Public
Edited
Jan 10
function sec(x) {
return 1 / Math.cos(x);
}
function lonlat_to_xyz(lon, lat, z) {
const tile_count = Math.pow(2, z);
const x = (lon + 180) / 360;
const y =
(1 - Math.log(Math.tan(radians(lat)) + sec(radians(lat))) / Math.PI) / 2;
return [Math.floor(tile_count * x), Math.floor(tile_count * y)];
}
function radians(degrees) {
return degrees * (Math.PI / 180);
}
function mercatorToLat(mercatorY) {
return Math.atan(Math.sinh(mercatorY)) * (180 / Math.PI);
}
function y_to_lat_edges(y, z) {
const tile_count = Math.pow(2, z);
const unit = 1 / tile_count;
const relative_y1 = y * unit;
const relative_y2 = relative_y1 + unit;
const lat1 = mercatorToLat(Math.PI * (1 - 2 * relative_y1));
const lat2 = mercatorToLat(Math.PI * (1 - 2 * relative_y2));
return [lat1, lat2];
}
function tile_edges(x, y, z) {
const lon = x_to_lon_edges(x, z);
const lat = y_to_lat_edges(y, z);
return [lon[0], lat[0], lon[1], lat[1]];
}
tile_edges(70424, 43017, 17)
bbox = [52.475411, 13.420666, 52.467127, 13.438159]
zoom = 18
topLeft = lonlat_to_xyz(bbox[1], bbox[0], zoom)
bottomRight = lonlat_to_xyz(bbox[3], bbox[2], zoom)
extent = {
const tl = tile_edges(...topLeft, zoom);
const br = tile_edges(...bottomRight, zoom);
return [br[3], tl[0], tl[1], br[2]];
}
url = 'https://tile.openstreetmap.org/{z}/{x}/{y}.png'
urls = {
const urls = [];
for (let x = topLeft[0]; x <= bottomRight[0]; ++x) {
for (let y = topLeft[1]; y <= bottomRight[1]; ++y) {
urls.push(url.replace("{z}", zoom).replace("{x}", x).replace("{y}", y));
}
}
return urls;
}
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