// 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.levelToTilesPerEdge = function(level) { var LEVEL_TO_TILES_PER_EDGE = [65536, 65536, 16384, 16384, 4096, 1536, 1024, 256, 32]; return LEVEL_TO_TILES_PER_EDGE[level]; } window.lngToTile = function(lng, level) { return Math.floor((lng + 180) / 360 * levelToTilesPerEdge(level)); } window.latToTile = function(lat, level) { return Math.floor((1 - Math.log(Math.tan(lat * Math.PI / 180) + 1 / Math.cos(lat * Math.PI / 180)) / Math.PI) / 2 * levelToTilesPerEdge(level)); } window.tileToLng = function(x, level) { return x / levelToTilesPerEdge(level) * 360 - 180; } window.tileToLat = function(y, level) { var n = Math.PI - 2 * Math.PI * y / levelToTilesPerEdge(level); return 180 / Math.PI * Math.atan(0.5 * (Math.exp(n) - Math.exp(-n))); } window.pointToTileId = function(level, x, y) { return level + "_" + 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) }; } window.getResonatorLatLng = function(dist, slot, portalLatLng) { // offset in meters var dn = dist*SLOT_TO_LAT[slot]; var de = dist*SLOT_TO_LNG[slot]; // Coordinate offset in radians var dLat = dn/EARTH_RADIUS; var dLon = de/(EARTH_RADIUS*Math.cos(Math.PI/180*portalLatLng[0])); // OffsetPosition, decimal degrees var lat0 = portalLatLng[0] + dLat * 180/Math.PI; var lon0 = portalLatLng[1] + dLon * 180/Math.PI; return [lat0, lon0]; }