cesium
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Cesium is a JavaScript library for creating 3D globes and 2D maps in a web browser without a plugin.
548 lines (494 loc) • 22.5 kB
JavaScript
/*global define*/
define([
'./arrayRemoveDuplicates',
'./BoundingSphere',
'./Cartesian3',
'./ComponentDatatype',
'./defaultValue',
'./defined',
'./DeveloperError',
'./Ellipsoid',
'./EllipsoidTangentPlane',
'./Geometry',
'./GeometryAttribute',
'./GeometryAttributes',
'./GeometryInstance',
'./GeometryPipeline',
'./IndexDatatype',
'./Math',
'./PolygonGeometryLibrary',
'./PolygonPipeline',
'./PrimitiveType',
'./Queue',
'./WindingOrder'
], function(
arrayRemoveDuplicates,
BoundingSphere,
Cartesian3,
ComponentDatatype,
defaultValue,
defined,
DeveloperError,
Ellipsoid,
EllipsoidTangentPlane,
Geometry,
GeometryAttribute,
GeometryAttributes,
GeometryInstance,
GeometryPipeline,
IndexDatatype,
CesiumMath,
PolygonGeometryLibrary,
PolygonPipeline,
PrimitiveType,
Queue,
WindingOrder) {
'use strict';
var createGeometryFromPositionsPositions = [];
var createGeometryFromPositionsSubdivided = [];
function createGeometryFromPositions(ellipsoid, positions, minDistance, perPositionHeight) {
var tangentPlane = EllipsoidTangentPlane.fromPoints(positions, ellipsoid);
var positions2D = tangentPlane.projectPointsOntoPlane(positions, createGeometryFromPositionsPositions);
var originalWindingOrder = PolygonPipeline.computeWindingOrder2D(positions2D);
if (originalWindingOrder === WindingOrder.CLOCKWISE) {
positions2D.reverse();
positions = positions.slice().reverse();
}
var subdividedPositions;
var i;
var length = positions.length;
var index = 0;
if (!perPositionHeight) {
var numVertices = 0;
for (i = 0; i < length; i++) {
numVertices += PolygonGeometryLibrary.subdivideLineCount(positions[i], positions[(i + 1) % length], minDistance);
}
subdividedPositions = new Float64Array(numVertices * 3);
for (i = 0; i < length; i++) {
var tempPositions = PolygonGeometryLibrary.subdivideLine(positions[i], positions[(i + 1) % length], minDistance, createGeometryFromPositionsSubdivided);
var tempPositionsLength = tempPositions.length;
for (var j = 0; j < tempPositionsLength; ++j) {
subdividedPositions[index++] = tempPositions[j];
}
}
} else {
subdividedPositions = new Float64Array(length * 2 * 3);
for (i = 0; i < length; i++) {
var p0 = positions[i];
var 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;
var indicesSize = length * 2;
var 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) {
var tangentPlane = EllipsoidTangentPlane.fromPoints(positions, ellipsoid);
var positions2D = tangentPlane.projectPointsOntoPlane(positions, createGeometryFromPositionsPositions);
var originalWindingOrder = PolygonPipeline.computeWindingOrder2D(positions2D);
if (originalWindingOrder === WindingOrder.CLOCKWISE) {
positions2D.reverse();
positions = positions.slice().reverse();
}
var subdividedPositions;
var i;
var length = positions.length;
var corners = new Array(length);
var index = 0;
if (!perPositionHeight) {
var numVertices = 0;
for (i = 0; i < length; i++) {
numVertices += PolygonGeometryLibrary.subdivideLineCount(positions[i], positions[(i + 1) % length], minDistance);
}
subdividedPositions = new Float64Array(numVertices * 3 * 2);
for (i = 0; i < length; ++i) {
corners[i] = index / 3;
var tempPositions = PolygonGeometryLibrary.subdivideLine(positions[i], positions[(i + 1) % length], minDistance, createGeometryFromPositionsSubdivided);
var tempPositionsLength = tempPositions.length;
for (var 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;
var p0 = positions[i];
var 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);
var cornersLength = corners.length;
var indicesSize = ((length * 2) + cornersLength) * 2;
var indices = IndexDatatype.createTypedArray(length, 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++) {
var 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.
*
* @see PolygonOutlineGeometry#createGeometry
* @see PolygonOutlineGeometry#fromPositions
*
* @example
* // 1. create a polygon outline from points
* var 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
* ])
* )
* });
* var geometry = Cesium.PolygonOutlineGeometry.createGeometry(polygon);
*
* // 2. create a nested polygon with holes outline
* var 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
* ])
* )]
* )]
* )]
* )
* });
* var geometry = Cesium.PolygonOutlineGeometry.createGeometry(polygonWithHole);
*
* // 3. create extruded polygon outline
* var 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
* });
* var geometry = Cesium.PolygonOutlineGeometry.createGeometry(extrudedPolygon);
*/
function PolygonOutlineGeometry(options) {
//>>includeStart('debug', pragmas.debug);
if (!defined(options) || !defined(options.polygonHierarchy)) {
throw new DeveloperError('options.polygonHierarchy is required.');
}
if (defined(options.perPositionHeight) && options.perPositionHeight && defined(options.height)) {
throw new DeveloperError('Cannot use both options.perPositionHeight and options.height');
}
//>>includeEnd('debug');
var polygonHierarchy = options.polygonHierarchy;
var ellipsoid = defaultValue(options.ellipsoid, Ellipsoid.WGS84);
var granularity = defaultValue(options.granularity, CesiumMath.RADIANS_PER_DEGREE);
var height = defaultValue(options.height, 0.0);
var perPositionHeight = defaultValue(options.perPositionHeight, false);
var extrudedHeight = options.extrudedHeight;
var extrude = defined(extrudedHeight);
if (extrude && !perPositionHeight) {
var h = extrudedHeight;
extrudedHeight = Math.min(h, height);
height = Math.max(h, height);
}
this._ellipsoid = Ellipsoid.clone(ellipsoid);
this._granularity = granularity;
this._height = height;
this._extrudedHeight = defaultValue(extrudedHeight, 0.0);
this._extrude = extrude;
this._polygonHierarchy = polygonHierarchy;
this._perPositionHeight = perPositionHeight;
this._workerName = 'createPolygonOutlineGeometry';
/**
* The number of elements used to pack the object into an array.
