Programming a Multiplayer FPS in DirectX/Programming a Multiplayer FPS in DirectX (Companion CD).iso/Source/Chapter 9/Engine/Network.cpp

C/C++ Source or Header | 2004-10-01 | 17.1 KB | 516 lines

//-----------------------------------------------------------------------------
// Network.h implementation.
// Refer to the Network.h interface for more details.
//
// Programming a Multiplayer First Person Shooter in DirectX
// Copyright (c) 2004 Vaughan Young
//-----------------------------------------------------------------------------
#include "Engine.h"

//-----------------------------------------------------------------------------
// The network class constructor.
//-----------------------------------------------------------------------------
Network::Network( GUID guid, void (*HandleNetworkMessageFunction)( ReceivedMessage *msg ) )
{
    // Initialise the critical sections.
    InitializeCriticalSection( &m_sessionCS );
    InitializeCriticalSection( &m_playerCS );
    InitializeCriticalSection( &m_messageCS );

    // Invalidate the DirectPlay peer interface and the device.
    m_dpp = NULL;
    m_device = NULL;

    // Store the application's GUID.
    memcpy( &m_guid, &guid, sizeof( GUID ) );

    // Create the enumerated session list.
    m_sessions = new LinkedList< SessionInfo >;

    // Create the player list.
    m_players = new LinkedList< PlayerInfo >;

    // Create the network message list.
    m_messages = new LinkedList< ReceivedMessage >;

    // Load the network settings.
    Script *settings = new Script( "NetworkSettings.txt" );
    if( settings->GetNumberData( "processing_time" ) == NULL )
    {
        m_port = 2509;
        m_sendTimeOut = 100;
        m_processingTime = 100;
    }
    else
    {
        m_port = *settings->GetNumberData( "port" );
        m_sendTimeOut = *settings->GetNumberData( "send_time_out" );
        m_processingTime = *settings->GetNumberData( "processing_time" );
    }
    SAFE_DELETE( settings );

    // Initially the network is not allowed to receive application specific messages.
    m_receiveAllowed = false;

    // Set the network message handler.
    HandleNetworkMessage = HandleNetworkMessageFunction;

    // Create and initialise the DirectPlay peer interface.
    CoCreateInstance( CLSID_DirectPlay8Peer, NULL, CLSCTX_INPROC, IID_IDirectPlay8Peer, (void**)&m_dpp );
    m_dpp->Initialize( (PVOID)this, NetworkMessageHandler, DPNINITIALIZE_HINT_LANSESSION );

    // Create the device address.
    CoCreateInstance( CLSID_DirectPlay8Address, NULL, CLSCTX_INPROC, IID_IDirectPlay8Address, (LPVOID*) &m_device );
    m_device->SetSP( &CLSID_DP8SP_TCPIP );
    m_device->AddComponent( DPNA_KEY_PORT, &m_port, sizeof(DWORD), DPNA_DATATYPE_DWORD );
}

//-----------------------------------------------------------------------------
// The network class destructor.
//-----------------------------------------------------------------------------
Network::~Network()
{
    // Save the network settings.
    Script *settings = new Script( "NetworkSettings.txt" );
    if( settings->GetNumberData( "processing_time" ) == NULL )
    {
        settings->AddVariable( "port", VARIABLE_NUMBER, &m_port );
        settings->AddVariable( "send_time_out", VARIABLE_NUMBER, &m_sendTimeOut );
        settings->AddVariable( "processing_time", VARIABLE_NUMBER, &m_processingTime );
    }
    else
    {
        settings->SetVariable( "port", &m_port );
        settings->SetVariable( "send_time_out", &m_sendTimeOut );
        settings->SetVariable( "processing_time", &m_processingTime );
    }
    settings->SaveScript();
    SAFE_DELETE( settings );

    // Release the device address.
    SAFE_RELEASE( m_device );

    // Close and release the DirectPlay peer interface.
    if( m_dpp != NULL )
        m_dpp->Close( DPNCLOSE_IMMEDIATE );
    SAFE_RELEASE( m_dpp );

    // Destroy the enumerated session list.
    SAFE_DELETE( m_sessions );

    // Destroy the player list.
    SAFE_DELETE( m_players );

    // Destroy the network message list.
    SAFE_DELETE( m_messages );

    // Delete the critical sections.
    DeleteCriticalSection( &m_sessionCS );
    DeleteCriticalSection( &m_playerCS );
    DeleteCriticalSection( &m_messageCS );
}

//-----------------------------------------------------------------------------
// Updates the network object, allowing it to process messages.
//-----------------------------------------------------------------------------
void Network::Update()
{
    EnterCriticalSection( &m_messageCS );

