Files
openlayers/src/ol/geom/Circle.js
2022-08-11 20:14:35 -06:00

283 lines
8.4 KiB
JavaScript

/**
* @module ol/geom/Circle
*/
import SimpleGeometry from './SimpleGeometry.js';
import {createOrUpdate, forEachCorner, intersects} from '../extent.js';
import {deflateCoordinate} from './flat/deflate.js';
import {rotate, translate} from './flat/transform.js';
/**
* @classdesc
* Circle geometry.
*
* @api
*/
class Circle extends SimpleGeometry {
/**
* @param {!import("../coordinate.js").Coordinate} center Center.
* For internal use, flat coordinates in combination with `layout` and no
* `radius` are also accepted.
* @param {number} [radius] Radius.
* @param {import("./Geometry.js").GeometryLayout} [layout] Layout.
*/
constructor(center, radius, layout) {
super();
if (layout !== undefined && radius === undefined) {
this.setFlatCoordinates(layout, center);
} else {
radius = radius ? radius : 0;
this.setCenterAndRadius(center, radius, layout);
}
}
/**
* Make a complete copy of the geometry.
* @return {!Circle} Clone.
* @api
*/
clone() {
const circle = new Circle(
this.flatCoordinates.slice(),
undefined,
this.layout
);
circle.applyProperties(this);
return circle;
}
/**
* @param {number} x X.
* @param {number} y Y.
* @param {import("../coordinate.js").Coordinate} closestPoint Closest point.
* @param {number} minSquaredDistance Minimum squared distance.
* @return {number} Minimum squared distance.
*/
closestPointXY(x, y, closestPoint, minSquaredDistance) {
const flatCoordinates = this.flatCoordinates;
const dx = x - flatCoordinates[0];
const dy = y - flatCoordinates[1];
const squaredDistance = dx * dx + dy * dy;
if (squaredDistance < minSquaredDistance) {
if (squaredDistance === 0) {
for (let i = 0; i < this.stride; ++i) {
closestPoint[i] = flatCoordinates[i];
}
} else {
const delta = this.getRadius() / Math.sqrt(squaredDistance);
closestPoint[0] = flatCoordinates[0] + delta * dx;
closestPoint[1] = flatCoordinates[1] + delta * dy;
for (let i = 2; i < this.stride; ++i) {
closestPoint[i] = flatCoordinates[i];
}
}
closestPoint.length = this.stride;
return squaredDistance;
} else {
return minSquaredDistance;
}
}
/**
* @param {number} x X.
* @param {number} y Y.
* @return {boolean} Contains (x, y).
*/
containsXY(x, y) {
const flatCoordinates = this.flatCoordinates;
const dx = x - flatCoordinates[0];
const dy = y - flatCoordinates[1];
return dx * dx + dy * dy <= this.getRadiusSquared_();
}
/**
* Return the center of the circle as {@link module:ol/coordinate~Coordinate coordinate}.
* @return {import("../coordinate.js").Coordinate} Center.
* @api
*/
getCenter() {
return this.flatCoordinates.slice(0, this.stride);
}
/**
* @param {import("../extent.js").Extent} extent Extent.
* @protected
* @return {import("../extent.js").Extent} extent Extent.
*/
computeExtent(extent) {
const flatCoordinates = this.flatCoordinates;
const radius = flatCoordinates[this.stride] - flatCoordinates[0];
return createOrUpdate(
flatCoordinates[0] - radius,
flatCoordinates[1] - radius,
flatCoordinates[0] + radius,
flatCoordinates[1] + radius,
extent
);
}
/**
* Return the radius of the circle.
* @return {number} Radius.
* @api
*/
getRadius() {
return Math.sqrt(this.getRadiusSquared_());
}
/**
* @private
* @return {number} Radius squared.
*/
getRadiusSquared_() {
const dx = this.flatCoordinates[this.stride] - this.flatCoordinates[0];
const dy = this.flatCoordinates[this.stride + 1] - this.flatCoordinates[1];
return dx * dx + dy * dy;
}
/**
* Get the type of this geometry.
* @return {import("./Geometry.js").Type} Geometry type.
* @api
*/
getType() {
return 'Circle';
}
/**
* Test if the geometry and the passed extent intersect.
