cg_predict.c

quakeIII源码这个不用我多说吧

		}
	}
}


/*
=========================
CG_TouchTriggerPrediction

Predict push triggers and items
=========================
*/
static void CG_TouchTriggerPrediction( void ) {
	int			i;
	trace_t		trace;
	entityState_t	*ent;
	clipHandle_t cmodel;
	centity_t	*cent;
	qboolean	spectator;

	// dead clients don't activate triggers
	if ( cg.predictedPlayerState.stats[STAT_HEALTH] <= 0 ) {
		return;
	}

	spectator = ( cg.predictedPlayerState.pm_type == PM_SPECTATOR );

	if ( cg.predictedPlayerState.pm_type != PM_NORMAL && !spectator ) {
		return;
	}

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

		if ( ent->eType == ET_ITEM && !spectator ) {
			CG_TouchItem( cent );
			continue;
		}

		if ( ent->solid != SOLID_BMODEL ) {
			continue;
		}

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

		trap_CM_BoxTrace( &trace, cg.predictedPlayerState.origin, cg.predictedPlayerState.origin, 
			cg_pmove.mins, cg_pmove.maxs, cmodel, -1 );

		if ( !trace.startsolid ) {
			continue;
		}

		if ( ent->eType == ET_TELEPORT_TRIGGER ) {
			cg.hyperspace = qtrue;
		} else if ( ent->eType == ET_PUSH_TRIGGER ) {
			BG_TouchJumpPad( &cg.predictedPlayerState, ent );
		}
	}

	// if we didn't touch a jump pad this pmove frame
	if ( cg.predictedPlayerState.jumppad_frame != cg.predictedPlayerState.pmove_framecount ) {
		cg.predictedPlayerState.jumppad_frame = 0;
		cg.predictedPlayerState.jumppad_ent = 0;
	}
}



/*
=================
CG_PredictPlayerState

Generates cg.predictedPlayerState for the current cg.time
cg.predictedPlayerState is guaranteed to be valid after exiting.

For demo playback, this will be an interpolation between two valid
playerState_t.

For normal gameplay, it will be the result of predicted usercmd_t on
top of the most recent playerState_t received from the server.

Each new snapshot will usually have one or more new usercmd over the last,
but we simulate all unacknowledged commands each time, not just the new ones.
This means that on an internet connection, quite a few pmoves may be issued
each frame.

OPTIMIZE: don't re-simulate unless the newly arrived snapshot playerState_t
differs from the predicted one.  Would require saving all intermediate
playerState_t during prediction.

We detect prediction errors and allow them to be decayed off over several frames
to ease the jerk.
=================
*/
void CG_PredictPlayerState( void ) {
	int			cmdNum, current;
	playerState_t	oldPlayerState;
	qboolean	moved;
	usercmd_t	oldestCmd;
	usercmd_t	latestCmd;

	cg.hyperspace = qfalse;	// will be set if touching a trigger_teleport

	// if this is the first frame we must guarantee
	// predictedPlayerState is valid even if there is some
	// other error condition
	if ( !cg.validPPS ) {
		cg.validPPS = qtrue;
		cg.predictedPlayerState = cg.snap->ps;
	}


	// demo playback just copies the moves
	if ( cg.demoPlayback || (cg.snap->ps.pm_flags & PMF_FOLLOW) ) {
		CG_InterpolatePlayerState( qfalse );
		return;
	}

	// non-predicting local movement will grab the latest angles
	if ( cg_nopredict.integer || cg_synchronousClients.integer ) {
		CG_InterpolatePlayerState( qtrue );
		return;
	}

	// prepare for pmove
	cg_pmove.ps = &cg.predictedPlayerState;
	cg_pmove.trace = CG_Trace;
	cg_pmove.pointcontents = CG_PointContents;
	if ( cg_pmove.ps->pm_type == PM_DEAD ) {
		cg_pmove.tracemask = MASK_PLAYERSOLID & ~CONTENTS_BODY;
	}
	else {
		cg_pmove.tracemask = MASK_PLAYERSOLID;
	}
	if ( cg.snap->ps.persistant[PERS_TEAM] == TEAM_SPECTATOR ) {
		cg_pmove.tracemask &= ~CONTENTS_BODY;	// spectators can fly through bodies
	}
	cg_pmove.noFootsteps = ( cgs.dmflags & DF_NO_FOOTSTEPS ) > 0;

	// save the state before the pmove so we can detect transitions
	oldPlayerState = cg.predictedPlayerState;

	current = trap_GetCurrentCmdNumber();

	// if we don't have the commands right after the snapshot, we
	// can't accurately predict a current position, so just freeze at
	// the last good position we had
	cmdNum = current - CMD_BACKUP + 1;
	trap_GetUserCmd( cmdNum, &oldestCmd );
	if ( oldestCmd.serverTime > cg.snap->ps.commandTime 
		&& oldestCmd.serverTime < cg.time ) {	// special check for map_restart
		if ( cg_showmiss.integer ) {
			CG_Printf ("exceeded PACKET_BACKUP on commands\n");
		}
		return;
	}

	// get the latest command so we can know which commands are from previous map_restarts
	trap_GetUserCmd( current, &latestCmd );

