ref: 002822dfa2bd78f946b7e4730004220919d4ddb9
dir: /src/d_loop.c/
// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
// 02111-1307, USA.
//
// DESCRIPTION:
//     Main loop code.
//
//-----------------------------------------------------------------------------
#include <stdlib.h>
#include <string.h>
#include "doomfeatures.h"
#include "d_event.h"
#include "d_loop.h"
#include "d_ticcmd.h"
#include "i_system.h"
#include "i_timer.h"
#include "i_video.h"
#include "m_argv.h"
#include "m_fixed.h"
#include "net_client.h"
#include "net_gui.h"
#include "net_io.h"
#include "net_query.h"
#include "net_server.h"
#include "net_sdl.h"
#include "net_loop.h"
// The complete set of data for a particular tic.
typedef struct
{
    ticcmd_t cmds[NET_MAXPLAYERS];
    boolean ingame[NET_MAXPLAYERS];
} ticcmd_set_t;
//
// gametic is the tic about to (or currently being) run
// maketic is the tic that hasn't had control made for it yet
// recvtic is the latest tic received from the server.
//
// a gametic cannot be run until ticcmds are received for it
// from all players.
//
static ticcmd_set_t ticdata[BACKUPTICS];
// The index of the next tic to be made (with a call to BuildTiccmd).
static int maketic;
// The number of complete tics received from the server so far.
static int recvtic;
// The number of tics that have been run (using RunTic) so far.
int gametic;
// When set to true, a single tic is run each time TryRunTics() is called.
// This is used for -timedemo mode.
boolean singletics = false;
// Index of the local player.
static int localplayer;
// Used for original sync code.
static int      skiptics = 0;
// Reduce the bandwidth needed by sampling game input less and transmitting
// less.  If ticdup is 2, sample half normal, 3 = one third normal, etc.
int		ticdup;
// Amount to offset the timer for game sync.
fixed_t         offsetms;
// Use new client syncronisation code
static boolean  new_sync = true;
// Callback functions for loop code.
static loop_interface_t *loop_interface = NULL;
// Current players in the multiplayer game.
// This is distinct from playeringame[] used by the game code, which may
// modify playeringame[] when playing back multiplayer demos.
static boolean local_playeringame[NET_MAXPLAYERS];
// Requested player class "sent" to the server on connect.
// If we are only doing a single player game then this needs to be remembered
// and saved in the game settings.
static int player_class;
// 35 fps clock adjusted by offsetms milliseconds
static int GetAdjustedTime(void)
{
    int time_ms;
    time_ms = I_GetTimeMS();
    if (new_sync)
    {
	// Use the adjustments from net_client.c only if we are
	// using the new sync mode.
        time_ms += (offsetms / FRACUNIT);
    }
    return (time_ms * TICRATE) / 1000;
}
static boolean BuildNewTic(void)
{
    int	gameticdiv;
    ticcmd_t cmd;
    gameticdiv = gametic/ticdup;
    I_StartTic ();
    loop_interface->ProcessEvents();
    // Always run the menu
    loop_interface->RunMenu();
    if (drone)
    {
        // In drone mode, do not generate any ticcmds.
        return false;
    }
    if (new_sync)
    {
       // If playing single player, do not allow tics to buffer
       // up very far
       if (!net_client_connected && maketic - gameticdiv > 2)
           return false;
       // Never go more than ~200ms ahead
       if (maketic - gameticdiv > 8)
           return false;
    }
    else
    {
       if (maketic - gameticdiv >= 5)
           return false;
    }
    //printf ("mk:%i ",maketic);
    memset(&cmd, 0, sizeof(ticcmd_t));
    loop_interface->BuildTiccmd(&cmd, maketic);
#ifdef FEATURE_MULTIPLAYER
    if (net_client_connected)
    {
        NET_CL_SendTiccmd(&cmd, maketic);
    }
#endif
    ticdata[maketic % BACKUPTICS].cmds[localplayer] = cmd;
    ticdata[maketic % BACKUPTICS].ingame[localplayer] = true;
    ++maketic;
    return true;
}
//
// NetUpdate
// Builds ticcmds for console player,
// sends out a packet
//
int      lasttime;
void NetUpdate (void)
{
    int nowtime;
    int newtics;
    int	i;
    // If we are running with singletics (timing a demo), this
    // is all done separately.
