PolygonOutlineGeometry.js

import ArcType from "./ArcType.js";
import arrayFill from "./arrayFill.js";
import BoundingSphere from "./BoundingSphere.js";
import Check from "./Check.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 EllipsoidTangentPlane from "./EllipsoidTangentPlane.js";
import Geometry from "./Geometry.js";
import GeometryAttribute from "./GeometryAttribute.js";
import GeometryAttributes from "./GeometryAttributes.js";
import GeometryInstance from "./GeometryInstance.js";
import GeometryOffsetAttribute from "./GeometryOffsetAttribute.js";
import GeometryPipeline from "./GeometryPipeline.js";
import IndexDatatype from "./IndexDatatype.js";
import CesiumMath from "./Math.js";
import PolygonGeometryLibrary from "./PolygonGeometryLibrary.js";
import PolygonPipeline from "./PolygonPipeline.js";
import PrimitiveType from "./PrimitiveType.js";
import WindingOrder from "./WindingOrder.js";
const createGeometryFromPositionsPositions = [];
const createGeometryFromPositionsSubdivided = [];

function createGeometryFromPositions(
  ellipsoid,
  positions,
  minDistance,
  perPositionHeight,
  arcType
) {
  const tangentPlane = EllipsoidTangentPlane.fromPoints(positions, ellipsoid);
  const positions2D = tangentPlane.projectPointsOntoPlane(
    positions,
    createGeometryFromPositionsPositions
  );

  const originalWindingOrder = PolygonPipeline.computeWindingOrder2D(
    positions2D
  );
  if (originalWindingOrder === WindingOrder.CLOCKWISE) {
    positions2D.reverse();
    positions = positions.slice().reverse();
  }

  let subdividedPositions;
  let i;

  let length = positions.length;
  let index = 0;

  if (!perPositionHeight) {
    let numVertices = 0;
    if (arcType === ArcType.GEODESIC) {
      for (i = 0; i < length; i++) {
        numVertices += PolygonGeometryLibrary.subdivideLineCount(
          positions[i],
          positions[(i + 1) % length],
          minDistance
        );
      }
    } else if (arcType === ArcType.RHUMB) {
      for (i = 0; i < length; i++) {
        numVertices += PolygonGeometryLibrary.subdivideRhumbLineCount(
          ellipsoid,
          positions[i],
          positions[(i + 1) % length],
          minDistance
        );
      }
    }
    subdividedPositions = new Float64Array(numVertices * 3);
    for (i = 0; i < length; i++) {
      let tempPositions;
      if (arcType === ArcType.GEODESIC) {
        tempPositions = PolygonGeometryLibrary.subdivideLine(
          positions[i],
          positions[(i + 1) % length],
          minDistance,
          createGeometryFromPositionsSubdivided
        );
      } else if (arcType === ArcType.RHUMB) {
        tempPositions = PolygonGeometryLibrary.subdivideRhumbLine(
          ellipsoid,
          positions[i],
          positions[(i + 1) % length],
          minDistance,
          createGeometryFromPositionsSubdivided
        );
      }
      const tempPositionsLength = tempPositions.length;
      for (let j = 0; j < tempPositionsLength; ++j) {
        subdividedPositions[index++] = tempPositions[j];
      }
    }
  } else {
    subdividedPositions = new Float64Array(length * 2 * 3);
    for (i = 0; i < length; i++) {
      const p0 = positions[i];
      const p1 = positions[(i + 1) % length];
      subdividedPositions[index++] = p0.x;
      subdividedPositions[index++] = p0.y;
      subdividedPositions[index++] = p0.z;
      subdividedPositions[index++] = p1.x;
      subdividedPositions[index++] = p1.y;
      subdividedPositions[index++] = p1.z;
    }
  }

