OpenMW/apps/openmw/mwmechanics/obstacle.hpp

#ifndef OPENMW_MECHANICS_OBSTACLE_H
#define OPENMW_MECHANICS_OBSTACLE_H

#include <osg/Vec3f>

#include <vector>

namespace MWWorld
{
    class Ptr;
    class ConstPtr;
}

namespace MWMechanics
{
    struct Movement;

    static constexpr int NUM_EVADE_DIRECTIONS = 4;

    /// tests actor's proximity to a closed door by default
    bool proximityToDoor(const MWWorld::Ptr& actor, float minDist);

    /// Returns door pointer within range. No guarantee is given as to which one
    /** \return Pointer to the door, or empty pointer if none exists **/
    const MWWorld::Ptr getNearbyDoor(const MWWorld::Ptr& actor, float minDist);

    bool isAreaOccupiedByOtherActor(const MWWorld::ConstPtr& actor, const osg::Vec3f& destination,
        bool ignorePlayer = false, std::vector<MWWorld::Ptr>* occupyingActors = nullptr);

    class ObstacleCheck
    {
    public:
        ObstacleCheck();

        // Clear the timers and set the state machine to default
        void clear();

        bool isEvading() const;

        // Updates internal state, call each frame for moving actor
        void update(const MWWorld::Ptr& actor, const osg::Vec3f& destination, float duration);

        // change direction to try to fix "stuck" actor
        void takeEvasiveAction(MWMechanics::Movement& actorMovement) const;

    private:
        osg::Vec3f mPrev;

        // directions to try moving in when get stuck
        static const float evadeDirections[NUM_EVADE_DIRECTIONS][2];

        enum class WalkState
        {
            Initial,
            Norm,
            CheckStuck,
            Evade
        };
        WalkState mWalkState;

        float mStateDuration;
        int mEvadeDirectionIndex;
        float mInitialDistance = 0;

        void chooseEvasionDirection();
    };
}

#endif