Test findAllPaths

onthegomap · Nov 2, 2024 · 9b4a65b · 9b4a65b
1 parent 6c2c338
commit 9b4a65b
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Showing 2 changed files with 119 additions and 48 deletions.
diff --git a/planetiler-core/src/main/java/com/onthegomap/planetiler/util/LoopLineMerger.java b/planetiler-core/src/main/java/com/onthegomap/planetiler/util/LoopLineMerger.java
@@ -56,7 +56,7 @@ private void add(LineString lineString) {
 
   }
 
-  public static Coordinate roundCoordinate(Coordinate cooridnate) {
+  protected static Coordinate roundCoordinate(Coordinate cooridnate) {
     Coordinate result = new Coordinate(cooridnate);
 
     double multiplier = 16.0;
@@ -67,7 +67,7 @@ public static Coordinate roundCoordinate(Coordinate cooridnate) {
     return result;
   }
 
-  public static List<LineString> split(LineString lineString) {
+  protected static List<LineString> split(LineString lineString) {
     List<LineString> segments = new ArrayList<>();
 
     Coordinate[] coordinates = lineString.getCoordinates();
@@ -82,7 +82,7 @@ public static List<LineString> split(LineString lineString) {
     return segments;
   }
 
-  public static LineString concat(LineString A, LineString B) {
+  protected static LineString concat(LineString A, LineString B) {
 
     List<Coordinate> coordinates = new ArrayList<>();
     List<Coordinate> coordsA = List.of(A.getCoordinates());
@@ -175,7 +175,7 @@ private void removeLoops(double loopMinLength) {
     }
   }
 
-  private List<List<LineString>> findAllPaths(Point start, Point end, double maxLength) {
+  protected List<List<LineString>> findAllPaths(Point start, Point end, double maxLength) {
     List<List<LineString>> allPaths = new ArrayList<>();
     Queue<List<LineString>> queue = new LinkedList<>();
 
@@ -245,7 +245,7 @@ private static double getLength(List<LineString> lines) {
     return result;
   }
 
-  public static boolean hasPointAppearingMoreThanTwice(List<LineString> lineStrings) {
+  protected static boolean hasPointAppearingMoreThanTwice(List<LineString> lineStrings) {
     HashMap<Point, Integer> pointCountMap = new HashMap<>();
     for (LineString line : lineStrings) {
       Point startPoint = line.getStartPoint();
@@ -320,50 +320,50 @@ public List<LineString> getMergedLineStrings(double minLength, double loopMinLen
 
     return result;
   }
-}
-
-class Node {
-  private Point point;
-  private List<LineString> edges;
-
-  public Node(Point point) {
-    this.point = point;
-    this.edges = new ArrayList<>();
-  }
-
-  public Point getPoint() {
-    return point;
-  }
 
-  public void setPoint(Point point) {
-    this.point = point;
-  }
-
-  public List<LineString> getEdges() {
-    return edges;
-  }
-
-  public void addEdge(LineString edge) {
-    if (!edges.contains(edge) && !edges.contains(edge.reverse())) {
-      edges.add(edge);
+  class Node {
+    private Point point;
+    private List<LineString> edges;
+
+    public Node(Point point) {
+      this.point = point;
+      this.edges = new ArrayList<>();
     }
-  }
-
-  public void removeEdge(LineString edge) {
-    if (edges.contains(edge)) {
-      edges.remove(edge);
-    } else if (edges.contains(edge.reverse())) {
-      edges.remove(edge.reverse());
-    } else {
-      // nothing to do
+
+    public Point getPoint() {
+      return point;
     }
-  }
-
-  @Override
-  public String toString() {
-    return "Node{" +
-        "point=" + point +
-        ", edges=" + edges +
-        '}';
-  }
+
+    public void setPoint(Point point) {
+      this.point = point;
+    }
+
+    public List<LineString> getEdges() {
+      return edges;
+    }
+
+    public void addEdge(LineString edge) {
+      if (!edges.contains(edge) && !edges.contains(edge.reverse())) {
+        edges.add(edge);
+      }
+    }
+
+    public void removeEdge(LineString edge) {
+      if (edges.contains(edge)) {
+        edges.remove(edge);
+      } else if (edges.contains(edge.reverse())) {
+        edges.remove(edge.reverse());
+      } else {
+        // nothing to do
+      }
+    }
+
+    @Override
+    public String toString() {
+      return "Node{" +
+          "point=" + point +
+          ", edges=" + edges +
+          '}';
+    }
+  }  
 }
diff --git a/planetiler-core/src/test/java/com/onthegomap/planetiler/util/LoopLineMergerTest.java b/planetiler-core/src/test/java/com/onthegomap/planetiler/util/LoopLineMergerTest.java
@@ -1,5 +1,6 @@
 package com.onthegomap.planetiler.util;
 import static com.onthegomap.planetiler.TestUtils.newLineString;
+import static com.onthegomap.planetiler.TestUtils.newPoint;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import java.util.List;
@@ -240,5 +241,75 @@ void testMerge() {
       merger.getMergedLineStrings(15, -1)
     );
   }
+
+  @Test
+  void testHasPointAppearingMoreThanTwice() {
+
+    // can revisit starting node once
+    assertEquals(
+      false,
+      LoopLineMerger.hasPointAppearingMoreThanTwice(
+        List.of(
+          newLineString(10, 0, 20, 0),
+          newLineString(20, 0, 20, 10),
+          newLineString(20, 10, 10, 0)
+        )
+      )
+    );
+
+    // cannot revisit starting node and continue on
+    assertEquals(
+      true,
+      LoopLineMerger.hasPointAppearingMoreThanTwice(
+        List.of(
+          newLineString(10, 0, 20, 0),
+          newLineString(20, 0, 20, 10),
+          newLineString(20, 10, 10, 0),
+          newLineString(10, 0, 10, 10)
+        )
+      )
+    );
+  }
+
+  @Test
+  void testFindAllPaths() {
+    // finds all paths and orders them by length
+    var merger = new LoopLineMerger();
+    /**                 10 20  30
+     *            10     o-----o
+     *                   |\    |
+     *                   | \   |
+     *            20     o--o--o
+     */
+    merger.add(newLineString(10, 10, 30, 10));
+    merger.add(newLineString(10, 10, 10, 20));
+    merger.add(newLineString(10, 10, 20, 20));
+    merger.add(newLineString(10, 20, 20, 20));
+    merger.add(newLineString(20, 20, 30, 20));
+    merger.add(newLineString(30, 20, 30, 10));
+
+    var allPaths = merger.findAllPaths(newPoint(10, 10), newPoint(20, 20), 1000);
+
+    assertEquals(3, allPaths.size());
+    assertEquals(
+      List.of(newLineString(10, 10, 20, 20)),
+      allPaths.get(0)
+    );
+    assertEquals(
+      List.of(
+        newLineString(10, 10, 10, 20),
+        newLineString(10, 20, 20, 20)
+      ),
+      allPaths.get(1)
+    );
+    assertEquals(
+      List.of(
+        newLineString(10, 10, 30, 10),
+        newLineString(30, 10, 30, 20),
+        newLineString(30, 20, 20, 20)
+      ),
+      allPaths.get(2)
+    );
+  }
 
 }