1 files changed, 403 insertions, 0 deletions
diff --git a/code/cgame/cg_snapshot.c b/code/cgame/cg_snapshot.c
new file mode 100644
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--- /dev/null
+++ b/code/cgame/cg_snapshot.c
@@ -0,0 +1,403 @@
+/*
+===========================================================================
+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 Quake III Arena source code; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+===========================================================================
+*/
+//
+// cg_snapshot.c -- things that happen on snapshot transition,
+// not necessarily every single rendered frame
+
+#include "cg_local.h"
+
+
+
+/*
+==================
+CG_ResetEntity
+==================
+*/
+static void CG_ResetEntity( centity_t *cent ) {
+	// if the previous snapshot this entity was updated in is at least
+	// an event window back in time then we can reset the previous event
+	if ( cent->snapShotTime < cg.time - EVENT_VALID_MSEC ) {
+		cent->previousEvent = 0;
+	}
+
+	cent->trailTime = cg.snap->serverTime;
+
+	VectorCopy (cent->currentState.origin, cent->lerpOrigin);
+	VectorCopy (cent->currentState.angles, cent->lerpAngles);
+	if ( cent->currentState.eType == ET_PLAYER ) {
+		CG_ResetPlayerEntity( cent );
+	}
+}
+
+/*
+===============
+CG_TransitionEntity
+
+cent->nextState is moved to cent->currentState and events are fired
+===============
+*/
+static void CG_TransitionEntity( centity_t *cent ) {
+	cent->currentState = cent->nextState;
+	cent->currentValid = qtrue;
+
+	// reset if the entity wasn't in the last frame or was teleported
+	if ( !cent->interpolate ) {
+		CG_ResetEntity( cent );
+	}
+
+	// clear the next state.  if will be set by the next CG_SetNextSnap
+	cent->interpolate = qfalse;
+
+	// check for events
+	CG_CheckEvents( cent );
+}
+
+
+/*
+==================
+CG_SetInitialSnapshot
+
+This will only happen on the very first snapshot, or
+on tourney restarts.  All other times will use 
+CG_TransitionSnapshot instead.
+
+FIXME: Also called by map_restart?
+==================
+*/
+void CG_SetInitialSnapshot( snapshot_t *snap ) {
+	int				i;
+	centity_t		*cent;
+	entityState_t	*state;
+
+	cg.snap = snap;
+
+	BG_PlayerStateToEntityState( &snap->ps, &cg_entities[ snap->ps.clientNum ].currentState, qfalse );
+
+	// sort out solid entities
+	CG_BuildSolidList();
+
+	CG_ExecuteNewServerCommands( snap->serverCommandSequence );
+
+	// set our local weapon selection pointer to
+	// what the server has indicated the current weapon is
+	CG_Respawn();
+
+	for ( i = 0 ; i < cg.snap->numEntities ; i++ ) {
+		state = &cg.snap->entities[ i ];
+		cent = &cg_entities[ state->number ];
+
+		memcpy(&cent->currentState, state, sizeof(entityState_t));
+		//cent->currentState = *state;
+		cent->interpolate = qfalse;
+		cent->currentValid = qtrue;
+
+		CG_ResetEntity( cent );
+
+		// check for events
+		CG_CheckEvents( cent );
+	}
+}
+
+
+/*
+===================
+CG_TransitionSnapshot
+
+The transition point from snap to nextSnap has passed
+===================
+*/
+static void CG_TransitionSnapshot( void ) {
+	centity_t			*cent;
+	snapshot_t			*oldFrame;
+	int					i;
+
+	if ( !cg.snap ) {
+		CG_Error( "CG_TransitionSnapshot: NULL cg.snap" );
+	}
+	if ( !cg.nextSnap ) {
+		CG_Error( "CG_TransitionSnapshot: NULL cg.nextSnap" );
+	}
+
+	// execute any server string commands before transitioning entities
