46 lines
1.5 KiB
JavaScript
46 lines
1.5 KiB
JavaScript
// MAP DATA REQUEST CALCULATORS //////////////////////////////////////
|
|
// Ingress Intel splits up requests for map data (portals, links,
|
|
// fields) into tiles. To get data for the current viewport (i.e. what
|
|
// is currently visible) it first calculates which tiles intersect.
|
|
// For all those tiles, it then calculates the lat/lng bounds of that
|
|
// tile and a quadkey. Both the bounds and the quadkey are “somewhat”
|
|
// required to get complete data.
|
|
//
|
|
// Convertion functions courtesy of
|
|
// http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
|
|
|
|
window.lngToTile = function(lng, zoom) {
|
|
return Math.floor((lng + 180) / 360 * Math.pow(2, zoom));
|
|
}
|
|
|
|
window.latToTile = function(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));
|
|
}
|
|
|
|
window.tileToLng = function(x, zoom) {
|
|
return x / Math.pow(2, zoom) * 360 - 180;
|
|
}
|
|
|
|
window.tileToLat = function(y, zoom) {
|
|
var n = Math.PI - 2 * Math.PI * y / Math.pow(2, zoom);
|
|
return 180 / Math.PI * Math.atan(0.5 * (Math.exp(n) - Math.exp(-n)));
|
|
}
|
|
|
|
window.pointToTileId = function(zoom, x, y) {
|
|
return zoom + "_" + x + "_" + y;
|
|
}
|
|
|
|
// given tile id and bounds, returns the format as required by the
|
|
// Ingress API to request map data.
|
|
window.generateBoundsParams = function(tile_id, minLat, minLng, maxLat, maxLng) {
|
|
return {
|
|
id: tile_id,
|
|
qk: tile_id,
|
|
minLatE6: Math.round(minLat * 1E6),
|
|
minLngE6: Math.round(minLng * 1E6),
|
|
maxLatE6: Math.round(maxLat * 1E6),
|
|
maxLngE6: Math.round(maxLng * 1E6)
|
|
};
|
|
}
|