Add merge tests

onthegomap · Nov 2, 2024 · 6c2c338 · 6c2c338
1 parent 06675f9
commit 6c2c338
Show file tree

Hide file tree

Showing 2 changed files with 168 additions and 1 deletion.
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
@@ -187,7 +187,13 @@ private List<List<LineString>> findAllPaths(Point start, Point end, double maxLe
       }
       List<LineString> path = new ArrayList<>();
       path.add(edge);
-      queue.add(path);
+      if (maxLength > 0.0) {
+        if (getLength(path) <= maxLength) {
+          queue.add(path);
+        }
+      } else {
+        queue.add(path);
+      }
     }
 
     while (!queue.isEmpty()) {

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
@@ -80,4 +80,165 @@ void testConcat() {
 
     // TODO: handle and test the case when A/B do not share end/start points
   }
+
+  @Test
+  void testMerge() {
+
+    // merges two touching linestrings
+    var merger = new LoopLineMerger();
+    merger.add(newLineString(10, 10, 20, 20));
+    merger.add(newLineString(20, 20, 30, 30));
+    assertEquals(
+      List.of(newLineString(10, 10, 20, 20, 30, 30)),
+      merger.getMergedLineStrings(-1, -1)
+    );
+
+    // keeps two separate linestrings separate
+    merger = new LoopLineMerger();
+    merger.add(newLineString(10, 10, 20, 20));
+    merger.add(newLineString(30, 30, 40, 40));
+    assertEquals(
+      List.of(
+        newLineString(10, 10, 20, 20),
+        newLineString(30, 30, 40, 40)
+      ),
+      merger.getMergedLineStrings(-1, -1)
+    );
+
+    // does not overcount already added linestrings
+    merger = new LoopLineMerger();
+    merger.add(newLineString(10, 10, 20, 20));
+    merger.add(newLineString(20, 20, 30, 30));
+    merger.add(newLineString(20, 20, 30, 30));
+    assertEquals(
+      List.of(newLineString(10, 10, 20, 20, 30, 30)),
+      merger.getMergedLineStrings(-1, -1)
+    );
+
+    // splits linestrings into linear segments before merging
+    merger = new LoopLineMerger();
+    merger.add(newLineString(10, 10, 20, 20, 30, 30));
+    merger.add(newLineString(20, 20, 30, 30, 40, 40));
+    assertEquals(
+      List.of(newLineString(10, 10, 20, 20, 30, 30, 40, 40)),
+      merger.getMergedLineStrings(-1, -1)
+    );
+
+    // rounds coordinates to 1/16 before merging
+    merger = new LoopLineMerger();
+    merger.add(newLineString(10.00043983098, 10, 20, 20));
+    merger.add(newLineString(20, 20, 30, 30));
+    assertEquals(
+      List.of(newLineString(10, 10, 20, 20, 30, 30)),
+      merger.getMergedLineStrings(-1, -1)
+    );
+
+    // removes small loops, keeps shortes path
+    merger = new LoopLineMerger();
+    /**
+     *              10  20 30 40
+     *        10     o--o--o
+     *                   \ |
+     *                    \|
+     *        20           o--o          
+     */
+    merger.add(newLineString(
+      10, 10,
+      20, 10,
+      30, 10,
+      30, 20,
+      40, 20
+    ));
+    merger.add(newLineString(
+      20, 10,
+      30, 20
+    ));
+    assertEquals(
+      List.of(
+        newLineString(
+          10, 10,
+          20, 10,
+          30, 20,
+          40, 20
+        )
+      ),
+      merger.getMergedLineStrings(-1, 100)
+    );
+
+    // does not remove large loops
+    merger = new LoopLineMerger();
+    /**
+     *              10 20 30  40
+     *        10     o--o--o
+     *                   \ |
+     *                    \|
+     *        20           o--o          
+     */
+    merger.add(newLineString(
+      10, 10,
+      20, 10,
+      30, 10,
+      30, 20,
+      40, 20
+    ));
+    merger.add(newLineString(
+      20, 10,
+      30, 20
+    ));
+    assertEquals(
+      List.of(
+        newLineString(
+          30, 20,
+          40, 20
+        ),
+        newLineString(
+          20, 10,
+          30, 20
+        ),
+        newLineString(
+          20, 10,
+          30, 10,
+          30, 20
+        ),
+        newLineString(
+          10, 10,
+          20, 10
+        )
+      ),
+      merger.getMergedLineStrings(-1, 0.001)
+    );
+
+    // removes linestrings that are too short after merging
+    merger = new LoopLineMerger();
+    merger.add(newLineString(10, 10, 11, 11));
+    merger.add(newLineString(20, 20, 30, 30));
+    merger.add(newLineString(30, 30, 40, 40));
+    assertEquals(
+      List.of(newLineString(20, 20, 30, 30, 40, 40)),
+      merger.getMergedLineStrings(10, -1)
+    );
+
+    // removes first short stubs, merges again, and only then 
+    // removes non-stubs that are too short
+    // stub = linestring that has at least one disconnected end
+    merger = new LoopLineMerger();
+
+    /**
+     *            0   20  30   50
+     *       0    o----o--o----o
+     *                 |  |
+     *       10        o  o
+     */
+    merger.add(newLineString(0, 0, 20, 0));
+    merger.add(newLineString(20, 0, 30, 0));
+    merger.add(newLineString(30, 0, 50, 0));
+    merger.add(newLineString(20, 0, 20, 10));
+    merger.add(newLineString(30, 0, 30, 10));
+
+    assertEquals(
+      List.of(newLineString(0, 0, 20, 0, 30, 0, 50, 0)),
+      merger.getMergedLineStrings(15, -1)
+    );
+  }
+
 }