    if (singletics)
        return;
#ifdef FEATURE_MULTIPLAYER
    // Run network subsystems
    NET_CL_Run();
    NET_SV_Run();
#endif
    // check time
    nowtime = GetAdjustedTime() / ticdup;
    newtics = nowtime - lasttime;
    lasttime = nowtime;
    if (skiptics <= newtics)
    {
        newtics -= skiptics;
        skiptics = 0;
    }
    else
    {
        skiptics -= newtics;
        newtics = 0;
    }
    // build new ticcmds for console player
    for (i=0 ; i<newtics ; i++)
    {
        if (!BuildNewTic())
        {
            break;
        }
    }
}
static void D_Disconnected(void)
{
    // In drone mode, the game cannot continue once disconnected.
    if (drone)
    {
        I_Error("Disconnected from server in drone mode.");
    }
    // disconnected from server
    printf("Disconnected from server.\n");
}
//
// Invoked by the network engine when a complete set of ticcmds is
// available.
//
void D_ReceiveTic(ticcmd_t *ticcmds, boolean *players_mask)
{
    int i;
    // Disconnected from server?
    if (ticcmds == NULL && players_mask == NULL)
    {
        D_Disconnected();
        return;
    }
    for (i = 0; i < NET_MAXPLAYERS; ++i)
    {
        if (!drone && i == localplayer)
        {
            // This is us.  Don't overwrite it.
        }
        else
        {
            ticdata[recvtic % BACKUPTICS].cmds[i] = ticcmds[i];
            ticdata[recvtic % BACKUPTICS].ingame[i] = players_mask[i];
        }
    }
    ++recvtic;
}
//
// Start game loop
//
// Called after the screen is set but before the game starts running.
//
void D_StartGameLoop(void)
{
    lasttime = GetAdjustedTime() / ticdup;
}
//
// Block until the game start message is received from the server.
//
static void BlockUntilStart(net_gamesettings_t *settings,
                            netgame_startup_callback_t callback)
{
    while (!NET_CL_GetSettings(settings))
    {
        NET_CL_Run();
        NET_SV_Run();
        if (!net_client_connected)
        {
            I_Error("Lost connection to server");
        }
        if (callback != NULL && !callback(net_client_wait_data.ready_players,
                                          net_client_wait_data.num_players))
        {
            I_Error("Netgame startup aborted.");
        }
        I_Sleep(100);
    }
}
void D_StartNetGame(net_gamesettings_t *settings,
                    netgame_startup_callback_t callback)
{
    int i;
    offsetms = 0;
    recvtic = 0;
    settings->consoleplayer = 0;
    settings->num_players = 1;
    settings->player_classes[0] = player_class;
    //!
    // @category net
    //
    // Use original game sync code.
    //
    if (M_CheckParm("-oldsync") > 0)
	settings->new_sync = 0;
    else
	settings->new_sync = 1;
    //!
    // @category net
    // @arg <n>
    //
    // Send n extra tics in every packet as insurance against dropped
    // packets.
    //
    i = M_CheckParmWithArgs("-extratics", 1);
    if (i > 0)
        settings->extratics = atoi(myargv[i+1]);
    else
        settings->extratics = 1;
    //!
    // @category net
    // @arg <n>
    //
    // Reduce the resolution of the game by a factor of n, reducing
    // the amount of network bandwidth needed.
    //
    i = M_CheckParmWithArgs("-dup", 1);
    if (i > 0)
        settings->ticdup = atoi(myargv[i+1]);
    else
        settings->ticdup = 1;
    if (net_client_connected)
    {
        // Send our game settings and block until game start is received
        // from the server.
        NET_CL_StartGame(settings);
        BlockUntilStart(settings, callback);
        // Read the game settings that were received.
