From 57ea5fae684d00192a3933e01fd6cbdb864a6c7c Mon Sep 17 00:00:00 2001
From: Athrva Pandhare <apandhare@neocis.com>
Date: Sat, 27 Jul 2024 15:43:38 -0400
Subject: [PATCH] Add multiple thread kdtree build support for
 KDTreeEigenMatrixAdaptor

---
 include/nanoflann.hpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/nanoflann.hpp b/include/nanoflann.hpp
index c19d7c4..142e4ad 100644
--- a/include/nanoflann.hpp
+++ b/include/nanoflann.hpp
@@ -2620,7 +2620,8 @@ struct KDTreeEigenMatrixAdaptor
     explicit KDTreeEigenMatrixAdaptor(
         const Dimension                                 dimensionality,
         const std::reference_wrapper<const MatrixType>& mat,
-        const int                                       leaf_max_size = 10)
+        const int                                       leaf_max_size = 10,
+        const unsigned int                              n_thread_build = 1)
         : m_data_matrix(mat)
     {
         const auto dims = row_major ? mat.get().cols() : mat.get().rows();
@@ -2634,7 +2635,9 @@ struct KDTreeEigenMatrixAdaptor
                 "argument");
         index_ = new index_t(
             dims, *this /* adaptor */,
-            nanoflann::KDTreeSingleIndexAdaptorParams(leaf_max_size));
+            nanoflann::KDTreeSingleIndexAdaptorParams(leaf_max_size,
+            nanoflann::KDTreeSingleIndexAdaptorFlags::None,
+            n_thread_build));
     }
 
    public: