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casic-smartcity-well-front / static / Cesium / Core / EllipsoidOutlineGeometry.js
[wangxitong] on 8 Jul 2021 16 KB mars3d总览
import arrayFill from "./arrayFill.js";
import BoundingSphere from "./BoundingSphere.js";
import Cartesian3 from "./Cartesian3.js";
import ComponentDatatype from "./ComponentDatatype.js";
import defaultValue from "./defaultValue.js";
import defined from "./defined.js";
import DeveloperError from "./DeveloperError.js";
import Ellipsoid from "./Ellipsoid.js";
import Geometry from "./Geometry.js";
import GeometryAttribute from "./GeometryAttribute.js";
import GeometryAttributes from "./GeometryAttributes.js";
import GeometryOffsetAttribute from "./GeometryOffsetAttribute.js";
import IndexDatatype from "./IndexDatatype.js";
import CesiumMath from "./Math.js";
import PrimitiveType from "./PrimitiveType.js";

var defaultRadii = new Cartesian3(1.0, 1.0, 1.0);
var cos = Math.cos;
var sin = Math.sin;

/**
 * A description of the outline of an ellipsoid centered at the origin.
 *
 * @alias EllipsoidOutlineGeometry
 * @constructor
 *
 * @param {Object} [options] Object with the following properties:
 * @param {Cartesian3} [options.radii=Cartesian3(1.0, 1.0, 1.0)] The radii of the ellipsoid in the x, y, and z directions.
 * @param {Cartesian3} [options.innerRadii=options.radii] The inner radii of the ellipsoid in the x, y, and z directions.
 * @param {Number} [options.minimumClock=0.0] The minimum angle lying in the xy-plane measured from the positive x-axis and toward the positive y-axis.
 * @param {Number} [options.maximumClock=2*PI] The maximum angle lying in the xy-plane measured from the positive x-axis and toward the positive y-axis.
 * @param {Number} [options.minimumCone=0.0] The minimum angle measured from the positive z-axis and toward the negative z-axis.
 * @param {Number} [options.maximumCone=PI] The maximum angle measured from the positive z-axis and toward the negative z-axis.
 * @param {Number} [options.stackPartitions=10] The count of stacks for the ellipsoid (1 greater than the number of parallel lines).
 * @param {Number} [options.slicePartitions=8] The count of slices for the ellipsoid (Equal to the number of radial lines).
 * @param {Number} [options.subdivisions=128] The number of points per line, determining the granularity of the curvature.
 *
 * @exception {DeveloperError} options.stackPartitions must be greater than or equal to one.
 * @exception {DeveloperError} options.slicePartitions must be greater than or equal to zero.
 * @exception {DeveloperError} options.subdivisions must be greater than or equal to zero.
 *
 * @example
 * var ellipsoid = new Cesium.EllipsoidOutlineGeometry({
 *   radii : new Cesium.Cartesian3(1000000.0, 500000.0, 500000.0),
 *   stackPartitions: 6,
 *   slicePartitions: 5
 * });
 * var geometry = Cesium.EllipsoidOutlineGeometry.createGeometry(ellipsoid);
 */
function EllipsoidOutlineGeometry(options) {
  options = defaultValue(options, defaultValue.EMPTY_OBJECT);

  var radii = defaultValue(options.radii, defaultRadii);
  var innerRadii = defaultValue(options.innerRadii, radii);
  var minimumClock = defaultValue(options.minimumClock, 0.0);
  var maximumClock = defaultValue(options.maximumClock, CesiumMath.TWO_PI);
  var minimumCone = defaultValue(options.minimumCone, 0.0);
  var maximumCone = defaultValue(options.maximumCone, CesiumMath.PI);
  var stackPartitions = Math.round(defaultValue(options.stackPartitions, 10));
  var slicePartitions = Math.round(defaultValue(options.slicePartitions, 8));
  var subdivisions = Math.round(defaultValue(options.subdivisions, 128));

  //>>includeStart('debug', pragmas.debug);
  if (stackPartitions < 1) {
    throw new DeveloperError("options.stackPartitions cannot be less than 1");
  }
  if (slicePartitions < 0) {
    throw new DeveloperError("options.slicePartitions cannot be less than 0");
  }
  if (subdivisions < 0) {
    throw new DeveloperError(
      "options.subdivisions must be greater than or equal to zero."
    );
  }
  if (
    defined(options.offsetAttribute) &&
    options.offsetAttribute === GeometryOffsetAttribute.TOP
  ) {
    throw new DeveloperError(
      "GeometryOffsetAttribute.TOP is not a supported options.offsetAttribute for this geometry."
    );
  }
  //>>includeEnd('debug');

  this._radii = Cartesian3.clone(radii);
  this._innerRadii = Cartesian3.clone(innerRadii);
  this._minimumClock = minimumClock;
  this._maximumClock = maximumClock;
  this._minimumCone = minimumCone;
  this._maximumCone = maximumCone;
  this._stackPartitions = stackPartitions;
  this._slicePartitions = slicePartitions;
  this._subdivisions = subdivisions;
  this._offsetAttribute = options.offsetAttribute;
  this._workerName = "createEllipsoidOutlineGeometry";
}

