GamePlay/gameplay/src/AIController.cpp

#include "Base.h"
#include "AIController.h"
#include "Game.h"

namespace gameplay
{

AIController::AIController()
    : _paused(false), _firstMessage(NULL), _firstAgent(NULL)
{
}

AIController::~AIController()
{
}

void AIController::initialize()
{
}

void AIController::finalize()
{
    // Remove all agents
    AIAgent* agent = _firstAgent;
    while (agent)
    {
        AIAgent* temp = agent;
        agent = agent->_next;
        SAFE_RELEASE(temp);
    }
    _firstAgent = NULL;

    // Remove all messages
    AIMessage* message = _firstMessage;
    while (message)
    {
        AIMessage* temp = message;
        message = message->_next;
        AIMessage::destroy(temp);
    }
    _firstMessage = NULL;
}

void AIController::pause()
{
    _paused = true;
}

void AIController::resume()
{
    _paused = false;
}

void AIController::sendMessage(AIMessage* message, float delay)
{
    if (delay <= 0)
    {
        // Send instantly
        if (message->getReceiver() == NULL || strlen(message->getReceiver()) == 0)
        {
            // Broadcast message to all agents
            AIAgent* agent = _firstAgent;
            while (agent)
            {
                if (agent->processMessage(message))
                    break; // message consumed by this agent - stop bubbling
                agent = agent->_next;
            }
        }
        else
        {
            // Single recipient
            AIAgent* agent = findAgent(message->getReceiver());
            if (agent)
            {
                agent->processMessage(message);
            }
            else
            {
                GP_WARN("Failed to locate AIAgent for message recipient: %s", message->getReceiver());
            }
        }

        // Delete the message, since it is finished being processed
        AIMessage::destroy(message);
    }
    else
    {
        // Queue for later delivery
        if (_firstMessage)
            message->_next = _firstMessage;
        _firstMessage = message;
    }
}

void AIController::update(float elapsedTime)
{
    if (_paused)
        return;

    static Game* game = Game::getInstance();

    // Send all pending messages that have expired
    AIMessage* prevMsg = NULL;
    AIMessage* msg = _firstMessage;
    while (msg)
    {
        // If the message delivery time has expired, send it (this also deletes it)
        if (msg->getDeliveryTime() >= game->getGameTime())
        {
            // Link the message out of our list
            if (prevMsg)
                prevMsg->_next = msg->_next;

            AIMessage* temp = msg;
            msg = msg->_next;
            temp->_next = NULL;
            sendMessage(temp);
        }
        else
        {
            prevMsg = msg;
            msg = msg->_next;
        }
    }

    // Update all enabled agents
    AIAgent* agent = _firstAgent;
    while (agent)
    {
        if (agent->isEnabled())
            agent->update(elapsedTime);

        agent = agent->_next;
    }
}

void AIController::addAgent(AIAgent* agent)
{
    agent->addRef();

    if (_firstAgent)
        agent->_next = _firstAgent;

    _firstAgent = agent;
}

void AIController::removeAgent(AIAgent* agent)
{
    // Search our linked list of agents and link this agent out.
    AIAgent* prevAgent = NULL;
    AIAgent* itr = _firstAgent;
    while (itr)
    {
        if (itr == agent)
        {
            if (prevAgent)
                prevAgent->_next = agent->_next;
            else
                _firstAgent = agent->_next;

            agent->_next = NULL;
            agent->release();
            break;
        }

        prevAgent = itr;
        itr = itr->_next;
    }
}

AIAgent* AIController::findAgent(const char* id) const
{
    GP_ASSERT(id);

    AIAgent* agent = _firstAgent;
    while (agent)
    {
        if (strcmp(id, agent->getId()) == 0)
            return agent;

        agent = agent->_next;
    }

    return NULL;
}

}