  length = subdividedPositions.length / 3;
  const indicesSize = length * 2;
  const indices = IndexDatatype.createTypedArray(length, indicesSize);
  index = 0;
  for (i = 0; i < length - 1; i++) {
    indices[index++] = i;
    indices[index++] = i + 1;
  }
  indices[index++] = length - 1;
  indices[index++] = 0;

  return new GeometryInstance({
    geometry: new Geometry({
      attributes: new GeometryAttributes({
        position: new GeometryAttribute({
          componentDatatype: ComponentDatatype.DOUBLE,
          componentsPerAttribute: 3,
          values: subdividedPositions,
        }),
      }),
      indices: indices,
      primitiveType: PrimitiveType.LINES,
    }),
  });
}

function createGeometryFromPositionsExtruded(
  ellipsoid,
  positions,
  minDistance,
  perPositionHeight,
  arcType
) {
  const tangentPlane = EllipsoidTangentPlane.fromPoints(positions, ellipsoid);
  const positions2D = tangentPlane.projectPointsOntoPlane(
    positions,
    createGeometryFromPositionsPositions
  );

  const originalWindingOrder = PolygonPipeline.computeWindingOrder2D(
    positions2D
  );
  if (originalWindingOrder === WindingOrder.CLOCKWISE) {
    positions2D.reverse();
    positions = positions.slice().reverse();
  }

  let subdividedPositions;
  let i;

  let length = positions.length;
  const corners = new Array(length);
  let index = 0;

  if (!perPositionHeight) {
    let numVertices = 0;
    if (arcType === ArcType.GEODESIC) {
      for (i = 0; i < length; i++) {
        numVertices += PolygonGeometryLibrary.subdivideLineCount(
          positions[i],
          positions[(i + 1) % length],
          minDistance
        );
      }
    } else if (arcType === ArcType.RHUMB) {
      for (i = 0; i < length; i++) {
        numVertices += PolygonGeometryLibrary.subdivideRhumbLineCount(
          ellipsoid,
          positions[i],
          positions[(i + 1) % length],
          minDistance
        );
      }
    }

    subdividedPositions = new Float64Array(numVertices * 3 * 2);
    for (i = 0; i < length; ++i) {
      corners[i] = index / 3;
      let tempPositions;
      if (arcType === ArcType.GEODESIC) {
        tempPositions = PolygonGeometryLibrary.subdivideLine(
          positions[i],
          positions[(i + 1) % length],
          minDistance,
          createGeometryFromPositionsSubdivided
        );
      } else if (arcType === ArcType.RHUMB) {
        tempPositions = PolygonGeometryLibrary.subdivideRhumbLine(
          ellipsoid,
          positions[i],
          positions[(i + 1) % length],
          minDistance,
          createGeometryFromPositionsSubdivided
        );
      }
      const tempPositionsLength = tempPositions.length;
      for (let j = 0; j < tempPositionsLength; ++j) {
        subdividedPositions[index++] = tempPositions[j];
      }
    }
  } else {
    subdividedPositions = new Float64Array(length * 2 * 3 * 2);
    for (i = 0; i < length; ++i) {
      corners[i] = index / 3;
      const p0 = positions[i];
      const p1 = positions[(i + 1) % length];

      subdividedPositions[index++] = p0.x;
      subdividedPositions[index++] = p0.y;
      subdividedPositions[index++] = p0.z;
      subdividedPositions[index++] = p1.x;
      subdividedPositions[index++] = p1.y;
      subdividedPositions[index++] = p1.z;
    }
  }

  length = subdividedPositions.length / (3 * 2);
  const cornersLength = corners.length;

  const indicesSize = (length * 2 + cornersLength) * 2;
  const indices = IndexDatatype.createTypedArray(
    length + cornersLength,
    indicesSize
  );

  index = 0;
  for (i = 0; i < length; ++i) {
    indices[index++] = i;
    indices[index++] = (i + 1) % length;
    indices[index++] = i + length;
    indices[index++] = ((i + 1) % length) + length;
  }

  for (i = 0; i < cornersLength; i++) {
    const corner = corners[i];
    indices[index++] = corner;
    indices[index++] = corner + length;
  }

  return new GeometryInstance({
    geometry: new Geometry({
      attributes: new GeometryAttributes({
        position: new GeometryAttribute({
          componentDatatype: ComponentDatatype.DOUBLE,
          componentsPerAttribute: 3,
          values: subdividedPositions,
        }),
      }),
      indices: indices,
      primitiveType: PrimitiveType.LINES,
    }),
  });
}

