text: /*
  Copyright (C) 1996-1997 Id Software, Inc.
  
  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.
  
  */
  // sv_user.c -- server code for moving users
  
  #include "quakedef.h"
  
  edict_t	*sv_player;
  
  extern	cvar_t	sv_friction;
  cvar_t	sv_edgefriction = {"edgefriction", "2"};
  extern	cvar_t	sv_stopspeed;
  
  static	vec3_t		forward, right, up;
  
  vec3_t	wishdir;
  float	wishspeed;
  
  // world
  float	*angles;
  float	*origin;
  float	*velocity;
  
  qboolean	onground;
  
  usercmd_t	cmd;
  
  cvar_t	sv_idealpitchscale = {"sv_idealpitchscale","0.8"};
  cvar_t	sv_altnoclip = {"sv_altnoclip", "0"};
  
  /*
  ===============
  SV_SetIdealPitch
  ===============
  */
  #define	MAX_FORWARD	6
  void SV_SetIdealPitch (void)
  {
  	float	angleval, sinval, cosval;
  	trace_t	tr;
  	vec3_t	top, bottom;
  	float	z[MAX_FORWARD];
  	int		i, j;
  	int		step, dir, steps;
  
  	if (!((int)sv_player->v.flags & FL_ONGROUND))
  		return;
  		
  	angleval = sv_player->v.angles[YAW] * M_PI*2 / 360;
  	sinval = sin(angleval);
  	cosval = cos(angleval);
  
  	for (i=0 ; i<MAX_FORWARD ; i++)
  	{
  		top[0] = sv_player->v.origin[0] + cosval*(i+3)*12;
  		top[1] = sv_player->v.origin[1] + sinval*(i+3)*12;
  		top[2] = sv_player->v.origin[2] + sv_player->v.view_ofs[2];
  		
  		bottom[0] = top[0];
  		bottom[1] = top[1];
  		bottom[2] = top[2] - 160;
  		
  		tr = SV_Move (top, vec3_origin, vec3_origin, bottom, 1, sv_player);
  		if (tr.allsolid)
  			return;	// looking at a wall, leave ideal the way is was
  
  		if (tr.fraction == 1)
  			return;	// near a dropoff
  		
  		z[i] = top[2] + tr.fraction*(bottom[2]-top[2]);
  	}
  	
  	dir = 0;
  	steps = 0;
  	for (j=1 ; j<i ; j++)
  	{
  		step = z[j] - z[j-1];
  		if (step > -ON_EPSILON && step < ON_EPSILON)
  			continue;
  
  		if (dir && ( step-dir > ON_EPSILON || step-dir < -ON_EPSILON ) )
  			return;		// mixed changes
  
  		steps++;	
  		dir = step;
  	}
  	
  	if (!dir)
  	{
  		sv_player->v.idealpitch = 0;
  		return;
  	}
  	
  	if (steps < 2)
  		return;
  	sv_player->v.idealpitch = -dir * sv_idealpitchscale.value;
  }
  
  
  /*
  ==================
  SV_UserFriction
  
  ==================
  */
  void SV_UserFriction (void)
  {
  	float	*vel;
  	float	speed, newspeed, control;
  	vec3_t	start, stop;
  	float	friction;
  	trace_t	trace;
  	
  	vel = velocity;
  	
  	speed = sqrt(vel[0]*vel[0] +vel[1]*vel[1]);
  	if (!speed)
  		return;
  
  // if the leading edge is over a dropoff, increase friction
  	start[0] = stop[0] = origin[0] + vel[0]/speed*16;
  	start[1] = stop[1] = origin[1] + vel[1]/speed*16;
  	start[2] = origin[2] + sv_player->v.mins[2];
  	stop[2] = start[2] - 34;
  
  	trace = SV_Move (start, vec3_origin, vec3_origin, stop, true, sv_player);
  
  	if (trace.fraction == 1.0)
  		friction = sv_friction.value*sv_edgefriction.value;
  	else
  		friction = sv_friction.value;
  
  // apply friction	
  	control = speed < sv_stopspeed.value ? sv_stopspeed.value : speed;
  	newspeed = speed - host_frametime*control*friction;
  	
  	if (newspeed < 0)
  		newspeed = 0;
  	newspeed /= speed;
  
  	vel[0] = vel[0] * newspeed;
  	vel[1] = vel[1] * newspeed;
  	vel[2] = vel[2] * newspeed;
  }
  
  /*
  ==============
  SV_Accelerate
  ==============
  */
  cvar_t	sv_maxspeed = {"sv_maxspeed", "320", false, true};
  cvar_t	sv_accelerate = {"sv_accelerate", "10"};
  #if 0
  void SV_Accelerate (vec3_t wishvel)
  {
  	int			i;
  	float		addspeed, accelspeed;
  	vec3_t		pushvec;
  
  	if (wishspeed == 0)
  		return;
  
