feat(hesai): add CUDA-accelerated point cloud decoder

src/nebula_hesai/nebula_hesai/CMakeLists.txt

@@ -109,6 +109,18 @@ if(BUILD_TESTING)
     nebula_hesai_common::nebula_hesai_common
     nebula_hesai_decoders::nebula_hesai_decoders
     diagnostic_updater::diagnostic_updater)
+
+  # CUDA decoder equivalence test (only when CUDA support is available)
+  ament_add_gtest(hesai_cuda_decoder_test_main
+                  tests/hesai_cuda_decoder_test.cpp)
+  target_include_directories(hesai_cuda_decoder_test_main PRIVATE tests)
+  target_link_libraries(
+    hesai_cuda_decoder_test_main
+    hesai_ros_decoder_test
+    nebula_core_common::nebula_core_common
+    nebula_hesai_common::nebula_hesai_common
+    nebula_hesai_decoders::nebula_hesai_decoders
+    diagnostic_updater::diagnostic_updater)
 endif()
 
 if(BUILD_EXAMPLES)

src/nebula_hesai/nebula_hesai/tests/hesai_cuda_decoder_test.cpp

@@ -0,0 +1,285 @@
+// Copyright 2026 TIER IV, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/// @file hesai_cuda_decoder_test.cpp
+/// @brief GPU-vs-CPU equivalence tests for the Hesai CUDA decoder (OT128 / Pandar128E4X).
+///
+/// Decodes the same rosbag with the CPU path (NEBULA_USE_CUDA unset) and the GPU path
+/// (NEBULA_USE_CUDA=1), then compares the resulting point clouds with tolerances.
+/// The GPU path differs at scan boundaries due to different overlap/FOV detection logic
+/// in the GPU kernel vs the CPU's ScanCutter.
+///
+/// Tolerances were derived from a single OT128 rosbag (ot128/1730271167765338806):
+///   - Scan 0: CPU=70275, GPU=72125 (diff=1850)
+///   - Scan 1: CPU=72240, GPU=72185 (diff=55)
+/// If additional rosbags show larger boundary diffs, tolerances may need adjustment.
+
+#include "hesai_ros_decoder_test.hpp"
+
+#include <rclcpp/rclcpp.hpp>
+
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <cmath>
+#include <cstdlib>
+#include <limits>
+#include <memory>
+#include <string>
+#include <vector>
+
+#ifdef NEBULA_CUDA_ENABLED
+
+namespace nebula::test
+{
+
+// OT128 config — matches TEST_CONFIGS[8] in hesai_ros_decoder_test_main.cpp
+static const nebula::ros::HesaiRosDecoderTestParams OT128_CONFIG = {
+  "Pandar128E4X",
+  "LastStrongest",
+  "Pandar128E4X.csv",
+  "ot128/1730271167765338806",
+  "hesai",
+  0,
+  0.0,
+  0.,
+  360.,
+  0.3f,
+  300.f};
+
+// Maximum allowed difference in point count between GPU and CPU per scan.
+// The GPU kernel assigns scan-boundary points differently than the CPU's ScanCutter,
+// causing up to ~2000 points to shift between adjacent scans.
+// Observed max diff: 1850 (scan 0 of test rosbag). Set to 2000 for ~8% headroom.
+static constexpr int kMaxPointCountDiff = 2000;
+// Coordinate tolerance (metres) for nearest-neighbour matching.
+// GPU uses pre-computed LUT with 0.01-degree resolution; small rounding differences expected.
+static constexpr float kXyzTolerance = 5e-3f;
+// Fraction of GPU points that must have a CPU match within tolerance.
+// ~2-3% of points are at scan boundaries and may not have an exact match.
+static constexpr double kMinMatchRatio = 0.97;
+
+/// Decoded scan: message timestamp + point cloud
+struct DecodedScan
+{
+  uint64_t msg_timestamp;
+  nebula::drivers::NebulaPointCloudPtr cloud;
+};
+
+/// Decode a rosbag with the given CUDA env setting.
+/// When @p use_cuda is true, sets NEBULA_USE_CUDA=1; otherwise unsets it.
+/// Returns one DecodedScan per completed scan.
+static std::vector<DecodedScan> decode_bag(
+  const nebula::ros::HesaiRosDecoderTestParams & params, bool use_cuda)
+{
+  // Toggle GPU/CPU path via environment variable
+  if (use_cuda) {
+    setenv("NEBULA_USE_CUDA", "1", 1);
+  } else {
+    unsetenv("NEBULA_USE_CUDA");
+  }
+
+  rclcpp::NodeOptions options;
+  auto driver =
