WebSVN - mkgmap - Rev 2621 - /u/Liquet/main/src/uk/me/parabola/mkgmap/reader/osm/SeaGenerator.java

/*
* Copyright (C) 2010-2012.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 or
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
package uk.me.parabola.mkgmap.reader.osm;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.Set;
import java.util.TreeMap;
import java.util.regex.Pattern;
import java.util.zip.GZIPInputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import uk.me.parabola.imgfmt.FormatException;
import uk.me.parabola.imgfmt.MapFailedException;
import uk.me.parabola.imgfmt.Utils;
import uk.me.parabola.imgfmt.app.Area;
import uk.me.parabola.imgfmt.app.Coord;
import uk.me.parabola.log.Logger;
import uk.me.parabola.mkgmap.general.LineClipper;
import uk.me.parabola.mkgmap.general.LoadableMapDataSource;
import uk.me.parabola.mkgmap.osmstyle.StyleImpl;
import uk.me.parabola.mkgmap.reader.osm.xml.Osm5PrecompSeaDataSource;
import uk.me.parabola.util.EnhancedProperties;

/**
* Code to generate sea polygons from the coastline ways.
*
* Currently there are a number of different options.
* Should pick one that works well and make it the default.
*
*/
public class SeaGenerator extends OsmReadingHooksAdaptor {
private static final Logger log = Logger.getLogger(SeaGenerator.class);

private boolean generateSeaUsingMP = true;
private int maxCoastlineGap;
private boolean allowSeaSectors = true;
private boolean extendSeaSectors;
private String[] landTag = { "natural", "land" };
private boolean floodblocker;
private int fbGap = 40;
private double fbRatio = 0.5d;
private int fbThreshold = 20;
private boolean fbDebug;

private ElementSaver saver;

private List<Way> shoreline = new ArrayList<Way>();
private boolean roadsReachBoundary; // todo needs setting somehow
private boolean generateSeaBackground = true;

private String[] coastlineFilenames;
private StyleImpl fbRules;

/** The size (lat and long) of the precompiled sea tiles */
public final static int PRECOMP_RASTER = 1 << 15;

/**
* The directory of the precompiled sea tiles or <code>null</code> if
* precompiled sea should not be used.
*/
private File precompSeaDir;

private static final byte SEA_TILE = 's';
private static final byte LAND_TILE = 'l';
private static final byte MIXED_TILE = 'm';

private static ThreadLocal<PrecompData> precompIndex = new ThreadLocal<PrecompData>();

// useful constants defining the min/max map units of the precompiled sea tiles
private static final int MIN_LAT = Utils.toMapUnit(-90.0);
private static final int MAX_LAT = Utils.toMapUnit(90.0);
private static final int MIN_LON = Utils.toMapUnit(-180.0);
private static final int MAX_LON = Utils.toMapUnit(180.0);
private final static Pattern keySplitter = Pattern.compile(Pattern.quote("_"));

private static final List<Class<? extends LoadableMapDataSource>> precompSeaLoader;

static {
String[] sources = {
"uk.me.parabola.mkgmap.reader.osm.bin.OsmBinPrecompSeaDataSource",
// must be last as it is the default
"uk.me.parabola.mkgmap.reader.osm.xml.Osm5PrecompSeaDataSource", };

precompSeaLoader = new ArrayList<Class<? extends LoadableMapDataSource>>();

for (String source : sources) {
try {
@SuppressWarnings({ "unchecked" })
Class<? extends LoadableMapDataSource> c = (Class<? extends LoadableMapDataSource>) Class
.forName(source);
precompSeaLoader.add(c);
} catch (ClassNotFoundException e) {
// not available, try the rest
} catch (NoClassDefFoundError e) {
// not available, try the rest
}
}
}

/**
* Sort out options from the command line.
* Returns true only if the option to generate the sea is active, so that
* the whole thing is omitted if not used.
*/
public boolean init(ElementSaver saver, EnhancedProperties props) {
this.saver = saver;

String precompSea = props.getProperty("precomp-sea", null);
if (precompSea != null) {
precompSeaDir = new File(precompSea);
if (precompSeaDir.exists()){
if (precompIndex.get() == null) {
PrecompData precompData = null;
String internalPath = null;
InputStream indexStream = null;
String indexFileName = "index.txt.gz";
ZipFile zipFile = null;
try{
if (precompSeaDir.isDirectory()){
File indexFile = new File(precompSeaDir, indexFileName);
if (indexFile.exists() == false) {
// check if the unzipped index file exists
indexFileName = "index.txt";
indexFile = new File(precompSeaDir, indexFileName);
}
if (indexFile.exists()) {
indexStream = new FileInputStream(indexFile);
}
} else if (precompSea.endsWith(".zip")){
zipFile = new ZipFile(precompSeaDir);
internalPath = "sea";
ZipEntry entry = zipFile.getEntry(internalPath);
if (entry == null)
internalPath = "";
else
internalPath = internalPath + "/";
entry = zipFile.getEntry(internalPath + indexFileName);
if (entry == null){
indexFileName = "index.txt";
entry = zipFile.getEntry(internalPath + indexFileName);
}
if (entry != null){
indexStream = zipFile.getInputStream(entry);
}
} else {
log.error("Don't know how to read " + precompSeaDir);
}
if (indexStream != null){
if (indexFileName.endsWith(".gz")) {
indexStream = new GZIPInputStream(indexStream);
}
try{
precompData = loadIndex(indexStream);
} catch (IOException exp) {
log.error("Cannot read index file " + indexFileName,
exp);
}

if (precompData != null){
if (zipFile != null){
precompData.precompZipFileInternalPath = internalPath;
precompData.zipFile = zipFile;
}
precompIndex.set(precompData);
}
indexStream.close();
}
} catch (IOException exp) {
log.error("Cannot read index file " + indexFileName,
exp);

