Human deduplicateAndSpliceTrackSegments v1

OsmAnd-java/src/main/java/net/osmand/gpx/GpxOptimizer.java

@@ -0,0 +1,93 @@
+package net.osmand.gpx;
+
+import net.osmand.shared.gpx.primitives.Track;
+import net.osmand.shared.gpx.primitives.TrkSegment;
+import net.osmand.shared.gpx.primitives.WptPt;
+import net.osmand.shared.util.KMapUtils;
+
+import java.util.*;
+
+// Human-based version of OverlappedSegmentsMergerDS / OverlappedSegmentsMergerGPT
+
+public class GpxOptimizer {
+	private static final double EDGE_POINTS_MAX_ORTHOGONAL_DISTANCE = 10.0;
+	private static final double PRECISION = KMapUtils.DEFAULT_LATLON_PRECISION;
+
+	public static Track deduplicateAndSpliceTrackSegments(Track track) {
+		Set<String> duplicates = new HashSet<>();
+		findDisplacedEdgePointsToDeduplicate(track, duplicates);
+
+		List<TrkSegment> cleanSegments = new ArrayList<>();
+		deduplicatePointsToCleanSegments(track, duplicates, cleanSegments);
+
+		Track cleanTrack = new Track();
+		cleanTrack.setSegments(cleanSegments);
+		return cleanTrack;
+	}
+
+	private static void deduplicatePointsToCleanSegments(Track track, Set<String> duplicates,
+	                                                     List<TrkSegment> cleanSegments) {
+		for (TrkSegment seg : track.getSegments()) {
+			TrkSegment cleanSeg = new TrkSegment();
+			List<WptPt> points = seg.getPoints();
+			if (!points.isEmpty()) {
+				Set<String> nextDuplicates = new HashSet<>();
+				for (int i = 0; i < points.size(); i++) {
+					WptPt p = points.get(i);
+					String key = llKey(p);
+					if (!duplicates.contains(key)) {
+						if (!isPossiblyDisplacedEdgePoint(i, points, duplicates)) {
+							cleanSeg.getPoints().add(p);
+						}
+						if (i != 0 && i != points.size() - 1) {
+							nextDuplicates.add(key);
+						}
+					}
+				}
+				duplicates.addAll(nextDuplicates);
+			}
+			if (!cleanSeg.getPoints().isEmpty()) {
+				cleanSegments.add(cleanSeg);
+			}
+		}
+	}
+
+	private static boolean isPossiblyDisplacedEdgePoint(int i, List<WptPt> points, Set<String> duplicates) {
+		// fast fallback method if findDisplacedEdgePointsToDeduplicate has failed
+		return (i == 0 && points.size() > 1 && duplicates.contains(llKey(points.get(i + 1))))
+		|| (i == points.size() - 1 && points.size() > 1 && duplicates.contains(llKey(points.get(i - 1))));
+	}
+
+	private static void findDisplacedEdgePointsToDeduplicate(Track track, Set<String> duplicates) {
+		Set<WptPt> edgePoints = new HashSet<>();
+		for (TrkSegment seg : track.getSegments()) {
+			List<WptPt> points = seg.getPoints();
+			if (!points.isEmpty()) {
+				edgePoints.add(points.get(0));
+				edgePoints.add(points.get(points.size() - 1));
+			}
+		}
+		if (!edgePoints.isEmpty()) {
+			for (TrkSegment seg : track.getSegments()) {
+				List<WptPt> points = seg.getPoints();
+				if (points.size() > 1) {
+					for (int i = 1; i < points.size(); i++) {
+						WptPt p1 = points.get(i);
+						WptPt p2 = points.get(i - 1);
+						for (WptPt edge : edgePoints) {
+							double d = KMapUtils.INSTANCE.getOrthogonalDistance(edge.getLatitude(), edge.getLongitude(),
+									p1.getLatitude(), p1.getLongitude(), p2.getLatitude(), p2.getLongitude());
+							if (d > 0 && d < EDGE_POINTS_MAX_ORTHOGONAL_DISTANCE) {
+								duplicates.add(llKey(edge));
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+
+	private static String llKey(WptPt edge) {
+		return (int) (edge.getLatitude() / PRECISION) + "," + (int) (edge.getLongitude() / PRECISION); // String is fast
+	}
+}