    ReceivedMessage *message = m_messages->GetFirst();

    unsigned long endTime = timeGetTime() + m_processingTime;
    while( endTime > timeGetTime() && message != NULL )
    {
        HandleNetworkMessage( message );
        m_messages->Remove( &message );
        message = m_messages->GetFirst();
    }

    LeaveCriticalSection( &m_messageCS );
}

//-----------------------------------------------------------------------------
// Enumerates for sessions on the local network.
//-----------------------------------------------------------------------------
void Network::EnumerateSessions()
{
    // Empty the lists.
    m_players->Empty();
    m_messages->Empty();
    m_sessions->Empty();

    // Prepare the application description.
    DPN_APPLICATION_DESC description;
    ZeroMemory( &description, sizeof( DPN_APPLICATION_DESC ) );
    description.dwSize = sizeof( DPN_APPLICATION_DESC );
    description.guidApplication = m_guid;

    // Enumerate sessions synchronously.
    m_dpp->EnumHosts( &description, NULL, m_device, NULL, 0, 1, 0, 0, NULL, NULL, DPNENUMHOSTS_SYNC );
}

//-----------------------------------------------------------------------------
// Attempts to host a session.
//-----------------------------------------------------------------------------
bool Network::Host( char *name, char *session, int players, void *playerData, unsigned long dataSize )
{
    WCHAR wide[MAX_PATH];

    // Prepare and set the player information structure.
    DPN_PLAYER_INFO player;
    ZeroMemory( &player, sizeof( DPN_PLAYER_INFO ) );
    player.dwSize = sizeof( DPN_PLAYER_INFO );
    player.pvData = playerData;
    player.dwDataSize = dataSize;
    player.dwInfoFlags = DPNINFO_NAME | DPNINFO_DATA;
    mbstowcs( wide, name, MAX_PATH );
    player.pwszName = wide;
    if( FAILED( m_dpp->SetPeerInfo( &player, NULL, NULL, DPNSETPEERINFO_SYNC ) ) )
        return false;

    // Prepare the application description.
    DPN_APPLICATION_DESC description;
    ZeroMemory( &description, sizeof( DPN_APPLICATION_DESC ) );
    description.dwSize = sizeof( DPN_APPLICATION_DESC );
    description.guidApplication = m_guid;
    description.dwMaxPlayers = players;
    mbstowcs( wide, session, MAX_PATH );
    description.pwszSessionName = wide;

    // Host the session.
    if( FAILED( m_dpp->Host( &description, &m_device, 1, NULL, NULL, NULL, 0 ) ) )
        return false;

    return true;
}

//-----------------------------------------------------------------------------
// Attempts to join a selected session from the enumerated session list.
//-----------------------------------------------------------------------------
bool Network::Join( char *name, int session, void *playerData, unsigned long dataSize )
{
    WCHAR wide[MAX_PATH];

    // Empty the player list and the newtork message.
    m_players->Empty();
    m_messages->Empty();

    // Ignore invalid sessions.
    if( session < 0 )
        return false;

    // Prepare and set the player information structure.
    DPN_PLAYER_INFO player;
    ZeroMemory( &player, sizeof( DPN_PLAYER_INFO ) );
    player.dwSize = sizeof( DPN_PLAYER_INFO );
    player.pvData = playerData;
    player.dwDataSize = dataSize;
    player.dwInfoFlags = DPNINFO_NAME | DPNINFO_DATA;
    mbstowcs( wide, name, MAX_PATH );
    player.pwszName = wide;
    if( FAILED( m_dpp->SetPeerInfo( &player, NULL, NULL, DPNSETPEERINFO_SYNC ) ) )
        return false;

    // Enter the sessions linked list critical section.
    EnterCriticalSection( &m_sessionCS );

    // Find the host of the selected session.
    m_sessions->Iterate( true );
    for( int s = 0; s < session + 1; s++ )
    {
        if( m_sessions->Iterate() ==  NULL )
        {
            LeaveCriticalSection( &m_sessionCS );
            return false;
        }
    }

    // Join the session.
    if( FAILED( m_dpp->Connect( &m_sessions->GetCurrent()->description, m_sessions->GetCurrent()->address, m_device, NULL, NULL, NULL, 0, NULL, NULL, NULL, DPNCONNECT_SYNC ) ) )
    {
        LeaveCriticalSection( &m_sessionCS );
        return false;
    }
    LeaveCriticalSection( &m_sessionCS );

    return true;
}

//-----------------------------------------------------------------------------
// Terminates the current session.
//-----------------------------------------------------------------------------
void Network::Terminate()
{
    // Only allow the host to terminate a session.
    if( m_dpnidHost == m_dpnidLocal )
        m_dpp->TerminateSession( NULL, 0, 0 );