        NET_CL_GetSettings(settings);
    }
    if (drone)
    {
        settings->consoleplayer = 0;
    }
    // Set the local player and playeringame[] values.
    localplayer = settings->consoleplayer;
    for (i = 0; i < NET_MAXPLAYERS; ++i)
    {
        local_playeringame[i] = i < settings->num_players;
    }
    // Copy settings to global variables.
    ticdup = settings->ticdup;
    new_sync = settings->new_sync;
    if (!new_sync)
    {
	printf("Syncing netgames like Vanilla Doom.\n");
    }
}
boolean D_InitNetGame(net_connect_data_t *connect_data)
{
    boolean result = false;
    net_addr_t *addr = NULL;
    int i;
    // Call D_QuitNetGame on exit:
    I_AtExit(D_QuitNetGame, true);
    player_class = connect_data->player_class;
#ifdef FEATURE_MULTIPLAYER
    //!
    // @category net
    //
    // Start a multiplayer server, listening for connections.
    //
    if (M_CheckParm("-server") > 0
     || M_CheckParm("-privateserver") > 0)
    {
        NET_SV_Init();
        NET_SV_AddModule(&net_loop_server_module);
        NET_SV_AddModule(&net_sdl_module);
        NET_SV_RegisterWithMaster();
        net_loop_client_module.InitClient();
        addr = net_loop_client_module.ResolveAddress(NULL);
    }
    else
    {
        //!
        // @category net
        //
        // Automatically search the local LAN for a multiplayer
        // server and join it.
        //
        i = M_CheckParm("-autojoin");
        if (i > 0)
        {
            addr = NET_FindLANServer();
            if (addr == NULL)
            {
                I_Error("No server found on local LAN");
            }
        }
        //!
        // @arg <address>
        // @category net
        //
        // Connect to a multiplayer server running on the given
        // address.
        //
        i = M_CheckParmWithArgs("-connect", 1);
        if (i > 0)
        {
            net_sdl_module.InitClient();
            addr = net_sdl_module.ResolveAddress(myargv[i+1]);
            if (addr == NULL)
            {
                I_Error("Unable to resolve '%s'\n", myargv[i+1]);
            }
        }
    }
    if (addr != NULL)
    {
        if (M_CheckParm("-drone") > 0)
        {
            connect_data->drone = true;
        }
        if (!NET_CL_Connect(addr, connect_data))
        {
            I_Error("D_InitNetGame: Failed to connect to %s\n",
                    NET_AddrToString(addr));
        }
        printf("D_InitNetGame: Connected to %s\n", NET_AddrToString(addr));
        // Wait for launch message received from server.
        NET_WaitForLaunch();
        result = true;
    }
#endif
    return result;
}
//
// D_QuitNetGame
// Called before quitting to leave a net game
// without hanging the other players
//
void D_QuitNetGame (void)
{
#ifdef FEATURE_MULTIPLAYER
    NET_SV_Shutdown();
    NET_CL_Disconnect();
#endif
}
static int GetLowTic(void)
{
    int lowtic;
    lowtic = maketic;
#ifdef FEATURE_MULTIPLAYER
    if (net_client_connected)
    {
        if (drone || recvtic < lowtic)
        {
            lowtic = recvtic;
        }
    }
#endif
    return lowtic;
}
static int frameon;
static int frameskip[4];
static int oldnettics;
static void OldNetSync(void)
{
    unsigned int i;
    unsigned int keyplayer = -1;
    frameon++;
    // ideally maketic should be 1 - 3 tics above lowtic
    // if we are consistantly slower, speed up time
    for (i=0 ; i<NET_MAXPLAYERS ; i++)
    {
        if (local_playeringame[i])
        {
            keyplayer = i;
            break;
        }
    }
    if (keyplayer < 0)
    {
        // If there are no players, we can never advance anyway
        return;
    }
    if (localplayer == keyplayer)
    {
        // the key player does not adapt
    }
    else
    {
        if (maketic <= recvtic)
        {
            lasttime--;
            // printf ("-");
        }
        frameskip[frameon & 3] = oldnettics > recvtic;
        oldnettics = maketic;
        if (frameskip[0] && frameskip[1] && frameskip[2] && frameskip[3])
        {
            skiptics = 1;
            // printf ("+");
        }
    }
}
// Returns true if there are players in the game:
static boolean PlayersInGame(void)
{
    boolean result = false;
    unsigned int i;
    // If we are connected to a server, check if there are any players
    // in the game.
    if (net_client_connected)
    {
        for (i = 0; i < NET_MAXPLAYERS; ++i)
        {
            result = result || local_playeringame[i];
        }
    }
    // Whether single or multi-player, unless we are running as a drone,
    // we are in the game.
    if (!drone)
    {
        result = true;
    }
    return result;
}
// When using ticdup, certain values must be cleared out when running
// the duplicate ticcmds.
static void TicdupSquash(ticcmd_set_t *set)
{
    ticcmd_t *cmd;
    unsigned int i;
    for (i = 0; i < NET_MAXPLAYERS ; ++i)
    {
        cmd = &set->cmds[i];
        cmd->chatchar = 0;
        if (cmd->buttons & BT_SPECIAL)
            cmd->buttons = 0;
    }
}
// When running in single player mode, clear all the ingame[] array
// except the local player.
static void SinglePlayerClear(ticcmd_set_t *set)
{
    unsigned int i;
    for (i = 0; i < NET_MAXPLAYERS; ++i)
    {
        if (i != localplayer)
        {
            set->ingame[i] = false;
        }
    }
}
//
// TryRunTics
//
void TryRunTics (void)
{
    int	i;
    int	lowtic;
    int	entertic;
    static int oldentertics;
    int realtics;
    int	availabletics;
    int	counts;
    // get real tics
    entertic = I_GetTime() / ticdup;
    realtics = entertic - oldentertics;
    oldentertics = entertic;
    // in singletics mode, run a single tic every time this function
    // is called.
    if (singletics)
    {
        BuildNewTic();
    }
    else
    {
        NetUpdate ();
    }
    lowtic = GetLowTic();
    availabletics = lowtic - gametic/ticdup;
    // decide how many tics to run
    if (new_sync)
    {
	counts = availabletics;
    }
    else
    {
        // decide how many tics to run
        if (realtics < availabletics-1)
            counts = realtics+1;
        else if (realtics < availabletics)
            counts = realtics;
        else
            counts = availabletics;
        if (counts < 1)
            counts = 1;
        if (net_client_connected)
        {
            OldNetSync();
        }
    }
    if (counts < 1)
	counts = 1;
    // wait for new tics if needed
    while (!PlayersInGame() || lowtic < gametic/ticdup + counts)
    {
	NetUpdate ();
        lowtic = GetLowTic();
	if (lowtic < gametic/ticdup)
	    I_Error ("TryRunTics: lowtic < gametic");
        // Don't stay in this loop forever.  The menu is still running,
        // so return to update the screen
	if (I_GetTime() / ticdup - entertic > 0)
	{
	    return;
	}
        I_Sleep(1);
    }
    // run the count * ticdup dics
    while (counts--)
    {
        ticcmd_set_t *set;
        if (!PlayersInGame())
        {
            return;
        }
        set = &ticdata[(gametic / ticdup) % BACKUPTICS];
        if (!net_client_connected)
        {
            SinglePlayerClear(set);
        }
	for (i=0 ; i<ticdup ; i++)
	{
            if (gametic/ticdup > lowtic)
                I_Error ("gametic>lowtic");
            memcpy(local_playeringame, set->ingame, sizeof(local_playeringame));
            loop_interface->RunTic(set->cmds, set->ingame);
	    gametic++;
	    // modify command for duplicated tics
            TicdupSquash(set);
	}
	NetUpdate ();	// check for new console commands
    }
}
void D_RegisterLoopCallbacks(loop_interface_t *i)
{
    loop_interface = i;
}