}
precompIndex.set(precompData);
}
} else {
log.error("Directory or zip file with precompiled sea does not exist: "
+ precompSea);
System.err.println("Directory or zip file with precompiled sea does not exist: "
+ precompSea);
precompSeaDir = null;
}
}
String gs = props.getProperty("generate-sea", null);
boolean generateSea = gs != null || precompSea != null;
if (gs != null) {
for(String o : gs.split(",")) {
if("no-mp".equals(o) ||
"polygon".equals(o) ||
"polygons".equals(o))
generateSeaUsingMP = false;
else if("multipolygon".equals(o))
generateSeaUsingMP = true;
else if(o.startsWith("land-tag="))
landTag = o.substring(9).split("=");
else if (precompSea == null) {
// the other options are valid only if not using precompiled sea data
if(o.startsWith("close-gaps="))
maxCoastlineGap = (int)Double.parseDouble(o.substring(11));
else if("no-sea-sectors".equals(o))
allowSeaSectors = false;
else if("extend-sea-sectors".equals(o)) {
allowSeaSectors = false;
extendSeaSectors = true;
}
else if("floodblocker".equals(o))
floodblocker = true;
else if(o.startsWith("fbgap="))
fbGap = (int)Double.parseDouble(o.substring("fbgap=".length()));
else if(o.startsWith("fbratio="))
fbRatio = Double.parseDouble(o.substring("fbratio=".length()));
else if(o.startsWith("fbthres="))
fbThreshold = (int)Double.parseDouble(o.substring("fbthres=".length()));
else if("fbdebug".equals(o))
fbDebug = true;
}
else if(o.isEmpty())
continue;
else {
if(!"help".equals(o))
System.err.println("Unknown sea generation option '" + o + "'");
System.err.println("Known sea generation options are:");
System.err.println(" multipolygon use a multipolygon (default)");
System.err.println(" polygons | no-mp use polygons rather than a multipolygon");
System.err.println(" no-sea-sectors disable use of \"sea sectors\"");
System.err.println(" extend-sea-sectors extend coastline to reach border");
System.err.println(" land-tag=TAG=VAL tag to use for land polygons (default natural=land)");
System.err.println(" close-gaps=NUM close gaps in coastline that are less than this distance (metres)");
System.err.println(" floodblocker enable the floodblocker (for multipolgon only)");
System.err.println(" fbgap=NUM points closer to the coastline are ignored for flood blocking (default 40)");
System.err.println(" fbthres=NUM min points contained in a polygon to be flood blocked (default 20)");
System.err.println(" fbratio=NUM min ratio (points/area size) for flood blocking (default 0.5)");
}
}

// init floodblocker and coastlinefile loader only
// if precompSea is not set
if (precompSea == null) {
if (floodblocker) {
try {
fbRules = new StyleImpl(null, "floodblocker");
} catch (FileNotFoundException e) {
log.error("Cannot load file floodblocker rules. Continue floodblocking disabled.");
floodblocker = false;
}
}

String coastlineFileOpt = props.getProperty("coastlinefile", null);
if (coastlineFileOpt != null) {
coastlineFilenames = coastlineFileOpt.split(",");
CoastlineFileLoader.getCoastlineLoader().setCoastlineFiles(
coastlineFilenames);
CoastlineFileLoader.getCoastlineLoader().loadCoastlines();
log.info("Coastlines loaded");
} else {
coastlineFilenames = null;
}
}
}

return generateSea;
}

/**
* Read the index from stream and populate the index grid.
* @param fileStream already opened stream
*/
private PrecompData loadIndex(InputStream fileStream) throws IOException{
int indexWidth = (SeaGenerator.getPrecompTileStart(MAX_LON) - SeaGenerator.getPrecompTileStart(MIN_LON)) / SeaGenerator.PRECOMP_RASTER;
int indexHeight = (SeaGenerator.getPrecompTileStart(MAX_LAT) - SeaGenerator.getPrecompTileStart(MIN_LAT)) / SeaGenerator.PRECOMP_RASTER;
PrecompData pi = null;
LineNumberReader indexReader = new LineNumberReader(
new InputStreamReader(fileStream));
Pattern csvSplitter = Pattern.compile(Pattern
.quote(";"));
String indexLine = null;

byte[][] indexGrid = new byte[indexWidth+1][indexHeight+1];
boolean detectExt = true;
String prefix = null;
String ext = null;

while ((indexLine = indexReader.readLine()) != null) {
if (indexLine.startsWith("#")) {
// comment
continue;
}
String[] items = csvSplitter.split(indexLine);
if (items.length != 2) {
log.warn("Invalid format in index file name:",
indexLine);
continue;
}
String precompKey = items[0];
byte type = updatePrecompSeaTileIndex(precompKey, items[1], indexGrid);
if (type == '?'){
log.warn("Invalid format in index file name:",
indexLine);
continue;
}
if (type == MIXED_TILE){
// make sure that all file names are using the same name scheme
int prePos = items[1].indexOf(items[0]);
if (prePos >= 0){
if (detectExt){
prefix = items[1].substring(0, prePos);
ext = items[1].substring(prePos+items[0].length());
detectExt = false;
} else {
StringBuilder sb = new StringBuilder(prefix);
sb.append(precompKey);
sb.append(ext);
if (items[1].equals(sb.toString()) == false){
log.warn("Unexpected file name in index file:",
indexLine);
}
}
}
}

}
//
pi = new PrecompData();
pi.precompIndex = indexGrid;
pi.precompSeaPrefix = prefix;
pi.precompSeaExt = ext;
return pi;
}

/**
* Retrieves the start value of the precompiled tile.
* @param value the value for which the start value is calculated
* @return the tile start value
*/
public static int getPrecompTileStart(int value) {
int rem = value % PRECOMP_RASTER;
if (rem == 0) {
return value;
} else if (value >= 0) {
return value - rem;
} else {
return value - PRECOMP_RASTER - rem;
}
}

