HFSMBase.c

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void fsmDebugPrint (string s)
{
    //Print("" + s); // comment/uncomment to hide/see debug logs
}
void fsmDebugSpam (string s)
{
    //Print("" + s); // comment/uncomment to hide/see debug spam
}
 
 
class HFSMBase<Class FSMStateBase, Class FSMEventBase, Class FSMActionBase, Class FSMGuardBase>
{
    protected ref FSMStateBase m_State; 
    protected FSMStateBase m_OwnerState; 
    protected ref FSMStateBase m_InitialState; 
    protected ref array<ref FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase>> m_Transitions = new array<ref FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase>>; 
    protected bool m_HasCompletions = false;
 
    void HFSMBase (FSMStateBase ownerState = NULL)
    {
        m_OwnerState = ownerState;
    }
 
    FSMStateBase GetCurrentState ()
    {
        return m_State;
    }
    FSMStateBase GetOwnerState ()
    {
        return m_OwnerState;
    }
    bool GetHierarchyPath (FSMStateBase state, out array<FSMStateBase> path)
    {
        FSMStateBase curr = state;
        while (curr)
        {
          path.Insert(curr);
          curr = curr.GetParentState();
        }
        return path.Count() > 0;
    }
 
    void SetInitialState (FSMStateBase initial_state)
    {
        m_InitialState = initial_state;
    }
    void AddTransition (FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t)
    {
        m_Transitions.Insert(t);
        //fsmDebugSpam("[hfsm] +++ ow=" + this.GetOwnerState() + " this=" + this + " t=" + t + " state=" + t.m_srcState + "-------- event=" + t.m_event + "[G=" + t.m_guard +"]/A=" + t.m_action + " --------|> dst=" + t.m_dstState);
        if (t.m_event == NULL)
        {
            Print("Warning (performance): FSM " + this + " has completion transition for src=" + t.m_srcState + " ---NULL----|> dst=" + t.m_dstState);
            m_HasCompletions = true;
        }
    }
 
    void Start (FSMEventBase initial_event = NULL, bool useExistingState = false)
    {
        fsmDebugPrint("[hfsm] " + this.ToString() + "::Start(" + initial_event.ToString() + "), init_state=" + m_InitialState.ToString());
 
        if (!useExistingState)
            m_State = m_InitialState;
        
        m_State.OnEntry(initial_event);
 
        if (m_HasCompletions)
            ProcessCompletionTransitions();
    }
    bool IsRunning () { return m_State != NULL; }
    void Terminate (FSMEventBase terminal_event = NULL)
    {
        fsmDebugPrint("[hfsm] " + this.ToString() + "::Terminate(" + terminal_event.ToString() + ")");
        if (IsRunning())
        {
            m_State.OnExit(terminal_event);
            m_State = NULL;
        }
    }
    void Abort (FSMEventBase abort_event = NULL)
    {
        fsmDebugPrint("[hfsm] " + this.ToString() + "::Abort(" + abort_event.ToString() + ")");
        if (IsRunning())
        {
            m_State.OnAbort(abort_event);
            m_State = NULL;
        }
    }
    void Update (float dt)
    {
        if (IsRunning())
            m_State.OnUpdate(dt);
    }
 
    protected ProcessEventResult ProcessAbortTransition (FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t, FSMEventBase e)
    {
        fsmDebugPrint("[hfsm] (local abort) state=" + t.m_srcState.ToString() + "-------- ABORT event=" + e.ToString() + "[G=" + t.m_guard.ToString() +"]/A=" + t.m_action.ToString() + " --------|> dst=" + t.m_dstState.ToString());
 
        m_State.OnAbort(e);         // 1) call onAbort on old state
 
        if (t.m_action)
            t.m_action.Action(e);   // 2) execute transition action (if any)
 
        auto tmp = t.m_srcState.GetParentState();
        if (tmp == t.m_dstState.GetParentState())
        {
            m_State = t.m_dstState;     // 3) change state to new (or NULL)
 
            if (t.m_dstState != NULL)
            {
                m_State.OnEntry(e);     // 4a1) call onEntry on new state (see 4a2) )
                return ProcessEventResult.FSM_OK;
            }
            else
            {
                fsmDebugPrint("[hfsm] abort & terminating fsm: state=" + t.m_srcState.ToString() + " event=" + e.ToString());
                return ProcessEventResult.FSM_TERMINATED; // 4b) or terminate
            }
        }
        else
        {
            m_State = NULL;
            return ProcessEventResult.FSM_ABORTED; // 4c) or signal abort to parent (with appropriate transition)
        }
    }
 
