/* daylight.js JavaScript interface to the DaylightMap.com tile server Copyright 2006-8 Udell Enterprises, Inc Free for low-traffic use. For more than 20,000 hits/month, see price guide at www.daylightmap.com/services.php Instructions for use: First, add the following line to the section of your HTML: Then in your JavaScript, after initializing your version 2 Google Map (using a statement like map = new GMap2(document.getElementById('map'));), add the following two lines of code: var daylight = new daylightMap.daylightLayer(); daylight.addToMap(map); obviously, changing "map" to match your own GMap2 object name as needed. Note also that this needs to occur before the first call to map.setCenter() in your code. You can also add the daylight layer to a single map type (such as Satellite or Hybrid) if desired by using daylight.addToMapType(G_SATELLITE_MAP); instead of the addToMap method. Any valid GMapType should work as a parameter. The daylightLayer object has the following properties you may find useful: when Date/time of the daylight plot. Type: Date. Default: current date/time opacity Effectively, the "darkness" of the shadow, where 0 is fully transparent (and hence invisible) and 1 is fully opaque. Type: Numeric. Default: 0.5 for map view, 0.8 for satellite/hybrid active Whether the daylight layer is displayed when the map is redrawn. Type: Boolean. Default: true cityLights Whether city lights are displayed on the night side. Type: Boolean. Default: true */ var daylightMap = window.daylightMap || {}; daylightMap._nTileSize = 256; /* Note: GMaps does not support other tile sizes (as of v2.38, 2 Mar 06) */ daylightMap._maxZoom = 20; daylightMap._defaultMapOpacity = 0.5; daylightMap._defaultSatelliteOpacity = 0.75; daylightMap._nightMode = false; // Init the pixel/degree array daylightMap._pixelsPerLonDegree = []; do { daylightMap._pixelsPerLonDegree.push(daylightMap._nTileSize * Math.pow(2, daylightMap._pixelsPerLonDegree.length) / 360); } while (daylightMap._pixelsPerLonDegree.length < daylightMap._maxZoom); if (location.hostname == 'dev.daylightmap.com') daylightMap._serverDomain = 'http://dev.daylightmap.com/'; else daylightMap._serverDomain = 'http://www.daylightmap.com/'; daylightMap._clientTime = Number(new Date()); daylightMap._serverTime = daylightMap._clientTime; document.write(''); daylightMap._timeCorrection = 0; function roundTo(number, places) { // Rounds the given number to the specifed number of decimal places. // Note that this is similar to the JS numer.toFixed(), but will accept a negative places parm, // which some browsers will not for toFixed(). // // Examples: roundTo(3.1415926535, 4) = 3.1416 // roundTo(314159.26535, -4) = 310000 return Math.round(number * Math.pow(10, places)) / Math.pow(10, places); }; daylightMap.daylightLayer = function() { // daylightLayer object constructor this.map = null; // Set default values for major properties this.when = null; this.opacity = null; this.active = true; this.cityLights = null; // Internal properties this.lastZoom = -1; this.lastRefresh = null; // These properties are required by GMaps this.isPng = function() {return true}; this.projection = new GMercatorProjection(daylightMap._maxZoom); daylightMap._timeCorrection = (daylightMap._serverTime - daylightMap._clientTime); }; // Compatibility if (window.GMap2 && GMap2.length) // Looks like we're running in the main Maps API, not as a mapplet daylightMap.daylightLayer.prototype = new GTileLayer(new GCopyrightCollection(''), 0, daylightMap._maxZoom); if (!window.daylightLayer) // Backward compatibility with pre-namespace versions of DM window.daylightLayer = daylightMap.daylightLayer; // daylightLayer methods daylightMap.daylightLayer.prototype.setMap = function() { try { if (!this.map) this.map = map; // try for a commonly-named global var } catch (e) {} return this.map; }; daylightMap.daylightLayer.prototype.getCopyright = function(bounds, zoom) { var opacity = daylightMap._defaultMapOpacity; for (var i = 0; i < this.map.getMapTypes().length; i++) if (this.map.getMapTypes()[i].opacity) { opacity = this.map.getMapTypes()[i].opacity; break; } if ((this.map.getCurrentMapType() == G_SATELLITE_MAP) || (this.map.getCurrentMapType() == G_HYBRID_MAP) || (opacity > 0.5)) var copyright = 'DaylightMap'; else var copyright = 'DaylightMap'; // return copyright; //GMap v2.44- return {prefix: '', copyrightTexts:[copyright]}; //GMap v2.45+ }; daylightMap.daylightLayer.prototype.getOpacity = function() { if (this.opacity != null) // Opacity as been overridden to a specific value result = parseFloat(this.opacity); else { // Otherwise, default opacity is adaptive if (this.setMap()) { if ((this.map.getCurrentMapType() == G_SATELLITE_MAP) || (this.map.getCurrentMapType() == G_HYBRID_MAP)) result = daylightMap._defaultSatelliteOpacity; else result = daylightMap._defaultMapOpacity; } else { if (this.getCityLights()) result = daylightMap._defaultSatelliteOpacity; else result = (daylightMap._defaultSatelliteOpacity + daylightMap._defaultMapOpacity) / 2; } } return result.toPrecision(2); // there's no need for any greater precision than this }; daylightMap.daylightLayer.prototype.getCityLights = function(mapType) { if (this.cityLights == false) // City lights have been specifically turned off return false; else if (this.cityLights == true) // City lights have been specifically turned on return true; else { // Default cases if (!this.setMap()) return true; if (!mapType) mapType = this.map.getCurrentMapType(); if (daylightMap._nightMode) return true; else if ((this.map.getCurrentMapType() == G_SATELLITE_MAP) || (this.map.getCurrentMapType() == G_HYBRID_MAP)) // City lights default to on for satellite-based views return true; else // City lights default to off for map views return false; } }; daylightMap.daylightLayer.prototype.addToMap = function(newMap) { // Add the daylight layer to the supplied GMap2 object this.map = newMap; var types = this.map.getMapTypes(); for (var i = 0; i < types.length; i++) this.addToMapType(types[i]); }; daylightMap.daylightLayer.prototype.addToMapType = function(mapType) { // Add the daylight layer to a single map type (like G_SATELLITE_MAP) mapType.getTileLayers().splice(1, 0, this); if (this.getCityLights(mapType)) mapType.getMaximumResolution = function(){return 8;}; }; daylightMap.daylightLayer.prototype.refresh = function() { // Refresh the daylight layer // This Zoom kludge refreshes all map tiles if (this.setMap()) { this.lastZoom = -1; this.map.setZoom(this.map.getZoom()); } }; daylightMap.daylightLayer.prototype.getTileUrl = function(point, zoom) { // Interface to the tile server // tile_n_2_0_0_1178264700.png // night_4_1_8.png if (!this.active) return ''; if (daylightMap._nightMode) var tileName = 'tiles/night_png/night_'; else { var tileName = 'tiles/cache/tile_'; if (this.getCityLights()) tileName += 'n_'; } tileName += zoom + '_' + point.x + '_' + point.y; if (!daylightMap._nightMode) { // Establish the date/time to send if (this.when != null) var timestamp = this.when; else { if (zoom != this.lastZoom) { if (daylightMap._timeCorrection == 0) daylightMap._timeCorrection = (daylightMap._serverTime - daylightMap._clientTime); // Using current date/time - Round it to the nearest minute and correct to server time this.lastRefresh = new Date(60000 * ((Number(new Date()) + daylightMap._timeCorrection) / 60000).toFixed(0)); this.lastZoom = zoom; } var timestamp = this.lastRefresh; } // Use some rounding based on zoom level to improve caching of tiles timestamp = roundTo(Number(timestamp) / 1000, Math.min(0, zoom - 3)); tileName += '_' + timestamp; } tileName = daylightMap._serverDomain + tileName + '.png'; if (typeof _IG_GetImageUrl == 'function') return _IG_GetImageUrl(tileName); else return tileName; };