/**
 * A description of the outline of a polygon on the ellipsoid. The polygon is defined by a polygon hierarchy.
 *
 * @alias PolygonOutlineGeometry
 * @constructor
 *
 * @param {Object} options Object with the following properties:
 * @param {PolygonHierarchy} options.polygonHierarchy A polygon hierarchy that can include holes.
 * @param {Number} [options.height=0.0] The distance in meters between the polygon and the ellipsoid surface.
 * @param {Number} [options.extrudedHeight] The distance in meters between the polygon's extruded face and the ellipsoid surface.
 * @param {VertexFormat} [options.vertexFormat=VertexFormat.DEFAULT] The vertex attributes to be computed.
 * @param {Ellipsoid} [options.ellipsoid=Ellipsoid.WGS84] The ellipsoid to be used as a reference.
 * @param {Number} [options.granularity=CesiumMath.RADIANS_PER_DEGREE] The distance, in radians, between each latitude and longitude. Determines the number of positions in the buffer.
 * @param {Boolean} [options.perPositionHeight=false] Use the height of options.positions for each position instead of using options.height to determine the height.
 * @param {ArcType} [options.arcType=ArcType.GEODESIC] The type of path the outline must follow. Valid options are {@link ArcType.GEODESIC} and {@link ArcType.RHUMB}.
 *
 * @see PolygonOutlineGeometry#createGeometry
 * @see PolygonOutlineGeometry#fromPositions
 *
 * @example
 * // 1. create a polygon outline from points
 * const polygon = new Cesium.PolygonOutlineGeometry({
 *   polygonHierarchy : new Cesium.PolygonHierarchy(
 *     Cesium.Cartesian3.fromDegreesArray([
 *       -72.0, 40.0,
 *       -70.0, 35.0,
 *       -75.0, 30.0,
 *       -70.0, 30.0,
 *       -68.0, 40.0
 *     ])
 *   )
 * });
 * const geometry = Cesium.PolygonOutlineGeometry.createGeometry(polygon);
 *
 * // 2. create a nested polygon with holes outline
 * const polygonWithHole = new Cesium.PolygonOutlineGeometry({
 *   polygonHierarchy : new Cesium.PolygonHierarchy(
 *     Cesium.Cartesian3.fromDegreesArray([
 *       -109.0, 30.0,
 *       -95.0, 30.0,
 *       -95.0, 40.0,
 *       -109.0, 40.0
 *     ]),
 *     [new Cesium.PolygonHierarchy(
 *       Cesium.Cartesian3.fromDegreesArray([
 *         -107.0, 31.0,
 *         -107.0, 39.0,
 *         -97.0, 39.0,
 *         -97.0, 31.0
 *       ]),
 *       [new Cesium.PolygonHierarchy(
 *         Cesium.Cartesian3.fromDegreesArray([
 *           -105.0, 33.0,
 *           -99.0, 33.0,
 *           -99.0, 37.0,
 *           -105.0, 37.0
 *         ]),
 *         [new Cesium.PolygonHierarchy(
 *           Cesium.Cartesian3.fromDegreesArray([
 *             -103.0, 34.0,
 *             -101.0, 34.0,
 *             -101.0, 36.0,
 *             -103.0, 36.0
 *           ])
 *         )]
 *       )]
 *     )]
 *   )
 * });
 * const geometry = Cesium.PolygonOutlineGeometry.createGeometry(polygonWithHole);
 *
 * // 3. create extruded polygon outline
 * const extrudedPolygon = new Cesium.PolygonOutlineGeometry({
 *   polygonHierarchy : new Cesium.PolygonHierarchy(
 *     Cesium.Cartesian3.fromDegreesArray([
 *       -72.0, 40.0,
 *       -70.0, 35.0,
 *       -75.0, 30.0,
 *       -70.0, 30.0,
 *       -68.0, 40.0
 *     ])
 *   ),
 *   extrudedHeight: 300000
 * });
 * const geometry = Cesium.PolygonOutlineGeometry.createGeometry(extrudedPolygon);
 */
function PolygonOutlineGeometry(options) {
  //>>includeStart('debug', pragmas.debug);
  Check.typeOf.object("options", options);
  Check.typeOf.object("options.polygonHierarchy", options.polygonHierarchy);

