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- import booleanPointInPolygon from "@turf/boolean-point-in-polygon";
- import { point } from "@turf/helpers";
- // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/sign#Polyfill
- function mathSign(x) {
- return ((x > 0) - (x < 0) || +x);
- }
- /**
- * Returns the direction of the point q relative to the vector p1 -> p2.
- *
- * Implementation of geos::algorithm::CGAlgorithm::orientationIndex()
- * (same as geos::algorithm::CGAlgorithm::computeOrientation())
- *
- * @param {number[]} p1 - the origin point of the vector
- * @param {number[]} p2 - the final point of the vector
- * @param {number[]} q - the point to compute the direction to
- *
- * @returns {number} - 1 if q is ccw (left) from p1->p2,
- * -1 if q is cw (right) from p1->p2,
- * 0 if q is colinear with p1->p2
- */
- export function orientationIndex(p1, p2, q) {
- var dx1 = p2[0] - p1[0], dy1 = p2[1] - p1[1], dx2 = q[0] - p2[0], dy2 = q[1] - p2[1];
- return mathSign(dx1 * dy2 - dx2 * dy1);
- }
- /**
- * Checks if two envelopes are equal.
- *
- * The function assumes that the arguments are envelopes, i.e.: Rectangular polygon
- *
- * @param {Feature<Polygon>} env1 - Envelope
- * @param {Feature<Polygon>} env2 - Envelope
- * @returns {boolean} - True if the envelopes are equal
- */
- export function envelopeIsEqual(env1, env2) {
- var envX1 = env1.geometry.coordinates[0].map(function (c) { return c[0]; }), envY1 = env1.geometry.coordinates[0].map(function (c) { return c[1]; }), envX2 = env2.geometry.coordinates[0].map(function (c) { return c[0]; }), envY2 = env2.geometry.coordinates[0].map(function (c) { return c[1]; });
- return (Math.max.apply(null, envX1) === Math.max.apply(null, envX2) &&
- Math.max.apply(null, envY1) === Math.max.apply(null, envY2) &&
- Math.min.apply(null, envX1) === Math.min.apply(null, envX2) &&
- Math.min.apply(null, envY1) === Math.min.apply(null, envY2));
- }
- /**
- * Check if a envelope is contained in other one.
- *
- * The function assumes that the arguments are envelopes, i.e.: Convex polygon
- * XXX: Envelopes are rectangular, checking if a point is inside a rectangule is something easy,
- * this could be further improved.
- *
- * @param {Feature<Polygon>} self - Envelope
- * @param {Feature<Polygon>} env - Envelope
- * @returns {boolean} - True if env is contained in self
- */
- export function envelopeContains(self, env) {
- return env.geometry.coordinates[0].every(function (c) {
- return booleanPointInPolygon(point(c), self);
- });
- }
- /**
- * Checks if two coordinates are equal.
- *
- * @param {number[]} coord1 - First coordinate
- * @param {number[]} coord2 - Second coordinate
- * @returns {boolean} - True if coordinates are equal
- */
- export function coordinatesEqual(coord1, coord2) {
- return coord1[0] === coord2[0] && coord1[1] === coord2[1];
- }
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