+    std::make_shared<nebula::ros::HesaiRosDecoderTest>(options, "cuda_test_node", params);
+  EXPECT_EQ(driver->get_status(), nebula::Status::OK);
+
+  std::vector<DecodedScan> scans;
+  auto cb = [&](uint64_t msg_ts, uint64_t /*scan_ts*/, nebula::drivers::NebulaPointCloudPtr cloud) {
+    if (cloud && !cloud->empty()) {
+      // Deep-copy: the decoder reuses its internal buffer after the callback returns
+      auto copy = std::make_shared<nebula::drivers::NebulaPointCloud>(*cloud);
+      scans.push_back({msg_ts, copy});
+    }
+  };
+  driver->read_bag(cb);
+  return scans;
+}
+
+/// Squared Euclidean distance between two points
+static float sq_dist(const nebula::drivers::NebulaPoint & a, const nebula::drivers::NebulaPoint & b)
+{
+  float dx = a.x - b.x;
+  float dy = a.y - b.y;
+  float dz = a.z - b.z;
+  return dx * dx + dy * dy + dz * dz;
+}
+
+// ---------------------------------------------------------------------------
+// Test 1: GPU vs CPU equivalence
+// ---------------------------------------------------------------------------
+TEST(HesaiCudaDecoderTest, OT128_GpuVsCpuEquivalence)
+{
+  auto cpu_scans = decode_bag(OT128_CONFIG, /*use_cuda=*/false);
+  auto gpu_scans = decode_bag(OT128_CONFIG, /*use_cuda=*/true);
+
+  // Both paths must produce the same number of scans
+  ASSERT_GT(cpu_scans.size(), 0u);
+  ASSERT_EQ(cpu_scans.size(), gpu_scans.size())
+    << "CPU produced " << cpu_scans.size() << " scans, GPU produced " << gpu_scans.size();
+
+  const float tol_sq = kXyzTolerance * kXyzTolerance;
+
+  for (size_t i = 0; i < cpu_scans.size(); ++i) {
+    const auto & cpu_cloud = cpu_scans[i].cloud;
+    const auto & gpu_cloud = gpu_scans[i].cloud;
+
+    // Point counts within tolerance
+    int diff = static_cast<int>(cpu_cloud->size()) - static_cast<int>(gpu_cloud->size());
+    EXPECT_LE(std::abs(diff), kMaxPointCountDiff)
+      << "Scan " << i << ": CPU=" << cpu_cloud->size() << " GPU=" << gpu_cloud->size();
+
+    // For each GPU point, find nearest CPU point (brute-force — clouds are small enough)
+    size_t matched = 0;
+    for (const auto & gp : *gpu_cloud) {
+      float best = std::numeric_limits<float>::max();
+      for (const auto & cp : *cpu_cloud) {
+        float d = sq_dist(gp, cp);
+        if (d < best) best = d;
+        if (d < tol_sq) break;  // early exit — found a match
+      }
+      if (best < tol_sq) ++matched;
+    }
+
+    double match_ratio =
+      gpu_cloud->empty() ? 1.0 : static_cast<double>(matched) / gpu_cloud->size();
+    EXPECT_GE(match_ratio, kMinMatchRatio)
+      << "Scan " << i << ": only " << matched << "/" << gpu_cloud->size()
+      << " GPU points matched a CPU point within " << kXyzTolerance << " m";
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Test 2: GPU output is non-empty
+// ---------------------------------------------------------------------------
+TEST(HesaiCudaDecoderTest, OT128_GpuOutputNonEmpty)
+{
+  auto gpu_scans = decode_bag(OT128_CONFIG, /*use_cuda=*/true);
+  ASSERT_GT(gpu_scans.size(), 0u) << "GPU path produced zero scans";
+  for (size_t i = 0; i < gpu_scans.size(); ++i) {
+    EXPECT_GT(gpu_scans[i].cloud->size(), 0u) << "Scan " << i << " is empty";
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Test 3: Basic field validity of GPU-decoded points
+// ---------------------------------------------------------------------------
+TEST(HesaiCudaDecoderTest, OT128_GpuFieldValidity)
+{
+  auto gpu_scans = decode_bag(OT128_CONFIG, /*use_cuda=*/true);
+  ASSERT_GT(gpu_scans.size(), 0u);
+
+  for (size_t i = 0; i < gpu_scans.size(); ++i) {
+    for (const auto & pt : *gpu_scans[i].cloud) {
+      // Distance must be positive (all valid points)
+      float dist = std::sqrt(pt.x * pt.x + pt.y * pt.y + pt.z * pt.z);