* @type {Number}
*/
this.packedLength = PolygonGeometryLibrary.computeHierarchyPackedLength(polygonHierarchy) + Ellipsoid.packedLength + 6;
}
/**
* 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.
*/
PolygonOutlineGeometry.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);
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._extrude ? 1.0 : 0.0;
array[startingIndex++] = value._perPositionHeight ? 1.0 : 0.0;
array[startingIndex++] = value.packedLength;
};
var scratchEllipsoid = Ellipsoid.clone(Ellipsoid.UNIT_SPHERE);
var 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);
if (!defined(array)) {
throw new DeveloperError('array is required');
}
//>>includeEnd('debug');
startingIndex = defaultValue(startingIndex, 0);
var polygonHierarchy = PolygonGeometryLibrary.unpackPolygonHierarchy(array, startingIndex);
startingIndex = polygonHierarchy.startingIndex;
delete polygonHierarchy.startingIndex;
var ellipsoid = Ellipsoid.unpack(array, startingIndex, scratchEllipsoid);
startingIndex += Ellipsoid.packedLength;
var height = array[startingIndex++];
var extrudedHeight = array[startingIndex++];
var granularity = array[startingIndex++];
var extrude = array[startingIndex++] === 1.0;
var perPositionHeight = array[startingIndex++] === 1.0;
var 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._extrude = extrude;
result._perPositionHeight = perPositionHeight;
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.
* @returns {PolygonOutlineGeometry}
*
*
* @example
* // create a polygon from points
* var 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
* ])
* });
* var geometry = Cesium.PolygonOutlineGeometry.createGeometry(polygon);
*
* @see PolygonOutlineGeometry#createGeometry
*/
PolygonOutlineGeometry.fromPositions = function(options) {
options = defaultValue(options, defaultValue.EMPTY_OBJECT);
//>>includeStart('debug', pragmas.debug);
if (!defined(options.positions)) {
throw new DeveloperError('options.positions is required.');
}
//>>includeEnd('debug');
var newOptions = {
polygonHierarchy : {
positions : options.positions
},
height : options.height,
extrudedHeight : options.extrudedHeight,
ellipsoid : options.ellipsoid,
granularity : options.granularity,
perPositionHeight : options.perPositionHeight
};
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) {
var ellipsoid = polygonGeometry._ellipsoid;
var granularity = polygonGeometry._granularity;
var height = polygonGeometry._height;
var extrudedHeight = polygonGeometry._extrudedHeight;
var extrude = polygonGeometry._extrude;
var polygonHierarchy = polygonGeometry._polygonHierarchy;
var perPositionHeight = polygonGeometry._perPositionHeight;
// create from a polygon hierarchy
// Algorithm adapted from http://www.geometrictools.com/Documentation/TriangulationByEarClipping.pdf
var polygons = [];
var queue = new Queue();
queue.enqueue(polygonHierarchy);
var i;
while (queue.length !== 0) {
var outerNode = queue.dequeue();
var outerRing = outerNode.positions;
outerRing = arrayRemoveDuplicates(outerRing, Cartesian3.equalsEpsilon, true);
if (outerRing.length < 3) {
continue;
}
var numChildren = outerNode.holes ? outerNode.holes.length : 0;
// The outer polygon contains inner polygons
for (i = 0; i < numChildren; i++) {
var hole = outerNode.holes[i];
hole.positions = arrayRemoveDuplicates(hole.positions, Cartesian3.equalsEpsilon, true);
if (hole.positions.length < 3) {
continue;
}
polygons.push(hole.positions);
var numGrandchildren = 0;
if (defined(hole.holes)) {
numGrandchildren = hole.holes.length;
}
for ( var j = 0; j < numGrandchildren; j++) {
queue.enqueue(hole.holes[j]);
}
}
polygons.push(outerRing);
}
if (polygons.length === 0) {
return undefined;
}
var geometry;
var geometries = [];
var minDistance = CesiumMath.chordLength(granularity, ellipsoid.maximumRadius);
if (extrude) {
for (i = 0; i < polygons.length; i++) {
geometry = createGeometryFromPositionsExtruded(ellipsoid, polygons[i], minDistance, perPositionHeight);
geometry.geometry = PolygonGeometryLibrary.scaleToGeodeticHeightExtruded(geometry.geometry, height, extrudedHeight, ellipsoid, perPositionHeight);
geometries.push(geometry);
}
} else {
for (i = 0; i < polygons.length; i++) {
geometry = createGeometryFromPositions(ellipsoid, polygons[i], minDistance, perPositionHeight);
geometry.geometry.attributes.position.values = PolygonPipeline.scaleToGeodeticHeight(geometry.geometry.attributes.position.values, height, ellipsoid, !perPositionHeight);
geometries.push(geometry);
}
}
geometry = GeometryPipeline.combineInstances(geometries)[0];
var boundingSphere = BoundingSphere.fromVertices(geometry.attributes.position.values);
return new Geometry({
attributes : geometry.attributes,
indices : geometry.indices,
primitiveType : geometry.primitiveType,
boundingSphere : boundingSphere
});
};
return PolygonOutlineGeometry;
});