/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.lucene.geo;
import org.apache.lucene.util.SloppyMath;
/** Draws shapes on the earth surface and renders using the very cool http://www.webglearth.org.
*
* Just instantiate this class, add the things you want plotted, and call {@link #finish} to get the
* resulting HTML that you should save and load with a browser. */
public class EarthDebugger {
final StringBuilder b = new StringBuilder();
private int nextShape;
private boolean finished;
public EarthDebugger() {
b.append("<!DOCTYPE HTML>\n");
b.append("<html>\n");
b.append(" <head>\n");
b.append(" <script src=\"http://www.webglearth.com/v2/api.js\"></script>\n");
b.append(" <script>\n");
b.append(" function initialize() {\n");
b.append(" var earth = new WE.map('earth_div');\n");
}
public EarthDebugger(double centerLat, double centerLon, double altitudeMeters) {
b.append("<!DOCTYPE HTML>\n");
b.append("<html>\n");
b.append(" <head>\n");
b.append(" <script src=\"http://www.webglearth.com/v2/api.js\"></script>\n");
b.append(" <script>\n");
b.append(" function initialize() {\n");
b.append(" var earth = new WE.map('earth_div', {center: [" + centerLat + ", " + centerLon + "], altitude: " + altitudeMeters + "});\n");
}
public void addPolygon(Polygon poly) {
addPolygon(poly, "#00ff00");
}
public void addPolygon(Polygon poly, String color) {
String name = "poly" + nextShape;
nextShape++;
b.append(" var " + name + " = WE.polygon([\n");
double[] polyLats = poly.getPolyLats();
double[] polyLons = poly.getPolyLons();
for(int i=0;i<polyLats.length;i++) {
b.append(" [" + polyLats[i] + ", " + polyLons[i] + "],\n");
}
b.append(" ], {color: '" + color + "', fillColor: \"#000000\", fillOpacity: 0.0001});\n");
b.append(" " + name + ".addTo(earth);\n");
for (Polygon hole : poly.getHoles()) {
addPolygon(hole, "#ffffff");
}
}
private static double MAX_KM_PER_STEP = 100.0;
// Web GL earth connects dots by tunneling under the earth, so we approximate a great circle by sampling it, to minimize how deep in the
// earth each segment tunnels:
private int getStepCount(double minLat, double maxLat, double minLon, double maxLon) {
double distanceMeters = SloppyMath.haversinMeters(minLat, minLon, maxLat, maxLon);
return Math.max(1, (int) Math.round((distanceMeters / 1000.0) / MAX_KM_PER_STEP));
}
// first point is inclusive, last point is exclusive!
private void drawSegment(double minLat, double maxLat, double minLon, double maxLon) {
int steps = getStepCount(minLat, maxLat, minLon, maxLon);
for(int i=0;i<steps;i++) {
b.append(" [" + (minLat + (maxLat - minLat) * i / steps) + ", " + (minLon + (maxLon - minLon) * i / steps) + "],\n");
}
}
public void addRect(double minLat, double maxLat, double minLon, double maxLon) {
addRect(minLat, maxLat, minLon, maxLon, "#ff0000");
}
public void addRect(double minLat, double maxLat, double minLon, double maxLon, String color) {
String name = "rect" + nextShape;
nextShape++;
b.append(" // lat: " + minLat + " TO " + maxLat + "; lon: " + minLon + " TO " + maxLon + "\n");
b.append(" var " + name + " = WE.polygon([\n");
b.append(" // min -> max lat, min lon\n");
drawSegment(minLat, maxLat, minLon, minLon);
b.append(" // max lat, min -> max lon\n");
drawSegment(maxLat, maxLat, minLon, maxLon);
b.append(" // max -> min lat, max lon\n");
drawSegment(maxLat, minLat, maxLon, maxLon);
b.append(" // min lat, max -> min lon\n");
drawSegment(minLat, minLat, maxLon, minLon);
b.append(" // min lat, min lon\n");
b.append(" [" + minLat + ", " + minLon + "]\n");
b.append(" ], {color: \"" + color + "\", fillColor: \"" + color + "\"});\n");
b.append(" " + name + ".addTo(earth);\n");
}
/** Draws a line a fixed latitude, spanning the min/max longitude */
public void addLatLine(double lat, double minLon, double maxLon) {
String name = "latline" + nextShape;
nextShape++;
b.append(" var " + name + " = WE.polygon([\n");
double lon;
int steps = getStepCount(lat, minLon, lat, maxLon);
for(lon = minLon;lon<=maxLon;lon += (maxLon-minLon)/steps) {
b.append(" [" + lat + ", " + lon + "],\n");
}
b.append(" [" + lat + ", " + maxLon + "],\n");
lon -= (maxLon-minLon)/steps;
for(;lon>=minLon;lon -= (maxLon-minLon)/steps) {
b.append(" [" + lat + ", " + lon + "],\n");
}
b.append(" ], {color: \"#ff0000\", fillColor: \"#ffffff\", opacity: 1, fillOpacity: 0.0001});\n");
b.append(" " + name + ".addTo(earth);\n");
}
/** Draws a line a fixed longitude, spanning the min/max latitude */
public void addLonLine(double minLat, double maxLat, double lon) {