+      EXPECT_GT(dist, 0.f) << "Scan " << i << ": zero-distance point found";
+
+      // Channel must be in [0, 127] for OT128
+      EXPECT_LE(pt.channel, 127u) << "Scan " << i << ": invalid channel " << pt.channel;
+    }
+  }
+}
+
+// ---------------------------------------------------------------------------
+// Test 4 (edge case): First and last scans have reasonable point counts
+// ---------------------------------------------------------------------------
+TEST(HesaiCudaDecoderTest, OT128_BoundaryScanPointCounts)
+{
+  auto gpu_scans = decode_bag(OT128_CONFIG, /*use_cuda=*/true);
+  ASSERT_GE(gpu_scans.size(), 2u) << "Need at least 2 scans for boundary test";
+
+  // First scan may be partial, but should still have a reasonable number of points.
+  // A full OT128 scan typically has ~100k+ points; even a partial scan should exceed 1000.
+  EXPECT_GT(gpu_scans.front().cloud->size(), 1000u)
+    << "First scan has suspiciously few points: " << gpu_scans.front().cloud->size();
+
+  // Last scan should also be non-trivial
+  EXPECT_GT(gpu_scans.back().cloud->size(), 1000u)
+    << "Last scan has suspiciously few points: " << gpu_scans.back().cloud->size();
+}
+
+// ---------------------------------------------------------------------------
+// Test 5 (edge case): GPU intensity matches CPU exactly
+// ---------------------------------------------------------------------------
+TEST(HesaiCudaDecoderTest, OT128_IntensityExactMatch)
+{
+  auto cpu_scans = decode_bag(OT128_CONFIG, /*use_cuda=*/false);
+  auto gpu_scans = decode_bag(OT128_CONFIG, /*use_cuda=*/true);
+
+  ASSERT_EQ(cpu_scans.size(), gpu_scans.size());
+
+  for (size_t i = 0; i < cpu_scans.size(); ++i) {
+    const auto & cpu_pts = *cpu_scans[i].cloud;
+    const auto & gpu_pts = *gpu_scans[i].cloud;
+
+    // For each GPU point, find the nearest CPU match and verify intensity is identical.
+    // Only compare points that have a close spatial match (same physical point).
+    size_t checked = 0;
+    size_t intensity_mismatch = 0;
+
+    // Use a tighter tolerance for intensity matching to ensure we're comparing the same point
+    const float tight_tol_sq = 1e-6f;
+
+    for (const auto & gp : gpu_pts) {
+      float best_dist = std::numeric_limits<float>::max();
+      size_t best_idx = 0;
+      for (size_t j = 0; j < cpu_pts.size(); ++j) {
+        float d = sq_dist(gp, cpu_pts[j]);
+        if (d < best_dist) {
+          best_dist = d;
+          best_idx = j;
+        }
+        if (d < tight_tol_sq) break;
+      }
+      if (best_dist < tight_tol_sq) {
+        ++checked;
+        if (gp.intensity != cpu_pts[best_idx].intensity) {
+          ++intensity_mismatch;
+        }
+      }
+    }
+
+    // The vast majority of matched points should have identical intensity.
+    // A small fraction (<1%) may differ at scan boundaries where the GPU kernel
+    // selects a different return than the CPU's dual-return filtering.
+    EXPECT_GT(checked, 0u) << "Scan " << i << ": no tight matches found";
+    double mismatch_ratio = checked > 0 ? static_cast<double>(intensity_mismatch) / checked : 0.0;
+    EXPECT_LT(mismatch_ratio, 0.01)
+      << "Scan " << i << ": " << intensity_mismatch << "/" << checked
+      << " matched points have different intensity (" << (mismatch_ratio * 100) << "%)";
+  }
+}
+
+}  // namespace nebula::test
+
+#else  // !NEBULA_CUDA_ENABLED
+
+TEST(HesaiCudaDecoderTest, SkippedNoCuda)
+{
+  GTEST_SKIP() << "CUDA not enabled at compile time";
+}
+
+#endif  // NEBULA_CUDA_ENABLED
+
+int main(int argc, char * argv[])
+{
+  rclcpp::init(argc, argv);
+  ::testing::InitGoogleTest(&argc, argv);
+  int result = RUN_ALL_TESTS();
+  // Restore env
+  unsetenv("NEBULA_USE_CUDA");
+  rclcpp::shutdown();
+  return result;
+}