  	VectorSubtract (wishvel, velocity, pushvec);
  	addspeed = VectorNormalize (pushvec);
  
  	accelspeed = sv_accelerate.value*host_frametime*addspeed;
  	if (accelspeed > addspeed)
  		accelspeed = addspeed;
  	
  	for (i=0 ; i<3 ; i++)
  		velocity[i] += accelspeed*pushvec[i];	
  }
  #endif
  void SV_Accelerate (void)
  {
  	int			i;
  	float		addspeed, accelspeed, currentspeed;
  
  	currentspeed = DotProduct (velocity, wishdir);
  	addspeed = wishspeed - currentspeed;
  	if (addspeed <= 0)
  		return;
  	accelspeed = sv_accelerate.value*host_frametime*wishspeed;
  	if (accelspeed > addspeed)
  		accelspeed = addspeed;
  	
  	for (i=0 ; i<3 ; i++)
  		velocity[i] += accelspeed*wishdir[i];	
  }
  
  void SV_AirAccelerate (vec3_t wishveloc)
  {
  	int			i;
  	float		addspeed, wishspd, accelspeed, currentspeed;
  		
  	wishspd = VectorNormalize (wishveloc);
  	if (wishspd > 30)
  		wishspd = 30;
  	currentspeed = DotProduct (velocity, wishveloc);
  	addspeed = wishspd - currentspeed;
  	if (addspeed <= 0)
  		return;
  //	accelspeed = sv_accelerate.value * host_frametime;
  	accelspeed = sv_accelerate.value*wishspeed * host_frametime;
  	if (accelspeed > addspeed)
  		accelspeed = addspeed;
  	
  	for (i=0 ; i<3 ; i++)
  		velocity[i] += accelspeed*wishveloc[i];	
  }
  
  
  void DropPunchAngle (void)
  {
  	float	len;
  	
  	len = VectorNormalize (sv_player->v.punchangle);
  	
  	len -= 10*host_frametime;
  	if (len < 0)
  		len = 0;
  	VectorScale (sv_player->v.punchangle, len, sv_player->v.punchangle);
  }
  
  /*
  ===================
  SV_WaterMove
  
  ===================
  */
  void SV_WaterMove (void)
  {
  	int		i;
  	vec3_t	wishvel;
  	float	speed, newspeed, wishspeed, addspeed, accelspeed;
  
  //
  // user intentions
  //
  	AngleVectors (sv_player->v.v_angle, forward, right, up);
  
  	for (i=0 ; i<3 ; i++)
  		wishvel[i] = forward[i]*cmd.forwardmove + right[i]*cmd.sidemove;
  
  	if (!cmd.forwardmove && !cmd.sidemove && !cmd.upmove)
  		wishvel[2] -= 60;		// drift towards bottom
  	else
  		wishvel[2] += cmd.upmove;
  
  	wishspeed = Length(wishvel);
  	if (wishspeed > sv_maxspeed.value)
  	{
  		VectorScale (wishvel, sv_maxspeed.value/wishspeed, wishvel);
  		wishspeed = sv_maxspeed.value;
  	}
  	wishspeed *= 0.7;
  
  //
  // water friction
  //
  	speed = Length (velocity);
  	if (speed)
  	{
  		newspeed = speed - host_frametime * speed * sv_friction.value;
  		if (newspeed < 0)
  			newspeed = 0;	
  		VectorScale (velocity, newspeed/speed, velocity);
  	}
  	else
  		newspeed = 0;
  	
  //
  // water acceleration
  //
  	if (!wishspeed)
  		return;
  
  	addspeed = wishspeed - newspeed;
  	if (addspeed <= 0)
  		return;
  
  	VectorNormalize (wishvel);
  	accelspeed = sv_accelerate.value * wishspeed * host_frametime;
  	if (accelspeed > addspeed)
  		accelspeed = addspeed;
  
  	for (i=0 ; i<3 ; i++)
  		velocity[i] += accelspeed * wishvel[i];
  }
  
  void SV_WaterJump (void)
  {
  	if (sv.time > sv_player->v.teleport_time
  	|| !sv_player->v.waterlevel)
  	{
  		sv_player->v.flags = (int)sv_player->v.flags & ~FL_WATERJUMP;
  		sv_player->v.teleport_time = 0;
  	}
  	sv_player->v.velocity[0] = sv_player->v.movedir[0];
  	sv_player->v.velocity[1] = sv_player->v.movedir[1];
  }
  