/**
* Retrieves the end value of the precompiled tile.
* @param value the value for which the end value is calculated
* @return the tile end value
*/
public static int getPrecompTileEnd(int value) {
int rem = value % PRECOMP_RASTER;
if (rem == 0) {
return value;
} else if (value >= 0) {
return value + PRECOMP_RASTER - rem;
} else {
return value - rem;
}
}

public Set<String> getUsedTags() {
HashSet<String> usedTags = new HashSet<String>();
if (coastlineFilenames == null) {
usedTags.add("natural");
}
if (floodblocker) {
usedTags.addAll(fbRules.getUsedTags());
}

if (log.isDebugEnabled())
log.debug("Sea generator used tags: "+usedTags);

return usedTags;
}

/**
* Test to see if the way is part of the shoreline and if it is
* we save it.
* @param way The way to test.
*/
public void onAddWay(Way way) {
String natural = way.getTag("natural");
if(natural != null) {
if("coastline".equals(natural)) {
way.deleteTag("natural");
if (coastlineFilenames == null && precompSeaDir == null)
shoreline.add(way);

if (precompSeaDir != null) {
// add a copy of this way to be able to draw the coastline which is not possible with precompiled sea
Way coastlineWay = new Way(FakeIdGenerator.makeFakeId(), way.getPoints());
coastlineWay.addTag("natural", "coastline");
// tag that this way is used as line only
coastlineWay.addTag(MultiPolygonRelation.STYLE_FILTER_TAG, MultiPolygonRelation.STYLE_FILTER_LINE);
saver.addWay(coastlineWay);
}
} else if (natural.contains(";")) {
// cope with compound tag value
String others = null;
boolean foundCoastline = false;
for(String n : natural.split(";")) {
if("coastline".equals(n.trim()))
foundCoastline = true;
else if(others == null)
others = n;
else
others += ";" + n;
}

if(foundCoastline) {
way.deleteTag("natural");
if(others != null)
way.addTag("natural", others);
if (coastlineFilenames == null && precompSeaDir == null)
shoreline.add(way);

if (precompSeaDir != null) {
// add a copy of this way to be able to draw the coastline which is not possible with precompiled sea
Way coastlineWay = new Way(FakeIdGenerator.makeFakeId(), way.getPoints());
coastlineWay.addTag("natural", "coastline");
// tag that this way is used as line only
coastlineWay.addTag(MultiPolygonRelation.STYLE_FILTER_TAG, MultiPolygonRelation.STYLE_FILTER_LINE);
saver.addWay(coastlineWay);
}
}
}
}
}

/**
* Creates a reader for the given filename of the precomiled sea tile.
* @param filename precompiled sea tile
* @return the reader for the tile
*/
private static OsmMapDataSource createTileReader(String filename) {
for (Class<? extends LoadableMapDataSource> loader : precompSeaLoader) {
try {
LoadableMapDataSource src = loader.newInstance();
if (filename != null && src instanceof OsmMapDataSource
&& src.isFileSupported(filename))
return (OsmMapDataSource) src;
} catch (InstantiationException e) {
// try the next one.
} catch (IllegalAccessException e) {
// try the next one.
} catch (NoClassDefFoundError e) {
// try the next one
}
}

// Give up and assume it is in the XML format. If it isn't we will get
// an error soon enough anyway.
return new Osm5PrecompSeaDataSource();
}

/**
* Loads the precomp sea tile with the given filename.
* @param filename the filename of the precomp sea tile
* @return all ways of the tile
* @throws FileNotFoundException if the tile could not be found
*/
private Collection<Way> loadPrecompTile(InputStream is, String filename) {
OsmMapDataSource src = createTileReader(filename);
src.config(new EnhancedProperties());
log.info("Started loading coastlines from", filename);
try{
src.load(is);
} catch (FormatException e) {
log.error("Failed to read " + filename);
log.error(e);
}
log.info("Finished loading coastlines from", filename);
return src.getElementSaver().getWays().values();
}

/**
* Calculates the key names of the precompiled sea tiles for the bounding box.
* The key names are compiled of {@code lat+"_"+lon}.
* @return the key names for the bounding box
*/
private List<String> getPrecompKeyNames() {
Area bounds = saver.getBoundingBox();
List<String> precompKeys = new ArrayList<String>();
for (int lat = getPrecompTileStart(bounds.getMinLat()); lat < getPrecompTileEnd(bounds
.getMaxLat()); lat += PRECOMP_RASTER) {
for (int lon = getPrecompTileStart(bounds.getMinLong()); lon < getPrecompTileEnd(bounds
.getMaxLong()); lon += PRECOMP_RASTER) {
precompKeys.add(lat+"_"+lon);
}
}
return precompKeys;
}

/**
* Get the tile name from the index.
* @param precompKey The key name is compiled of {@code lat+"_"+lon}.
* @return either "land" or "sea" or a file name or null
*/
private String getTileName(String precompKey){
PrecompData pi = precompIndex.get();
String[] tileCoords = keySplitter.split(precompKey);
int lat = Integer.valueOf(tileCoords[0]);
int lon = Integer.valueOf(tileCoords[1]);
int latIndex = (MAX_LAT-lat) / PRECOMP_RASTER;
int lonIndex = (MAX_LON-lon) / PRECOMP_RASTER;
byte type = pi.precompIndex[lonIndex][latIndex];
switch (type){
case SEA_TILE: return "sea";
case LAND_TILE: return "land";
case MIXED_TILE: return pi.precompSeaPrefix + precompKey + pi.precompSeaExt;
default: return null;
}
}

