cg_predict.c

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/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code 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.

Quake III Arena source code 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 Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
//
// cg_predict.c -- this file generates cg.predictedPlayerState by either
// interpolating between snapshots from the server or locally predicting
// ahead the client's movement.
// It also handles local physics interaction, like fragments bouncing off walls

#include "cg_local.h"

static	pmove_t		cg_pmove;

static	int			cg_numSolidEntities;
static	centity_t	*cg_solidEntities[MAX_ENTITIES_IN_SNAPSHOT];
static	int			cg_numTriggerEntities;
static	centity_t	*cg_triggerEntities[MAX_ENTITIES_IN_SNAPSHOT];

/*
====================
CG_BuildSolidList

When a new cg.snap has been set, this function builds a sublist
of the entities that are actually solid, to make for more
efficient collision detection
====================
*/
void CG_BuildSolidList( void ) {
	int			i;
	centity_t	*cent;
	snapshot_t	*snap;
	entityState_t	*ent;

	cg_numSolidEntities = 0;
	cg_numTriggerEntities = 0;

	if ( cg.nextSnap && !cg.nextFrameTeleport && !cg.thisFrameTeleport ) {
		snap = cg.nextSnap;
	} else {
		snap = cg.snap;
	}

	for ( i = 0 ; i < snap->numEntities ; i++ ) {
		cent = &cg_entities[ snap->entities[ i ].number ];
		ent = &cent->currentState;

		if ( ent->eType == ET_ITEM || ent->eType == ET_PUSH_TRIGGER || ent->eType == ET_TELEPORT_TRIGGER ) {
			cg_triggerEntities[cg_numTriggerEntities] = cent;
			cg_numTriggerEntities++;
			continue;
		}

		if ( cent->nextState.solid ) {
			cg_solidEntities[cg_numSolidEntities] = cent;
			cg_numSolidEntities++;
			continue;
		}
	}
}

/*
====================
CG_ClipMoveToEntities

====================
*/
static void CG_ClipMoveToEntities ( const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end,
							int skipNumber, int mask, trace_t *tr ) {
	int			i, x, zd, zu;
	trace_t		trace;
	entityState_t	*ent;
	clipHandle_t 	cmodel;
	vec3_t		bmins, bmaxs;
	vec3_t		origin, angles;
	centity_t	*cent;

	for ( i = 0 ; i < cg_numSolidEntities ; i++ ) {
		cent = cg_solidEntities[ i ];
		ent = &cent->currentState;

		if ( ent->number == skipNumber ) {
			continue;
		}

		if ( ent->solid == SOLID_BMODEL ) {
			// special value for bmodel
			cmodel = trap_CM_InlineModel( ent->modelindex );
			VectorCopy( cent->lerpAngles, angles );
			BG_EvaluateTrajectory( &cent->currentState.pos, cg.physicsTime, origin );
		} else {
			// encoded bbox
			x = (ent->solid & 255);
			zd = ((ent->solid>>8) & 255);
			zu = ((ent->solid>>16) & 255) - 32;

			bmins[0] = bmins[1] = -x;
			bmaxs[0] = bmaxs[1] = x;
			bmins[2] = -zd;
			bmaxs[2] = zu;

			cmodel = trap_CM_TempBoxModel( bmins, bmaxs );
			VectorCopy( vec3_origin, angles );
			VectorCopy( cent->lerpOrigin, origin );
		}


		trap_CM_TransformedBoxTrace ( &trace, start, end,
			mins, maxs, cmodel,  mask, origin, angles);

		if (trace.allsolid || trace.fraction < tr->fraction) {
			trace.entityNum = ent->number;
			*tr = trace;
		} else if (trace.startsolid) {
			tr->startsolid = qtrue;
		}
		if ( tr->allsolid ) {
			return;
		}
	}
}

/*
================
CG_Trace
================
*/
void	CG_Trace( trace_t *result, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, 
					 int skipNumber, int mask ) {
	trace_t	t;

	trap_CM_BoxTrace ( &t, start, end, mins, maxs, 0, mask);
	t.entityNum = t.fraction != 1.0 ? ENTITYNUM_WORLD : ENTITYNUM_NONE;
	// check all other solid models
	CG_ClipMoveToEntities (start, mins, maxs, end, skipNumber, mask, &t);