    FSMStateBase FindAbortDestinationState (FSMEventBase e)
    {
        if (GetOwnerState())
            fsmDebugPrint("[hfsm] SUB! " + GetOwnerState().Type().ToString() + "::FindAbortDestinationState(" + e.Type().ToString() + ")");
        else
            fsmDebugPrint("[hfsm] root::FindAbortDestinationState(" + e.Type().ToString() + ")");
 
        // 1) look in submachine first (if any)
        if (m_State.HasFSM())
        {
            HFSMBase<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> a = m_State.GetFSM();
            FSMStateBase abort_dst = a.FindAbortDestinationState(e);
 
            if (abort_dst)
            {
                return abort_dst;
            }
        }
 
        // 2) local transitions
        int i = FindFirstUnguardedTransition(e);
        if (i == -1)
        {
            fsmDebugPrint("[hfsm] abort event has no transition: src=" + m_State.ToString() + " e=" + e.Type().ToString());
            return NULL;
        }
 
        FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t = m_Transitions.Get(i);
        return t.m_dstState;
    }
    
    FSMStateBase ProcessAbortEvent (FSMEventBase e, out ProcessEventResult result)
    {
        if (GetOwnerState())
            fsmDebugPrint("[hfsm] SUB! " + GetOwnerState().Type().ToString() + "::ProcessAbortEvent(" + e.Type().ToString() + ")");
        else
            fsmDebugPrint("[hfsm] root::ProcessAbortEvent(" + e.Type().ToString() + ")");
 
        // 1) look in submachine first (if any)
        if (m_State.HasFSM())
        {
            HFSMBase<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> a = m_State.GetFSM();
            ProcessEventResult subfsm_res;
            FSMStateBase abort_dst = a.ProcessAbortEvent(e, subfsm_res);
 
            switch (subfsm_res)
            {
                case ProcessEventResult.FSM_OK:
                {
                    fsmDebugPrint("[hfsm] event processed by sub machine=" + m_State.ToString());
                    result = subfsm_res;        // 1.1) submachine accepted event
                    return NULL;
                }
                case ProcessEventResult.FSM_ABORTED:
                {
                    fsmDebugPrint("[hfsm] aborted sub machine=" + m_State.ToString());
                    
                    m_State.OnAbort(e); // 1.2) submachine aborted, abort submachine owner (i.e. this)
 
                    if (GetOwnerState() == abort_dst.GetParentState())
                    {
                        fsmDebugPrint("[hfsm] aborted sub machine=" + m_State.ToString() + " & abort destination reached.");
                        m_State = abort_dst;
                        m_State.OnEntry(e);     // 1.3) submachine aborted, call onEntry on new state (cross-hierarchy transition)
                        result = ProcessEventResult.FSM_OK;
                        return NULL;
                    }
                    else
                    {
                        result = ProcessEventResult.FSM_ABORTED; // 1.4) submachine has aborted, look for destination state in parent
                        return NULL;
                    }
 
                    break;
                }
                case ProcessEventResult.FSM_TERMINATED:
                {
                    break; // submachine has finished, look for local transitions from exited submachine
                }
                case ProcessEventResult.FSM_NO_TRANSITION:
                {
                    fsmDebugPrint("[hfsm] aborted (but no transition) sub machine=" + m_State.ToString());
                    break; // submachine has no transition, look for transitions in local machine
                }
            }
        }
 
        // 2) local transitions
        int i = FindFirstUnguardedTransition(e);
        if (i == -1)
        {
            fsmDebugPrint("[hfsm] abort event has no transition: src=" + m_State.ToString() + " e=" + e.Type().ToString());
            result = ProcessEventResult.FSM_NO_TRANSITION;
            return NULL;
        }
 
        FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t = m_Transitions.Get(i);
        ProcessEventResult res = ProcessAbortTransition(t, e);
        result = res;
        switch (res)
        {
            case ProcessEventResult.FSM_OK:
            {
                //fsmDebugSpam("[hfsm] abort event processed by machine=" + m_State.ToString());
                return NULL; // machine accepted event
            }
            case ProcessEventResult.FSM_ABORTED:
            {
                fsmDebugPrint("[hfsm] aborted sub machine=" + m_State.ToString() + " will fall-through to dst=" + t.m_dstState);
                return t.m_dstState; // store destination state for parent(s)
            }
 
            case ProcessEventResult.FSM_TERMINATED:
            {
                fsmDebugPrint("[hfsm] aborted & terminated sub machine=" + m_State.ToString());
                break; // submachine has finished, look for local transitions from exited submachine
            }
            case ProcessEventResult.FSM_NO_TRANSITION:
            {   
                break; // submachine has no transition, look for transitions in local machine
            }
        }
        return NULL;
    }
 
 
    ProcessEventResult ProcessEvent (FSMEventBase e)
    {
        if (GetOwnerState())
            fsmDebugPrint("[hfsm] SUB!::" + GetOwnerState().Type().ToString() + "::ProcessEvent(" + e.Type().ToString() + ")");
        else
            fsmDebugPrint("[hfsm] root::ProcessEvent(" + e.Type().ToString() + " =" + e.DumpToString());
 
        // 1) completion transitions have priority (if any)
        if (m_HasCompletions)
            ProcessCompletionTransitions();
 
        // 2) submachine then (if any)
        if (m_State.HasFSM())
        {
            ProcessEventResult subfsm_res = m_State.ProcessEvent(e);
 
            switch (subfsm_res)
            {
                case ProcessEventResult.FSM_OK:
                {
                    fsmDebugSpam("[hfsm] event processed by sub machine=" + m_State.ToString());
                    return subfsm_res; // submachine accepted event
                }
                case ProcessEventResult.FSM_TERMINATED:
                {
                    break; // submachine has finished, look for local transitions from exited submachine
                }
                case ProcessEventResult.FSM_NO_TRANSITION:
                {   
                    break; // submachine has no transition, look for transitions in local machine
                }
            }
        }
 
        // 3) local transitions
        int i = FindFirstUnguardedTransition(e);
        if (i == -1)
        {
            fsmDebugPrint("[hfsm] event has no transition: src=" + m_State.ToString() + " e=" + e.Type().ToString());
            return ProcessEventResult.FSM_NO_TRANSITION;
        }
 
        FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> row = m_Transitions.Get(i);
        ProcessEventResult res;
        if (row.m_dstState != NULL)
        {
            // this is regular transition
            if (row.m_srcState.GetParentState() == row.m_dstState.GetParentState())
                res = LocalTransition(i, e); // transition is within this state machine
            else
                Error("cross-hierarchy transition or misconfigured transition detected!");
                //res = HierarchicTransition(i, e); // transition has to cross hierarchy
        }
        else
        {
            // this is terminating transition
            if (row.m_srcState.GetParentState() == GetOwnerState())
                res = LocalTransition(i, e); // terminating transition is within this state machine
            else
                Error("cross-hierarchy transition or misconfigured transition detected!");
                //res = HierarchicTransition(i, e); // source node crosses hierarchy (terminate lies always within this machine)
        }
        return res;
    }
 
    protected int FindFirstUnguardedTransition (FSMEventBase e)
    {
        FSMStateBase curr_state = m_State;
 
        int count = m_Transitions.Count();
        for (int i = 0; i < count; ++i)
        {
            FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t = m_Transitions.Get(i);
            if ((t.m_srcState == curr_state) && (t.m_event != NULL) && (t.m_event.Type() == e.Type()))
            {
                //fsmDebugSpam("[hfsm] [" + i + "/" + count + "] *** matched! t=" + t + " state=" + t.m_srcState + "-------- event=" + t.m_event + "[G=" + t.m_guard +"]/A=" + t.m_action + " --------|> dst=" + t.m_dstState);
                bool hasGuard = t.m_guard != NULL;
                if (!hasGuard || (hasGuard && t.m_guard.GuardCondition(e)))     // 1) exec guard (if any)
                {
                    return i;
                }
            }
            //else fsmDebugSpam("[hfsm][" + i + "/" + count + "] ... matching  t=" + t + " state=" + t.m_srcState + "-------- event=" + t.m_event + "[G=" + t.m_guard +"]/A=" + t.m_action + " --------|> dst=" + t.m_dstState);
        }
        return -1;
    }
    
    FSMStateBase FindTransitionState(FSMStateBase s, FSMEventBase e)
    {
        FSMStateBase curr_state = s;
 
        int count = m_Transitions.Count();
        for (int i = 0; i < count; ++i)
        {
            FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t = m_Transitions.Get(i);
            if ((t.m_srcState == curr_state) && (t.m_event != NULL) && (t.m_event.Type() == e.Type()))
            {
                return t.m_dstState;
            }
        }
        return null;
    }
    
