributes[attribute].values.push(
            attr.values[index * attr.componentsPerAttribute + k]
          );
        }
      }
    }
  }

  /**
   * Splits a geometry into multiple geometries, if necessary, to ensure that indices in the
   * <code>indices</code> fit into unsigned shorts.  This is used to meet the WebGL requirements
   * when unsigned int indices are not supported.
   * <p>
   * If the geometry does not have any <code>indices</code>, this function has no effect.
   * </p>
   *
   * @param {Geometry} geometry The geometry to be split into multiple geometries.
   * @returns {Geometry[]} An array of geometries, each with indices that fit into unsigned shorts.
   *
   * @exception {DeveloperError} geometry.primitiveType must equal to PrimitiveType.TRIANGLES, PrimitiveType.LINES, or PrimitiveType.POINTS
   * @exception {DeveloperError} All geometry attribute lists must have the same number of attributes.
   *
   * @example
   * const geometries = Cesium.GeometryPipeline.fitToUnsignedShortIndices(geometry);
   */
  GeometryPipeline.fitToUnsignedShortIndices = function (geometry) {
    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(geometry)) {
      throw new RuntimeError.DeveloperError("geometry is required.");
    }
    if (
      defaultValue.defined(geometry.indices) &&
      geometry.primitiveType !== GeometryAttribute.PrimitiveType.TRIANGLES &&
      geometry.primitiveType !== GeometryAttribute.PrimitiveType.LINES &&
      geometry.primitiveType !== GeometryAttribute.PrimitiveType.POINTS
    ) {
      throw new RuntimeError.DeveloperError(
        "geometry.primitiveType must equal to PrimitiveType.TRIANGLES, PrimitiveType.LINES, or PrimitiveType.POINTS."
      );
    }
    //>>includeEnd('debug');

    const geometries = [];

    // If there's an index list and more than 64K attributes, it is possible that
    // some indices are outside the range of unsigned short [0, 64K - 1]
    const numberOfVertices = GeometryAttribute.Geometry.computeNumberOfVertices(geometry);
    if (
      defaultValue.defined(geometry.indices) &&
      numberOfVertices >= ComponentDatatype.CesiumMath.SIXTY_FOUR_KILOBYTES
    ) {
      let oldToNewIndex = [];
      let newIndices = [];
      let currentIndex = 0;
      let newAttributes = copyAttributesDescriptions(geometry.attributes);

      const originalIndices = geometry.indices;
      const numberOfIndices = originalIndices.length;

      let indicesPerPrimitive;

      if (geometry.primitiveType === GeometryAttribute.PrimitiveType.TRIANGLES) {
        indicesPerPrimitive = 3;
      } else if (geometry.primitiveType === GeometryAttribute.PrimitiveType.LINES) {
        indicesPerPrimitive = 2;
      } else if (geometry.primitiveType === GeometryAttribute.PrimitiveType.POINTS) {
        indicesPerPrimitive = 1;
      }

      for (let j = 0; j < numberOfIndices; j += indicesPerPrimitive) {
        for (let k = 0; k < indicesPerPrimitive; ++k) {
          const x = originalIndices[j + k];
          let i = oldToNewIndex[x];
          if (!defaultValue.defined(i)) {
            i = currentIndex++;
            oldToNewIndex[x] = i;
            copyVertex(newAttributes, geometry.attributes, x);
          }
          newIndices.push(i);
        }

        if (
          currentIndex + indicesPerPrimitive >=
          ComponentDatatype.CesiumMath.SIXTY_FOUR_KILOBYTES
        ) {
          geometries.push(
            new GeometryAttribute.Geometry({
              attributes: newAttributes,
              indices: newIndices,
              primitiveType: geometry.primitiveType,
              boundingSphere: geometry.boundingSphere,
              boundingSphereCV: geometry.boundingSphereCV,
            })
          );

