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Merge pull request #48 from phanecak-maptiler/ne_lake_with_osm_id
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NE lakes with OSM IDs
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@phanecak-maptiler
phanecak-maptiler authored Mar 28, 2024
2 parents c04b0aa + af13750 commit ea95a6c
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Showing 2 changed files with 273 additions and 53 deletions.
200 changes: 190 additions & 10 deletions src/main/java/org/openmaptiles/layers/Water.java
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Original file line number Diff line number Diff line change
Expand Up @@ -42,10 +42,20 @@ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
import com.onthegomap.planetiler.config.PlanetilerConfig;
import com.onthegomap.planetiler.expression.MultiExpression;
import com.onthegomap.planetiler.geo.GeometryException;
import com.onthegomap.planetiler.reader.SimpleFeature;
import com.onthegomap.planetiler.reader.SourceFeature;
import com.onthegomap.planetiler.stats.Stats;
import com.onthegomap.planetiler.util.Translations;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Consumer;
import org.locationtech.jts.geom.Envelope;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.TopologyException;
import org.locationtech.jts.geom.util.GeometryFixer;
import org.locationtech.jts.index.strtree.STRtree;
import org.openmaptiles.OpenMapTilesProfile;
import org.openmaptiles.generated.OpenMapTilesSchema;
import org.openmaptiles.generated.Tables;
Expand All @@ -62,7 +72,8 @@ public class Water implements
Tables.OsmWaterPolygon.Handler,
OpenMapTilesProfile.NaturalEarthProcessor,
OpenMapTilesProfile.OsmWaterPolygonProcessor,
ForwardingProfile.FeaturePostProcessor {
ForwardingProfile.FeaturePostProcessor,
OpenMapTilesProfile.FinishHandler {

/*
* At low zoom levels, use natural earth for oceans and major lakes, and at high zoom levels
Expand All @@ -71,12 +82,21 @@ public class Water implements
* which infers ocean polygons by preprocessing all coastline elements.
*/

// smallest NE lake is around 4.42E-13, smallest matching OSM lake is 9.34E-13, this is slightly bellow that
// and approx. 33% of OSM features are smaller than this, hence to save some CPU cycles:
private static final double OSM_ID_MATCH_AREA_LIMIT = Math.pow(4, -20);

private final MultiExpression.Index<String> classMapping;
private final PlanetilerConfig config;
private final Stats stats;
private final Map<String, STRtree> neLakeIndexes = new ConcurrentHashMap<>();
private final Map<String, Map<String, LakeInfo>> neLakeNameMaps = new ConcurrentHashMap<>();
private final List<LakeInfo> neAllLakeInfos = new ArrayList<>();

public Water(Translations translations, PlanetilerConfig config, Stats stats) {
this.classMapping = FieldMappings.Class.index();
this.config = config;
this.stats = stats;
}

@Override
Expand All @@ -86,21 +106,57 @@ record WaterInfo(int minZoom, int maxZoom, String clazz) {}
case "ne_110m_ocean" -> new WaterInfo(0, 1, FieldValues.CLASS_OCEAN);
case "ne_50m_ocean" -> new WaterInfo(2, 4, FieldValues.CLASS_OCEAN);
case "ne_10m_ocean" -> new WaterInfo(5, 5, FieldValues.CLASS_OCEAN);

// TODO: get OSM ID from low-zoom natural earth lakes
case "ne_110m_lakes" -> new WaterInfo(0, 1, FieldValues.CLASS_LAKE);
case "ne_50m_lakes" -> new WaterInfo(2, 3, FieldValues.CLASS_LAKE);
case "ne_10m_lakes" -> new WaterInfo(4, 5, FieldValues.CLASS_LAKE);
default -> null;
};
if (info != null) {
features.polygon(LAYER_NAME)
.setBufferPixels(BUFFER_SIZE)
.setZoomRange(info.minZoom, info.maxZoom)
.setAttr(Fields.CLASS, info.clazz);
setupNeWaterFeature(features, info.minZoom, info.maxZoom, info.clazz, null);
return;
}

LakeInfo lakeInfo = switch (table) {
case "ne_110m_lakes" -> new LakeInfo(0, 1, FieldValues.CLASS_LAKE);
case "ne_50m_lakes" -> new LakeInfo(2, 3, FieldValues.CLASS_LAKE);
case "ne_10m_lakes" -> new LakeInfo(4, 5, FieldValues.CLASS_LAKE);
default -> null;
};
if (lakeInfo != null) {
try {
var geom = feature.worldGeometry();
lakeInfo.geom = geom;
lakeInfo.name = feature.getString("name");

var index = neLakeIndexes.computeIfAbsent(table, t -> new STRtree());
var neLakeNameMap = neLakeNameMaps.computeIfAbsent(table, t -> new ConcurrentHashMap<>());