/**
* Update the index grid for the element identified by precompKey.
* @param precompKey The key name is compiled of {@code lat+"_"+lon}.
* @param fileName either "land", "sea", or a file name containing OSM data
* @param indexGrid the previously allocated index grid
* @return the byte that was saved in the index grid
*/
private byte updatePrecompSeaTileIndex (String precompKey, String fileName, byte[][] indexGrid){
String[] tileCoords = keySplitter.split(precompKey);
byte type = '?';
if (tileCoords.length == 2){
int lat = Integer.valueOf(tileCoords[0]);
int lon = Integer.valueOf(tileCoords[1]);
int latIndex = (MAX_LAT - lat) / PRECOMP_RASTER;
int lonIndex = (MAX_LON - lon) / PRECOMP_RASTER;

if ("sea".equals(fileName))
type = SEA_TILE;
else if ("land".equals(fileName))
type = LAND_TILE;
else
type = MIXED_TILE;

indexGrid[lonIndex][latIndex] = type;
}
return type;
}

/**
* Loads the precompiled sea tiles and adds the data to the
* element saver.
*/
private void addPrecompSea() {
log.info("Load precompiled sea tiles");

// flag if all tiles contains sea or way only
// this is important for polygon processing
boolean distinctTilesOnly = true;

List<Way> landWays = new ArrayList<Way>();
List<Way> seaWays = new ArrayList<Way>();
// get the index with assignment key => sea/land/tilename

ZipFile zipFile = null;
PrecompData pd = precompIndex.get();
if (precompSeaDir.getName().endsWith(".zip")){
zipFile = pd.zipFile;
}

for (String precompKey : getPrecompKeyNames()) {
String tileName = getTileName(precompKey);

if (tileName == null ) {
log.error("Precompile sea tile "+precompKey+" is missing in the index. Skipping.");
continue;
}

if ("sea".equals(tileName) || "land".equals(tileName)) {
// the whole precompiled tile is filled with either land or sea
// => create a rectangle that covers the whole precompiled tile
Way w = new Way(FakeIdGenerator.makeFakeId());
w.addTag("natural", tileName);
String[] tileCoords = keySplitter.split(precompKey);
int minLat = Integer.valueOf(tileCoords[0]);
int minLon = Integer.valueOf(tileCoords[1]);
int maxLat = minLat + PRECOMP_RASTER;
int maxLon = minLon + PRECOMP_RASTER;
w.addPoint(new Coord(minLat,minLon));
w.addPoint(new Coord(minLat,maxLon));
w.addPoint(new Coord(maxLat,maxLon));
w.addPoint(new Coord(maxLat,minLon));
w.addPoint(new Coord(minLat,minLon));

if ("sea".equals(tileName)) {
seaWays.add(w);
} else {
landWays.add(w);
}

} else {
distinctTilesOnly = false;
try {
InputStream is = null;
if (zipFile != null){
ZipEntry entry = zipFile.getEntry(pd.precompZipFileInternalPath + tileName);
if (entry != null){
is = zipFile.getInputStream(entry);
} else {
log.error("Preompiled sea tile " + tileName + " not found.");
}
} else {
File precompTile = new File(precompSeaDir,tileName);
is = new FileInputStream(precompTile);
}
if (is != null){
Collection<Way> seaPrecompWays = loadPrecompTile(is, tileName);
if (log.isDebugEnabled())
log.debug(seaPrecompWays.size(), "precomp sea ways from",
tileName, "loaded.");

for (Way w : seaPrecompWays) {
// set a new id to be sure that the precompiled ids do not
// interfere with the ids of this run
w.setId(FakeIdGenerator.makeFakeId());

if ("land".equals(w.getTag("natural"))) {
landWays.add(w);
} else {
seaWays.add(w);
}
}
}
} catch (FileNotFoundException exp) {
log.error("Preompiled sea tile " + tileName + " not found.");
} catch (Exception exp) {
log.error(exp);
exp.printStackTrace();
}
}
}

// check if the land tags need to be changed
if (landTag != null && ("natural".equals(landTag[0]) && "land".equals(landTag[1])) == false) {
for (Way w : landWays) {
w.deleteTag("natural");
w.addTag(landTag[0], landTag[1]);
}
}

if (generateSeaUsingMP || distinctTilesOnly) {
// when using multipolygons use the data directly from the precomp files
// also with polygons if all tiles are using either sea or land only
for (Way w : landWays) {
saver.addWay(w);
}
for (Way w : seaWays) {
saver.addWay(w);
}
} else {
// using polygons

Area bounds = saver.getBoundingBox();
// first add the complete bounding box as sea
Way sea = new Way(FakeIdGenerator.makeFakeId());
sea.addPoint(new Coord(bounds.getMinLat(), bounds.getMinLong()));
sea.addPoint(new Coord(bounds.getMinLat(), bounds.getMaxLong()));
sea.addPoint(new Coord(bounds.getMaxLat(), bounds.getMaxLong()));
sea.addPoint(new Coord(bounds.getMaxLat(), bounds.getMinLong()));
sea.addPoint(new Coord(bounds.getMinLat(), bounds.getMinLong()));
sea.addTag("natural", "sea");

for (Way w : landWays) {
saver.addWay(w);
}
}
}

/**
* Joins the given segments to closed ways as good as possible.
* @param segments a list of closed and unclosed ways
* @return a list of ways completely joined
*/
public static ArrayList<Way> joinWays(Collection<Way> segments) {
ArrayList<Way> joined = new ArrayList<Way>((int)Math.ceil(segments.size()*0.5));
Map<Coord, Way> beginMap = new HashMap<Coord, Way>();

for (Way w : segments) {
if (w.isClosed()) {
joined.add(w);
} else if (w.getPoints() != null && w.getPoints().size() > 1){
List<Coord> points = w.getPoints();
beginMap.put(points.get(0), w);
} else {
log.info("Discard coastline way",w.getId(),"because consists of less than 2 points");
}
}
segments.clear();

int merged = 1;
while (merged > 0) {
merged = 0;
for (Way w1 : beginMap.values()) {
if (w1.isClosed()) {
// this should not happen
log.error("joinWays2: Way "+w1+" is closed but contained in the begin map");
joined.add(w1);
beginMap.remove(w1.getPoints().get(0));
merged=1;
break;
}