          // Reset for next vertex-array
          oldToNewIndex = [];
          newIndices = [];
          currentIndex = 0;
          newAttributes = copyAttributesDescriptions(geometry.attributes);
        }
      }

      if (newIndices.length !== 0) {
        geometries.push(
          new GeometryAttribute.Geometry({
            attributes: newAttributes,
            indices: newIndices,
            primitiveType: geometry.primitiveType,
            boundingSphere: geometry.boundingSphere,
            boundingSphereCV: geometry.boundingSphereCV,
          })
        );
      }
    } else {
      // No need to split into multiple geometries
      geometries.push(geometry);
    }

    return geometries;
  };

  const scratchProjectTo2DCartesian3 = new Matrix2.Cartesian3();
  const scratchProjectTo2DCartographic = new Matrix2.Cartographic();

  /**
   * Projects a geometry's 3D <code>position</code> attribute to 2D, replacing the <code>position</code>
   * attribute with separate <code>position3D</code> and <code>position2D</code> attributes.
   * <p>
   * If the geometry does not have a <code>position</code>, this function has no effect.
   * </p>
   *
   * @param {Geometry} geometry The geometry to modify.
   * @param {String} attributeName The name of the attribute.
   * @param {String} attributeName3D The name of the attribute in 3D.
   * @param {String} attributeName2D The name of the attribute in 2D.
   * @param {Object} [projection=new GeographicProjection()] The projection to use.
   * @returns {Geometry} The modified <code>geometry</code> argument with <code>position3D</code> and <code>position2D</code> attributes.
   *
   * @exception {DeveloperError} geometry must have attribute matching the attributeName argument.
   * @exception {DeveloperError} The attribute componentDatatype must be ComponentDatatype.DOUBLE.
   * @exception {DeveloperError} Could not project a point to 2D.
   *
   * @example
   * geometry = Cesium.GeometryPipeline.projectTo2D(geometry, 'position', 'position3D', 'position2D');
   */
  GeometryPipeline.projectTo2D = function (
    geometry,
    attributeName,
    attributeName3D,
    attributeName2D,
    projection
  ) {
    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(geometry)) {
      throw new RuntimeError.DeveloperError("geometry is required.");
    }
    if (!defaultValue.defined(attributeName)) {
      throw new RuntimeError.DeveloperError("attributeName is required.");
    }
    if (!defaultValue.defined(attributeName3D)) {
      throw new RuntimeError.DeveloperError("attributeName3D is required.");
    }
    if (!defaultValue.defined(attributeName2D)) {
      throw new RuntimeError.DeveloperError("attributeName2D is required.");
    }
    if (!defaultValue.defined(geometry.attributes[attributeName])) {
      throw new RuntimeError.DeveloperError(
        `geometry must have attribute matching the attributeName argument: ${attributeName}.`
      );
    }
    if (
      geometry.attributes[attributeName].componentDatatype !==
      ComponentDatatype.ComponentDatatype.DOUBLE
    ) {
      throw new RuntimeError.DeveloperError(
        "The attribute componentDatatype must be ComponentDatatype.DOUBLE."
      );
    }
    //>>includeEnd('debug');

    const attribute = geometry.attributes[attributeName];
    projection = defaultValue.defined(projection) ? projection : new Transforms.GeographicProjection();
    const ellipsoid = projection.ellipsoid;

    // Project original values to 2D.
    const values3D = attribute.values;
    const projectedValues = new Float64Array(values3D.length);
    let index = 0;

    for (let i = 0; i < values3D.length; i += 3) {
      const value = Matrix2.Cartesian3.fromArray(
        values3D,
        i,
        scratchProjectTo2DCartesian3
      );

      const lonLat = ellipsoid.cartesianToCartographic(
        value,
        scratchProjectTo2DCartographic
      );
      //>>includeStart('debug', pragmas.debug);
      if (!defaultValue.defined(lonLat)) {
        throw new RuntimeError.DeveloperError(
          `Could not project point (${value.x}, ${value.y}, ${value.z}) to 2D.`
        );
      }
      //>>includeEnd('debug');

      const projectedLonLat = projection.project(
        lonLat,
        scratchProjectTo2DCartesian3
      );

      projectedValues[index++] = projectedLonLat.x;
      projectedValues[index++] = projectedLonLat.y;
      projectedValues[index++] = projectedLonLat.z;
    }

