blackboard_precondition.h

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/*  Copyright (C) 2018-2020 Davide Faconti, Eurecat -  All Rights Reserved
*
*   Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
*   to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
*   and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*   The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
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#ifndef DECORATOR_BLACKBOARD_PRECONDITION_NODE_H
#define DECORATOR_BLACKBOARD_PRECONDITION_NODE_H
 
#include "behaviortree_cpp_v3/decorator_node.h"
#include <type_traits>
 
namespace BT
{
template <typename T>
class BlackboardPreconditionNode : public DecoratorNode
{
public:
  BlackboardPreconditionNode(const std::string& name, const NodeConfiguration& config) :
    DecoratorNode(name, config)
  {
    if (std::is_same<T, int>::value)
      setRegistrationID("BlackboardCheckInt");
    else if (std::is_same<T, double>::value)
      setRegistrationID("BlackboardCheckDouble");
    else if (std::is_same<T, std::string>::value)
      setRegistrationID("BlackboardCheckString");
    else if (std::is_same<T, bool>::value)
      setRegistrationID("BlackboardCheckBool");
  }
 
  virtual ~BlackboardPreconditionNode() override = default;
 
  static PortsList providedPorts()
  {
    return {InputPort("value_A"), InputPort("value_B"),
            InputPort<NodeStatus>("return_on_mismatch")};
  }
 
private:
  virtual BT::NodeStatus tick() override;
};
 
//----------------------------------------------------
 
template <typename T>
inline bool IsSame(const T& a, const T& b)
{
  return a == b;
}
 
inline bool IsSame(const double& a, const double& b)
{
  constexpr double EPS = static_cast<double>(std::numeric_limits<float>::epsilon());
  return std::abs(a - b) <= EPS;
}
 
template <typename T>
inline NodeStatus BlackboardPreconditionNode<T>::tick()
{
  T value_A;
  T value_B;
  NodeStatus default_return_status = NodeStatus::FAILURE;
 
  setStatus(NodeStatus::RUNNING);
 
  if (getInput("value_A", value_A) && getInput("value_B", value_B) &&
      IsSame(value_A, value_B))
  {
    return child_node_->executeTick();
  }
 
  if (child()->status() == NodeStatus::RUNNING)
  {
    haltChild();
  }
  getInput("return_on_mismatch", default_return_status);
  return default_return_status;
}
 
}   // namespace BT
 
#endif