geoplex/ice/indexed-coordinates.js

Nested spherical triangles based on a regular icosahedron model of Earth; a library for use with rwt-orthographic-earth GIS layers

/* Copyright (c) 2022 Read Write Tools. */
import expect from'softlib/expect.js';import aver from'softlib/aver.js';export default class IndexedCoordinates{constructor(){this.meridians=new Array,this.parallels=new Array,this.inverseMeridians=new Map,this.inverseParallels=new Map}get packedWidth(){return this.meridians.length>65536||this.parallels.length>65536?4:2}registerCoordinates(e,r){return[this.registerLongitude(e),this.registerLatitude(r)]}registerLongitude(e){expect(e,'Number'),aver(e>=-180&&e<=180);e=Math.fround(e);var r=this.inverseMeridians.get(e);if(null==r){r=this.meridians.push(e)-1,this.inverseMeridians.set(e,r)}return r}registerLatitude(e){expect(e,'Number'),aver(e>=-90&&e<=90);e=Math.fround(e);var r=this.inverseParallels.get(e);if(null==r){r=this.parallels.push(e)-1,this.inverseParallels.set(e,r)}return r}getLongitude(e){return e<0||e>=this.meridians.length?null:this.meridians[e]}getLatitude(e){return e<0||e>=this.parallels.length?null:this.parallels[e]}getIceX(e){e=Math.fround(e);return this.inverseMeridians.get(e)}getIceY(e){e=Math.fround(e);return this.inverseParallels.get(e)}uidFromIce(e,r){return expect(e,'Number'),expect(r,'Number'),aver(e>=0&&e<this.meridians.length),aver(r>=0&&r<this.parallels.length),`${e}×${r}`}}