001// License: GPL. For details, see Readme.txt file. 002package org.openstreetmap.gui.jmapviewer.tilesources; 003 004import java.util.Random; 005 006import org.openstreetmap.gui.jmapviewer.OsmMercator; 007 008/** 009 * This tilesource uses different to OsmMercator projection. 010 * 011 * Earth is assumed an ellipsoid in this projection, unlike 012 * sphere in OsmMercator, so latitude calculation differs a lot. 013 * 014 * The longitude calculation is the same as in OsmMercator, 015 * we inherit it from AbstractTMSTileSource. 016 * 017 * TODO: correct getDistance() method. 018 */ 019public class ScanexTileSource extends TMSTileSource { 020 private static final String DEFAULT_URL = "http://maps.kosmosnimki.ru"; 021 private static final int DEFAULT_MAXZOOM = 14; 022 private static final String API_KEY = "4018C5A9AECAD8868ED5DEB2E41D09F7"; 023 024 // Latitude to Y and back calculations. 025 026 /** eccentricity of Earth's ellipsoid */ 027 private static double E = 0.0818191908426; 028 029 private enum ScanexLayer { 030 IRS("irs", "/TileSender.ashx?ModeKey=tile&MapName=F7B8CF651682420FA1749D894C8AD0F6&LayerName=BAC78D764F0443BD9AF93E7A998C9F5B"), 031 SPOT("spot", "/TileSender.ashx?ModeKey=tile&MapName=F7B8CF651682420FA1749D894C8AD0F6&LayerName=F51CE95441284AF6B2FC319B609C7DEC"); 032 033 private String name; 034 private String uri; 035 036 ScanexLayer(String name, String uri) { 037 this.name = name; 038 this.uri = uri; 039 } 040 041 public String getName() { 042 return name; 043 } 044 045 public String getUri() { 046 return uri; 047 } 048 } 049 050 /** IRS by default */ 051 private ScanexLayer layer = ScanexLayer.IRS; 052 053 /** cached latitude used in {@link #tileYToLat(double, int)} */ 054 private double cachedLat; 055 056 /** 057 * Constructs a new {@code ScanexTileSource}. 058 * @param info tile source info 059 */ 060 public ScanexTileSource(TileSourceInfo info) { 061 super(info); 062 String url = info.getUrl(); 063 064 for (ScanexLayer slayer : ScanexLayer.values()) { 065 if (url.equalsIgnoreCase(slayer.getName())) { 066 this.layer = slayer; 067 // Override baseUrl and maxZoom in base class. 068 this.baseUrl = DEFAULT_URL; 069 if (maxZoom == 0) 070 this.maxZoom = DEFAULT_MAXZOOM; 071 break; 072 } 073 } 074 } 075 076 @Override 077 public String getExtension() { 078 return "jpeg"; 079 } 080 081 @Override 082 public String getTilePath(int zoom, int tilex, int tiley) { 083 int tmp = (int) Math.pow(2.0, zoom - 1); 084 085 tilex = tilex - tmp; 086 tiley = tmp - tiley - 1; 087 088 return this.layer.getUri() + "&apikey=" + API_KEY + "&x=" + tilex + "&y=" + tiley + "&z=" + zoom; 089 } 090 091 /* 092 * To solve inverse formula latitude = f(y) we use 093 * Newton's method. We cache previous calculated latitude, 094 * because new one is usually close to the old one. In case 095 * if solution gets out of bounds, we reset to a new random value. 096 */ 097 private double tileYToLat(double y, int zoom) { 098 double lat0; 099 double lat = cachedLat; 100 do { 101 lat0 = lat; 102 lat = lat - Math.toDegrees(nextTerm(Math.toRadians(lat), y, zoom)); 103 if (lat > OsmMercator.MAX_LAT || lat < OsmMercator.MIN_LAT) { 104 Random r = new Random(); 105 lat = OsmMercator.MIN_LAT + 106 r.nextInt((int) (OsmMercator.MAX_LAT - OsmMercator.MIN_LAT)); 107 } 108 } while (Math.abs(lat0 - lat) > 0.000001); 109 110 cachedLat = lat; 111 112 return lat; 113 } 114 115 /* Next term in Newton's polynomial */ 116 private static double nextTerm(double lat, double y, int zoom) { 117 double sinl = Math.sin(lat); 118 double cosl = Math.cos(lat); 119 120 zoom = (int) Math.pow(2.0, zoom - 1); 121 double ec = Math.exp((1 - y/zoom)*Math.PI); 122 123 double f = Math.tan(Math.PI/4+lat/2) - 124 ec * Math.pow(Math.tan(Math.PI/4 + Math.asin(E * sinl)/2), E); 125 double df = 1/(1 - sinl) - ec * E * cosl/((1 - E * sinl) * 126 (Math.sqrt(1 - E * E * sinl * sinl))); 127 128 return f/df; 129 } 130}