fs2open.github.com/code/network/multi_ping.cpp

/*
 * Copyright (C) Volition, Inc. 1999.  All rights reserved.
 *
 * All source code herein is the property of Volition, Inc. You may not sell 
 * or otherwise commercially exploit the source or things you created based on the 
 * source.
 *
*/

/*
 * $Logfile: /Freespace2/code/Network/multi_ping.cpp $
 * $Revision: 2.6 $
 * $Date: 2005-10-10 17:21:07 $
 * $Author: taylor $
 *
 * $Log: not supported by cvs2svn $
 * Revision 2.5  2005/07/13 03:35:32  Goober5000
 * remove PreProcDefine #includes in FS2
 * --Goober5000
 *
 * Revision 2.4  2005/03/02 21:18:19  taylor
 * better support for Inferno builds (in PreProcDefines.h now, no networking support)
 * make sure NO_NETWORK builds are as friendly on Windows as it is on Linux/OSX
 * revert a timeout in Client.h back to the original value before Linux merge
 *
 * Revision 2.3  2004/07/26 20:47:42  Kazan
 * remove MCD complete
 *
 * Revision 2.2  2004/07/12 16:32:57  Kazan
 * MCD - define _MCD_CHECK to use memory tracking
 *
 * Revision 2.1  2002/08/01 01:41:08  penguin
 * The big include file move
 *
 * Revision 2.0  2002/06/03 04:02:26  penguin
 * Warpcore CVS sync
 *
 * Revision 1.1  2002/05/02 18:03:11  mharris
 * Initial checkin - converted filenames and includes to lower case
 *  
 * 
 * 5     8/19/99 10:59a Dave
 * Packet loss detection.
 * 
 * 4     11/17/98 11:12a Dave
 * Removed player identification by address. Now assign explicit id #'s.
 * 
 * 3     11/05/98 5:55p Dave
 * Big pass at reducing #includes
 * 
 * 2     10/07/98 10:53a Dave
 * Initial checkin.
 * 
 * 1     10/07/98 10:50a Dave
 * 
 * 4     6/30/98 2:17p Dave
 * Revised object update system. Removed updates for all weapons. Put
 * button info back into control info packet.
 * 
 * 3     6/12/98 2:49p Dave
 * Patch 1.02 changes.
 * 
 * 2     3/15/98 4:17p Dave
 * Fixed oberver hud problems. Put in handy netplayer macros. Reduced size
 * of network orientation matrices.
 * 
 * 1     3/03/98 5:09p Dave
 *  
 * $NoKeywords: $
 */


#include "network/multi.h"
#include "network/multi_ping.h"
#include "network/multimsgs.h"
#include "io/timer.h"



// ------------------------------------------------------------------------------------
// MULTIPLAYER PING DEFINES/VARS
//


// ------------------------------------------------------------------------------------
// MULTIPLAYER PING FUNCTIONS
//

// initialize all player ping times
void multi_ping_reset_players()
{
	int idx;

	// reset the pings for all players
	for(idx=0;idx<MAX_PLAYERS;idx++){
		multi_ping_reset(&Net_players[idx].s_info.ping);
	}
}

// initialize the given ping struct
void multi_ping_reset(ping_struct *ps)
{
	// blast the struct clear
	memset(ps,0,sizeof(ping_struct));

	ps->ping_add = 0;

	// set the ping start to be -1
	ps->ping_start = -1.0f;

	ps->ping_avg = -1;

	ps->num_pings = 0;
}

// evaluate a pong return on the given struct
void multi_ping_eval_pong(ping_struct *ps)
{	
	int idx;
	float ping_sum;
	
	// if the ping technically hasn't started,
	if(ps->ping_start < 0.0f){
		nprintf(("Network","Processing pong for ping which hasn't started yet!\n"));
		return;
	}
	
	// if we still have room to add a ping
	if(ps->num_pings < MAX_PINGS){
		ps->ping_times[ps->ping_add++] = f2fl(timer_get_fixed_seconds()) - ps->ping_start;		
		ps->num_pings++;
	} 
	// otherwise if we've wrapped around
	else {		
		// increment the place to add the ping time
		if(ps->ping_add >= MAX_PINGS - 1){
			ps->ping_add = 0;
		} else {
			ps->ping_add++;
		}

		ps->ping_times[ps->ping_add] = f2fl(timer_get_fixed_seconds()) - ps->ping_start;
	}

	// calculate the average ping time
	ping_sum = 0.0f;
	for(idx=0;idx<ps->num_pings;idx++){
		ping_sum += ps->ping_times[idx];
	}
	ps->ping_avg = (int)(1000.0f * (ping_sum / (float)ps->num_pings));	
}

// start a ping - call this when sending a ping packet
void multi_ping_start(ping_struct *ps)
{
	ps->ping_start = f2fl(timer_get_fixed_seconds());
}

// send a ping to a specific player
void multi_ping_send(net_player *p)
{
	multi_ping_start(&p->s_info.ping);
	send_ping(&p->p_info.addr);
}

// send a ping to the specified address
void multi_ping_send(net_addr *addr,ping_struct *ps)
{
	multi_ping_start(ps);
	send_ping(addr);
}

// send a ping to all players
void multi_ping_send_all()
{
	int idx;
	for(idx = 0;idx < MAX_PLAYERS;idx++){
		if(MULTI_CONNECTED(Net_players[idx]) && (Net_player != NULL) && (Net_player->player_id != Net_players[idx].player_id)){
			// start the ping
			multi_ping_start(&Net_players[idx].s_info.ping);			

			// send the ping packet
			send_ping(&Net_players[idx].p_info.addr);
		}
	}
}

// get the lowest existing ping in the ping struct, returning -1 if no pings
int multi_ping_get_lowest(ping_struct *ps)
{
	int idx, lowest_index;
	float lowest;
	
	// if there are no recorded pings, return -1
	if(ps->num_pings == 0){
		return -1;
	}

	// otherwise find the lowest
	lowest = -1.0f;
	for(idx=0;idx<ps->num_pings;idx++){
		// if we found a lower value
		if((lowest == -1) || (ps->ping_times[idx] < lowest)){
			lowest = ps->ping_times[idx];
			lowest_index = idx;
		}
	}

	// return the lowest val
	return lowest < 0.0f ? -1 : (int)(lowest * 1000.0f)/2;
}

// (average ping + lowest ping)/2
int multi_ping_lowest_avg(ping_struct *ps)
{
	int lowest = multi_ping_get_lowest(ps);

	// if we couldn't get a valid lowest ping, bail
	if(lowest == -1){
		return -1;
	}

	// if we have no average ping, bail
	if(ps->ping_avg == -1){
		return -1;
	}

	// otherwise return the average of the 2
	return (lowest + ps->ping_avg)/2;
}