From 630fe34f1b87a851a5fb1d38ae64ba89303bbab5 Mon Sep 17 00:00:00 2001
From: havoc <havoc@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Wed, 30 Dec 2009 19:27:03 +0000
Subject: [PATCH] buffer up to 32 recent frame numbers for clc_ack to prevent
 entity resyncs on the server when the client framerate is much lower than the
 server framerate, repeat frame numbers of previous input packet
 (cl_netrepeatinput cvar, just like clc_move repeats)

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@9752 d7cf8633-e32d-0410-b094-e92efae38249
---
 cl_input.c | 26 +++++++++++++++++++++-----
 client.h   |  4 +++-
 protocol.c | 21 +++++++++------------
 3 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/cl_input.c b/cl_input.c
index f5714fa6..f6d90d4f 100644
--- a/cl_input.c
+++ b/cl_input.c
@@ -1572,6 +1572,15 @@ void QW_MSG_WriteDeltaUsercmd(sizebuf_t *buf, usercmd_t *from, usercmd_t *to)
 	MSG_WriteByte(buf, to->msec);
 }
 
+void CL_NewFrameReceived(int num)
+{
+	if (developer_networkentities.integer >= 10)
+		Con_Printf("recv: svc_entities %i\n", num);
+	cl.latestframenums[cl.latestframenumsposition] = num;
+	cl.latestsendnums[cl.latestframenumsposition] = cl.cmd.sequence;
+	cl.latestframenumsposition = (cl.latestframenumsposition + 1) % LATESTFRAMENUMS;
+}
+
 /*
 ==============
 CL_SendMove
@@ -1882,17 +1891,24 @@ void CL_SendMove(void)
 
 	if (cls.protocol != PROTOCOL_QUAKEWORLD && buf.cursize)
 	{
-		// ack the last few frame numbers
+		// ack entity frame numbers received since the last input was sent
 		// (redundent to improve handling of client->server packet loss)
-		// for LATESTFRAMENUMS == 3 case this is 15 bytes
+		// if cl_netrepeatinput is 1 and client framerate matches server
+		// framerate, this is 10 bytes, if client framerate is lower this
+		// will be more...
+		int i, j;
+		int oldsequence = cl.cmd.sequence - bound(1, cl_netrepeatinput.integer + 1, 3);
+		if (oldsequence < 1)
+			oldsequence = 1;
 		for (i = 0;i < LATESTFRAMENUMS;i++)
 		{
-			if (cl.latestframenums[i] > 0)
+			j = (cl.latestframenumsposition + i) % LATESTFRAMENUMS;
+			if (cl.latestsendnums[j] >= oldsequence)
 			{
 				if (developer_networkentities.integer >= 10)
-					Con_Printf("send clc_ackframe %i\n", cl.latestframenums[i]);
+					Con_Printf("send clc_ackframe %i\n", cl.latestframenums[j]);
 				MSG_WriteByte(&buf, clc_ackframe);
-				MSG_WriteLong(&buf, cl.latestframenums[i]);
+				MSG_WriteLong(&buf, cl.latestframenums[j]);
 			}
 		}
 	}
diff --git a/client.h b/client.h
index 525754b5..07945307 100644
--- a/client.h
+++ b/client.h
@@ -1043,8 +1043,10 @@ typedef struct client_state_s
 
 	// entity database stuff
 	// latest received entity frame numbers
-#define LATESTFRAMENUMS 3
+#define LATESTFRAMENUMS 32
+	int latestframenumsposition;
 	int latestframenums[LATESTFRAMENUMS];
+	int latestsendnums[LATESTFRAMENUMS];
 	entityframe_database_t *entitydatabase;
 	entityframe4_database_t *entitydatabase4;
 	entityframeqw_database_t *entitydatabaseqw;
diff --git a/protocol.c b/protocol.c
index 31c2e54c..85826a7a 100644
--- a/protocol.c
+++ b/protocol.c
@@ -1217,6 +1217,8 @@ void EntityState_ReadFields(entity_state_t *e, unsigned int bits)
 	}
 }
 
+extern void CL_NewFrameReceived(int num);
+
 // (client and server) allocates a new empty database
 entityframe_database_t *EntityFrame_AllocDatabase(mempool_t *mempool)
 {
@@ -1423,9 +1425,8 @@ void EntityFrame_CL_ReadFrame(void)
 	// read the frame header info
 	f->time = cl.mtime[0];
 	number = MSG_ReadLong();
-	for (i = 0;i < LATESTFRAMENUMS-1;i++)
-		cl.latestframenums[i] = cl.latestframenums[i+1];
-	cl.latestframenums[LATESTFRAMENUMS-1] = f->framenum = MSG_ReadLong();
+	f->framenum = MSG_ReadLong();
+	CL_NewFrameReceived(f->framenum);
 	f->eye[0] = MSG_ReadFloat();
 	f->eye[1] = MSG_ReadFloat();
 	f->eye[2] = MSG_ReadFloat();
@@ -1690,9 +1691,8 @@ void EntityFrame4_CL_ReadFrame(void)
 	// read the number of the frame this refers to
 	referenceframenum = MSG_ReadLong();
 	// read the number of this frame
-	for (i = 0;i < LATESTFRAMENUMS-1;i++)
-		cl.latestframenums[i] = cl.latestframenums[i+1];
-	cl.latestframenums[LATESTFRAMENUMS-1] = framenum = MSG_ReadLong();
+	framenum = MSG_ReadLong();
+	CL_NewFrameReceived(framenum);
 	// read the start number
 	enumber = (unsigned short) MSG_ReadShort();
 	if (developer_networkentities.integer >= 10)
@@ -2390,15 +2390,12 @@ static int EntityState5_DeltaBits(const entity_state_t *o, const entity_state_t
 
 void EntityFrame5_CL_ReadFrame(void)
 {
-	int i, n, enumber;
+	int i, n, enumber, framenum;
 	entity_t *ent;
 	entity_state_t *s;
 	// read the number of this frame to echo back in next input packet
-	for (i = 0;i < LATESTFRAMENUMS-1;i++)
-		cl.latestframenums[i] = cl.latestframenums[i+1];
-	cl.latestframenums[LATESTFRAMENUMS-1] = MSG_ReadLong();
-	if (developer_networkentities.integer >= 10)
-		Con_Printf("recv: svc_entities %i\n", cl.latestframenums[LATESTFRAMENUMS-1]);
+	framenum = MSG_ReadLong();
+	CL_NewFrameReceived(framenum);
 	if (cls.protocol != PROTOCOL_QUAKE && cls.protocol != PROTOCOL_QUAKEDP && cls.protocol != PROTOCOL_NEHAHRAMOVIE && cls.protocol != PROTOCOL_DARKPLACES1 && cls.protocol != PROTOCOL_DARKPLACES2 && cls.protocol != PROTOCOL_DARKPLACES3 && cls.protocol != PROTOCOL_DARKPLACES4 && cls.protocol != PROTOCOL_DARKPLACES5 && cls.protocol != PROTOCOL_DARKPLACES6)
 		cls.servermovesequence = MSG_ReadLong();
 	// read entity numbers until we find a 0x8000
-- 
2.39.2