List<Coord> points1 = w1.getPoints();
Way w2 = beginMap.get(points1.get(points1.size() - 1));
if (w2 != null) {
log.info("merging: ", beginMap.size(), w1.getId(),
w2.getId());
List<Coord> points2 = w2.getPoints();
Way wm;
if (FakeIdGenerator.isFakeId(w1.getId())) {
wm = w1;
} else {
wm = new Way(FakeIdGenerator.makeFakeId());
wm.getPoints().addAll(points1);
beginMap.put(points1.get(0), wm);
}
wm.getPoints().addAll(points2.subList(1, points2.size()));
beginMap.remove(points2.get(0));
merged++;

if (wm.isClosed()) {
joined.add(wm);
beginMap.remove(wm.getPoints().get(0));
}
break;
}
}
}
log.info(joined.size(),"closed ways.",beginMap.size(),"unclosed ways.");
joined.addAll(beginMap.values());
return joined;
}

/**
* All done, process the saved shoreline information and construct the polygons.
*/
public void end() {
// precompiled sea has highest priority
// if it is set do not perform any other algorithm
if (precompSeaDir != null) {
addPrecompSea();
return;
}

Area seaBounds = saver.getBoundingBox();
if (coastlineFilenames == null) {
log.info("Shorelines before join", shoreline.size());
shoreline = joinWays(shoreline);
} else {
shoreline.addAll(CoastlineFileLoader.getCoastlineLoader()
.getCoastlines(seaBounds));
log.info("Shorelines from extra file:", shoreline.size());
}

int closedS = 0;
int unclosedS = 0;
for (Way w : shoreline) {
if (w.isClosed()) {
closedS++;
} else {
unclosedS++;
}
}
log.info("Closed shorelines", closedS);
log.info("Unclosed shorelines", unclosedS);

// clip all shoreline segments
clipShorlineSegments(shoreline, seaBounds);

log.info("generating sea, seaBounds=", seaBounds);
int minLat = seaBounds.getMinLat();
int maxLat = seaBounds.getMaxLat();
int minLong = seaBounds.getMinLong();
int maxLong = seaBounds.getMaxLong();
Coord nw = new Coord(minLat, minLong);
Coord ne = new Coord(minLat, maxLong);
Coord sw = new Coord(maxLat, minLong);
Coord se = new Coord(maxLat, maxLong);

if(shoreline.isEmpty()) {
// no sea required
// even though there is no sea, generate a land
// polygon so that the tile's background colour will
// match the land colour on the tiles that do contain
// some sea
long landId = FakeIdGenerator.makeFakeId();
Way land = new Way(landId);
land.addPoint(nw);
land.addPoint(sw);
land.addPoint(se);
land.addPoint(ne);
land.addPoint(nw);
land.addTag(landTag[0], landTag[1]);
// no matter if the multipolygon option is used it is
// only necessary to create a land polygon
saver.addWay(land);
// nothing more to do
return;
}

long multiId = FakeIdGenerator.makeFakeId();
Relation seaRelation = null;
if(generateSeaUsingMP) {
log.debug("Generate seabounds relation",multiId);
seaRelation = new GeneralRelation(multiId);
seaRelation.addTag("type", "multipolygon");
seaRelation.addTag("natural", "sea");
}

List<Way> islands = new ArrayList<Way>();

// handle islands (closed shoreline components) first (they're easy)
handleIslands(shoreline, seaBounds, islands);

// the remaining shoreline segments should intersect the boundary
// find the intersection points and store them in a SortedMap
NavigableMap<EdgeHit, Way> hitMap = findIntesectionPoints(shoreline, seaBounds, seaRelation);

// now construct inner ways from these segments
boolean shorelineReachesBoundary = createInnerWays(seaBounds, islands, hitMap);

if(!shorelineReachesBoundary && roadsReachBoundary) {
// try to avoid tiles being flooded by anti-lakes or other
// bogus uses of natural=coastline
generateSeaBackground = false;
}

List<Way> antiIslands = removeAntiIslands(seaRelation, islands);
if (islands.isEmpty()) {
// the tile doesn't contain any islands so we can assume
// that it's showing a land mass that contains some
// enclosed sea areas - in which case, we don't want a sea
// coloured background
generateSeaBackground = false;
}

if (generateSeaBackground) {
// the background is sea so all anti-islands should be
// contained by land otherwise they won't be visible

for (Way ai : antiIslands) {
boolean containedByLand = false;
for(Way i : islands) {
if(i.containsPointsOf(ai)) {
containedByLand = true;
break;
}
}

if (!containedByLand) {
// found an anti-island that is not contained by
// land so convert it back into an island
ai.deleteTag("natural");
ai.addTag(landTag[0], landTag[1]);
if (generateSeaUsingMP) {
// create a "inner" way for the island
assert seaRelation != null;
seaRelation.addElement("inner", ai);
}
log.warn("Converting anti-island starting at", ai.getPoints().get(0).toOSMURL() , "into an island as it is surrounded by water");
}
}

long seaId = FakeIdGenerator.makeFakeId();
Way sea = new Way(seaId);
// the sea background area must be a little bigger than all
// inner land areas. this is a workaround for a mp shortcoming:
// mp is not able to combine outer and inner if they intersect
// or have overlaying lines
// the added area will be clipped later by the style generator
sea.addPoint(new Coord(nw.getLatitude() - 1,
nw.getLongitude() - 1));
sea.addPoint(new Coord(sw.getLatitude() + 1,
sw.getLongitude() - 1));
sea.addPoint(new Coord(se.getLatitude() + 1,
se.getLongitude() + 1));
sea.addPoint(new Coord(ne.getLatitude() - 1,
ne.getLongitude() + 1));
sea.addPoint(new Coord(nw.getLatitude() - 1,
nw.getLongitude() - 1));
sea.addTag("natural", "sea");

log.info("sea: ", sea);
saver.addWay(sea);
if(generateSeaUsingMP) {
assert seaRelation != null;
seaRelation.addElement("outer", sea);
}
} else {
// background is land

