feat: Global extraction function in BinnedSPGroup (#810)

This PR adds a user-defined function for extracting both position and covariance in BinnedSPGroup as a std::pair<Acts::Vector3,Acts::Vector2> obejct.
This new function replaces the old user-defined function used for extracting the covariance, and would allow the user to introduce additional computations.

Core/include/Acts/Seeding/BinnedSPGroup.hpp

@@ -240,9 +240,8 @@ class BinnedSPGroup {
   template <typename spacepoint_iterator_t>
   BinnedSPGroup<external_spacepoint_t>(
       spacepoint_iterator_t spBegin, spacepoint_iterator_t spEnd,
-      std::function<Acts::Vector2(const external_spacepoint_t&, float, float,
-                                  float)>
-          covTool,
+      std::function<std::pair<Acts::Vector3, Acts::Vector2>(
+          const external_spacepoint_t&, float, float, float)>,
       std::shared_ptr<Acts::BinFinder<external_spacepoint_t>> botBinFinder,
       std::shared_ptr<Acts::BinFinder<external_spacepoint_t>> tBinFinder,
       std::unique_ptr<SpacePointGrid<external_spacepoint_t>> grid,

Core/include/Acts/Seeding/BinnedSPGroup.ipp

@@ -10,9 +10,9 @@ template <typename external_spacepoint_t>
 template <typename spacepoint_iterator_t>
 Acts::BinnedSPGroup<external_spacepoint_t>::BinnedSPGroup(
     spacepoint_iterator_t spBegin, spacepoint_iterator_t spEnd,
-    std::function<Acts::Vector2(const external_spacepoint_t&, float, float,
-                                float)>
-        covTool,
+    std::function<std::pair<Acts::Vector3, Acts::Vector2>(
+        const external_spacepoint_t&, float, float, float)>
+        globTool,
     std::shared_ptr<Acts::BinFinder<external_spacepoint_t>> botBinFinder,
     std::shared_ptr<Acts::BinFinder<external_spacepoint_t>> tBinFinder,
     std::unique_ptr<SpacePointGrid<external_spacepoint_t>> grid,
@@ -42,9 +42,12 @@ Acts::BinnedSPGroup<external_spacepoint_t>::BinnedSPGroup(
       continue;
     }
     const external_spacepoint_t& sp = **it;
-    float spX = sp.x();
-    float spY = sp.y();
-    float spZ = sp.z();
+    const auto& [spPosition, variance] =
+        globTool(sp, config.zAlign, config.rAlign, config.sigmaError);
+
+    float spX = spPosition[0];
+    float spY = spPosition[1];
+    float spZ = spPosition[2];
 
     if (spZ > zMax || spZ < zMin) {
       continue;
@@ -54,10 +57,6 @@ Acts::BinnedSPGroup<external_spacepoint_t>::BinnedSPGroup(
       continue;
     }
 
-    // 2D variance tool provided by user
-    Acts::Vector2 variance =
-        covTool(sp, config.zAlign, config.rAlign, config.sigmaError);
-    Acts::Vector3 spPosition(spX, spY, spZ);
     auto isp =
         std::make_unique<const InternalSpacePoint<external_spacepoint_t>>(
             sp, spPosition, config.beamPos, variance);

Examples/Algorithms/TrackFinding/src/SeedingAlgorithm.cpp

@@ -92,17 +92,21 @@ ActsExamples::ProcessCode ActsExamples::SeedingAlgorithm::execute(
 
   // construct the seeding tools
   // covariance tool, extracts covariances per spacepoint as required
-  auto extractCovariance = [=](const SimSpacePoint& sp, float, float,
-                               float) -> Acts::Vector2 {
-    return {sp.varianceR(), sp.varianceZ()};
+  auto extractGlobalQuantities =
+      [=](const SimSpacePoint& sp, float, float,
+          float) -> std::pair<Acts::Vector3, Acts::Vector2> {
+    Acts::Vector3 position{sp.x(), sp.y(), sp.z()};
+    Acts::Vector2 covariance{sp.varianceR(), sp.varianceZ()};
+    return std::make_pair(position, covariance);
   };
+
   auto bottomBinFinder = std::make_shared<Acts::BinFinder<SimSpacePoint>>(
       Acts::BinFinder<SimSpacePoint>());
   auto topBinFinder = std::make_shared<Acts::BinFinder<SimSpacePoint>>(
       Acts::BinFinder<SimSpacePoint>());
   auto grid = Acts::SpacePointGridCreator::createGrid<SimSpacePoint>(m_gridCfg);
   auto spacePointsGrouping = Acts::BinnedSPGroup<SimSpacePoint>(
-      spacePointPtrs.begin(), spacePointPtrs.end(), extractCovariance,
+      spacePointPtrs.begin(), spacePointPtrs.end(), extractGlobalQuantities,
       bottomBinFinder, topBinFinder, std::move(grid), m_finderCfg);
   auto finder = Acts::Seedfinder<SimSpacePoint>(m_finderCfg);
 

