From 93c58533567477de7a4a7185713cc517d1af3c9c Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Wed, 18 Dec 2024 06:57:07 +0300
Subject: [PATCH] engine: server: merge SV_FindBestBaseline for normal entities
 and static entities into single function

---
 engine/server/server.h   |  2 +-
 engine/server/sv_frame.c | 53 +++++++++++-----------------------------
 engine/server/sv_game.c  |  2 +-
 3 files changed, 16 insertions(+), 41 deletions(-)

diff --git a/engine/server/server.h b/engine/server/server.h
index d0d864d98e..2f145fc60f 100644
--- a/engine/server/server.h
+++ b/engine/server/server.h
@@ -593,7 +593,7 @@ qboolean SV_CheckID( const char *id );
 // sv_frame.c
 //
 void SV_InactivateClients( void );
-int SV_FindBestBaselineForStatic( int index, entity_state_t **baseline, entity_state_t *to );
+int SV_FindBestBaseline( int index, entity_state_t **baseline, entity_state_t *to, client_frame_t *frame, qboolean player );
 void SV_SkipUpdates( void );
 
 //
diff --git a/engine/server/sv_frame.c b/engine/server/sv_frame.c
index 07641fa054..5d94d9f12c 100644
--- a/engine/server/sv_frame.c
+++ b/engine/server/sv_frame.c
@@ -178,9 +178,10 @@ Encode a client frame onto the network channel
 SV_FindBestBaseline
 
 trying to deltas with previous entities
+set frame to NULL to check for static entities
 =============
 */
-static int SV_FindBestBaseline( sv_client_t *cl, int index, entity_state_t **baseline, entity_state_t *to, client_frame_t *frame, qboolean player )
+int SV_FindBestBaseline( int index, entity_state_t **baseline, entity_state_t *to, client_frame_t *frame, qboolean player )
 {
 	int	bestBitCount;
 	int	i, bitCount;
@@ -193,7 +194,13 @@ static int SV_FindBestBaseline( sv_client_t *cl, int index, entity_state_t **bas
 	for( i = index - 1; bestBitCount > 0 && i >= 0 && ( index - i ) < ( MAX_CUSTOM_BASELINES - 1 ); i-- )
 	{
 		// don't worry about underflow in circular buffer
-		entity_state_t	*test = &svs.packet_entities[(frame->first_entity+i) % svs.num_client_entities];
+		entity_state_t *test;
+
+		// if set, then it's normal entity
+		if( frame != NULL )
+			test = &svs.packet_entities[(frame->first_entity+i) % svs.num_client_entities];
+		else
+			test = &svs.static_entities[i];
 
 		if( to->entityType == test->entityType )
 		{
@@ -209,44 +216,12 @@ static int SV_FindBestBaseline( sv_client_t *cl, int index, entity_state_t **bas
 
 	// using delta from previous entity as baseline for current
 	if( index != bestfound )
-		*baseline = &svs.packet_entities[(frame->first_entity+bestfound) % svs.num_client_entities];
-	return index - bestfound;
-}
-
-/*
-=============
-SV_FindBestBaselineForStatic
-
-trying to deltas with previous static entities
-=============
-*/
-int SV_FindBestBaselineForStatic( int index, entity_state_t **baseline, entity_state_t *to )
-{
-	int	bestBitCount;
-	int	i, bitCount;
-	int	bestfound, j;
-
-	bestBitCount = j = Delta_TestBaseline( *baseline, to, false, sv.time );
-	bestfound = index;
-
-	// lookup backward for previous 64 states and try to interpret current delta as baseline
-	for( i = index - 1; bestBitCount > 0 && i >= 0 && ( index - i ) < ( MAX_CUSTOM_BASELINES - 1 ); i-- )
 	{
-		// don't worry about underflow in circular buffer
-		entity_state_t	*test = &svs.static_entities[i];
-
-		bitCount = Delta_TestBaseline( test, to, false, sv.time );
-
-		if( bitCount < bestBitCount )
-		{
-			bestBitCount = bitCount;
-			bestfound = i;
-		}
+		if( frame != NULL )
+			*baseline = &svs.packet_entities[(frame->first_entity+bestfound) % svs.num_client_entities];
+		else
+			*baseline = &svs.static_entities[bestfound];
 	}
-
-	// using delta from previous entity as baseline for current
-	if( index != bestfound )
-		*baseline = &svs.static_entities[bestfound];
 	return index - bestfound;
 }
 
@@ -347,7 +322,7 @@ static void SV_EmitPacketEntities( sv_client_t *cl, client_frame_t *to, sizebuf_
 			// trying to reduce message by select optimal baseline
 			if( !sv_instancedbaseline.value || !sv.num_instanced || sv.last_valid_baseline > newnum )
 			{
-				offset = SV_FindBestBaseline( cl, newindex, &baseline, newent, to, player );
+				offset = SV_FindBestBaseline( newindex, &baseline, newent, to, player );
 			}
 			else
 			{
diff --git a/engine/server/sv_game.c b/engine/server/sv_game.c
index 664794f143..0eae8650b7 100644
--- a/engine/server/sv_game.c
+++ b/engine/server/sv_game.c
@@ -578,7 +578,7 @@ qboolean SV_CreateStaticEntity( sizebuf_t *msg, int index )
 	state->number = 0;
 
 	// trying to compress with previous delta's
-	offset = SV_FindBestBaselineForStatic( index, &baseline, state );
+	offset = SV_FindBestBaseline( index, &baseline, state, NULL, false );
 
 	MSG_BeginServerCmd( msg, svc_spawnstatic );
 	MSG_WriteDeltaEntity( baseline, state, msg, true, DELTA_STATIC, sv.time, offset );