// generate a land polygon so that the tile's
// background colour will match the land colour on the
// tiles that do contain some sea
long landId = FakeIdGenerator.makeFakeId();
Way land = new Way(landId);
land.addPoint(nw);
land.addPoint(sw);
land.addPoint(se);
land.addPoint(ne);
land.addPoint(nw);
land.addTag(landTag[0], landTag[1]);
saver.addWay(land);
if (generateSeaUsingMP) {
seaRelation.addElement("inner", land);
}
}

if (generateSeaUsingMP) {
SeaPolygonRelation coastRel = saver.createSeaPolyRelation(seaRelation);
coastRel.setFloodBlocker(floodblocker);
if (floodblocker) {
coastRel.setFloodBlockerGap(fbGap);
coastRel.setFloodBlockerRatio(fbRatio);
coastRel.setFloodBlockerThreshold(fbThreshold);
coastRel.setFloodBlockerRules(fbRules.getWayRules());
coastRel.setLandTag(landTag[0], landTag[1]);
coastRel.setDebug(fbDebug);
}
saver.addRelation(coastRel);
}

shoreline = null;
}

/**
* Clip the shoreline ways to the bounding box of the map.
* @param shoreline All the the ways making up the coast.
* @param bounds The map bounds.
*/
private void clipShorlineSegments(List<Way> shoreline, Area bounds) {
List<Way> toBeRemoved = new ArrayList<Way>();
List<Way> toBeAdded = new ArrayList<Way>();
for (Way segment : shoreline) {
List<Coord> points = segment.getPoints();
List<List<Coord>> clipped = LineClipper.clip(bounds, points);
if (clipped != null) {
log.info("clipping", segment);
toBeRemoved.add(segment);
for (List<Coord> pts : clipped) {
long id = FakeIdGenerator.makeFakeId();
Way shore = new Way(id, pts);
toBeAdded.add(shore);
}
}
}

log.info("clipping: adding", toBeAdded.size(), ", removing", toBeRemoved.size());
shoreline.removeAll(toBeRemoved);
shoreline.addAll(toBeAdded);
}

/**
* Pick out the islands and save them for later. They are removed from the
* shore line list and added to the island list.
*
* @param shoreline The collected shore line ways.
* @param seaBounds The map boundary.
* @param islands The islands are saved to this list.
*/
private void handleIslands(List<Way> shoreline, Area seaBounds, List<Way> islands) {
Iterator<Way> it = shoreline.iterator();
while (it.hasNext()) {
Way w = it.next();
if (w.isClosed()) {
log.info("adding island", w);
islands.add(w);
it.remove();
}
}

closeGaps(shoreline, seaBounds);
// there may be more islands now
it = shoreline.iterator();
while (it.hasNext()) {
Way w = it.next();
if (w.isClosed()) {
log.debug("island after concatenating");
islands.add(w);
it.remove();
}
}
}

private boolean createInnerWays(Area seaBounds, List<Way> islands, NavigableMap<EdgeHit, Way> hitMap) {
NavigableSet<EdgeHit> hits = hitMap.navigableKeySet();
boolean shorelineReachesBoundary = false;
while (!hits.isEmpty()) {
long id = FakeIdGenerator.makeFakeId();
Way w = new Way(id);
saver.addWay(w);

EdgeHit hit = hits.first();
EdgeHit hFirst = hit;
do {
Way segment = hitMap.get(hit);
log.info("current hit:", hit);
EdgeHit hNext;
if (segment != null) {
// add the segment and get the "ending hit"
log.info("adding:", segment);
for(Coord p : segment.getPoints())
w.addPointIfNotEqualToLastPoint(p);
hNext = getEdgeHit(seaBounds, segment.getPoints().get(segment.getPoints().size()-1));
} else {
w.addPointIfNotEqualToLastPoint(hit.getPoint(seaBounds));
hNext = hits.higher(hit);
if (hNext == null)
hNext = hFirst;

Coord p;
if (hit.compareTo(hNext) < 0) {
log.info("joining: ", hit, hNext);
for (int i=hit.edge; i<hNext.edge; i++) {
EdgeHit corner = new EdgeHit(i, 1.0);
p = corner.getPoint(seaBounds);
log.debug("way: ", corner, p);
w.addPointIfNotEqualToLastPoint(p);
}
} else if (hit.compareTo(hNext) > 0) {
log.info("joining: ", hit, hNext);
for (int i=hit.edge; i<4; i++) {
EdgeHit corner = new EdgeHit(i, 1.0);
p = corner.getPoint(seaBounds);
log.debug("way: ", corner, p);
w.addPointIfNotEqualToLastPoint(p);
}
for (int i=0; i<hNext.edge; i++) {
EdgeHit corner = new EdgeHit(i, 1.0);
p = corner.getPoint(seaBounds);
log.debug("way: ", corner, p);
w.addPointIfNotEqualToLastPoint(p);
}
}
w.addPointIfNotEqualToLastPoint(hNext.getPoint(seaBounds));
}
hits.remove(hit);
hit = hNext;
} while (!hits.isEmpty() && !hit.equals(hFirst));

if (!w.isClosed())
w.getPoints().add(w.getPoints().get(0));
log.info("adding non-island landmass, hits.size()=" + hits.size());
islands.add(w);
shorelineReachesBoundary = true;
}
return shorelineReachesBoundary;
}