src/nebula_hesai/nebula_hesai_decoders/CMakeLists.txt

@@ -5,7 +5,39 @@ find_package(autoware_cmake REQUIRED)
 find_package(Boost REQUIRED)
 autoware_package()
 
-# Hesai Decoder
+# Option to enable CUDA support
+option(BUILD_CUDA "Build with CUDA support" ON)
+
+# CUDA Configuration
+if(BUILD_CUDA)
+  find_package(CUDAToolkit QUIET)
+  if(NOT CUDAToolkit_FOUND)
+    message(WARNING "CUDA Toolkit not found, building without CUDA support")
+    set(BUILD_CUDA OFF)
+  else()
+    message(STATUS "CUDA Toolkit found: ${CUDAToolkit_VERSION}")
+
+    # GPU architectures — set via -DCMAKE_CUDA_ARCHITECTURES on the command line,
+    # or fall back to a default set covering Turing through Ada + PTX for forward
+    # compatibility (e.g. Blackwell GPUs JIT from compute_89 PTX).
+    # Example: -DCMAKE_CUDA_ARCHITECTURES=89  (single-arch for fast builds)
+    if(NOT DEFINED CMAKE_CUDA_ARCHITECTURES OR CMAKE_CUDA_ARCHITECTURES STREQUAL "")
+      set(CMAKE_CUDA_ARCHITECTURES "75;86;87;89" CACHE STRING "CUDA architectures" FORCE)
+    endif()
+
+    # Check if CUDA kernel source exists
+    if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/src/cuda/hesai_cuda_kernels.cu")
+      set(CUDA_KERNELS_EXIST TRUE)
+      message(STATUS "CUDA kernel source found, will build CUDA decoder")
+    else()
+      set(CUDA_KERNELS_EXIST FALSE)
+      message(WARNING "CUDA kernel source (src/cuda/hesai_cuda_kernels.cu) not found")
+      message(WARNING "Building without CUDA decoder support")
+    endif()
+  endif()
+endif()
+
+# Hesai Decoder library (CPU)
 add_library(nebula_hesai_decoders SHARED src/hesai_driver.cpp)
 
 target_include_directories(
@@ -20,6 +52,52 @@ target_link_libraries(
          nebula_core_decoders::nebula_core_decoders rclcpp::rclcpp
          Boost::headers)
 
+# CUDA Decoder library
+if(BUILD_CUDA AND CUDA_KERNELS_EXIST)
+  enable_language(CUDA)
+
+  set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} -O3 -diag-suppress 20012")
+
+  add_library(nebula_hesai_decoders_cuda SHARED
+    src/cuda/hesai_cuda_kernels.cu
+  )
+
+  set_target_properties(nebula_hesai_decoders_cuda PROPERTIES
+    CUDA_SEPARABLE_COMPILATION ON
+    POSITION_INDEPENDENT_CODE ON
+    CUDA_STANDARD 17
+    CUDA_STANDARD_REQUIRED ON
+    CUDA_RESOLVE_DEVICE_SYMBOLS ON
+  )
+
+  # Clear any inherited compile options that might be incompatible with CUDA
+  set_property(TARGET nebula_hesai_decoders_cuda PROPERTY COMPILE_OPTIONS "")
+
+  target_include_directories(
+    nebula_hesai_decoders_cuda
+    PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+           $<INSTALL_INTERFACE:include>)
+
+  target_link_libraries(nebula_hesai_decoders_cuda
+    PRIVATE CUDA::cudart_static)
+
+  target_compile_definitions(nebula_hesai_decoders_cuda PUBLIC NEBULA_CUDA_ENABLED)
+  target_compile_definitions(nebula_hesai_decoders PUBLIC NEBULA_CUDA_ENABLED)
+
+  # Add CUDA include directories to main library for header resolution
+  target_include_directories(nebula_hesai_decoders
+    PUBLIC ${CUDAToolkit_INCLUDE_DIRS})
+
+  # Link CUDA library to main library (CUDA::cudart is PRIVATE so it won't
+  # propagate the imported target to downstream packages that lack CUDAToolkit)
+  target_link_libraries(nebula_hesai_decoders
+    PUBLIC nebula_hesai_decoders_cuda
+    PRIVATE CUDA::cudart)
+
+  install(TARGETS nebula_hesai_decoders_cuda EXPORT export_nebula_hesai_decoders_cuda)
+  ament_export_targets(export_nebula_hesai_decoders_cuda)
+endif()
+
 install(TARGETS nebula_hesai_decoders EXPORT export_nebula_hesai_decoders)
 install(DIRECTORY include/${PROJECT_NAME}/ DESTINATION include/${PROJECT_NAME})