openlayers
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Build tools and sources for developing OpenLayers based mapping applications
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JavaScript
goog.provide('ol.geom.Polygon');
goog.require('ol');
goog.require('ol.array');
goog.require('ol.extent');
goog.require('ol.geom.GeometryLayout');
goog.require('ol.geom.GeometryType');
goog.require('ol.geom.LinearRing');
goog.require('ol.geom.Point');
goog.require('ol.geom.SimpleGeometry');
goog.require('ol.geom.flat.area');
goog.require('ol.geom.flat.closest');
goog.require('ol.geom.flat.contains');
goog.require('ol.geom.flat.deflate');
goog.require('ol.geom.flat.inflate');
goog.require('ol.geom.flat.interiorpoint');
goog.require('ol.geom.flat.intersectsextent');
goog.require('ol.geom.flat.orient');
goog.require('ol.geom.flat.simplify');
goog.require('ol.math');
/**
* @classdesc
* Polygon geometry.
*
* @constructor
* @extends {ol.geom.SimpleGeometry}
* @param {Array.<Array.<ol.Coordinate>>} coordinates Coordinates.
* @param {ol.geom.GeometryLayout=} opt_layout Layout.
* @api stable
*/
ol.geom.Polygon = function(coordinates, opt_layout) {
ol.geom.SimpleGeometry.call(this);
/**
* @type {Array.<number>}
* @private
*/
this.ends_ = [];
/**
* @private
* @type {number}
*/
this.flatInteriorPointRevision_ = -1;
/**
* @private
* @type {ol.Coordinate}
*/
this.flatInteriorPoint_ = null;
/**
* @private
* @type {number}
*/
this.maxDelta_ = -1;
/**
* @private
* @type {number}
*/
this.maxDeltaRevision_ = -1;
/**
* @private
* @type {number}
*/
this.orientedRevision_ = -1;
/**
* @private
* @type {Array.<number>}
*/
this.orientedFlatCoordinates_ = null;
this.setCoordinates(coordinates, opt_layout);
};
ol.inherits(ol.geom.Polygon, ol.geom.SimpleGeometry);
/**
* Append the passed linear ring to this polygon.
* @param {ol.geom.LinearRing} linearRing Linear ring.
* @api stable
*/
ol.geom.Polygon.prototype.appendLinearRing = function(linearRing) {
ol.DEBUG && console.assert(linearRing.getLayout() == this.layout,
'layout of linearRing should match layout');
if (!this.flatCoordinates) {
this.flatCoordinates = linearRing.getFlatCoordinates().slice();
} else {
ol.array.extend(this.flatCoordinates, linearRing.getFlatCoordinates());
}
this.ends_.push(this.flatCoordinates.length);
this.changed();
};
/**
* Make a complete copy of the geometry.
* @return {!ol.geom.Polygon} Clone.
* @api stable
*/
ol.geom.Polygon.prototype.clone = function() {
var polygon = new ol.geom.Polygon(null);
polygon.setFlatCoordinates(
this.layout, this.flatCoordinates.slice(), this.ends_.slice());
return polygon;
};
/**
* @inheritDoc
*/
ol.geom.Polygon.prototype.closestPointXY = function(x, y, closestPoint, minSquaredDistance) {
if (minSquaredDistance <
ol.extent.closestSquaredDistanceXY(this.getExtent(), x, y)) {
return minSquaredDistance;
}
if (this.maxDeltaRevision_ != this.getRevision()) {
this.maxDelta_ = Math.sqrt(ol.geom.flat.closest.getsMaxSquaredDelta(
this.flatCoordinates, 0, this.ends_, this.stride, 0));
this.maxDeltaRevision_ = this.getRevision();
}
return ol.geom.flat.closest.getsClosestPoint(
this.flatCoordinates, 0, this.ends_, this.stride,
this.maxDelta_, true, x, y, closestPoint, minSquaredDistance);
};
/**
* @inheritDoc
*/
ol.geom.Polygon.prototype.containsXY = function(x, y) {
return ol.geom.flat.contains.linearRingsContainsXY(
this.getOrientedFlatCoordinates(), 0, this.ends_, this.stride, x, y);
};
/**
* Return the area of the polygon on projected plane.