/**
* An 'anti-island' is something that has been detected as an island, but the water
* is on the inside. I think you would call this a lake.
* @param seaRelation The relation holding the sea. Only set if we are using multi-polygons for
* the sea.
* @param islands The island list that was found earlier.
* @return The so-called anti-islands.
*/
private List<Way> removeAntiIslands(Relation seaRelation, List<Way> islands) {
List<Way> antiIslands = new ArrayList<Way>();
for (Way w : islands) {

if (!FakeIdGenerator.isFakeId(w.getId())) {
Way w1 = new Way(FakeIdGenerator.makeFakeId());
w1.getPoints().addAll(w.getPoints());
// only copy the name tags
for(String tag : w)
if(tag.equals("name") || tag.endsWith(":name"))
w1.addTag(tag, w.getTag(tag));
w = w1;
}

// determine where the water is
if (Way.clockwise(w.getPoints())) {
// water on the inside of the poly, it's an
// "anti-island" so tag with natural=water (to
// make it visible above the land)
w.addTag("natural", "water");
antiIslands.add(w);
saver.addWay(w);
} else {
// water on the outside of the poly, it's an island
w.addTag(landTag[0], landTag[1]);
saver.addWay(w);
if(generateSeaUsingMP) {
// create a "inner" way for each island
seaRelation.addElement("inner", w);
}
}
}

islands.removeAll(antiIslands);
return antiIslands;
}

/**
* Find the points where the remaining shore line segments intersect with the
* map boundary.
*
* @param shoreline The remaining shore line segments.
* @param seaBounds The map boundary.
* @param seaRelation If we are using a multi-polygon, this is it. Otherwise it will be null.
* @return A map of the 'hits' where the shore line intersects the boundary.
*/
private NavigableMap<EdgeHit, Way> findIntesectionPoints(List<Way> shoreline, Area seaBounds, Relation seaRelation) {
assert !generateSeaUsingMP || seaRelation != null;

NavigableMap<EdgeHit, Way> hitMap = new TreeMap<EdgeHit, Way>();
for (Way w : shoreline) {
List<Coord> points = w.getPoints();
Coord pStart = points.get(0);
Coord pEnd = points.get(points.size()-1);

EdgeHit hStart = getEdgeHit(seaBounds, pStart);
EdgeHit hEnd = getEdgeHit(seaBounds, pEnd);
if (hStart == null || hEnd == null) {

/*
* This problem occurs usually when the shoreline is cut by osmosis (e.g. country-extracts from geofabrik)
* There are two possibilities to solve this problem:
* 1. Close the way and treat it as an island. This is sometimes the best solution (Germany: Usedom at the
* border to Poland)
* 2. Create a "sea sector" only for this shoreline segment. This may also be the best solution
* (see German border to the Netherlands where the shoreline continues in the Netherlands)
* The first choice may lead to "flooded" areas, the second may lead to "triangles".
*
* Usually, the first choice is appropriate if the segment is "nearly" closed.
*/
double length = 0;
Coord p0 = pStart;
for (Coord p1 : points.subList(1, points.size()-1)) {
length += p0.distance(p1);
p0 = p1;
}
boolean nearlyClosed = pStart.distance(pEnd) < 0.1 * length;

if (nearlyClosed) {
// close the way
points.add(pStart);

if(!FakeIdGenerator.isFakeId(w.getId())) {
Way w1 = new Way(FakeIdGenerator.makeFakeId());
w1.getPoints().addAll(w.getPoints());
// only copy the name tags
for(String tag : w)
if(tag.equals("name") || tag.endsWith(":name"))
w1.addTag(tag, w.getTag(tag));
w = w1;
}
w.addTag(landTag[0], landTag[1]);
saver.addWay(w);
if(generateSeaUsingMP)
{
seaRelation.addElement("inner", w);
}
} else if(allowSeaSectors) {
long seaId = FakeIdGenerator.makeFakeId();
Way sea = new Way(seaId);
sea.getPoints().addAll(points);
sea.addPoint(new Coord(pEnd.getLatitude(), pStart.getLongitude()));
sea.addPoint(pStart);
sea.addTag("natural", "sea");
log.info("sea: ", sea);
saver.addWay(sea);
if(generateSeaUsingMP)
seaRelation.addElement("outer", sea);
generateSeaBackground = false;
} else if (extendSeaSectors) {
// create additional points at next border to prevent triangles from point 2
if (null == hStart) {
hStart = getNextEdgeHit(seaBounds, pStart);
w.getPoints().add(0, hStart.getPoint(seaBounds));
}
if (null == hEnd) {
hEnd = getNextEdgeHit(seaBounds, pEnd);
w.getPoints().add(hEnd.getPoint(seaBounds));
}
log.debug("hits (second try): ", hStart, hEnd);
hitMap.put(hStart, w);
hitMap.put(hEnd, null);
} else {
// show the coastline even though we can't produce
// a polygon for the land
w.addTag("natural", "coastline");
saver.addWay(w);
}
} else {
log.debug("hits: ", hStart, hEnd);
hitMap.put(hStart, w);
hitMap.put(hEnd, null);
}
}
return hitMap;
}

/**
* Specifies where an edge of the bounding box is hit.
*/
private static class EdgeHit implements Comparable<EdgeHit>
{
private final int edge;
private final double t;