    // Close the connection. This will also uninitialise the DirectPlay peer interface.
    if( m_dpp != NULL )
        m_dpp->Close( DPNCLOSE_IMMEDIATE );

    // Initialise the DirectPlay peer interface.
    m_dpp->Initialize( (PVOID)this, NetworkMessageHandler, DPNINITIALIZE_HINT_LANSESSION );
}

//-----------------------------------------------------------------------------
// Sets the receive allowed flag.
//-----------------------------------------------------------------------------
void Network::SetReceiveAllowed( bool allowed )
{
    m_receiveAllowed = allowed;
}

//-----------------------------------------------------------------------------
// Returns the next iterated session from the enumerated session list.
//-----------------------------------------------------------------------------
SessionInfo *Network::GetNextSession( bool restart )
{
    EnterCriticalSection( &m_sessionCS );

    m_sessions->Iterate( restart );
    if( restart == true )
        m_sessions->Iterate();

    LeaveCriticalSection( &m_sessionCS );

    return m_sessions->GetCurrent();
}

//-----------------------------------------------------------------------------
// Returns a pointer to the player information structure of the given player.
//-----------------------------------------------------------------------------
PlayerInfo *Network::GetPlayer( DPNID dpnid )
{
    EnterCriticalSection( &m_playerCS );

    m_players->Iterate( true );
    while( m_players->Iterate() )
    {
        if( m_players->GetCurrent()->dpnid == dpnid )
        {
            LeaveCriticalSection( &m_playerCS );

            return m_players->GetCurrent();
        }
    }

    LeaveCriticalSection( &m_playerCS );

    return NULL;
}

//-----------------------------------------------------------------------------
// Returns the local player's DirectPlay ID.
//-----------------------------------------------------------------------------
DPNID Network::GetLocalID()
{
    return m_dpnidLocal;
}

//-----------------------------------------------------------------------------
// Returns the host's DirectPlay ID.
//-----------------------------------------------------------------------------
DPNID Network::GetHostID()
{
    return m_dpnidHost;
}

//-----------------------------------------------------------------------------
// Indicates if the current network object is hosting or not.
//-----------------------------------------------------------------------------
bool Network::IsHost()
{
    if( m_dpnidHost == m_dpnidLocal )
        return true;
    else
        return false;
}

//-----------------------------------------------------------------------------
// Sends a network message.
//-----------------------------------------------------------------------------
void Network::Send( void *data, long size, DPNID dpnid, long flags )
{
    DPNHANDLE hAsync;
    DPN_BUFFER_DESC dpbd;

    if( ( dpbd.dwBufferSize = size ) == 0 )
        return;
    dpbd.pBufferData = (BYTE*)data;

    m_dpp->SendTo( dpnid, &dpbd, 1, m_sendTimeOut, NULL, &hAsync, flags | DPNSEND_NOCOMPLETE | DPNSEND_COALESCE );
}

//-----------------------------------------------------------------------------
// The internal network message handler.
//-----------------------------------------------------------------------------
HRESULT WINAPI Network::NetworkMessageHandler( PVOID context, DWORD msgid, PVOID data )
{
    // Get a pointer to the calling network object.
    Network *network = (Network*)context;

    // Process the incoming message based on its type.
    switch( msgid )
    {
        case DPN_MSGID_CREATE_PLAYER:
        {
            unsigned long size = 0;
            DPN_PLAYER_INFO *info = NULL;
            HRESULT hr = DPNERR_CONNECTING;
            PDPNMSG_CREATE_PLAYER msgCreatePlayer = (PDPNMSG_CREATE_PLAYER)data;

            // Create a player information structure for the new player.
            PlayerInfo *playerInfo = new PlayerInfo;
            ZeroMemory( playerInfo, sizeof( PlayerInfo ) );
            playerInfo->dpnid = msgCreatePlayer->dpnidPlayer;

            // Keep calling GetPeerInfo(), as it may still be trying to connect.
            while( hr == DPNERR_CONNECTING )
                hr = network->m_dpp->GetPeerInfo( playerInfo->dpnid, info, &size, 0 );

            // Check if GetPeerInfo() has returned the size of the DPN_PLAYER_INFO structure.
            if( hr == DPNERR_BUFFERTOOSMALL )
            {
                info = (DPN_PLAYER_INFO*) new BYTE[size];
                ZeroMemory( info, size );
                info->dwSize = sizeof( DPN_PLAYER_INFO );

                // Try again using the correct size.
                if( SUCCEEDED( network->m_dpp->GetPeerInfo( playerInfo->dpnid, info, &size, 0 ) ) )
                {
                    // Store the name of the new player.
                    playerInfo->name = new char[wcslen( info->pwszName ) + 1];
                    ZeroMemory( playerInfo->name, wcslen( info->pwszName ) + 1 );
                    wcstombs( playerInfo->name, info->pwszName, wcslen( info->pwszName ) );