* @return {number} Area (on projected plane).
* @api stable
*/
ol.geom.Polygon.prototype.getArea = function() {
return ol.geom.flat.area.linearRings(
this.getOrientedFlatCoordinates(), 0, this.ends_, this.stride);
};
/**
* Get the coordinate array for this geometry. This array has the structure
* of a GeoJSON coordinate array for polygons.
*
* @param {boolean=} opt_right Orient coordinates according to the right-hand
* rule (counter-clockwise for exterior and clockwise for interior rings).
* If `false`, coordinates will be oriented according to the left-hand rule
* (clockwise for exterior and counter-clockwise for interior rings).
* By default, coordinate orientation will depend on how the geometry was
* constructed.
* @return {Array.<Array.<ol.Coordinate>>} Coordinates.
* @api stable
*/
ol.geom.Polygon.prototype.getCoordinates = function(opt_right) {
var flatCoordinates;
if (opt_right !== undefined) {
flatCoordinates = this.getOrientedFlatCoordinates().slice();
ol.geom.flat.orient.orientLinearRings(
flatCoordinates, 0, this.ends_, this.stride, opt_right);
} else {
flatCoordinates = this.flatCoordinates;
}
return ol.geom.flat.inflate.coordinatess(
flatCoordinates, 0, this.ends_, this.stride);
};
/**
* @return {Array.<number>} Ends.
*/
ol.geom.Polygon.prototype.getEnds = function() {
return this.ends_;
};
/**
* @return {Array.<number>} Interior point.
*/
ol.geom.Polygon.prototype.getFlatInteriorPoint = function() {
if (this.flatInteriorPointRevision_ != this.getRevision()) {
var flatCenter = ol.extent.getCenter(this.getExtent());
this.flatInteriorPoint_ = ol.geom.flat.interiorpoint.linearRings(
this.getOrientedFlatCoordinates(), 0, this.ends_, this.stride,
flatCenter, 0);
this.flatInteriorPointRevision_ = this.getRevision();
}
return this.flatInteriorPoint_;
};
/**
* Return an interior point of the polygon.
* @return {ol.geom.Point} Interior point.
* @api stable
*/
ol.geom.Polygon.prototype.getInteriorPoint = function() {
return new ol.geom.Point(this.getFlatInteriorPoint());
};
/**
* Return the number of rings of the polygon, this includes the exterior
* ring and any interior rings.
*
* @return {number} Number of rings.
* @api
*/
ol.geom.Polygon.prototype.getLinearRingCount = function() {
return this.ends_.length;
};
/**
* Return the Nth linear ring of the polygon geometry. Return `null` if the
* given index is out of range.
* The exterior linear ring is available at index `0` and the interior rings
* at index `1` and beyond.
*
* @param {number} index Index.
* @return {ol.geom.LinearRing} Linear ring.
* @api stable
*/
ol.geom.Polygon.prototype.getLinearRing = function(index) {
ol.DEBUG && console.assert(0 <= index && index < this.ends_.length,
'index should be in between 0 and and length of this.ends_');
if (index < 0 || this.ends_.length <= index) {
return null;
}
var linearRing = new ol.geom.LinearRing(null);
linearRing.setFlatCoordinates(this.layout, this.flatCoordinates.slice(
index === 0 ? 0 : this.ends_[index - 1], this.ends_[index]));
return linearRing;
};
/**
* Return the linear rings of the polygon.
* @return {Array.<ol.geom.LinearRing>} Linear rings.
* @api stable
*/
ol.geom.Polygon.prototype.getLinearRings = function() {
var layout = this.layout;
var flatCoordinates = this.flatCoordinates;
var ends = this.ends_;
var linearRings = [];
var offset = 0;
var i, ii;
for (i = 0, ii = ends.length; i < ii; ++i) {
var end = ends[i];
var linearRing = new ol.geom.LinearRing(null);
linearRing.setFlatCoordinates(layout, flatCoordinates.slice(offset, end));
linearRings.push(linearRing);
offset = end;
}
return linearRings;
};
/**
* @return {Array.<number>} Oriented flat coordinates.