  if (options.perPositionHeight && defined(options.height)) {
    throw new DeveloperError(
      "Cannot use both options.perPositionHeight and options.height"
    );
  }
  if (
    defined(options.arcType) &&
    options.arcType !== ArcType.GEODESIC &&
    options.arcType !== ArcType.RHUMB
  ) {
    throw new DeveloperError(
      "Invalid arcType. Valid options are ArcType.GEODESIC and ArcType.RHUMB."
    );
  }
  //>>includeEnd('debug');

  const polygonHierarchy = options.polygonHierarchy;
  const ellipsoid = defaultValue(options.ellipsoid, Ellipsoid.WGS84);
  const granularity = defaultValue(
    options.granularity,
    CesiumMath.RADIANS_PER_DEGREE
  );
  const perPositionHeight = defaultValue(options.perPositionHeight, false);
  const perPositionHeightExtrude =
    perPositionHeight && defined(options.extrudedHeight);
  const arcType = defaultValue(options.arcType, ArcType.GEODESIC);

  let height = defaultValue(options.height, 0.0);
  let extrudedHeight = defaultValue(options.extrudedHeight, height);

  if (!perPositionHeightExtrude) {
    const h = Math.max(height, extrudedHeight);
    extrudedHeight = Math.min(height, extrudedHeight);
    height = h;
  }

  this._ellipsoid = Ellipsoid.clone(ellipsoid);
  this._granularity = granularity;
  this._height = height;
  this._extrudedHeight = extrudedHeight;
  this._arcType = arcType;
  this._polygonHierarchy = polygonHierarchy;
  this._perPositionHeight = perPositionHeight;
  this._perPositionHeightExtrude = perPositionHeightExtrude;
  this._offsetAttribute = options.offsetAttribute;
  this._workerName = "createPolygonOutlineGeometry";

  /**
   * The number of elements used to pack the object into an array.
   * @type {Number}
   */
  this.packedLength =
    PolygonGeometryLibrary.computeHierarchyPackedLength(polygonHierarchy) +
    Ellipsoid.packedLength +
    8;
}

/**
 * Stores the provided instance into the provided array.
 *
 * @param {PolygonOutlineGeometry} 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
 */
PolygonOutlineGeometry.pack = function (value, array, startingIndex) {
  //>>includeStart('debug', pragmas.debug);
  Check.typeOf.object("value", value);
  Check.defined("array", array);
  //>>includeEnd('debug');

  startingIndex = defaultValue(startingIndex, 0);

  startingIndex = PolygonGeometryLibrary.packPolygonHierarchy(
    value._polygonHierarchy,
    array,
    startingIndex
  );

  Ellipsoid.pack(value._ellipsoid, array, startingIndex);
  startingIndex += Ellipsoid.packedLength;

  array[startingIndex++] = value._height;
  array[startingIndex++] = value._extrudedHeight;
  array[startingIndex++] = value._granularity;
  array[startingIndex++] = value._perPositionHeightExtrude ? 1.0 : 0.0;
  array[startingIndex++] = value._perPositionHeight ? 1.0 : 0.0;
  array[startingIndex++] = value._arcType;
  array[startingIndex++] = defaultValue(value._offsetAttribute, -1);
  array[startingIndex] = value.packedLength;

  return array;
};

const scratchEllipsoid = Ellipsoid.clone(Ellipsoid.UNIT_SPHERE);
const dummyOptions = {
  polygonHierarchy: {},
};

