Linkage.hpp

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#ifndef DART_DYNAMICS_LINKAGE_HPP_
#define DART_DYNAMICS_LINKAGE_HPP_

#include <unordered_set>
#include "dart/dynamics/ReferentialSkeleton.hpp"

namespace dart {
namespace dynamics {

class Linkage : public ReferentialSkeleton
{
public:
  struct Criteria
  {
    enum ExpansionPolicy
    {
      INCLUDE = 0, 
      EXCLUDE, 
      DOWNSTREAM, 
      UPSTREAM    
    };

    std::vector<BodyNode*> satisfy() const;

    struct Target
    {
      Target(
          BodyNode* _target = nullptr,
          ExpansionPolicy _policy = INCLUDE,
          bool _chain = false);

      WeakBodyNodePtr mNode;

      ExpansionPolicy mPolicy;

      bool mChain;
    };

    Target mStart;

    std::vector<Target> mTargets;

    struct Terminal
    {
      Terminal(BodyNode* _terminal = nullptr, bool _inclusive = true);

      WeakBodyNodePtr mTerminal;

      bool mInclusive;
    };

    std::vector<Terminal> mTerminals;

    Criteria() = default;

    Criteria(
        BodyNode* start,
        BodyNode* target,
        bool includeUpstreamParentJoint = false);

  protected:
    void refreshTerminalMap() const;

    void expansionPolicy(
        BodyNode* _start,
        ExpansionPolicy _policy,
        std::vector<BodyNode*>& _bns) const;

    void expandDownstream(
        BodyNode* _start,
        std::vector<BodyNode*>& _bns,
        bool _includeStart) const;

    void expandUpstream(
        BodyNode* _start,
        std::vector<BodyNode*>& _bns,
        bool _includeStart) const;

    void expandToTarget(
        const Target& _start,
        const Target& _target,
        std::vector<BodyNode*>& _bns) const;

    std::vector<BodyNode*> climbToTarget(
        BodyNode* _start, BodyNode* _target) const;

    std::vector<BodyNode*> climbToCommonRoot(
        const Target& _start, const Target& _target, bool _chain) const;

    void trimBodyNodes(
        std::vector<BodyNode*>& _bns, bool _chain, bool _movingUpstream) const;

    mutable std::unordered_map<BodyNode*, bool> mMapOfTerminals;
  };

  static LinkagePtr create(
      const Criteria& _criteria, const std::string& _name = "Linkage");

  LinkagePtr cloneLinkage() const;

  LinkagePtr cloneLinkage(const std::string& cloneName) const;

  // To expose MetaSkeleton::cloneMetaSkeleton(), which takes no cloneName.
  using MetaSkeleton::cloneMetaSkeleton;

  // Documentation inherited
  MetaSkeletonPtr cloneMetaSkeleton(
      const std::string& cloneName) const override;

  bool isAssembled() const;

  void reassemble();

  void satisfyCriteria();

protected:
  Linkage(const Criteria& _criteria, const std::string& _name = "Linkage");

  virtual void update();

  Criteria mCriteria;

  std::vector<WeakBodyNodePtr> mParentBodyNodes;
};

} // namespace dynamics
} // namespace dart

#endif // DART_DYNAMICS_LINKAGE_HPP_