	// get the most recent information we have, even if
	// the server time is beyond our current cg.time,
	// because predicted player positions are going to 
	// be ahead of everything else anyway
	if ( cg.nextSnap && !cg.nextFrameTeleport && !cg.thisFrameTeleport ) {
		cg.predictedPlayerState = cg.nextSnap->ps;
		cg.physicsTime = cg.nextSnap->serverTime;
	} else {
		cg.predictedPlayerState = cg.snap->ps;
		cg.physicsTime = cg.snap->serverTime;
	}

	if ( pmove_msec.integer < 8 ) {
		trap_Cvar_Set("pmove_msec", "8");
	}
	else if (pmove_msec.integer > 33) {
		trap_Cvar_Set("pmove_msec", "33");
	}

	cg_pmove.pmove_fixed = pmove_fixed.integer;// | cg_pmove_fixed.integer;
	cg_pmove.pmove_msec = pmove_msec.integer;

	// run cmds
	moved = qfalse;
	for ( cmdNum = current - CMD_BACKUP + 1 ; cmdNum <= current ; cmdNum++ ) {
		// get the command
		trap_GetUserCmd( cmdNum, &cg_pmove.cmd );

		if ( cg_pmove.pmove_fixed ) {
			PM_UpdateViewAngles( cg_pmove.ps, &cg_pmove.cmd );
		}

		// don't do anything if the time is before the snapshot player time
		if ( cg_pmove.cmd.serverTime <= cg.predictedPlayerState.commandTime ) {
			continue;
		}

		// don't do anything if the command was from a previous map_restart
		if ( cg_pmove.cmd.serverTime > latestCmd.serverTime ) {
			continue;
		}

		// check for a prediction error from last frame
		// on a lan, this will often be the exact value
		// from the snapshot, but on a wan we will have
		// to predict several commands to get to the point
		// we want to compare
		if ( cg.predictedPlayerState.commandTime == oldPlayerState.commandTime ) {
			vec3_t	delta;
			float	len;

			if ( cg.thisFrameTeleport ) {
				// a teleport will not cause an error decay
				VectorClear( cg.predictedError );
				if ( cg_showmiss.integer ) {
					CG_Printf( "PredictionTeleport\n" );
				}
				cg.thisFrameTeleport = qfalse;
			} else {
				vec3_t	adjusted;
				CG_AdjustPositionForMover( cg.predictedPlayerState.origin, 
					cg.predictedPlayerState.groundEntityNum, cg.physicsTime, cg.oldTime, adjusted );

				if ( cg_showmiss.integer ) {
					if (!VectorCompare( oldPlayerState.origin, adjusted )) {
						CG_Printf("prediction error\n");
					}
				}
				VectorSubtract( oldPlayerState.origin, adjusted, delta );
				len = VectorLength( delta );
				if ( len > 0.1 ) {
					if ( cg_showmiss.integer ) {
						CG_Printf("Prediction miss: %f\n", len);
					}
					if ( cg_errorDecay.integer ) {
						int		t;
						float	f;

						t = cg.time - cg.predictedErrorTime;
						f = ( cg_errorDecay.value - t ) / cg_errorDecay.value;
						if ( f < 0 ) {
							f = 0;
						}
						if ( f > 0 && cg_showmiss.integer ) {
							CG_Printf("Double prediction decay: %f\n", f);
						}
						VectorScale( cg.predictedError, f, cg.predictedError );
					} else {
						VectorClear( cg.predictedError );
					}
					VectorAdd( delta, cg.predictedError, cg.predictedError );
					cg.predictedErrorTime = cg.oldTime;
				}
			}
		}

		// don't predict gauntlet firing, which is only supposed to happen
		// when it actually inflicts damage
		cg_pmove.gauntletHit = qfalse;

		if ( cg_pmove.pmove_fixed ) {
			cg_pmove.cmd.serverTime = ((cg_pmove.cmd.serverTime + pmove_msec.integer-1) / pmove_msec.integer) * pmove_msec.integer;
		}

		Pmove (&cg_pmove);

		moved = qtrue;

		// add push trigger movement effects
		CG_TouchTriggerPrediction();

		// check for predictable events that changed from previous predictions
		//CG_CheckChangedPredictableEvents(&cg.predictedPlayerState);
	}

	if ( cg_showmiss.integer > 1 ) {
		CG_Printf( "[%i : %i] ", cg_pmove.cmd.serverTime, cg.time );
	}

	if ( !moved ) {
		if ( cg_showmiss.integer ) {
			CG_Printf( "not moved\n" );
		}
		return;
	}

	// adjust for the movement of the groundentity
	CG_AdjustPositionForMover( cg.predictedPlayerState.origin, 
		cg.predictedPlayerState.groundEntityNum, 
		cg.physicsTime, cg.time, cg.predictedPlayerState.origin );

	if ( cg_showmiss.integer ) {
		if (cg.predictedPlayerState.eventSequence > oldPlayerState.eventSequence + MAX_PS_EVENTS) {
			CG_Printf("WARNING: dropped event\n");
		}
	}

	// fire events and other transition triggered things
	CG_TransitionPlayerState( &cg.predictedPlayerState, &oldPlayerState );

	if ( cg_showmiss.integer ) {
		if (cg.eventSequence > cg.predictedPlayerState.eventSequence) {
			CG_Printf("WARNING: double event\n");
			cg.eventSequence = cg.predictedPlayerState.eventSequence;
		}
	}
}