/**
 * The number of elements used to pack the object into an array.
 * @type {Number}
 */
EllipsoidOutlineGeometry.packedLength = 2 * Cartesian3.packedLength + 8;

/**
 * Stores the provided instance into the provided array.
 *
 * @param {EllipsoidOutlineGeometry} value The value to pack.
 * @param {Number[]} array The array to pack into.
 * @param {Number} [startingIndex=0] The index into the array at which to start packing the elements.
 *
 * @returns {Number[]} The array that was packed into
 */
EllipsoidOutlineGeometry.pack = function (value, array, startingIndex) {
  //>>includeStart('debug', pragmas.debug);
  if (!defined(value)) {
    throw new DeveloperError("value is required");
  }
  if (!defined(array)) {
    throw new DeveloperError("array is required");
  }
  //>>includeEnd('debug');

  startingIndex = defaultValue(startingIndex, 0);

  Cartesian3.pack(value._radii, array, startingIndex);
  startingIndex += Cartesian3.packedLength;

  Cartesian3.pack(value._innerRadii, array, startingIndex);
  startingIndex += Cartesian3.packedLength;

  array[startingIndex++] = value._minimumClock;
  array[startingIndex++] = value._maximumClock;
  array[startingIndex++] = value._minimumCone;
  array[startingIndex++] = value._maximumCone;
  array[startingIndex++] = value._stackPartitions;
  array[startingIndex++] = value._slicePartitions;
  array[startingIndex++] = value._subdivisions;
  array[startingIndex] = defaultValue(value._offsetAttribute, -1);

  return array;
};

var scratchRadii = new Cartesian3();
var scratchInnerRadii = new Cartesian3();
var scratchOptions = {
  radii: scratchRadii,
  innerRadii: scratchInnerRadii,
  minimumClock: undefined,
  maximumClock: undefined,
  minimumCone: undefined,
  maximumCone: undefined,
  stackPartitions: undefined,
  slicePartitions: undefined,
  subdivisions: undefined,
  offsetAttribute: undefined,
};

/**
 * 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 {EllipsoidOutlineGeometry} [result] The object into which to store the result.
 * @returns {EllipsoidOutlineGeometry} The modified result parameter or a new EllipsoidOutlineGeometry instance if one was not provided.
 */
EllipsoidOutlineGeometry.unpack = function (array, startingIndex, result) {
  //>>includeStart('debug', pragmas.debug);
  if (!defined(array)) {
    throw new DeveloperError("array is required");
  }
  //>>includeEnd('debug');

  startingIndex = defaultValue(startingIndex, 0);

  var radii = Cartesian3.unpack(array, startingIndex, scratchRadii);
  startingIndex += Cartesian3.packedLength;

  var innerRadii = Cartesian3.unpack(array, startingIndex, scratchInnerRadii);
  startingIndex += Cartesian3.packedLength;

  var minimumClock = array[startingIndex++];
  var maximumClock = array[startingIndex++];
  var minimumCone = array[startingIndex++];
  var maximumCone = array[startingIndex++];
  var stackPartitions = array[startingIndex++];
  var slicePartitions = array[startingIndex++];
  var subdivisions = array[startingIndex++];
  var offsetAttribute = array[startingIndex];

  if (!defined(result)) {
    scratchOptions.minimumClock = minimumClock;
    scratchOptions.maximumClock = maximumClock;
    scratchOptions.minimumCone = minimumCone;
    scratchOptions.maximumCone = maximumCone;
    scratchOptions.stackPartitions = stackPartitions;
    scratchOptions.slicePartitions = slicePartitions;
    scratchOptions.subdivisions = subdivisions;
    scratchOptions.offsetAttribute =
      offsetAttribute === -1 ? undefined : offsetAttribute;
    return new EllipsoidOutlineGeometry(scratchOptions);
  }

  result._radii = Cartesian3.clone(radii, result._radii);
  result._innerRadii = Cartesian3.clone(innerRadii, result._innerRadii);
  result._minimumClock = minimumClock;
  result._maximumClock = maximumClock;
  result._minimumCone = minimumCone;
  result._maximumCone = maximumCone;
  result._stackPartitions = stackPartitions;
  result._slicePartitions = slicePartitions;
  result._subdivisions = subdivisions;
  result._offsetAttribute =
    offsetAttribute === -1 ? undefined : offsetAttribute;

  return result;
};