  /*
  ===================
  SV_NoclipMove
  
  new, alternate noclip. old noclip is still handled in SV_AirMove
  ===================
  */
  void SV_NoclipMove (void)
  {
  	AngleVectors (sv_player->v.v_angle, forward, right, up);
  	
  	velocity[0] = forward[0]*cmd.forwardmove + right[0]*cmd.sidemove;
  	velocity[1] = forward[1]*cmd.forwardmove + right[1]*cmd.sidemove;
  	velocity[2] = forward[2]*cmd.forwardmove + right[2]*cmd.sidemove;
  	velocity[2] += cmd.upmove*2; //doubled to match running speed
  		
  	if (Length (velocity) > sv_maxspeed.value)
  	{
  		VectorNormalize (velocity);
  		VectorScale (velocity, sv_maxspeed.value, velocity);
  	}
  }
  
  /*
  ===================
  SV_AirMove
  
  ===================
  */
  void SV_AirMove (void)
  {
  	int			i;
  	vec3_t		wishvel;
  	float		fmove, smove;
  
  	AngleVectors (sv_player->v.angles, forward, right, up);
  
  	fmove = cmd.forwardmove;
  	smove = cmd.sidemove;
  	
  // hack to not let you back into teleporter
  	if (sv.time < sv_player->v.teleport_time && fmove < 0)
  		fmove = 0;
  		
  	for (i=0 ; i<3 ; i++)
  		wishvel[i] = forward[i]*fmove + right[i]*smove;
  
  	if ( (int)sv_player->v.movetype != MOVETYPE_WALK)
  		wishvel[2] = cmd.upmove;
  	else
  		wishvel[2] = 0;
  
  	VectorCopy (wishvel, wishdir);
  	wishspeed = VectorNormalize(wishdir);
  	if (wishspeed > sv_maxspeed.value)
  	{
  		VectorScale (wishvel, sv_maxspeed.value/wishspeed, wishvel);
  		wishspeed = sv_maxspeed.value;
  	}
  	
  	if ( sv_player->v.movetype == MOVETYPE_NOCLIP)
  	{	// noclip
  		VectorCopy (wishvel, velocity);
  	}
  	else if ( onground )
  	{
  		SV_UserFriction ();
  		SV_Accelerate ();
  	}
  	else
  	{	// not on ground, so little effect on velocity
  		SV_AirAccelerate (wishvel);
  	}		
  }
  
  /*
  ===================
  SV_ClientThink
  
  the move fields specify an intended velocity in pix/sec
  the angle fields specify an exact angular motion in degrees
  ===================
  */
  void SV_ClientThink (void)
  {
  	vec3_t		v_angle;
  
  	if (sv_player->v.movetype == MOVETYPE_NONE)
  		return;
  	
  	onground = (int)sv_player->v.flags & FL_ONGROUND;
  
  	origin = sv_player->v.origin;
  	velocity = sv_player->v.velocity;
  
  	DropPunchAngle ();
  	
  //
  // if dead, behave differently
  //
  	if (sv_player->v.health <= 0)
  		return;
  
  //
  // angles
  // show 1/3 the pitch angle and all the roll angle
  	cmd = host_client->cmd;
  	angles = sv_player->v.angles;
  	
  	VectorAdd (sv_player->v.v_angle, sv_player->v.punchangle, v_angle);
  	angles[ROLL] = V_CalcRoll (sv_player->v.angles, sv_player->v.velocity)*4;
  	if (!sv_player->v.fixangle)
  	{
  		angles[PITCH] = -v_angle[PITCH]/3;
  		angles[YAW] = v_angle[YAW];
  	}
  
  	if (sv_player->v.movetype == MOVETYPE_NOCLIP)
  		sv_player->v.waterlevel = 0; // Avoid annoying waterjumps in noclip
  
  	if ( (int)sv_player->v.flags & FL_WATERJUMP )
  	{
  		SV_WaterJump ();
  		return;
  	}
  //
  // walk
  //
  	// Alternate noclip
  	if (sv_altnoclip.value && sv_player->v.movetype == MOVETYPE_NOCLIP)
  		SV_NoclipMove ();
  	else if (sv_player->v.waterlevel >= 2 && sv_player->v.movetype != MOVETYPE_NOCLIP)
  		SV_WaterMove ();
  	else
  		SV_AirMove ();	
  }
  
  
  /*
  ===================
  SV_ReadClientMove
  ===================
  */
  void SV_ReadClientMove (usercmd_t *move)
  {
  	int		i;
  	vec3_t	angle;
  	int		bits;
  	
  // read ping time
  	host_client->ping_times[host_client->num_pings%NUM_PING_TIMES]
  		= sv.time - MSG_ReadFloat ();
  	host_client->num_pings++;
  
  // read current angles	
  	for (i=0 ; i<3 ; i++)
  		angle[i] = MSG_ReadAngle ();
  
  	VectorCopy (angle, host_client->edict->v.v_angle);
  		
