node-red-contrib-tak-registration
Version:
A Node-RED node to register to TAK and to help wrap files as datapackages to send to TAK
163 lines (162 loc) • 6.73 kB
JavaScript
"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
var distance_1 = __importDefault(require("@turf/distance"));
var intersect_1 = __importDefault(require("@turf/intersect"));
var helpers_1 = require("@turf/helpers");
/**
* Takes a bounding box and the diameter of the cell and returns a {@link FeatureCollection} of flat-topped
* hexagons or triangles ({@link Polygon} features) aligned in an "odd-q" vertical grid as
* described in [Hexagonal Grids](http://www.redblobgames.com/grids/hexagons/).
*
* @name hexGrid
* @param {BBox} bbox extent in [minX, minY, maxX, maxY] order
* @param {number} cellSide length of the side of the the hexagons or triangles, in units. It will also coincide with the
* radius of the circumcircle of the hexagons.
* @param {Object} [options={}] Optional parameters
* @param {string} [options.units='kilometers'] used in calculating cell size, can be degrees, radians, miles, or kilometers
* @param {Object} [options.properties={}] passed to each hexagon or triangle of the grid
* @param {Feature<Polygon>} [options.mask] if passed a Polygon or MultiPolygon, the grid Points will be created only inside it
* @param {boolean} [options.triangles=false] whether to return as triangles instead of hexagons
* @returns {FeatureCollection<Polygon>} a hexagonal grid
* @example
* var bbox = [-96,31,-84,40];
* var cellSide = 50;
* var options = {units: 'miles'};
*
* var hexgrid = turf.hexGrid(bbox, cellSide, options);
*
* //addToMap
* var addToMap = [hexgrid];
*/
function hexGrid(bbox, cellSide, options) {
if (options === void 0) { options = {}; }
// Issue => https://github.com/Turfjs/turf/issues/1284
var clonedProperties = JSON.stringify(options.properties || {});
var west = bbox[0], south = bbox[1], east = bbox[2], north = bbox[3];
var centerY = (south + north) / 2;
var centerX = (west + east) / 2;
// https://github.com/Turfjs/turf/issues/758
var xFraction = (cellSide * 2) / distance_1.default([west, centerY], [east, centerY], options);
var cellWidth = xFraction * (east - west);
var yFraction = (cellSide * 2) / distance_1.default([centerX, south], [centerX, north], options);
var cellHeight = yFraction * (north - south);
var radius = cellWidth / 2;
var hex_width = radius * 2;
var hex_height = (Math.sqrt(3) / 2) * cellHeight;
var box_width = east - west;
var box_height = north - south;
var x_interval = (3 / 4) * hex_width;
var y_interval = hex_height;
// adjust box_width so all hexagons will be inside the bbox
var x_span = (box_width - hex_width) / (hex_width - radius / 2);
var x_count = Math.floor(x_span);
var x_adjust = (x_count * x_interval - radius / 2 - box_width) / 2 -
radius / 2 +
x_interval / 2;
// adjust box_height so all hexagons will be inside the bbox
var y_count = Math.floor((box_height - hex_height) / hex_height);
var y_adjust = (box_height - y_count * hex_height) / 2;
var hasOffsetY = y_count * hex_height - box_height > hex_height / 2;
if (hasOffsetY) {
y_adjust -= hex_height / 4;
}
// Precompute cosines and sines of angles used in hexagon creation for performance gain
var cosines = [];
var sines = [];
for (var i = 0; i < 6; i++) {
var angle = ((2 * Math.PI) / 6) * i;
cosines.push(Math.cos(angle));
sines.push(Math.sin(angle));
}
var results = [];
for (var x = 0; x <= x_count; x++) {
for (var y = 0; y <= y_count; y++) {
var isOdd = x % 2 === 1;
if (y === 0 && isOdd)
continue;
if (y === 0 && hasOffsetY)
continue;
var center_x = x * x_interval + west - x_adjust;
var center_y = y * y_interval + south + y_adjust;
if (isOdd) {
center_y -= hex_height / 2;
}
if (options.triangles === true) {
hexTriangles([center_x, center_y], cellWidth / 2, cellHeight / 2, JSON.parse(clonedProperties), cosines, sines).forEach(function (triangle) {
if (options.mask) {
if (intersect_1.default(options.mask, triangle))
results.push(triangle);
}
else {
results.push(triangle);
}
});
}
else {
var hex = hexagon([center_x, center_y], cellWidth / 2, cellHeight / 2, JSON.parse(clonedProperties), cosines, sines);
if (options.mask) {
if (intersect_1.default(options.mask, hex))
results.push(hex);
}
else {
results.push(hex);
}
}
}
}
return helpers_1.featureCollection(results);
}
/**
* Creates hexagon
*
* @private
* @param {Array<number>} center of the hexagon
* @param {number} rx half hexagon width
* @param {number} ry half hexagon height
* @param {Object} properties passed to each hexagon
* @param {Array<number>} cosines precomputed
* @param {Array<number>} sines precomputed
* @returns {Feature<Polygon>} hexagon
*/
function hexagon(center, rx, ry, properties, cosines, sines) {
var vertices = [];
for (var i = 0; i < 6; i++) {
var x = center[0] + rx * cosines[i];
var y = center[1] + ry * sines[i];
vertices.push([x, y]);
}
//first and last vertex must be the same
vertices.push(vertices[0].slice());
return helpers_1.polygon([vertices], properties);
}
/**
* Creates triangles composing an hexagon
*
* @private
* @param {Array<number>} center of the hexagon
* @param {number} rx half triangle width
* @param {number} ry half triangle height
* @param {Object} properties passed to each triangle
* @param {Array<number>} cosines precomputed
* @param {Array<number>} sines precomputed
* @returns {Array<Feature<Polygon>>} triangles
*/
function hexTriangles(center, rx, ry, properties, cosines, sines) {
var triangles = [];
for (var i = 0; i < 6; i++) {
var vertices = [];
vertices.push(center);
vertices.push([center[0] + rx * cosines[i], center[1] + ry * sines[i]]);
vertices.push([
center[0] + rx * cosines[(i + 1) % 6],
center[1] + ry * sines[(i + 1) % 6],
]);
vertices.push(center);
triangles.push(helpers_1.polygon([vertices], properties));
}
return triangles;
}
exports.default = hexGrid;