is_pose_occupied_condition.cpp

// Copyright (c) 2025 Maurice Alexander Purnawan
//
// 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.
 
#include "nav2_behavior_tree/plugins/condition/is_pose_occupied_condition.hpp"
#include <chrono>
#include <memory>
#include <string>
 
namespace nav2_behavior_tree
{
 
IsPoseOccupiedCondition::IsPoseOccupiedCondition(
  const std::string & condition_name,
  const BT::NodeConfiguration & conf)
: BT::ConditionNode(condition_name, conf),
  use_footprint_(true), consider_unknown_as_obstacle_(false), cost_threshold_(254),
  service_name_("global_costmap/get_cost_global_costmap")
{
  node_ = config().blackboard->get<nav2::LifecycleNode::SharedPtr>("node");
  server_timeout_ = config().blackboard->template get<std::chrono::milliseconds>("server_timeout");
}
 
void IsPoseOccupiedCondition::initialize()
{
  getInput<std::string>("service_name", service_name_);
  getInput<double>("cost_threshold", cost_threshold_);
  getInput<bool>("use_footprint", use_footprint_);
  getInput<bool>("consider_unknown_as_obstacle", consider_unknown_as_obstacle_);
  getInput<std::chrono::milliseconds>("server_timeout", server_timeout_);
  client_ =
    node_->create_client<nav2_msgs::srv::GetCosts>(
    service_name_,
    false /* Does not create and spin an internal executor*/);
}
 
BT::NodeStatus IsPoseOccupiedCondition::tick()
{
  if (!BT::isStatusActive(status())) {
    initialize();
  }
  geometry_msgs::msg::PoseStamped pose;
  getInput("pose", pose);
 
  auto request = std::make_shared<nav2_msgs::srv::GetCosts::Request>();
  request->use_footprint = use_footprint_;
  request->poses.push_back(pose);
 
  auto response = client_->invoke(request, server_timeout_);
 
  if(!response->success) {
    RCLCPP_ERROR(
      node_->get_logger(),
      "GetCosts service call failed");
    return BT::NodeStatus::FAILURE;
  }
 
  if((response->costs[0] == 255 && !consider_unknown_as_obstacle_) ||
    response->costs[0] < cost_threshold_)
  {
    return BT::NodeStatus::FAILURE;
  } else {
    return BT::NodeStatus::SUCCESS;
  }
}
 
}  // namespace nav2_behavior_tree
 
#include "behaviortree_cpp/bt_factory.h"
BT_REGISTER_NODES(factory)
{
  factory.registerNodeType<nav2_behavior_tree::IsPoseOccupiedCondition>("IsPoseOccupied");
}