  // read movement
  	move->forwardmove = MSG_ReadShort ();
  	move->sidemove = MSG_ReadShort ();
  	move->upmove = MSG_ReadShort ();
  	
  // read buttons
  	bits = MSG_ReadByte ();
  	host_client->edict->v.button0 = bits & 1;
  	host_client->edict->v.button2 = (bits & 2)>>1;
  
  	i = MSG_ReadByte ();
  	if (i)
  		host_client->edict->v.impulse = i;
  
  #ifdef QUAKE2
  // read light level
  	host_client->edict->v.light_level = MSG_ReadByte ();
  #endif
  }
  
  /*
  ===================
  SV_ReadClientMessage
  
  Returns false if the client should be killed
  ===================
  */
  qboolean SV_ReadClientMessage (void)
  {
  	int		ret;
  	int		cmd;
  	char		*s;
  	
  	do
  	{
  nextmsg:
  		ret = NET_GetMessage (host_client->netconnection);
  		if (ret == -1)
  		{
  			Sys_Printf ("SV_ReadClientMessage: NET_GetMessage failed\n");
  			return false;
  		}
  		if (!ret)
  			return true;
  					
  		MSG_BeginReading ();
  		
  		while (1)
  		{
  			if (!host_client->active)
  				return false;	// a command caused an error
  
  			if (msg_badread)
  			{
  				Sys_Printf ("SV_ReadClientMessage: badread\n");
  				return false;
  			}	
  	
  			cmd = MSG_ReadChar ();
  			
  			switch (cmd)
  			{
  			case -1:
  				goto nextmsg;		// end of message
  				
  			default:
  				Sys_Printf ("SV_ReadClientMessage: unknown command char\n");
  				return false;
  							
  			case clc_nop:
  //				Sys_Printf ("clc_nop\n");
  				break;
  				
  			case clc_stringcmd:	
  				s = MSG_ReadString ();
  				if (host_client->privileged)
  					ret = 2;
  				else
  					ret = 0;
  				
  				if (nehahra)
  				{
  					if (Q_strncasecmp(s, "max", 3) == 0)
  						ret = 1;
  					else if (Q_strncasecmp(s, "monster", 7) == 0)
  						ret = 1;
  					else if (Q_strncasecmp(s, "scrag", 5) == 0)
  						ret = 1;
  					else if (Q_strncasecmp(s, "wraith", 6) == 0)
  						ret = 1;
  					else if (Q_strncasecmp(s, "gimme", 5) == 0)
  						ret = 1;
  				}
  				else
  				{
  					if (Q_strncasecmp(s, "god", 3) == 0)
  						ret = 1;
  					else if (Q_strncasecmp(s, "notarget", 8) == 0)
  						ret = 1;
  					else if (Q_strncasecmp(s, "fly", 3) == 0)
  						ret = 1;
  					else if (Q_strncasecmp(s, "noclip", 6) == 0)
  						ret = 1;
  					else if (Q_strncasecmp(s, "give", 4) == 0)
  						ret = 1;
  				}
  
  				if (Q_strncasecmp(s, "status", 6) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "name", 4) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "say", 3) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "say_team", 8) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "tell", 4) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "color", 5) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "kill", 4) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "pause", 5) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "spawn", 5) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "begin", 5) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "prespawn", 8) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "kick", 4) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "ping", 4) == 0)
  					ret = 1;
  				else if (Q_strncasecmp(s, "ban", 3) == 0)
  					ret = 1;
  				if (ret == 2)
  					Cbuf_InsertText (s);
  				else if (ret == 1)
  					Cmd_ExecuteString (s, src_client);
  				else
  					Con_DPrintf("%s tried to %s\n", host_client->name, s);
  				break;
  				
  			case clc_disconnect:
  //				Sys_Printf ("SV_ReadClientMessage: client disconnected\n");
  				return false;
  			
  			case clc_move:
  				SV_ReadClientMove (&host_client->cmd);
  				break;
  			}
  		}
  	} while (ret == 1);
  	
  	return true;
  }
  
  
  /*
  ==================
  SV_RunClients
  ==================
  */
  void SV_RunClients (void)
  {
  	int				i;
  	
  	for (i=0, host_client = svs.clients ; i<svs.maxclients ; i++, host_client++)
  	{
  		if (!host_client->active)
  			continue;
  	
  		sv_player = host_client->edict;
  
  		if (!SV_ReadClientMessage ())
  		{
  			SV_DropClient (false);	// client misbehaved...
  			continue;
  		}
  
  		if (!host_client->spawned)
  		{
  		// clear client movement until a new packet is received
  			memset (&host_client->cmd, 0, sizeof(host_client->cmd));
  			continue;
  		}
  
  // always pause in single player if in console or menus
  		if (!SV_IsPaused ())
  			SV_ClientThink ();
  	}
  }
  
  