/**
 * Computes the geometric representation of an outline of an ellipsoid, including its vertices, indices, and a bounding sphere.
 *
 * @param {EllipsoidOutlineGeometry} ellipsoidGeometry A description of the ellipsoid outline.
 * @returns {Geometry|undefined} The computed vertices and indices.
 */
EllipsoidOutlineGeometry.createGeometry = function (ellipsoidGeometry) {
  var radii = ellipsoidGeometry._radii;
  if (radii.x <= 0 || radii.y <= 0 || radii.z <= 0) {
    return;
  }

  var innerRadii = ellipsoidGeometry._innerRadii;
  if (innerRadii.x <= 0 || innerRadii.y <= 0 || innerRadii.z <= 0) {
    return;
  }

  var minimumClock = ellipsoidGeometry._minimumClock;
  var maximumClock = ellipsoidGeometry._maximumClock;
  var minimumCone = ellipsoidGeometry._minimumCone;
  var maximumCone = ellipsoidGeometry._maximumCone;
  var subdivisions = ellipsoidGeometry._subdivisions;
  var ellipsoid = Ellipsoid.fromCartesian3(radii);

  // Add an extra slice and stack to remain consistent with EllipsoidGeometry
  var slicePartitions = ellipsoidGeometry._slicePartitions + 1;
  var stackPartitions = ellipsoidGeometry._stackPartitions + 1;

  slicePartitions = Math.round(
    (slicePartitions * Math.abs(maximumClock - minimumClock)) /
      CesiumMath.TWO_PI
  );
  stackPartitions = Math.round(
    (stackPartitions * Math.abs(maximumCone - minimumCone)) / CesiumMath.PI
  );

  if (slicePartitions < 2) {
    slicePartitions = 2;
  }
  if (stackPartitions < 2) {
    stackPartitions = 2;
  }

  var extraIndices = 0;
  var vertexMultiplier = 1.0;
  var hasInnerSurface =
    innerRadii.x !== radii.x ||
    innerRadii.y !== radii.y ||
    innerRadii.z !== radii.z;
  var isTopOpen = false;
  var isBotOpen = false;
  if (hasInnerSurface) {
    vertexMultiplier = 2.0;
    // Add 2x slicePartitions to connect the top/bottom of the outer to
    // the top/bottom of the inner
    if (minimumCone > 0.0) {
      isTopOpen = true;
      extraIndices += slicePartitions;
    }
    if (maximumCone < Math.PI) {
      isBotOpen = true;
      extraIndices += slicePartitions;
    }
  }

  var vertexCount =
    subdivisions * vertexMultiplier * (stackPartitions + slicePartitions);
  var positions = new Float64Array(vertexCount * 3);

  // Multiply by two because two points define each line segment
  var numIndices =
    2 *
    (vertexCount +
      extraIndices -
      (slicePartitions + stackPartitions) * vertexMultiplier);
  var indices = IndexDatatype.createTypedArray(vertexCount, numIndices);

  var i;
  var j;
  var theta;
  var phi;
  var index = 0;

  // Calculate sin/cos phi
  var sinPhi = new Array(stackPartitions);
  var cosPhi = new Array(stackPartitions);
  for (i = 0; i < stackPartitions; i++) {
    phi =
      minimumCone + (i * (maximumCone - minimumCone)) / (stackPartitions - 1);
    sinPhi[i] = sin(phi);
    cosPhi[i] = cos(phi);
  }

  // Calculate sin/cos theta
  var sinTheta = new Array(subdivisions);
  var cosTheta = new Array(subdivisions);
  for (i = 0; i < subdivisions; i++) {
    theta =
      minimumClock + (i * (maximumClock - minimumClock)) / (subdivisions - 1);
    sinTheta[i] = sin(theta);
    cosTheta[i] = cos(theta);
  }

  // Calculate the latitude lines on the outer surface
  for (i = 0; i < stackPartitions; i++) {
    for (j = 0; j < subdivisions; j++) {
      positions[index++] = radii.x * sinPhi[i] * cosTheta[j];
      positions[index++] = radii.y * sinPhi[i] * sinTheta[j];
      positions[index++] = radii.z * cosPhi[i];
    }
  }

  // Calculate the latitude lines on the inner surface
  if (hasInnerSurface) {
    for (i = 0; i < stackPartitions; i++) {
      for (j = 0; j < subdivisions; j++) {
        positions[index++] = innerRadii.x * sinPhi[i] * cosTheta[j];
        positions[index++] = innerRadii.y * sinPhi[i] * sinTheta[j];
        positions[index++] = innerRadii.z * cosPhi[i];
      }
    }
  }

