y2023/vision/aprilrobotics.cc

#include "y2023/vision/aprilrobotics.h"

DEFINE_bool(
    debug, false,
    "If true, dump a ton of debug and crash on the first valid detection.");

DEFINE_int32(team_number, 971,
             "Use the calibration for a node with this team number");
namespace y2023 {
namespace vision {

namespace chrono = std::chrono;

AprilRoboticsDetector::AprilRoboticsDetector(aos::EventLoop *event_loop,
                                             std::string_view channel_name)
    : calibration_data_(CalibrationData()),
      ftrace_(),
      image_callback_(
          event_loop, channel_name,
          [&](cv::Mat image_color_mat,
              const aos::monotonic_clock::time_point eof) {
            HandleImage(image_color_mat, eof);
          },
          chrono::milliseconds(5)),
      target_map_sender_(
          event_loop->MakeSender<frc971::vision::TargetMap>("/camera")) {
  tag_family_ = tag16h5_create();
  tag_detector_ = apriltag_detector_create();

  apriltag_detector_add_family_bits(tag_detector_, tag_family_, 1);
  tag_detector_->nthreads = 6;
  tag_detector_->wp = workerpool_create(tag_detector_->nthreads);
  tag_detector_->qtp.min_white_black_diff = 5;
  tag_detector_->debug = FLAGS_debug;

  std::string hostname = aos::network::GetHostname();

  // Check team string is valid
  std::optional<uint16_t> pi_number = aos::network::ParsePiNumber(hostname);
  std::optional<uint16_t> team_number =
      aos::network::team_number_internal::ParsePiTeamNumber(hostname);
  CHECK(pi_number) << "Unable to parse pi number from '" << hostname << "'";
  CHECK(team_number);

  calibration_ = FindCameraCalibration(&calibration_data_.message(),
                                       "pi" + std::to_string(*pi_number));
  intrinsics_ = CameraIntrinsics(calibration_);
  camera_distortion_coeffs_ = CameraDistCoeffs(calibration_);

  image_callback_.set_format(frc971::vision::ImageCallback::Format::GRAYSCALE);
}

AprilRoboticsDetector::~AprilRoboticsDetector() {
  apriltag_detector_destroy(tag_detector_);
  free(tag_family_);
}

void AprilRoboticsDetector::SetWorkerpoolAffinities() {
  for (int i = 0; i < tag_detector_->wp->nthreads; i++) {
    cpu_set_t affinity;
    CPU_ZERO(&affinity);
    CPU_SET(i, &affinity);
    pthread_setaffinity_np(tag_detector_->wp->threads[i], sizeof(affinity),
                           &affinity);
    struct sched_param param;
    param.sched_priority = 20;
    int res = pthread_setschedparam(tag_detector_->wp->threads[i], SCHED_FIFO,
                                    &param);
    PCHECK(res == 0) << "Failed to set priority of threadpool threads";
  }
}

void AprilRoboticsDetector::HandleImage(cv::Mat image_color_mat,
                                        aos::monotonic_clock::time_point eof) {
  std::vector<std::pair<apriltag_detection_t, apriltag_pose_t>> detections =
      DetectTags(image_color_mat);

  auto builder = target_map_sender_.MakeBuilder();
  std::vector<flatbuffers::Offset<frc971::vision::TargetPoseFbs>> target_poses;
  for (const auto &[detection, pose] : detections) {
    target_poses.emplace_back(
        BuildTargetPose(pose, detection.id, builder.fbb()));
  }
  const auto target_poses_offset = builder.fbb()->CreateVector(target_poses);
  auto target_map_builder = builder.MakeBuilder<frc971::vision::TargetMap>();
  target_map_builder.add_target_poses(target_poses_offset);
  target_map_builder.add_monotonic_timestamp_ns(eof.time_since_epoch().count());
  builder.CheckOk(builder.Send(target_map_builder.Finish()));
}

flatbuffers::Offset<frc971::vision::TargetPoseFbs>
AprilRoboticsDetector::BuildTargetPose(
    const apriltag_pose_t &pose,
    frc971::vision::TargetMapper::TargetId target_id,
    flatbuffers::FlatBufferBuilder *fbb) {
  const auto T =
      Eigen::Translation3d(pose.t->data[0], pose.t->data[1], pose.t->data[2]);
  const auto position_offset =
      frc971::vision::CreatePosition(*fbb, T.x(), T.y(), T.z());

  const auto orientation = Eigen::Quaterniond(Eigen::Matrix3d(pose.R->data));
  const auto orientation_offset = frc971::vision::CreateQuaternion(
      *fbb, orientation.w(), orientation.x(), orientation.y(), orientation.z());

  return frc971::vision::CreateTargetPoseFbs(*fbb, target_id, position_offset,
                                             orientation_offset);
}

std::vector<std::pair<apriltag_detection_t, apriltag_pose_t>>
AprilRoboticsDetector::DetectTags(cv::Mat image) {
  const aos::monotonic_clock::time_point start_time =
      aos::monotonic_clock::now();

  image_u8_t im = {
      .width = image.cols,
      .height = image.rows,
      .stride = image.cols,
      .buf = image.data,
  };

  ftrace_.FormatMessage("Starting detect\n");
  zarray_t *detections = apriltag_detector_detect(tag_detector_, &im);
  ftrace_.FormatMessage("Done detecting\n");

  std::vector<std::pair<apriltag_detection_t, apriltag_pose_t>> results;

  for (int i = 0; i < zarray_size(detections); i++) {
    apriltag_detection_t *det;
    zarray_get(detections, i, &det);

    if (det->decision_margin > 30) {
      VLOG(1) << "Found tag number " << det->id << " hamming: " << det->hamming
              << " margin: " << det->decision_margin;

      const aos::monotonic_clock::time_point before_pose_estimation =
          aos::monotonic_clock::now();
      // First create an apriltag_detection_info_t struct using your known
      // parameters.
      apriltag_detection_info_t info;
      info.det = det;
      info.tagsize = 0.1524;
      info.fx = intrinsics_.at<double>(0, 0);
      info.fy = intrinsics_.at<double>(1, 1);
      info.cx = intrinsics_.at<double>(0, 2);
      info.cy = intrinsics_.at<double>(1, 2);

      apriltag_pose_t pose;
      double err = estimate_tag_pose(&info, &pose);

      VLOG(1) << "err: " << err;

      results.emplace_back(*det, pose);

      const aos::monotonic_clock::time_point after_pose_estimation =
          aos::monotonic_clock::now();

      VLOG(1) << "Took "
              << chrono::duration<double>(after_pose_estimation -
                                          before_pose_estimation)
                     .count()
              << " seconds for pose estimation";
    }
  }

  apriltag_detections_destroy(detections);

  const aos::monotonic_clock::time_point end_time = aos::monotonic_clock::now();

  timeprofile_display(tag_detector_->tp);

  VLOG(1) << "Took " << chrono::duration<double>(end_time - start_time).count()
          << " seconds to detect overall";

  return results;
}

}  // namespace vision
}  // namespace y2023