+	CG_ExecuteNewServerCommands( cg.nextSnap->serverCommandSequence );
+
+	// if we had a map_restart, set everthing with initial
+	if ( !cg.snap ) {
+	}
+
+	// clear the currentValid flag for all entities in the existing snapshot
+	for ( i = 0 ; i < cg.snap->numEntities ; i++ ) {
+		cent = &cg_entities[ cg.snap->entities[ i ].number ];
+		cent->currentValid = qfalse;
+	}
+
+	// move nextSnap to snap and do the transitions
+	oldFrame = cg.snap;
+	cg.snap = cg.nextSnap;
+
+	BG_PlayerStateToEntityState( &cg.snap->ps, &cg_entities[ cg.snap->ps.clientNum ].currentState, qfalse );
+	cg_entities[ cg.snap->ps.clientNum ].interpolate = qfalse;
+
+	for ( i = 0 ; i < cg.snap->numEntities ; i++ ) {
+		cent = &cg_entities[ cg.snap->entities[ i ].number ];
+		CG_TransitionEntity( cent );
+
+		// remember time of snapshot this entity was last updated in
+		cent->snapShotTime = cg.snap->serverTime;
+	}
+
+	cg.nextSnap = NULL;
+
+	// check for playerstate transition events
+	if ( oldFrame ) {
+		playerState_t	*ops, *ps;
+
+		ops = &oldFrame->ps;
+		ps = &cg.snap->ps;
+		// teleporting checks are irrespective of prediction
+		if ( ( ps->eFlags ^ ops->eFlags ) & EF_TELEPORT_BIT ) {
+			cg.thisFrameTeleport = qtrue;	// will be cleared by prediction code
+		}
+
+		// if we are not doing client side movement prediction for any
+		// reason, then the client events and view changes will be issued now
+		if ( cg.demoPlayback || (cg.snap->ps.pm_flags & PMF_FOLLOW)
+			|| cg_nopredict.integer || cg_synchronousClients.integer ) {
+			CG_TransitionPlayerState( ps, ops );
+		}
+	}
+
+}
+
+
+/*
+===================
+CG_SetNextSnap
+
+A new snapshot has just been read in from the client system.
+===================
+*/
+static void CG_SetNextSnap( snapshot_t *snap ) {
+	int					num;
+	entityState_t		*es;
+	centity_t			*cent;
+
+	cg.nextSnap = snap;
+
+	BG_PlayerStateToEntityState( &snap->ps, &cg_entities[ snap->ps.clientNum ].nextState, qfalse );
+	cg_entities[ cg.snap->ps.clientNum ].interpolate = qtrue;
+
+	// check for extrapolation errors
+	for ( num = 0 ; num < snap->numEntities ; num++ ) {
+		es = &snap->entities[num];
+		cent = &cg_entities[ es->number ];
+
+		memcpy(&cent->nextState, es, sizeof(entityState_t));
+		//cent->nextState = *es;
+
+		// if this frame is a teleport, or the entity wasn't in the
+		// previous frame, don't interpolate
+		if ( !cent->currentValid || ( ( cent->currentState.eFlags ^ es->eFlags ) & EF_TELEPORT_BIT )  ) {
+			cent->interpolate = qfalse;
+		} else {
+			cent->interpolate = qtrue;
+		}
+	}
+
+	// if the next frame is a teleport for the playerstate, we
+	// can't interpolate during demos
+	if ( cg.snap && ( ( snap->ps.eFlags ^ cg.snap->ps.eFlags ) & EF_TELEPORT_BIT ) ) {
+		cg.nextFrameTeleport = qtrue;
+	} else {
+		cg.nextFrameTeleport = qfalse;
+	}
+
+	// if changing follow mode, don't interpolate
+	if ( cg.nextSnap->ps.clientNum != cg.snap->ps.clientNum ) {
+		cg.nextFrameTeleport = qtrue;
+	}
+
+	// if changing server restarts, don't interpolate
+	if ( ( cg.nextSnap->snapFlags ^ cg.snap->snapFlags ) & SNAPFLAG_SERVERCOUNT ) {
+		cg.nextFrameTeleport = qtrue;
+	}
+
+	// sort out solid entities
+	CG_BuildSolidList();
+}
+
+
+/*
+========================
+CG_ReadNextSnapshot
+
+This is the only place new snapshots are requested
+This may increment cgs.processedSnapshotNum multiple
+times if the client system fails to return a
+valid snapshot.