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

  startingIndex = defaultValue(startingIndex, 0);

  const polygonHierarchy = PolygonGeometryLibrary.unpackPolygonHierarchy(
    array,
    startingIndex
  );
  startingIndex = polygonHierarchy.startingIndex;
  delete polygonHierarchy.startingIndex;

  const ellipsoid = Ellipsoid.unpack(array, startingIndex, scratchEllipsoid);
  startingIndex += Ellipsoid.packedLength;

  const height = array[startingIndex++];
  const extrudedHeight = array[startingIndex++];
  const granularity = array[startingIndex++];
  const perPositionHeightExtrude = array[startingIndex++] === 1.0;
  const perPositionHeight = array[startingIndex++] === 1.0;
  const arcType = array[startingIndex++];
  const offsetAttribute = array[startingIndex++];
  const packedLength = array[startingIndex];

  if (!defined(result)) {
    result = new PolygonOutlineGeometry(dummyOptions);
  }

  result._polygonHierarchy = polygonHierarchy;
  result._ellipsoid = Ellipsoid.clone(ellipsoid, result._ellipsoid);
  result._height = height;
  result._extrudedHeight = extrudedHeight;
  result._granularity = granularity;
  result._perPositionHeight = perPositionHeight;
  result._perPositionHeightExtrude = perPositionHeightExtrude;
  result._arcType = arcType;
  result._offsetAttribute =
    offsetAttribute === -1 ? undefined : offsetAttribute;
  result.packedLength = packedLength;

  return result;
};

/**
 * A description of a polygon outline from an array of positions.
 *
 * @param {Object} options Object with the following properties:
 * @param {Cartesian3[]} options.positions An array of positions that defined the corner points of the polygon.
 * @param {Number} [options.height=0.0] The height of the polygon.
 * @param {Number} [options.extrudedHeight] The height of the polygon extrusion.
 * @param {Ellipsoid} [options.ellipsoid=Ellipsoid.WGS84] The ellipsoid to be used as a reference.
 * @param {Number} [options.granularity=CesiumMath.RADIANS_PER_DEGREE] The distance, in radians, between each latitude and longitude. Determines the number of positions in the buffer.
 * @param {Boolean} [options.perPositionHeight=false] Use the height of options.positions for each position instead of using options.height to determine the height.
 * @param {ArcType} [options.arcType=ArcType.GEODESIC] The type of path the outline must follow. Valid options are {@link LinkType.GEODESIC} and {@link ArcType.RHUMB}.
 * @returns {PolygonOutlineGeometry}
 *
 *
 * @example
 * // create a polygon from points
 * const polygon = Cesium.PolygonOutlineGeometry.fromPositions({
 *   positions : Cesium.Cartesian3.fromDegreesArray([
 *     -72.0, 40.0,
 *     -70.0, 35.0,
 *     -75.0, 30.0,
 *     -70.0, 30.0,
 *     -68.0, 40.0
 *   ])
 * });
 * const geometry = Cesium.PolygonOutlineGeometry.createGeometry(polygon);
 *
 * @see PolygonOutlineGeometry#createGeometry
 */
PolygonOutlineGeometry.fromPositions = function (options) {
  options = defaultValue(options, defaultValue.EMPTY_OBJECT);

  //>>includeStart('debug', pragmas.debug);
  Check.defined("options.positions", options.positions);
  //>>includeEnd('debug');

  const newOptions = {
    polygonHierarchy: {
      positions: options.positions,
    },
    height: options.height,
    extrudedHeight: options.extrudedHeight,
    ellipsoid: options.ellipsoid,
    granularity: options.granularity,
    perPositionHeight: options.perPositionHeight,
    arcType: options.arcType,
    offsetAttribute: options.offsetAttribute,
  };
  return new PolygonOutlineGeometry(newOptions);
};