*/
ol.geom.Polygon.prototype.getOrientedFlatCoordinates = function() {
if (this.orientedRevision_ != this.getRevision()) {
var flatCoordinates = this.flatCoordinates;
if (ol.geom.flat.orient.linearRingsAreOriented(
flatCoordinates, 0, this.ends_, this.stride)) {
this.orientedFlatCoordinates_ = flatCoordinates;
} else {
this.orientedFlatCoordinates_ = flatCoordinates.slice();
this.orientedFlatCoordinates_.length =
ol.geom.flat.orient.orientLinearRings(
this.orientedFlatCoordinates_, 0, this.ends_, this.stride);
}
this.orientedRevision_ = this.getRevision();
}
return this.orientedFlatCoordinates_;
};
/**
* @inheritDoc
*/
ol.geom.Polygon.prototype.getSimplifiedGeometryInternal = function(squaredTolerance) {
var simplifiedFlatCoordinates = [];
var simplifiedEnds = [];
simplifiedFlatCoordinates.length = ol.geom.flat.simplify.quantizes(
this.flatCoordinates, 0, this.ends_, this.stride,
Math.sqrt(squaredTolerance),
simplifiedFlatCoordinates, 0, simplifiedEnds);
var simplifiedPolygon = new ol.geom.Polygon(null);
simplifiedPolygon.setFlatCoordinates(
ol.geom.GeometryLayout.XY, simplifiedFlatCoordinates, simplifiedEnds);
return simplifiedPolygon;
};
/**
* @inheritDoc
* @api stable
*/
ol.geom.Polygon.prototype.getType = function() {
return ol.geom.GeometryType.POLYGON;
};
/**
* @inheritDoc
* @api stable
*/
ol.geom.Polygon.prototype.intersectsExtent = function(extent) {
return ol.geom.flat.intersectsextent.linearRings(
this.getOrientedFlatCoordinates(), 0, this.ends_, this.stride, extent);
};
/**
* Set the coordinates of the polygon.
* @param {Array.<Array.<ol.Coordinate>>} coordinates Coordinates.
* @param {ol.geom.GeometryLayout=} opt_layout Layout.
* @api stable
*/
ol.geom.Polygon.prototype.setCoordinates = function(coordinates, opt_layout) {
if (!coordinates) {
this.setFlatCoordinates(ol.geom.GeometryLayout.XY, null, this.ends_);
} else {
this.setLayout(opt_layout, coordinates, 2);
if (!this.flatCoordinates) {
this.flatCoordinates = [];
}
var ends = ol.geom.flat.deflate.coordinatess(
this.flatCoordinates, 0, coordinates, this.stride, this.ends_);
this.flatCoordinates.length = ends.length === 0 ? 0 : ends[ends.length - 1];
this.changed();
}
};
/**
* @param {ol.geom.GeometryLayout} layout Layout.
* @param {Array.<number>} flatCoordinates Flat coordinates.
* @param {Array.<number>} ends Ends.
*/
ol.geom.Polygon.prototype.setFlatCoordinates = function(layout, flatCoordinates, ends) {
if (!flatCoordinates) {
ol.DEBUG && console.assert(ends && ends.length === 0,
'ends must be an empty array');
} else if (ends.length === 0) {
ol.DEBUG && console.assert(flatCoordinates.length === 0,
'flatCoordinates should be an empty array');
} else {
ol.DEBUG && console.assert(flatCoordinates.length == ends[ends.length - 1],
'the length of flatCoordinates should be the last entry of ends');
}
this.setFlatCoordinatesInternal(layout, flatCoordinates);
this.ends_ = ends;
this.changed();
};
/**
* Create an approximation of a circle on the surface of a sphere.