Tests/UnitTests/Core/Seeding/SeedfinderTest.cpp

@@ -143,8 +143,11 @@ int main(int argc, char** argv) {
   Acts::Seedfinder<SpacePoint> a(config);
 
   // covariance tool, sets covariances per spacepoint as required
-  auto ct = [=](const SpacePoint& sp, float, float, float) -> Acts::Vector2 {
-    return {sp.varianceR, sp.varianceZ};
+  auto ct = [=](const SpacePoint& sp, float, float,
+                float) -> std::pair<Acts::Vector3, Acts::Vector2> {
+    Acts::Vector3 position(sp.x(), sp.y(), sp.z());
+    Acts::Vector2 covariance(sp.varianceR, sp.varianceZ);
+    return std::make_pair(position, covariance);
   };
 
   // setup spacepoint grid config

Tests/UnitTests/Plugins/Cuda/Seeding/SeedfinderCudaTest.cpp

@@ -206,8 +206,11 @@ int main(int argc, char** argv) {
   Acts::Seedfinder<SpacePoint, Acts::Cuda> seedfinder_cuda(config);
 
   // covariance tool, sets covariances per spacepoint as required
-  auto ct = [=](const SpacePoint& sp, float, float, float) -> Acts::Vector2 {
-    return {sp.varianceR, sp.varianceZ};
+  auto ct = [=](const SpacePoint& sp, float, float,
+                float) -> std::pair<Acts::Vector3, Acts::Vector2> {
+    Acts::Vector3 position(sp.x(), sp.y(), sp.z());
+    Acts::Vector2 variance(sp.varianceR, sp.varianceZ);
+    return std::make_pair(position, variance);
   };
 
   // setup spacepoint grid config

Tests/UnitTests/Plugins/Cuda/Seeding2/main.cpp

@@ -94,8 +94,10 @@ int main(int argc, char* argv[]) {
 
   // Covariance tool, sets covariances per spacepoint as required.
   auto ct = [=](const TestSpacePoint& sp, float, float,
-                float) -> Acts::Vector2 {
-    return {sp.m_varianceR, sp.m_varianceZ};
+                float) -> std::pair<Acts::Vector3, Acts::Vector2> {
+    Acts::Vector3 position(sp.x(), sp.y(), sp.z());
+    Acts::Vector2 covariance(sp.m_varianceR, sp.m_varianceZ);
+    return std::make_pair(position, covariance);
   };
 
   // Create a grid with bin sizes according to the configured geometry, and

Tests/UnitTests/Plugins/Sycl/Seeding/SeedfinderSyclTest.cpp

@@ -152,17 +152,20 @@ auto main(int argc, char** argv) -> int {
           cmdlTool.deviceName,
           Acts::getDefaultLogger("Sycl::QueueWrapper", logLvl)));
   Acts::Seedfinder<SpacePoint> normalSeedfinder(config);
-  auto covarianceTool = [=](const SpacePoint& sp, float /*unused*/,
-                            float /*unused*/,
-                            float_t /*unused*/) -> Acts::Vector2 {
-    return {sp.varianceR, sp.varianceZ};
+  auto globalTool =
+      [=](const SpacePoint& sp, float /*unused*/, float /*unused*/,
+          float_t /*unused*/) -> std::pair<Acts::Vector3, Acts::Vector2> {
+    Acts::Vector3 position(sp.x(), sp.y(), sp.z());
+    Acts::Vector2 covariance(sp.varianceR, sp.varianceZ);
+    return std::make_pair(position, covariance);
   };
+
   std::unique_ptr<Acts::SpacePointGrid<SpacePoint>> grid =
       Acts::SpacePointGridCreator::createGrid<SpacePoint>(
           setupSpacePointGridConfig(config));
 
   auto spGroup = Acts::BinnedSPGroup<SpacePoint>(
-      spVec.begin(), spVec.end(), covarianceTool, bottomBinFinder, topBinFinder,
+      spVec.begin(), spVec.end(), globalTool, bottomBinFinder, topBinFinder,
       std::move(grid), config);
 
   auto end_prep = std::chrono::system_clock::now();