                    // Store the player data.
                    playerInfo->data = new BYTE[info->dwDataSize];
                    memcpy( playerInfo->data, info->pvData, info->dwDataSize );
                    playerInfo->size = info->dwDataSize;

                    // Store any local and host player details.
                    if( info->dwPlayerFlags & DPNPLAYER_LOCAL )
                        network->m_dpnidLocal = playerInfo->dpnid;
                    if( info->dwPlayerFlags & DPNPLAYER_HOST )
                        network->m_dpnidHost = playerInfo->dpnid;
                }

                SAFE_DELETE_ARRAY( info );
            }

            // Add the new player to the player list.
            EnterCriticalSection( &network->m_playerCS );
            network->m_players->Add( playerInfo );
            LeaveCriticalSection( &network->m_playerCS );

            // If there is no network message handler, then break now.
            if( network->HandleNetworkMessage == NULL )
                break;

            // Create a create player message.
            ReceivedMessage *message = new ReceivedMessage;
            message->msgid = MSGID_CREATE_PLAYER;
            message->dpnid = playerInfo->dpnid;

            // Store the message so that it can be processed by the application later.
            EnterCriticalSection( &network->m_messageCS );
            network->m_messages->Add( message );
            LeaveCriticalSection( &network->m_messageCS );

            break;
        }

        case DPN_MSGID_DESTROY_PLAYER:
        {
            // Find the player to destroy and remove it from the player list.
            EnterCriticalSection( &network->m_playerCS );
            network->m_players->Iterate( true );
            while( network->m_players->Iterate() )
            {
                if( network->m_players->GetCurrent()->dpnid == ( (PDPNMSG_DESTROY_PLAYER)data )->dpnidPlayer )
                {
                    network->m_players->Remove( (PlayerInfo**)network->m_players->GetCurrent() );
                    break;
                }
            }
            LeaveCriticalSection( &network->m_playerCS );

            // If there is no network message handler, then break now.
            if( network->HandleNetworkMessage == NULL )
                break;

            // Create a destroy player message.
            ReceivedMessage *message = new ReceivedMessage;
            message->msgid = MSGID_DESTROY_PLAYER;
            message->dpnid = ( (PDPNMSG_DESTROY_PLAYER)data )->dpnidPlayer;

            // Store the message so that it can be processed by the application later.
            EnterCriticalSection( &network->m_messageCS );
            network->m_messages->Add( message );
            LeaveCriticalSection( &network->m_messageCS );

            break;
        }

        case DPN_MSGID_ENUM_HOSTS_RESPONSE:
        {
            PDPNMSG_ENUM_HOSTS_RESPONSE response = (PDPNMSG_ENUM_HOSTS_RESPONSE)data;

            // Create a session information structure for the new session.
            SessionInfo *sessionInfo = new SessionInfo;
            response->pAddressSender->Duplicate( &sessionInfo->address );
            memcpy( &sessionInfo->description, response->pApplicationDescription, sizeof( DPN_APPLICATION_DESC ) );

            // Add the new session to the session list.
            EnterCriticalSection( &network->m_sessionCS );
            network->m_sessions->Add( sessionInfo );
            LeaveCriticalSection( &network->m_sessionCS );

            break;
        }

        case DPN_MSGID_RECEIVE:
        {
            // If there is no network message handler, then break now.
            if( network->HandleNetworkMessage == NULL )
                break;

            // Check if the network is allowed to receive application specific messages.
            if( network->m_receiveAllowed == false )
                break;

            // Create a receive message.
            ReceivedMessage *message = new ReceivedMessage;
            memcpy( message, ( (PDPNMSG_RECEIVE)data )->pReceiveData, ( (PDPNMSG_RECEIVE)data )->dwReceiveDataSize );

            // Store the message so that it can be processed by the application later.
            EnterCriticalSection( &network->m_messageCS );
            network->m_messages->Add( message );
            LeaveCriticalSection( &network->m_messageCS );

            break;
        }

        case DPN_MSGID_TERMINATE_SESSION:
        {
            // If there is no network message handler, then break now.
            if( network->HandleNetworkMessage == NULL )
                break;

            // Create a terminate session message.
            ReceivedMessage *message = new ReceivedMessage;
            message->msgid = MSGID_TERMINATE_SESSION;

            // Store the message so that it can be processed by the application later.
            EnterCriticalSection( &network->m_messageCS );
            network->m_messages->Add( message );
            LeaveCriticalSection( &network->m_messageCS );

            break;
        }
    }

    return S_OK;
}