* @param {ol.Sphere} sphere The sphere.
* @param {ol.Coordinate} center Center (`[lon, lat]` in degrees).
* @param {number} radius The great-circle distance from the center to
* the polygon vertices.
* @param {number=} opt_n Optional number of vertices for the resulting
* polygon. Default is `32`.
* @return {ol.geom.Polygon} The "circular" polygon.
* @api stable
*/
ol.geom.Polygon.circular = function(sphere, center, radius, opt_n) {
var n = opt_n ? opt_n : 32;
/** @type {Array.<number>} */
var flatCoordinates = [];
var i;
for (i = 0; i < n; ++i) {
ol.array.extend(
flatCoordinates, sphere.offset(center, radius, 2 * Math.PI * i / n));
}
flatCoordinates.push(flatCoordinates[0], flatCoordinates[1]);
var polygon = new ol.geom.Polygon(null);
polygon.setFlatCoordinates(
ol.geom.GeometryLayout.XY, flatCoordinates, [flatCoordinates.length]);
return polygon;
};
/**
* Create a polygon from an extent. The layout used is `XY`.
* @param {ol.Extent} extent The extent.
* @return {ol.geom.Polygon} The polygon.
* @api
*/
ol.geom.Polygon.fromExtent = function(extent) {
var minX = extent[0];
var minY = extent[1];
var maxX = extent[2];
var maxY = extent[3];
var flatCoordinates =
[minX, minY, minX, maxY, maxX, maxY, maxX, minY, minX, minY];
var polygon = new ol.geom.Polygon(null);
polygon.setFlatCoordinates(
ol.geom.GeometryLayout.XY, flatCoordinates, [flatCoordinates.length]);
return polygon;
};
/**
* Create a regular polygon from a circle.
* @param {ol.geom.Circle} circle Circle geometry.
* @param {number=} opt_sides Number of sides of the polygon. Default is 32.
* @param {number=} opt_angle Start angle for the first vertex of the polygon in
* radians. Default is 0.
* @return {ol.geom.Polygon} Polygon geometry.
* @api
*/
ol.geom.Polygon.fromCircle = function(circle, opt_sides, opt_angle) {
var sides = opt_sides ? opt_sides : 32;
var stride = circle.getStride();
var layout = circle.getLayout();
var polygon = new ol.geom.Polygon(null, layout);
var arrayLength = stride * (sides + 1);
var flatCoordinates = new Array(arrayLength);
for (var i = 0; i < arrayLength; i++) {
flatCoordinates[i] = 0;
}
var ends = [flatCoordinates.length];
polygon.setFlatCoordinates(layout, flatCoordinates, ends);
ol.geom.Polygon.makeRegular(
polygon, circle.getCenter(), circle.getRadius(), opt_angle);
return polygon;
};
/**
* Modify the coordinates of a polygon to make it a regular polygon.
* @param {ol.geom.Polygon} polygon Polygon geometry.
* @param {ol.Coordinate} center Center of the regular polygon.
* @param {number} radius Radius of the regular polygon.
* @param {number=} opt_angle Start angle for the first vertex of the polygon in
* radians. Default is 0.
*/
ol.geom.Polygon.makeRegular = function(polygon, center, radius, opt_angle) {
var flatCoordinates = polygon.getFlatCoordinates();
var layout = polygon.getLayout();
var stride = polygon.getStride();
var ends = polygon.getEnds();
ol.DEBUG && console.assert(ends.length === 1, 'only 1 ring is supported');
var sides = flatCoordinates.length / stride - 1;
var startAngle = opt_angle ? opt_angle : 0;
var angle, offset;
for (var i = 0; i <= sides; ++i) {
offset = i * stride;
angle = startAngle + (ol.math.modulo(i, sides) * 2 * Math.PI / sides);
flatCoordinates[offset] = center[0] + (radius * Math.cos(angle));
flatCoordinates[offset + 1] = center[1] + (radius * Math.sin(angle));
}
polygon.setFlatCoordinates(layout, flatCoordinates, ends);
};