String name = "lonline" + nextShape;
nextShape++;
b.append(" var " + name + " = WE.polygon([\n");
double lat;
int steps = getStepCount(minLat, lon, maxLat, lon);
for(lat = minLat;lat<=maxLat;lat += (maxLat-minLat)/steps) {
b.append(" [" + lat + ", " + lon + "],\n");
}
b.append(" [" + maxLat + ", " + lon + "],\n");
lat -= (maxLat-minLat)/36;
for(;lat>=minLat;lat -= (maxLat-minLat)/steps) {
b.append(" [" + lat + ", " + lon + "],\n");
}
b.append(" ], {color: \"#ff0000\", fillColor: \"#ffffff\", opacity: 1, fillOpacity: 0.0001});\n");
b.append(" " + name + ".addTo(earth);\n");
}
public void addPoint(double lat, double lon) {
b.append(" WE.marker([" + lat + ", " + lon + "]).addTo(earth);\n");
}
public void addCircle(double centerLat, double centerLon, double radiusMeters, boolean alsoAddBBox) {
addPoint(centerLat, centerLon);
String name = "circle" + nextShape;
nextShape++;
b.append(" var " + name + " = WE.polygon([\n");
inverseHaversin(b, centerLat, centerLon, radiusMeters);
b.append(" ], {color: '#00ff00', fillColor: \"#000000\", fillOpacity: 0.0001 });\n");
b.append(" " + name + ".addTo(earth);\n");
if (alsoAddBBox) {
Rectangle box = Rectangle.fromPointDistance(centerLat, centerLon, radiusMeters);
addRect(box.minLat, box.maxLat, box.minLon, box.maxLon);
addLatLine(Rectangle.axisLat(centerLat, radiusMeters), box.minLon, box.maxLon);
}
}
public String finish() {
if (finished) {
throw new IllegalStateException("already finished");
}
finished = true;
b.append(" WE.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',{\n");
b.append(" attribution: '© OpenStreetMap contributors'\n");
b.append(" }).addTo(earth);\n");
b.append(" }\n");
b.append(" </script>\n");
b.append(" <style>\n");
b.append(" html, body{padding: 0; margin: 0;}\n");
b.append(" #earth_div{top: 0; right: 0; bottom: 0; left: 0; position: absolute !important;}\n");
b.append(" </style>\n");
b.append(" <title>WebGL Earth API: Hello World</title>\n");
b.append(" </head>\n");
b.append(" <body onload=\"initialize()\">\n");
b.append(" <div id=\"earth_div\"></div>\n");
b.append(" </body>\n");
b.append("</html>\n");
return b.toString();
}
private static void inverseHaversin(StringBuilder b, double centerLat, double centerLon, double radiusMeters) {
double angle = 0;
int steps = 100;
newAngle:
while (angle < 360) {
double x = Math.cos(SloppyMath.toRadians(angle));
double y = Math.sin(SloppyMath.toRadians(angle));
double factor = 2.0;
double step = 1.0;
int last = 0;
double lastDistanceMeters = 0.0;
//System.out.println("angle " + angle + " slope=" + slope);
while (true) {
double lat = wrapLat(centerLat + y * factor);
double lon = wrapLon(centerLon + x * factor);
double distanceMeters = SloppyMath.haversinMeters(centerLat, centerLon, lat, lon);
if (last == 1 && distanceMeters < lastDistanceMeters) {
// For large enough circles, some angles are not possible:
//System.out.println(" done: give up on angle " + angle);
angle += 360./steps;
continue newAngle;
}
if (last == -1 && distanceMeters > lastDistanceMeters) {
// For large enough circles, some angles are not possible:
//System.out.println(" done: give up on angle " + angle);
angle += 360./steps;
continue newAngle;
}
lastDistanceMeters = distanceMeters;
//System.out.println(" iter lat=" + lat + " lon=" + lon + " distance=" + distanceMeters + " vs " + radiusMeters);
if (Math.abs(distanceMeters - radiusMeters) < 0.1) {
b.append(" [" + lat + ", " + lon + "],\n");
break;
}
if (distanceMeters > radiusMeters) {
// too big
//System.out.println(" smaller");
factor -= step;
if (last == 1) {
//System.out.println(" half-step");
step /= 2.0;
}
last = -1;
} else if (distanceMeters < radiusMeters) {
// too small
//System.out.println(" bigger");
factor += step;
if (last == -1) {
//System.out.println(" half-step");
step /= 2.0;
}
last = 1;
}
}
angle += 360./steps;
}
}
// craziness for plotting stuff :)
private static double wrapLat(double lat) {
//System.out.println("wrapLat " + lat);
if (lat > 90) {
//System.out.println(" " + (180 - lat));
return 180 - lat;
} else if (lat < -90) {
//System.out.println(" " + (-180 - lat));
return -180 - lat;
} else {
//System.out.println(" " + lat);
return lat;
}
}
private static double wrapLon(double lon) {
//System.out.println("wrapLon " + lon);
if (lon > 180) {
//System.out.println(" " + (lon - 360));
return lon - 360;
} else if (lon < -180) {
//System.out.println(" " + (lon + 360));
return lon + 360;
} else {
//System.out.println(" " + lon);
return lon;
}
}
}