/**
 * Computes the geometric representation of a polygon outline, including its vertices, indices, and a bounding sphere.
 *
 * @param {PolygonOutlineGeometry} polygonGeometry A description of the polygon outline.
 * @returns {Geometry|undefined} The computed vertices and indices.
 */
PolygonOutlineGeometry.createGeometry = function (polygonGeometry) {
  const ellipsoid = polygonGeometry._ellipsoid;
  const granularity = polygonGeometry._granularity;
  const polygonHierarchy = polygonGeometry._polygonHierarchy;
  const perPositionHeight = polygonGeometry._perPositionHeight;
  const arcType = polygonGeometry._arcType;

  const polygons = PolygonGeometryLibrary.polygonOutlinesFromHierarchy(
    polygonHierarchy,
    !perPositionHeight,
    ellipsoid
  );

  if (polygons.length === 0) {
    return undefined;
  }

  let geometryInstance;
  const geometries = [];
  const minDistance = CesiumMath.chordLength(
    granularity,
    ellipsoid.maximumRadius
  );

  const height = polygonGeometry._height;
  const extrudedHeight = polygonGeometry._extrudedHeight;
  const extrude =
    polygonGeometry._perPositionHeightExtrude ||
    !CesiumMath.equalsEpsilon(height, extrudedHeight, 0, CesiumMath.EPSILON2);
  let offsetValue;
  let i;
  if (extrude) {
    for (i = 0; i < polygons.length; i++) {
      geometryInstance = createGeometryFromPositionsExtruded(
        ellipsoid,
        polygons[i],
        minDistance,
        perPositionHeight,
        arcType
      );
      geometryInstance.geometry = PolygonGeometryLibrary.scaleToGeodeticHeightExtruded(
        geometryInstance.geometry,
        height,
        extrudedHeight,
        ellipsoid,
        perPositionHeight
      );
      if (defined(polygonGeometry._offsetAttribute)) {
        const size =
          geometryInstance.geometry.attributes.position.values.length / 3;
        let offsetAttribute = new Uint8Array(size);
        if (polygonGeometry._offsetAttribute === GeometryOffsetAttribute.TOP) {
          offsetAttribute = arrayFill(offsetAttribute, 1, 0, size / 2);
        } else {
          offsetValue =
            polygonGeometry._offsetAttribute === GeometryOffsetAttribute.NONE
              ? 0
              : 1;
          offsetAttribute = arrayFill(offsetAttribute, offsetValue);
        }

        geometryInstance.geometry.attributes.applyOffset = new GeometryAttribute(
          {
            componentDatatype: ComponentDatatype.UNSIGNED_BYTE,
            componentsPerAttribute: 1,
            values: offsetAttribute,
          }
        );
      }
      geometries.push(geometryInstance);
    }
  } else {
    for (i = 0; i < polygons.length; i++) {
      geometryInstance = createGeometryFromPositions(
        ellipsoid,
        polygons[i],
        minDistance,
        perPositionHeight,
        arcType
      );
      geometryInstance.geometry.attributes.position.values = PolygonPipeline.scaleToGeodeticHeight(
        geometryInstance.geometry.attributes.position.values,
        height,
        ellipsoid,
        !perPositionHeight
      );

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

      geometries.push(geometryInstance);
    }
  }

  const geometry = GeometryPipeline.combineInstances(geometries)[0];
  const boundingSphere = BoundingSphere.fromVertices(
    geometry.attributes.position.values
  );

  return new Geometry({
    attributes: geometry.attributes,
    indices: geometry.indices,
    primitiveType: geometry.primitiveType,
    boundingSphere: boundingSphere,
    offsetAttribute: polygonGeometry._offsetAttribute,
  });
};
export default PolygonOutlineGeometry;