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Find My Tiles: lat/long to zxy
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| <!DOCTYPE html> | |
| <html lang="en"> | |
| <head> | |
| <meta charset="utf-8" /> | |
| <title>Find My Tiles</title> | |
| <link rel="stylesheet" href="http://husk.org/collected.css"> | |
| </head> | |
| <body> | |
| <h1>Find My Tiles</h1> | |
| <p id="latitude">Finding your lat/long…</p> | |
| <ul id="zooms"> | |
| </ul> | |
| <script> | |
| function sec(aValue) { | |
| return 1/Math.cos(aValue); | |
| } | |
| Math.constructor.prototype.sec = sec; | |
| function getLocation() { | |
| if (location.hash) { | |
| coords = location.hash.split("/") | |
| lat = parseFloat(coords[0].substr(1)) | |
| lng = parseFloat(coords[1]) | |
| position = {'coords': {'latitude': lat, 'longitude': lng}} | |
| showTiles(position) | |
| } | |
| else if (navigator.geolocation) { | |
| navigator.geolocation.getCurrentPosition(showTiles); | |
| } else { | |
| alert("Your browser doesn't do geolocation, sorry."); | |
| } | |
| } | |
| function showTiles(position) { | |
| var zooms = document.getElementById('zooms'), | |
| latitude = document.getElementById('latitude'); | |
| longitude = document.getElementById('longitude'); | |
| lat_rad = position.coords.latitude * Math.PI/180 | |
| // http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#lon.2Flat_to_tile_numbers_2 | |
| for (var z=0; z<=21; z++) { | |
| n = Math.pow(2, z) | |
| x = Math.floor(n * ((position.coords.longitude + 180) / 360)) | |
| y = Math.floor(n * (1-(Math.log(Math.tan(lat_rad) + Math.sec(lat_rad)) / Math.PI))/2) | |
| var el = document.createElement('li') | |
| txt = document.createTextNode("ZXY: "+z+"/"+x+"/"+y) | |
| el.appendChild(txt) | |
| zooms.appendChild(el) | |
| } | |
| var txt = document.createTextNode('Your lat/long is ' + position.coords.latitude.toFixed(1) + '°, '+position.coords.longitude.toFixed(1)+ '°'); | |
| latitude.replaceChild(txt, latitude.firstChild); | |
| } | |
| getLocation() | |
| </script> | |
| </body> | |
| </html> |
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