    // Rename original cartesians to WGS84 cartesians.
    geometry.attributes[attributeName3D] = attribute;

    // Replace original cartesians with 2D projected cartesians
    geometry.attributes[attributeName2D] = new GeometryAttribute.GeometryAttribute({
      componentDatatype: ComponentDatatype.ComponentDatatype.DOUBLE,
      componentsPerAttribute: 3,
      values: projectedValues,
    });
    delete geometry.attributes[attributeName];

    return geometry;
  };

  const encodedResult = {
    high: 0.0,
    low: 0.0,
  };

  /**
   * Encodes floating-point geometry attribute values as two separate attributes to improve
   * rendering precision.
   * <p>
   * This is commonly used to create high-precision position vertex attributes.
   * </p>
   *
   * @param {Geometry} geometry The geometry to modify.
   * @param {String} attributeName The name of the attribute.
   * @param {String} attributeHighName The name of the attribute for the encoded high bits.
   * @param {String} attributeLowName The name of the attribute for the encoded low bits.
   * @returns {Geometry} The modified <code>geometry</code> argument, with its encoded attribute.
   *
   * @exception {DeveloperError} geometry must have attribute matching the attributeName argument.
   * @exception {DeveloperError} The attribute componentDatatype must be ComponentDatatype.DOUBLE.
   *
   * @example
   * geometry = Cesium.GeometryPipeline.encodeAttribute(geometry, 'position3D', 'position3DHigh', 'position3DLow');
   */
  GeometryPipeline.encodeAttribute = function (
    geometry,
    attributeName,
    attributeHighName,
    attributeLowName
  ) {
    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(geometry)) {
      throw new RuntimeError.DeveloperError("geometry is required.");
    }
    if (!defaultValue.defined(attributeName)) {
      throw new RuntimeError.DeveloperError("attributeName is required.");
    }
    if (!defaultValue.defined(attributeHighName)) {
      throw new RuntimeError.DeveloperError("attributeHighName is required.");
    }
    if (!defaultValue.defined(attributeLowName)) {
      throw new RuntimeError.DeveloperError("attributeLowName is required.");
    }
    if (!defaultValue.defined(geometry.attributes[attributeName])) {
      throw new RuntimeError.DeveloperError(
        `geometry must have attribute matching the attributeName argument: ${attributeName}.`
      );
    }
    if (
      geometry.attributes[attributeName].componentDatatype !==
      ComponentDatatype.ComponentDatatype.DOUBLE
    ) {
      throw new RuntimeError.DeveloperError(
        "The attribute componentDatatype must be ComponentDatatype.DOUBLE."
      );
    }
    //>>includeEnd('debug');

    const attribute = geometry.attributes[attributeName];
    const values = attribute.values;
    const length = values.length;
    const highValues = new Float32Array(length);
    const lowValues = new Float32Array(length);

    for (let i = 0; i < length; ++i) {
      EncodedCartesian3.EncodedCartesian3.encode(values[i], encodedResult);
      highValues[i] = encodedResult.high;
      lowValues[i] = encodedResult.low;
    }

    const componentsPerAttribute = attribute.componentsPerAttribute;

    geometry.attributes[attributeHighName] = new GeometryAttribute.GeometryAttribute({
      componentDatatype: ComponentDatatype.ComponentDatatype.FLOAT,
      componentsPerAttribute: componentsPerAttribute,
      values: highValues,
    });
    geometry.attributes[attributeLowName] = new GeometryAttribute.GeometryAttribute({
      componentDatatype: ComponentDatatype.ComponentDatatype.FLOAT,
      componentsPerAttribute: componentsPerAttribute,
      values: lowValues,
    });
    delete geometry.attributes[attributeName];

    return geometry;
  };

  let scratchCartesian3 = new Matrix2.Cartesian3();

