From 62c8817a70ad6b1ab5d2b53ca49894319479200a Mon Sep 17 00:00:00 2001
From: Daniel Schramm <xschramm@fi.muni.cz>
Date: Mon, 22 Mar 2021 17:07:54 +0100
Subject: [PATCH] ClosestNodeMultipleVisitor repeated tree traversal reduced
---
.../kdtree/ClosestNodeMultipleVisitor.java | 63 +++++--------------
.../ClosestNodeMultipleVisitorTest.java | 51 +++++++++++++++
2 files changed, 65 insertions(+), 49 deletions(-)
diff --git a/Comparison/src/main/java/cz/fidentis/analyst/visitors/kdtree/ClosestNodeMultipleVisitor.java b/Comparison/src/main/java/cz/fidentis/analyst/visitors/kdtree/ClosestNodeMultipleVisitor.java
index 4c510c66..221637b1 100644
--- a/Comparison/src/main/java/cz/fidentis/analyst/visitors/kdtree/ClosestNodeMultipleVisitor.java
+++ b/Comparison/src/main/java/cz/fidentis/analyst/visitors/kdtree/ClosestNodeMultipleVisitor.java
@@ -59,54 +59,18 @@ public class ClosestNodeMultipleVisitor extends ClosestNodeAbstractVisitor {
return;
}
- KdNode foundNode = closestNode(kdTree.getRoot());
- final double closestDistance = MeshPoint.distance(getPoint3d(), foundNode.getLocation());
- synchronized (this) {
- if (updateMinimalDistance(closestDistance)) {
- closest.clear();
- }
- }
-
- // There is no closer point than the 'closestFound' in our tree.
- // Search for other closest points with the same distance.
- while (foundNode != null) {
- final double distanceFound = MeshPoint.distance(getPoint3d(), foundNode.getLocation());
- synchronized (this) {
- if (distanceFound == getDistance()) {
- closest.add(foundNode);
- } else { // There is a closer point found in some other tree visited by this visitor
- return;
- }
- }
- foundNode = closestNodeOmitting(root);
- }
- }
-
- /*
- * Find an undiscovered node with its distance equal to 'distance'.
- *
- * - Discovered nodes are those stored in the 'closest' set.
- * - We are not looking for distance closer than 'distance' because
- * from the method {@link cz.fidentis.analyst.visitors.kdtree.ClosestNodeMultipleVisitor#visitKdTree}
- * we already know distance to the closest node of the visited tree.
- */
- private KdNode closestNodeOmitting(KdNode root) {
- if (root == null) {
- return null;
- }
+ KdNode searchedNode = root;
/*
- * First, find the closest node
+ * Reduce the search space by exploring the area where the closest node
+ * may theoretically be located.
*/
- KdNode nearNode = null;
- KdNode searchedNode = root;
-
while (searchedNode != null) {
final Vector3d nodePos = searchedNode.getLocation();
final double dist = MeshPoint.distance(getPoint3d(), nodePos);
synchronized (this) {
- if (dist == getDistance() && !closest.contains(searchedNode)) {
- nearNode = searchedNode;
+ if (updateMinimalDistance(dist) && !closest.isEmpty()) {
+ closest.clear();
}
}
@@ -118,20 +82,23 @@ public class ClosestNodeMultipleVisitor extends ClosestNodeAbstractVisitor {
}
/*
- * Second, search for a vertex that could be potentially closer than
- * the nearest vertex already found
+ * Search for vertices that could be potentially closer than
+ * the closest distance already found or at the same distance.
*/
final Queue<KdNode> queue = new LinkedList<>();
queue.add(root);
while (!queue.isEmpty()) {
searchedNode = queue.poll();
- Vector3d nodePos = searchedNode.getLocation();
+ final Vector3d nodePos = searchedNode.getLocation();
final double dist = MeshPoint.distance(getPoint3d(), nodePos);
synchronized (this) {
- if (dist == getDistance() && !closest.contains(searchedNode)) {
- nearNode = searchedNode;
+ if (updateMinimalDistance(dist)) {
+ closest.clear();
+ closest.add(searchedNode);
+ } else if (dist == getDistance()) {
+ closest.add(searchedNode);
}
}
@@ -156,8 +123,6 @@ public class ClosestNodeMultipleVisitor extends ClosestNodeAbstractVisitor {
}
}
}
-
- return nearNode;
}
-
+
}
diff --git a/Comparison/src/test/java/cz/fidentis/analyst/visitors/kdtree/ClosestNodeMultipleVisitorTest.java b/Comparison/src/test/java/cz/fidentis/analyst/visitors/kdtree/ClosestNodeMultipleVisitorTest.java
index a0ba2374..89e0d65a 100644
--- a/Comparison/src/test/java/cz/fidentis/analyst/visitors/kdtree/ClosestNodeMultipleVisitorTest.java
+++ b/Comparison/src/test/java/cz/fidentis/analyst/visitors/kdtree/ClosestNodeMultipleVisitorTest.java
@@ -110,4 +110,55 @@ public class ClosestNodeMultipleVisitorTest {
assertEquals(8, closestFound.size());
testContainsExactlyPositions(closest, closestFound);
}
+
+ @Test
+ public void threeTreesSingleClosestTest() {
+ final Set<MeshPoint> closest = getTreeNodesSymmetric(1);
+ final KdTree kdTreeClosest = new KdTree(closest);
+
+ final KdTree kdTree1 = new KdTree(getTreeNodesSymmetric(2));
+ final KdTree kdTree2 = new KdTree(getTreeNodesSymmetric(3));
+
+ final ClosestNodeMultipleVisitor visitor = new ClosestNodeMultipleVisitor(centerNode, false);
+ kdTree1.accept(visitor);
+ kdTreeClosest.accept(visitor);
+ kdTree2.accept(visitor);
+
+ final Set<KdNode> closestFound = visitor.getClosestNodes();
+ assertEquals(8, closestFound.size());
+ testContainsExactlyPositions(closest, closestFound);
+ }
+
+ @Test
+ public void threeTreesTwoClosestTest() {
+ final Set<MeshPoint> closest = getTreeNodesSymmetric(1);
+ final Set<MeshPoint> closest1 = new HashSet<>();
+ final Set<MeshPoint> closest2 = new HashSet<>();
+ boolean odd = true;
+ for (final MeshPoint point: closest) {
+ if (odd) {
+ closest1.add(point);
+ } else {
+ closest2.add(point);
+ }
+ odd = !odd;
+ }
+ assertEquals(8, closest.size());
+ assertEquals(4, closest1.size());
+ assertEquals(4, closest2.size());
+
+ final KdTree kdTreeClosest1 = new KdTree(closest1);
+ final KdTree kdTreeClosest2 = new KdTree(closest2);
+ final KdTree kdTree = new KdTree(getTreeNodesSymmetric(2));
+
+ final ClosestNodeMultipleVisitor visitor = new ClosestNodeMultipleVisitor(centerNode, false);
+ kdTreeClosest1.accept(visitor);
+ kdTree.accept(visitor);
+ kdTreeClosest2.accept(visitor);
+
+ final Set<KdNode> closestFound = visitor.getClosestNodes();
+ assertEquals(8, closestFound.size());
+ testContainsExactlyPositions(closest, closestFound);
+ }
+
}
--
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