From 74a534c4f33c4e9609c010c4e12c39d8eaaf400d Mon Sep 17 00:00:00 2001
From: cepprice <super.cepprice@gmail.com>
Date: Sun, 11 Apr 2021 18:46:33 +0500
Subject: [PATCH] Fix inconsistency of track geometry

---
 .../java/net/osmand/osm/edit/OsmMapUtils.java | 24 +++++++++++++++++++
 .../java/net/osmand/router/RouteColorize.java | 10 ++++----
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/OsmAnd-java/src/main/java/net/osmand/osm/edit/OsmMapUtils.java b/OsmAnd-java/src/main/java/net/osmand/osm/edit/OsmMapUtils.java
index cf86ca88ed..c4823cf9ea 100644
--- a/OsmAnd-java/src/main/java/net/osmand/osm/edit/OsmMapUtils.java
+++ b/OsmAnd-java/src/main/java/net/osmand/osm/edit/OsmMapUtils.java
@@ -619,6 +619,30 @@ public class OsmMapUtils {
         return new Cell(x / area, y / area, 0, rings);
     }
 
+	public static void simplifyDouglasPeucker(List<Node> nodes, int start, int end, List<Node> survivedNodes, double epsilon) {
+		double dmax = Double.NEGATIVE_INFINITY;
+		int index = -1;
+
+		Node startPt = nodes.get(start);
+		Node endPt = nodes.get(end);
+
+		for (int i = start + 1; i < end; i++) {
+			Node pt = nodes.get(i);
+			double d = MapUtils.getOrthogonalDistance(pt.getLatitude(), pt.getLongitude(),
+					startPt.getLatitude(), startPt.getLongitude(), endPt.getLatitude(), endPt.getLongitude());
+			if (d > dmax) {
+				dmax = d;
+				index = i;
+			}
+		}
+		if (dmax > epsilon) {
+			simplifyDouglasPeucker(nodes, start, index, survivedNodes, epsilon);
+			simplifyDouglasPeucker(nodes, index, end, survivedNodes, epsilon);
+		} else {
+			survivedNodes.add(nodes.get(end));
+		}
+	}
+
     private static class CellComparator implements Comparator<Cell> {
         @Override
         public int compare(Cell o1, Cell o2) {
diff --git a/OsmAnd-java/src/main/java/net/osmand/router/RouteColorize.java b/OsmAnd-java/src/main/java/net/osmand/router/RouteColorize.java
index 88b6555e19..6abb9c47c0 100644
--- a/OsmAnd-java/src/main/java/net/osmand/router/RouteColorize.java
+++ b/OsmAnd-java/src/main/java/net/osmand/router/RouteColorize.java
@@ -35,6 +35,7 @@ public class RouteColorize {
     public static final int RED = rgbaToDecimal(243, 55, 77, 255);
     public static final int[] colors = new int[] {GREEN, YELLOW, RED};
 
+    private static final float DEFAULT_BASE = 17.2f;
     private static final int MAX_SLOPE_VALUE = 25;
 
     public enum ColorizationType {
@@ -241,7 +242,6 @@ public class RouteColorize {
         if (dataList == null) {
             dataList = new ArrayList<>();
             for (int i = 0; i < latitudes.length; i++) {
-                //System.out.println(latitudes[i] + " " + longitudes[i] + " " + values[i]);
                 dataList.add(new RouteColorizationPoint(i, latitudes[i], longitudes[i], values[i]));
             }
         }
@@ -250,11 +250,13 @@ public class RouteColorize {
         for (RouteColorizationPoint data : dataList) {
             nodes.add(new net.osmand.osm.edit.Node(data.lat, data.lon, data.id));
         }
-        OsmMapUtils.simplifyDouglasPeucker(nodes, zoom + 5, 1, result, true);
+
+        double epsilon = Math.pow(2.0, DEFAULT_BASE - zoom);
+        result.add(nodes.get(0));
+        OsmMapUtils.simplifyDouglasPeucker(nodes, 0, nodes.size() - 1, result, epsilon);
 
         List<RouteColorizationPoint> simplified = new ArrayList<>();
-
-        for (int i = 1; i < result.size() - 1; i++) {
+        for (int i = 1; i < result.size(); i++) {
             int prevId = (int) result.get(i - 1).getId();
             int currentId = (int) result.get(i).getId();
             List<RouteColorizationPoint> sublist = dataList.subList(prevId, currentId);