* @param {import("../extent.js").Extent} extent Extent.
* @return {boolean} `true` if the geometry and the extent intersect.
* @api
*/
intersectsExtent(extent) {
const circleExtent = this.getExtent();
if (intersects(extent, circleExtent)) {
const center = this.getCenter();
if (extent[0] <= center[0] && extent[2] >= center[0]) {
return true;
}
if (extent[1] <= center[1] && extent[3] >= center[1]) {
return true;
}
return forEachCorner(extent, this.intersectsCoordinate.bind(this));
}
return false;
}
/**
* Set the center of the circle as {@link module:ol/coordinate~Coordinate coordinate}.
* @param {import("../coordinate.js").Coordinate} center Center.
* @api
*/
setCenter(center) {
const stride = this.stride;
const radius = this.flatCoordinates[stride] - this.flatCoordinates[0];
const flatCoordinates = center.slice();
flatCoordinates[stride] = flatCoordinates[0] + radius;
for (let i = 1; i < stride; ++i) {
flatCoordinates[stride + i] = center[i];
}
this.setFlatCoordinates(this.layout, flatCoordinates);
this.changed();
}
/**
* Set the center (as {@link module:ol/coordinate~Coordinate coordinate}) and the radius (as
* number) of the circle.
* @param {!import("../coordinate.js").Coordinate} center Center.
* @param {number} radius Radius.
* @param {import("./Geometry.js").GeometryLayout} [layout] Layout.
* @api
*/
setCenterAndRadius(center, radius, layout) {
this.setLayout(layout, center, 0);
if (!this.flatCoordinates) {
this.flatCoordinates = [];
}
/** @type {Array<number>} */
const flatCoordinates = this.flatCoordinates;
let offset = deflateCoordinate(flatCoordinates, 0, center, this.stride);
flatCoordinates[offset++] = flatCoordinates[0] + radius;
for (let i = 1, ii = this.stride; i < ii; ++i) {
flatCoordinates[offset++] = flatCoordinates[i];
}
flatCoordinates.length = offset;
this.changed();
}
getCoordinates() {
return null;
}
setCoordinates(coordinates, layout) {}
/**
* Set the radius of the circle. The radius is in the units of the projection.
* @param {number} radius Radius.
* @api
*/
setRadius(radius) {
this.flatCoordinates[this.stride] = this.flatCoordinates[0] + radius;
this.changed();
}
/**
* Rotate the geometry around a given coordinate. This modifies the geometry
* coordinates in place.
* @param {number} angle Rotation angle in counter-clockwise radians.
* @param {import("../coordinate.js").Coordinate} anchor The rotation center.
* @api
*/
rotate(angle, anchor) {
const center = this.getCenter();
const stride = this.getStride();
this.setCenter(
rotate(center, 0, center.length, stride, angle, anchor, center)
);
this.changed();
}
/**
* Translate the geometry. This modifies the geometry coordinates in place. If
* instead you want a new geometry, first `clone()` this geometry.
* @param {number} deltaX Delta X.
* @param {number} deltaY Delta Y.
* @api
*/
translate(deltaX, deltaY) {
const center = this.getCenter();
const stride = this.getStride();
this.setCenter(
translate(center, 0, center.length, stride, deltaX, deltaY, center)
);
this.changed();
}
}
/**
* Transform each coordinate of the circle from one coordinate reference system
* to another. The geometry is modified in place.
* If you do not want the geometry modified in place, first clone() it and
* then use this function on the clone.
*
* Internally a circle is currently represented by two points: the center of
* the circle `[cx, cy]`, and the point to the right of the circle
* `[cx + r, cy]`. This `transform` function just transforms these two points.
* So the resulting geometry is also a circle, and that circle does not
* correspond to the shape that would be obtained by transforming every point
* of the original circle.
*
* @param {import("../proj.js").ProjectionLike} source The current projection. Can be a
* string identifier or a {@link module:ol/proj/Projection~Projection} object.
* @param {import("../proj.js").ProjectionLike} destination The desired projection. Can be a
* string identifier or a {@link module:ol/proj/Projection~Projection} object.
* @return {Circle} This geometry. Note that original geometry is
* modified in place.
* @function
* @api
*/
Circle.prototype.transform;
export default Circle;