  // Calculate sin/cos phi
  sinPhi.length = subdivisions;
  cosPhi.length = subdivisions;
  for (i = 0; i < subdivisions; i++) {
    phi = minimumCone + (i * (maximumCone - minimumCone)) / (subdivisions - 1);
    sinPhi[i] = sin(phi);
    cosPhi[i] = cos(phi);
  }

  // Calculate sin/cos theta for each slice partition
  sinTheta.length = slicePartitions;
  cosTheta.length = slicePartitions;
  for (i = 0; i < slicePartitions; i++) {
    theta =
      minimumClock +
      (i * (maximumClock - minimumClock)) / (slicePartitions - 1);
    sinTheta[i] = sin(theta);
    cosTheta[i] = cos(theta);
  }

  // Calculate the longitude lines on the outer surface
  for (i = 0; i < subdivisions; i++) {
    for (j = 0; j < slicePartitions; j++) {
      positions[index++] = radii.x * sinPhi[i] * cosTheta[j];
      positions[index++] = radii.y * sinPhi[i] * sinTheta[j];
      positions[index++] = radii.z * cosPhi[i];
    }
  }

  // Calculate the longitude lines on the inner surface
  if (hasInnerSurface) {
    for (i = 0; i < subdivisions; i++) {
      for (j = 0; j < slicePartitions; j++) {
        positions[index++] = innerRadii.x * sinPhi[i] * cosTheta[j];
        positions[index++] = innerRadii.y * sinPhi[i] * sinTheta[j];
        positions[index++] = innerRadii.z * cosPhi[i];
      }
    }
  }

  // Create indices for the latitude lines
  index = 0;
  for (i = 0; i < stackPartitions * vertexMultiplier; i++) {
    var topOffset = i * subdivisions;
    for (j = 0; j < subdivisions - 1; j++) {
      indices[index++] = topOffset + j;
      indices[index++] = topOffset + j + 1;
    }
  }

  // Create indices for the outer longitude lines
  var offset = stackPartitions * subdivisions * vertexMultiplier;
  for (i = 0; i < slicePartitions; i++) {
    for (j = 0; j < subdivisions - 1; j++) {
      indices[index++] = offset + i + j * slicePartitions;
      indices[index++] = offset + i + (j + 1) * slicePartitions;
    }
  }

  // Create indices for the inner longitude lines
  if (hasInnerSurface) {
    offset =
      stackPartitions * subdivisions * vertexMultiplier +
      slicePartitions * subdivisions;
    for (i = 0; i < slicePartitions; i++) {
      for (j = 0; j < subdivisions - 1; j++) {
        indices[index++] = offset + i + j * slicePartitions;
        indices[index++] = offset + i + (j + 1) * slicePartitions;
      }
    }
  }

  if (hasInnerSurface) {
    var outerOffset = stackPartitions * subdivisions * vertexMultiplier;
    var innerOffset = outerOffset + subdivisions * slicePartitions;
    if (isTopOpen) {
      // Draw lines from the top of the inner surface to the top of the outer surface
      for (i = 0; i < slicePartitions; i++) {
        indices[index++] = outerOffset + i;
        indices[index++] = innerOffset + i;
      }
    }

    if (isBotOpen) {
      // Draw lines from the top of the inner surface to the top of the outer surface
      outerOffset += subdivisions * slicePartitions - slicePartitions;
      innerOffset += subdivisions * slicePartitions - slicePartitions;
      for (i = 0; i < slicePartitions; i++) {
        indices[index++] = outerOffset + i;
        indices[index++] = innerOffset + i;
      }
    }
  }

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

  if (defined(ellipsoidGeometry._offsetAttribute)) {
    var length = positions.length;
    var applyOffset = new Uint8Array(length / 3);
    var offsetValue =
      ellipsoidGeometry._offsetAttribute === GeometryOffsetAttribute.NONE
        ? 0
        : 1;
    arrayFill(applyOffset, offsetValue);
    attributes.applyOffset = new GeometryAttribute({
      componentDatatype: ComponentDatatype.UNSIGNED_BYTE,
      componentsPerAttribute: 1,
      values: applyOffset,
    });
  }

  return new Geometry({
    attributes: attributes,
    indices: indices,
    primitiveType: PrimitiveType.LINES,
    boundingSphere: BoundingSphere.fromEllipsoid(ellipsoid),
    offsetAttribute: ellipsoidGeometry._offsetAttribute,
  });
};
export default EllipsoidOutlineGeometry;