  function transformPoint(matrix, attribute) {
    if (defaultValue.defined(attribute)) {
      const values = attribute.values;
      const length = values.length;
      for (let i = 0; i < length; i += 3) {
        Matrix2.Cartesian3.unpack(values, i, scratchCartesian3);
        Matrix2.Matrix4.multiplyByPoint(matrix, scratchCartesian3, scratchCartesian3);
        Matrix2.Cartesian3.pack(scratchCartesian3, values, i);
      }
    }
  }

  function transformVector(matrix, attribute) {
    if (defaultValue.defined(attribute)) {
      const values = attribute.values;
      const length = values.length;
      for (let i = 0; i < length; i += 3) {
        Matrix2.Cartesian3.unpack(values, i, scratchCartesian3);
        Matrix2.Matrix3.multiplyByVector(matrix, scratchCartesian3, scratchCartesian3);
        scratchCartesian3 = Matrix2.Cartesian3.normalize(
          scratchCartesian3,
          scratchCartesian3
        );
        Matrix2.Cartesian3.pack(scratchCartesian3, values, i);
      }
    }
  }

  const inverseTranspose = new Matrix2.Matrix4();
  const normalMatrix = new Matrix2.Matrix3();

  /**
   * Transforms a geometry instance to world coordinates.  This changes
   * the instance's <code>modelMatrix</code> to {@link Matrix4.IDENTITY} and transforms the
   * following attributes if they are present: <code>position</code>, <code>normal</code>,
   * <code>tangent</code>, and <code>bitangent</code>.
   *
   * @param {GeometryInstance} instance The geometry instance to modify.
   * @returns {GeometryInstance} The modified <code>instance</code> argument, with its attributes transforms to world coordinates.
   *
   * @example
   * Cesium.GeometryPipeline.transformToWorldCoordinates(instance);
   */
  GeometryPipeline.transformToWorldCoordinates = function (instance) {
    //>>includeStart('debug', pragmas.debug);
    if (!defaultValue.defined(instance)) {
      throw new RuntimeError.DeveloperError("instance is required.");
    }
    //>>includeEnd('debug');

    const modelMatrix = instance.modelMatrix;

    if (Matrix2.Matrix4.equals(modelMatrix, Matrix2.Matrix4.IDENTITY)) {
      // Already in world coordinates
      return instance;
    }

    const attributes = instance.geometry.attributes;

    // Transform attributes in known vertex formats
    transformPoint(modelMatrix, attributes.position);
    transformPoint(modelMatrix, attributes.prevPosition);
    transformPoint(modelMatrix, attributes.nextPosition);

    if (
      defaultValue.defined(attributes.normal) ||
      defaultValue.defined(attributes.tangent) ||
      defaultValue.defined(attributes.bitangent)
    ) {
      Matrix2.Matrix4.inverse(modelMatrix, inverseTranspose);
      Matrix2.Matrix4.transpose(inverseTranspose, inverseTranspose);
      Matrix2.Matrix4.getMatrix3(inverseTranspose, normalMatrix);

      transformVector(normalMatrix, attributes.normal);
      transformVector(normalMatrix, attributes.tangent);
      transformVector(normalMatrix, attributes.bitangent);
    }

    const boundingSphere = instance.geometry.boundingSphere;
    if (defaultValue.defined(boundingSphere)) {
      instance.geometry.boundingSphere = Transforms.BoundingSphere.transform(
        boundingSphere,
        modelMatrix,
        boundingSphere
      );
    }

    instance.modelMatrix = Matrix2.Matrix4.clone(Matrix2.Matrix4.IDENTITY);

    return instance;
  };

  function findAttributesInAllGeometries(instances, propertyName) {
    const length = instances.length;

    const attributesInAllGeometries = {};

    const attributes0 = instances[0][propertyName].attributes;
    let name;

    for (name in attributes0) {
      if (
        attributes0.hasOwnProperty(name) &&
        defaultValue.defined(attributes0[name]) &&
        defaultValue.defined(attributes0[name].values)
      ) {
        const attribute = attributes0[name];
        let numberOfComponents = attribute.values.length;
        let inAllGeometries = true;