+========================
+*/
+static snapshot_t *CG_ReadNextSnapshot( void ) {
+	qboolean	r;
+	snapshot_t	*dest;
+
+	if ( cg.latestSnapshotNum > cgs.processedSnapshotNum + 1000 ) {
+		CG_Printf( "WARNING: CG_ReadNextSnapshot: way out of range, %i > %i", 
+			cg.latestSnapshotNum, cgs.processedSnapshotNum );
+	}
+
+	while ( cgs.processedSnapshotNum < cg.latestSnapshotNum ) {
+		// decide which of the two slots to load it into
+		if ( cg.snap == &cg.activeSnapshots[0] ) {
+			dest = &cg.activeSnapshots[1];
+		} else {
+			dest = &cg.activeSnapshots[0];
+		}
+
+		// try to read the snapshot from the client system
+		cgs.processedSnapshotNum++;
+		r = trap_GetSnapshot( cgs.processedSnapshotNum, dest );
+
+		// FIXME: why would trap_GetSnapshot return a snapshot with the same server time
+		if ( cg.snap && r && dest->serverTime == cg.snap->serverTime ) {
+			//continue;
+		}
+
+		// if it succeeded, return
+		if ( r ) {
+			CG_AddLagometerSnapshotInfo( dest );
+			return dest;
+		}
+
+		// a GetSnapshot will return failure if the snapshot
+		// never arrived, or  is so old that its entities
+		// have been shoved off the end of the circular
+		// buffer in the client system.
+
+		// record as a dropped packet
+		CG_AddLagometerSnapshotInfo( NULL );
+
+		// If there are additional snapshots, continue trying to
+		// read them.
+	}
+
+	// nothing left to read
+	return NULL;
+}
+
+
+/*
+============
+CG_ProcessSnapshots
+
+We are trying to set up a renderable view, so determine
+what the simulated time is, and try to get snapshots
+both before and after that time if available.
+
+If we don't have a valid cg.snap after exiting this function,
+then a 3D game view cannot be rendered.  This should only happen
+right after the initial connection.  After cg.snap has been valid
+once, it will never turn invalid.
+
+Even if cg.snap is valid, cg.nextSnap may not be, if the snapshot
+hasn't arrived yet (it becomes an extrapolating situation instead
+of an interpolating one)
+
+============
+*/
+void CG_ProcessSnapshots( void ) {
+	snapshot_t		*snap;
+	int				n;
+
+	// see what the latest snapshot the client system has is
+	trap_GetCurrentSnapshotNumber( &n, &cg.latestSnapshotTime );
+	if ( n != cg.latestSnapshotNum ) {
+		if ( n < cg.latestSnapshotNum ) {
+			// this should never happen
+			CG_Error( "CG_ProcessSnapshots: n < cg.latestSnapshotNum" );
+		}
+		cg.latestSnapshotNum = n;
+	}
+
+	// If we have yet to receive a snapshot, check for it.
+	// Once we have gotten the first snapshot, cg.snap will
+	// always have valid data for the rest of the game
+	while ( !cg.snap ) {
+		snap = CG_ReadNextSnapshot();
+		if ( !snap ) {
+			// we can't continue until we get a snapshot
+			return;
+		}
+
+		// set our weapon selection to what
+		// the playerstate is currently using
+		if ( !( snap->snapFlags & SNAPFLAG_NOT_ACTIVE ) ) {
+			CG_SetInitialSnapshot( snap );
+		}
+	}
+
+	// loop until we either have a valid nextSnap with a serverTime
+	// greater than cg.time to interpolate towards, or we run
+	// out of available snapshots
+	do {
+		// if we don't have a nextframe, try and read a new one in
+		if ( !cg.nextSnap ) {
+			snap = CG_ReadNextSnapshot();
+
+			// if we still don't have a nextframe, we will just have to
+			// extrapolate
+			if ( !snap ) {
+				break;
+			}
+
+			CG_SetNextSnap( snap );
+
+
+			// if time went backwards, we have a level restart
+			if ( cg.nextSnap->serverTime < cg.snap->serverTime ) {
+				CG_Error( "CG_ProcessSnapshots: Server time went backwards" );
+			}
+		}
+
+		// if our time is < nextFrame's, we have a nice interpolating state
+		if ( cg.time >= cg.snap->serverTime && cg.time < cg.nextSnap->serverTime ) {
+			break;
+		}
+
+		// we have passed the transition from nextFrame to frame
+		CG_TransitionSnapshot();
+	} while ( 1 );
+
+	// assert our valid conditions upon exiting
+	if ( cg.snap == NULL ) {
+		CG_Error( "CG_ProcessSnapshots: cg.snap == NULL" );
+	}
+	if ( cg.time < cg.snap->serverTime ) {
+		// this can happen right after a vid_restart
+		cg.time = cg.snap->serverTime;
+	}
+	if ( cg.nextSnap != NULL && cg.nextSnap->serverTime <= cg.time ) {
+		CG_Error( "CG_ProcessSnapshots: cg.nextSnap->serverTime <= cg.time" );
+	}
+
+}
+