Patryk Kalinowski patrykkalinowski
patrykkalinowski
/ savetiles.js
Created
August 29, 2023 08:57
Code to save slippy map tiles to indexedDB as blobs. Uses Dexie
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| function lon2tile(lon,zoom) { | |
| return (Math.floor((lon+180)/360*Math.pow(2,zoom))) | |
| } | |
| function lat2tile(lat,zoom) { | |
| return (Math.floor((1-Math.log(Math.tan(lat*Math.PI/180) + 1/Math.cos(lat*Math.PI/180))/Math.PI)/2 *Math.pow(2,zoom))) | |
| } | |
| async function downloadTile(zoom, column, tile) { | |
| let row = await db.tiles.get({ |
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