        // Does this same attribute exist in all geometries?
        for (let i = 1; i < length; ++i) {
          const otherAttribute = instances[i][propertyName].attributes[name];

          if (
            !defaultValue.defined(otherAttribute) ||
            attribute.componentDatatype !== otherAttribute.componentDatatype ||
            attribute.componentsPerAttribute !==
              otherAttribute.componentsPerAttribute ||
            attribute.normalize !== otherAttribute.normalize
          ) {
            inAllGeometries = false;
            break;
          }

          numberOfComponents += otherAttribute.values.length;
        }

        if (inAllGeometries) {
          attributesInAllGeometries[name] = new GeometryAttribute.GeometryAttribute({
            componentDatatype: attribute.componentDatatype,
            componentsPerAttribute: attribute.componentsPerAttribute,
            normalize: attribute.normalize,
            values: ComponentDatatype.ComponentDatatype.createTypedArray(
              attribute.componentDatatype,
              numberOfComponents
            ),
          });
        }
      }
    }

    return attributesInAllGeometries;
  }

  const tempScratch = new Matrix2.Cartesian3();

  function combineGeometries(instances, propertyName) {
    const length = instances.length;

    let name;
    let i;
    let j;
    let k;

    const m = instances[0].modelMatrix;
    const haveIndices = defaultValue.defined(instances[0][propertyName].indices);
    const primitiveType = instances[0][propertyName].primitiveType;

    //>>includeStart('debug', pragmas.debug);
    for (i = 1; i < length; ++i) {
      if (!Matrix2.Matrix4.equals(instances[i].modelMatrix, m)) {
        throw new RuntimeError.DeveloperError("All instances must have the same modelMatrix.");
      }
      if (defaultValue.defined(instances[i][propertyName].indices) !== haveIndices) {
        throw new RuntimeError.DeveloperError(
          "All instance geometries must have an indices or not have one."
        );
      }
      if (instances[i][propertyName].primitiveType !== primitiveType) {
        throw new RuntimeError.DeveloperError(
          "All instance geometries must have the same primitiveType."
        );
      }
    }
    //>>includeEnd('debug');

    // Find subset of attributes in all geometries
    const attributes = findAttributesInAllGeometries(instances, propertyName);
    let values;
    let sourceValues;
    let sourceValuesLength;

    // Combine attributes from each geometry into a single typed array
    for (name in attributes) {
      if (attributes.hasOwnProperty(name)) {
        values = attributes[name].values;

        k = 0;
        for (i = 0; i < length; ++i) {
          sourceValues = instances[i][propertyName].attributes[name].values;
          sourceValuesLength = sourceValues.length;

          for (j = 0; j < sourceValuesLength; ++j) {
            values[k++] = sourceValues[j];
          }
        }
      }
    }

    // Combine index lists
    let indices;

    if (haveIndices) {
      let numberOfIndices = 0;
      for (i = 0; i < length; ++i) {
        numberOfIndices += instances[i][propertyName].indices.length;
      }

      const numberOfVertices = GeometryAttribute.Geometry.computeNumberOfVertices(
        new GeometryAttribute.Geometry({
          attributes: attributes,
          primitiveType: GeometryAttribute.PrimitiveType.POINTS,
        })
      );
      const destIndices = IndexDatatype.IndexDatatype.createTypedArray(
        numberOfVertices,
        numberOfIndices
      );

      let destOffset = 0;
      let offset = 0;

      for (i = 0; i < length; ++i) {
        const sourceIndices = instances[i][propertyName].indices;
        const sourceIndicesLen = sourceIndices.length;

        for (k = 0; k < sourceIndicesLen; ++k) {
          destIndices[destOffset++] = offset + sourceIndices[k];
        }

        offset += GeometryAttribute.Geometry.computeNumberOfVertices(instances[i][propertyName]);
      }

      indices = destIndices;
    }

    // Create bounding sphere that includes all instances
    let center = new Ma