EdgeHit(int edge, double t) {
this.edge = edge;
this.t = t;
}

public int compareTo(EdgeHit o) {
if (edge < o.edge)
return -1;
else if (edge > o.edge)
return +1;
else if (t > o.t)
return +1;
else if (t < o.t)
return -1;
else
return 0;
}

public boolean equals(Object o) {
if (o instanceof EdgeHit) {
EdgeHit h = (EdgeHit) o;
return (h.edge == edge && Double.compare(h.t, t) == 0);
} else
return false;
}

private Coord getPoint(Area a) {
log.info("getPoint: ", this, a);
switch (edge) {
case 0:
return new Coord(a.getMinLat(), (int) (a.getMinLong() + t * (a.getMaxLong()-a.getMinLong())));

case 1:
return new Coord((int)(a.getMinLat() + t * (a.getMaxLat()-a.getMinLat())), a.getMaxLong());

case 2:
return new Coord(a.getMaxLat(), (int)(a.getMaxLong() - t * (a.getMaxLong()-a.getMinLong())));

case 3:
return new Coord((int)(a.getMaxLat() - t * (a.getMaxLat()-a.getMinLat())), a.getMinLong());

default:
throw new MapFailedException("illegal state");
}
}

public String toString() {
return "EdgeHit " + edge + "@" + t;
}
}

private EdgeHit getEdgeHit(Area a, Coord p) {
return getEdgeHit(a, p, 10);
}

private EdgeHit getEdgeHit(Area a, Coord p, int tolerance) {
int lat = p.getLatitude();
int lon = p.getLongitude();
int minLat = a.getMinLat();
int maxLat = a.getMaxLat();
int minLong = a.getMinLong();
int maxLong = a.getMaxLong();

log.info(String.format("getEdgeHit: (%d %d) (%d %d %d %d)", lat, lon, minLat, minLong, maxLat, maxLong));
if (lat <= minLat+tolerance) {
return new EdgeHit(0, ((double)(lon - minLong))/(maxLong-minLong));
} else if (lon >= maxLong-tolerance) {
return new EdgeHit(1, ((double)(lat - minLat))/(maxLat-minLat));
} else if (lat >= maxLat-tolerance) {
return new EdgeHit(2, ((double)(maxLong - lon))/(maxLong-minLong));
} else if (lon <= minLong+tolerance) {
return new EdgeHit(3, ((double)(maxLat - lat))/(maxLat-minLat));
} else
return null;
}

/**
* Find the nearest edge for supplied Coord p.
*/
private EdgeHit getNextEdgeHit(Area a, Coord p)
{
int lat = p.getLatitude();
int lon = p.getLongitude();
int minLat = a.getMinLat();
int maxLat = a.getMaxLat();
int minLong = a.getMinLong();
int maxLong = a.getMaxLong();

log.info(String.format("getNextEdgeHit: (%d %d) (%d %d %d %d)", lat, lon, minLat, minLong, maxLat, maxLong));
// shortest distance to border (init with distance to southern border)
int min = lat - minLat;
// number of edge as used in getEdgeHit.
// 0 = southern
// 1 = eastern
// 2 = northern
// 3 = western edge of Area a
int i = 0;
// normalized position at border (0..1)
double l = ((double)(lon - minLong))/(maxLong-minLong);
// now compare distance to eastern border with already known distance
if (maxLong - lon < min) {
// update data if distance is shorter
min = maxLong - lon;
i = 1;
l = ((double)(lat - minLat))/(maxLat-minLat);
}
// same for northern border
if (maxLat - lat < min) {
min = maxLat - lat;
i = 2;
l = ((double)(maxLong - lon))/(maxLong-minLong);
}
// same for western border
if (lon - minLong < min) {
i = 3;
l = ((double)(maxLat - lat))/(maxLat-minLat);
}
// now created the EdgeHit for found values
return new EdgeHit(i, l);
}

private void closeGaps(List<Way> ways, Area bounds) {

// join up coastline segments whose end points are less than
// maxCoastlineGap metres apart
if (maxCoastlineGap > 0) {
boolean changed = true;
while (changed) {
changed = false;
for (Way w1 : ways) {
if(w1.isClosed())
continue;
List<Coord> points1 = w1.getPoints();
Coord w1e = points1.get(points1.size() - 1);
if(bounds.onBoundary(w1e))
continue;
Way nearest = null;
double smallestGap = Double.MAX_VALUE;
for (Way w2 : ways) {
if(w1 == w2 || w2.isClosed())
continue;
List<Coord> points2 = w2.getPoints();
Coord w2s = points2.get(0);
if(bounds.onBoundary(w2s))
continue;
double gap = w1e.distance(w2s);
if(gap < smallestGap) {
nearest = w2;
smallestGap = gap;
}
}
if (nearest != null && smallestGap < maxCoastlineGap) {
Coord w2s = nearest.getPoints().get(0);
log.warn("Bridging " + (int)smallestGap + "m gap in coastline from " + w1e.toOSMURL() + " to " + w2s.toOSMURL());
Way wm;
if (FakeIdGenerator.isFakeId(w1.getId())) {
wm = w1;
} else {
wm = new Way(FakeIdGenerator.makeFakeId());
ways.remove(w1);
ways.add(wm);
wm.getPoints().addAll(points1);
wm.copyTags(w1);
}
wm.getPoints().addAll(nearest.getPoints());
ways.remove(nearest);
// make a line that shows the filled gap
Way w = new Way(FakeIdGenerator.makeFakeId());
w.addTag("natural", "mkgmap:coastline-gap");
w.addPoint(w1e);
w.addPoint(w2s);
saver.addWay(w);
changed = true;
break;
}
}
}
}
}

/**
* Helper class for threadlocal vars
*
*
*/
class PrecompData {
/**
* The index is a grid [lon][lat]. Each element defines the content of one precompiled
* sea tile which are {@link #SEA_TYPE}, {@link #LAND_TYPE}, or {@link #MIXED_TYPE}, or 0 for unknown
*/
private byte[][] precompIndex;
private String precompSeaExt;
private String precompSeaPrefix;
private String precompZipFileInternalPath;
private ZipFile zipFile;

}
}

Subversion Repositories mkgmap

(root)/u/Liquet/main/src/uk/me/parabola/mkgmap/reader/osm/SeaGenerator.java - Rev 2621