// need to externally synchronize inserts into the STRTree and ArrayList
synchronized (this) {
index.insert(geom.getEnvelopeInternal(), lakeInfo);
neAllLakeInfos.add(lakeInfo);
}
if (lakeInfo.name != null) {
if (!neLakeNameMap.containsKey(lakeInfo.name) ||
lakeInfo.geom.getArea() > neLakeNameMap.get(lakeInfo.name).geom.getArea()) {
// on name collision, bigger lake gets on the name list
neLakeNameMap.put(lakeInfo.name, lakeInfo);
}
}
} catch (GeometryException e) {
e.log(stats, "omt_water_ne",
"Error getting geometry for natural earth feature " + table + " " + feature.getTag("ogc_fid"));
// make sure we have this NE lake even if without OSM ID
setupNeWaterFeature(features, lakeInfo.minZoom, lakeInfo.maxZoom, lakeInfo.clazz, null);
}
}
}

private void setupNeWaterFeature(FeatureCollector features, int minZoom, int maxZoom, String clazz, Long osmId) {
features.polygon(LAYER_NAME)
.setBufferPixels(BUFFER_SIZE)
.setZoomRange(minZoom, maxZoom)
.setAttr(Fields.CLASS, clazz)
.setAttr(Fields.ID, osmId);
}

@Override
public void processOsmWater(SourceFeature feature, FeatureCollector features) {
features.polygon(LAYER_NAME)
Expand All @@ -121,11 +177,135 @@ public void process(Tables.OsmWaterPolygon element, FeatureCollector features) {
.setAttr(Fields.INTERMITTENT, element.isIntermittent() ? 1 : 0)
.setAttrWithMinzoom(Fields.BRUNNEL, Utils.brunnel(element.isBridge(), element.isTunnel()), 12)
.setAttr(Fields.CLASS, clazz);

fillOsmIdIntoNeLake(element);
}
}

void fillOsmIdIntoNeLake(Tables.OsmWaterPolygon element) {
try {
// match by name:
boolean match = false;
if (element.name() != null) {
for (var map : neLakeNameMaps.values()) {
var lakeInfo = map.get(element.name());
if (lakeInfo != null) {
match = true;
fillOsmIdIntoNeLake(element, element.source().worldGeometry(), lakeInfo);
}
}
}
if (match) {
return;
}

// if OSM lake is too small for Z6 (e.g. area bellow ~4px) we assume there is no matching NE lake
Geometry geom = element.source().worldGeometry();
if (geom.getArea() < OSM_ID_MATCH_AREA_LIMIT) {
return;
}

// match by intersection:
Envelope envelope = geom.getEnvelopeInternal();

for (var index : neLakeIndexes.values()) {
var items = index.query(envelope);
if (items.size() == 1) {
if (items.getFirst() instanceof LakeInfo lakeInfo) {
fillOsmIdIntoNeLake(element, geom, lakeInfo);
}
} else if (!items.isEmpty()) {
for (var item : items) {
if (item instanceof LakeInfo lakeInfo) {
fillOsmIdIntoNeLake(element, geom, lakeInfo);
}
}
}
}
} catch (GeometryException e) {
e.log(stats, "omt_water",
"Error getting geometry for OSM feature " + element.source().id());
}
}

void fillOsmIdIntoNeLake(Tables.OsmWaterPolygon element, Geometry geom, LakeInfo lakeInfo) throws GeometryException {
Geometry neGeom = lakeInfo.geom;
Geometry intersection;
try {
if (!neGeom.intersects(geom)) {
return;
}
intersection = neGeom.intersection(geom);
} catch (TopologyException e) {
try {
Geometry fixedGeom = GeometryFixer.fix(geom);
if (!neGeom.intersects(fixedGeom)) {
return;
}
intersection = neGeom.intersection(fixedGeom);
} catch (TopologyException e2) {
throw new GeometryException("fix_omt_water_topology_error",
"error fixing polygon: " + e2 + "; original error: " + e);
}
}

// should match following in OpenMapTiles: Distinct on keeps just the first occurence -> order by 'area_ratio DESC'
double areaRatio = intersection.getArea() / neGeom.getArea();
if (areaRatio > lakeInfo.areaRatio) {
lakeInfo.osmId = element.source().id();
lakeInfo.areaRatio = areaRatio;
}
}

@Override
public void finish(String sourceName, FeatureCollector.Factory featureCollectors,
Consumer<FeatureCollector.Feature> emit) {
if (OpenMapTilesProfile.NATURAL_EARTH_SOURCE.equals(sourceName)) {
var timer = stats.startStage("ne_lake_index");
for (var index : neLakeIndexes.values()) {
index.build();
}
timer.stop();
} else if (OpenMapTilesProfile.OSM_SOURCE.equals(sourceName)) {
var timer = stats.startStage("ne_lakes");
for (var item : neAllLakeInfos) {
var features = featureCollectors.get(SimpleFeature.fromWorldGeometry(item.geom));
setupNeWaterFeature(features, item.minZoom, item.maxZoom, item.clazz, item.osmId);
for (var feature : features) {
emit.accept(feature);
}
}
neLakeNameMaps.clear();
neLakeIndexes.clear();
neAllLakeInfos.clear();
timer.stop();
}
}

@Override
public List<VectorTile.Feature> postProcess(int zoom, List<VectorTile.Feature> items) throws GeometryException {
return items.size() > 1 ? FeatureMerge.mergeOverlappingPolygons(items, config.minFeatureSize(zoom)) : items;
}

/**
* Information to hold onto from processing an NE lake to determine OSM ID later.
*/
private static class LakeInfo {
String name;
int minZoom;
int maxZoom;
String clazz;
Geometry geom;
Long osmId;
double areaRatio;

public LakeInfo(int minZoom, int maxZoom, String clazz) {
this.name = null;
this.minZoom = minZoom;
this.maxZoom = maxZoom;
this.clazz = clazz;
this.osmId = null;
this.areaRatio = 0;
}
}
}
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