thematic-earth/joe/spherical-earth/coordinate-translations.js

HTML-based, whole-Earth thematic maps using locally hosted data layers

/* Copyright (c) 2023 Read Write Tools. Legal use subject to the Thematic Earth Software License Agreement. */
const degreesToRadians=Math.PI/180,radiansToDegrees=180/Math.PI,EARTH_RADIUS=6371;export function ll2rtp(t,a){return{rho:1,theta:a*degreesToRadians,phi:(90-t)*degreesToRadians}}export function ll2xyz(t,a){var n=(90-t)*degreesToRadians,r=a*degreesToRadians;return{x:1*Math.sin(n)*Math.cos(r),y:1*Math.sin(n)*Math.sin(r),z:1*Math.cos(n)}}export function rtp2xyz(t,a,n){return{x:t*Math.sin(n)*Math.cos(a),y:t*Math.sin(n)*Math.sin(a),z:t*Math.cos(n)}}export function rtp2ll(t,a,n){Math.sin(n),Math.cos(a),Math.sin(n),Math.sin(a),Math.cos(n);return{latitude:-1*(n*radiansToDegrees-90),longitude:a*radiansToDegrees}}export function xyz2rtp(t,a,n){return{rho:Math.sqrt(t*t+a*a+n*n),theta:Math.atan2(a,t),phi:Math.atan2(Math.sqrt(t*t+a*a),n)}}export function xyz2ll(t,a,n){Math.sqrt(t*t+a*a+n*n);var r=Math.atan2(a,t);return{latitude:-1*(Math.atan2(Math.sqrt(t*t+a*a),n)*radiansToDegrees-90),longitude:r*radiansToDegrees}}export function lat2colat(t){return 90-t}export function colat2lat(t){return-1*(t-90)}export function phi2cophi(t){return Math.PI/2-t}export function cophi2phi(t){return-1*(t-Math.PI/2)}export function rotateX(t,a,n,r){return{x1:t,y1:a*Math.cos(r)-n*Math.sin(r),z1:a*Math.sin(r)+n*Math.cos(r)}}export function rotateY(t,a,n,r){return{x1:t*Math.cos(r)+n*Math.sin(r),y1:a,z1:n*Math.cos(r)-t*Math.sin(r)}}export function rotateZ(t,a,n,r){return{x1:t*Math.cos(r)-a*Math.sin(r),y1:t*Math.sin(r)+a*Math.cos(r),z1:n}}