	*result = t;
}

/*
================
CG_PointContents
================
*/
int		CG_PointContents( const vec3_t point, int passEntityNum ) {
	int			i;
	entityState_t	*ent;
	centity_t	*cent;
	clipHandle_t cmodel;
	int			contents;

	contents = trap_CM_PointContents (point, 0);

	for ( i = 0 ; i < cg_numSolidEntities ; i++ ) {
		cent = cg_solidEntities[ i ];

		ent = &cent->currentState;

		if ( ent->number == passEntityNum ) {
			continue;
		}

		if (ent->solid != SOLID_BMODEL) { // special value for bmodel
			continue;
		}

		cmodel = trap_CM_InlineModel( ent->modelindex );
		if ( !cmodel ) {
			continue;
		}

		contents |= trap_CM_TransformedPointContents( point, cmodel, ent->origin, ent->angles );
	}

	return contents;
}


/*
========================
CG_InterpolatePlayerState

Generates cg.predictedPlayerState by interpolating between
cg.snap->player_state and cg.nextFrame->player_state
========================
*/
static void CG_InterpolatePlayerState( qboolean grabAngles ) {
	float			f;
	int				i;
	playerState_t	*out;
	snapshot_t		*prev, *next;

	out = &cg.predictedPlayerState;
	prev = cg.snap;
	next = cg.nextSnap;

	*out = cg.snap->ps;

	// if we are still allowing local input, short circuit the view angles
	if ( grabAngles ) {
		usercmd_t	cmd;
		int			cmdNum;

		cmdNum = trap_GetCurrentCmdNumber();
		trap_GetUserCmd( cmdNum, &cmd );

		PM_UpdateViewAngles( out, &cmd );
	}

	// if the next frame is a teleport, we can't lerp to it
	if ( cg.nextFrameTeleport ) {
		return;
	}

	if ( !next || next->serverTime <= prev->serverTime ) {
		return;
	}

	f = (float)( cg.time - prev->serverTime ) / ( next->serverTime - prev->serverTime );

	i = next->ps.bobCycle;
	if ( i < prev->ps.bobCycle ) {
		i += 256;		// handle wraparound
	}
	out->bobCycle = prev->ps.bobCycle + f * ( i - prev->ps.bobCycle );

	for ( i = 0 ; i < 3 ; i++ ) {
		out->origin[i] = prev->ps.origin[i] + f * (next->ps.origin[i] - prev->ps.origin[i] );
		if ( !grabAngles ) {
			out->viewangles[i] = LerpAngle( 
				prev->ps.viewangles[i], next->ps.viewangles[i], f );
		}
		out->velocity[i] = prev->ps.velocity[i] + 
			f * (next->ps.velocity[i] - prev->ps.velocity[i] );
	}

}

/*
===================
CG_TouchItem
===================
*/
static void CG_TouchItem( centity_t *cent ) {
	gitem_t		*item;

	if ( !cg_predictItems.integer ) {
		return;
	}
	if ( !BG_PlayerTouchesItem( &cg.predictedPlayerState, &cent->currentState, cg.time ) ) {
		return;
	}

	// never pick an item up twice in a prediction
	if ( cent->miscTime == cg.time ) {
		return;
	}

	if ( !BG_CanItemBeGrabbed( cgs.gametype, &cent->currentState, &cg.predictedPlayerState ) ) {
		return;		// can't hold it
	}

	item = &bg_itemlist[ cent->currentState.modelindex ];

	// Special case for flags.  
	// We don't predict touching our own flag
#ifdef MISSIONPACK
	if( cgs.gametype == GT_1FCTF ) {
		if( item->giTag != PW_NEUTRALFLAG ) {
			return;
		}
	}
	if( cgs.gametype == GT_CTF || cgs.gametype == GT_HARVESTER ) {
#else
	if( cgs.gametype == GT_CTF ) {
#endif
		if (cg.predictedPlayerState.persistant[PERS_TEAM] == TEAM_RED &&
			item->giTag == PW_REDFLAG)
			return;
		if (cg.predictedPlayerState.persistant[PERS_TEAM] == TEAM_BLUE &&
			item->giTag == PW_BLUEFLAG)
			return;
	}

	// grab it
	BG_AddPredictableEventToPlayerstate( EV_ITEM_PICKUP, cent->currentState.modelindex , &cg.predictedPlayerState);

	// remove it from the frame so it won't be drawn
	cent->currentState.eFlags |= EF_NODRAW;

	// don't touch it again this prediction
	cent->miscTime = cg.time;

	// if its a weapon, give them some predicted ammo so the autoswitch will work
	if ( item->giType == IT_WEAPON ) {
		cg.predictedPlayerState.stats[ STAT_WEAPONS ] |= 1 << item->giTag;
		if ( !cg.predictedPlayerState.ammo[ item->giTag ] ) {
			cg.predictedPlayerState.ammo[ item->giTag ] = 1;