36 lines
885 B
TypeScript
36 lines
885 B
TypeScript
export interface Point {
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x: number;
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y: number;
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}
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export interface geoPoint {
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lon: number;
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lat: number;
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}
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// cf https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#ECMAScript_(JavaScript/ActionScript,_etc.)
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export const lon2tile = (lon: number, zoom: number) => {
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return ((Number(lon) + 180) / 360) * Math.pow(2, zoom);
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};
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export const lat2tile = (lat: number, zoom: number) => {
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return (
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((1 -
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Math.log(
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Math.tan((Number(lat) * Math.PI) / 180) +
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1 / Math.cos((Number(lat) * Math.PI) / 180)
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) /
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Math.PI) /
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2) *
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Math.pow(2, zoom)
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);
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};
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export function tile2long(x: number, z: number) {
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return (x / Math.pow(2, z)) * 360 - 180;
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}
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export function tile2lat(y: number, z: number) {
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var n = Math.PI - (2 * Math.PI * y) / Math.pow(2, z);
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return (180 / Math.PI) * Math.atan(0.5 * (Math.exp(n) - Math.exp(-n)));
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}
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