    FSMStateBase FindGuardedTransitionState(FSMStateBase s, FSMEventBase e)
    {
        FSMStateBase curr_state = s;
 
        int count = m_Transitions.Count();
        for (int i = 0; i < count; ++i)
        {
            FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t = m_Transitions.Get(i);
            if ((t.m_srcState == curr_state) && (t.m_event != NULL) && (t.m_event.Type() == e.Type()))
            {
                bool hasGuard = t.m_guard != NULL;
                if (!hasGuard || (hasGuard && t.m_guard.GuardCondition(e)))     // 1) exec guard (if any)
                {
                    return t.m_dstState;
                }
            }
        }
        return null;
    }
 
    protected int FindFirstCompletionTransition ()
    {
        if (IsRunning())
        {
            FSMStateBase curr_state = m_State;
 
            int count = m_Transitions.Count();
            for (int i = 0; i < count; ++i)
            {
                FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t = m_Transitions.Get(i);
 
                //fsmDebugPrint("[hfsm] (local) matching state=" + t.m_srcState + "-------- event=" + t.m_event + "[G=" + t.m_guard +"]/A=" + t.m_action + " --------|> dst=" + t.m_dstState);
                if ((t.m_srcState.Type() == curr_state.Type()) && (t.m_event == NULL))
                {
                    bool hasGuard = t.m_guard != NULL;
                    if (!hasGuard || (hasGuard && t.m_guard.GuardCondition(NULL)))      // 1) exec guard (if any)
                    {
                        return i;
                    }
                }
            }
        }
        return -1;
    }
 
 
    protected ProcessEventResult ProcessLocalTransition (FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t, FSMEventBase e)
    {
        fsmDebugPrint("[hfsm] (local) state=" + t.m_srcState.ToString() + "-------- event=" + e.ToString() + "[G=" + t.m_guard.ToString() +"]/A=" + t.m_action.ToString() + " --------|> dst=" + t.m_dstState.ToString());
 
        m_State.OnExit(e);          // 1) call onExit on old state
 
        if (t.m_action)
            t.m_action.Action(e);   // 2) execute transition action (if any)
 
        m_State = t.m_dstState;     // 3) change state to new
 
        if (t.m_dstState != NULL)
        {
            m_State.OnEntry(e);     // 4a) call onEntry on new state
 
            if (GetOwnerState())
                GetOwnerState().OnSubMachineChanged(t.m_srcState, t.m_dstState);    // 5a) notify owner state about change in submachine
            
            if (m_State)
                m_State.OnStateChanged(t.m_srcState, t.m_dstState); // 5b) notify current state about change in machine
 
            return ProcessEventResult.FSM_OK;
        }
        else
        {
            fsmDebugPrint("[hfsm] terminating fsm: state=" + t.m_srcState.ToString() + " event=" + e.ToString());
 
            if (GetOwnerState())
                GetOwnerState().OnSubMachineChanged(t.m_srcState, NULL);    // 5) notify owner state about change in submachine
            return ProcessEventResult.FSM_TERMINATED; // 4b) or terminate
        }
    }
    protected ProcessEventResult LocalTransition (int i, FSMEventBase e)
    {
        FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> t = m_Transitions.Get(i);
        ProcessEventResult ret = ProcessLocalTransition(t, e);
        return ret;
    }
 
    protected ProcessEventResult ProcessCompletionTransitions ()
    {
        int completionIdx = FindFirstCompletionTransition();
        while (completionIdx != -1)
        {
            FSMTransition<FSMStateBase, FSMEventBase, FSMActionBase, FSMGuardBase> row = m_Transitions.Get(completionIdx);
            ProcessEventResult res;
            if (row.m_dstState != NULL)
            {
                // this is regular completion transition
                if (row.m_srcState.GetParentState() == row.m_dstState.GetParentState())
                    res = LocalTransition(completionIdx, NULL); // transition is within this state machine
                else
                    Error("cross-hierarchy transition or misconfigured transition detected!");
                    //res = HierarchicTransition(completionIdx, NULL); // transition has to cross hierarchy
            }
            else
            {
                // this is terminating completion transition
                if (row.m_srcState.GetParentState() == GetOwnerState())
                    res = LocalTransition(completionIdx, NULL); // terminating transition is within this state machine
                else
                    Error("cross-hierarchy transition or misconfigured transition detected!");
                    //res = HierarchicTransition(completionIdx, NULL); // source node crosses hierarchy (terminate lies always within this machine)
            }
 
            completionIdx = FindFirstCompletionTransition();
        }
        return ProcessEventResult.FSM_NO_TRANSITION;
    }
};