From 4f0d46024bd3e76fb017f5f0481ac6daa5f944c3 Mon Sep 17 00:00:00 2001
From: serge_shubin <serge@generalarcade.com>
Date: Mon, 23 Mar 2026 05:41:18 +0800
Subject: [PATCH] Record and replay broadcast server commands (chat, prints)

Capture broadcast server commands (chat, print, cp, etc.) from
SV_SendServerCommand when cl==NULL. Buffer up to 64 commands per
frame. Written after configstrings in the demo file, replayed to
the spectator client during playback.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 code/server/server.h     |  1 +
 code/server/sv_main.c    |  3 +++
 code/server/sv_netdemo.c | 49 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)

diff --git a/code/server/server.h b/code/server/server.h
index ac787c9..3fd1106 100644
--- a/code/server/server.h
+++ b/code/server/server.h
@@ -349,6 +349,7 @@ void		SVD_StopRecord_f( void );
 void		SVD_RecordFrame( void );
 void		SVD_ResetDeltaState( void );
 void		SVD_AutoRecord( void );
+void		SVD_CaptureServerCommand( const char *cmd );
 void		SVD_Play_f( void );
 void		SVD_StopPlay_f( void );
 void		SVD_Stop_f( void );
diff --git a/code/server/sv_main.c b/code/server/sv_main.c
index da5e89a..7d980b2 100644
--- a/code/server/sv_main.c
+++ b/code/server/sv_main.c
@@ -177,6 +177,9 @@ void QDECL SV_SendServerCommand(client_t *cl, const char *fmt, ...) {
 		return;
 	}
 
+	// capture broadcast commands for demo recording
+	SVD_CaptureServerCommand( (char *)message );
+
 	// hack to echo broadcast prints to console
 	if ( com_dedicated->integer && !strncmp( (char *)message, "print", 5) ) {
 		Com_Printf ("broadcast: %s\n", SV_ExpandNewlines((char *)message) );
diff --git a/code/server/sv_netdemo.c b/code/server/sv_netdemo.c
index 75067ac..0ea122f 100644
--- a/code/server/sv_netdemo.c
+++ b/code/server/sv_netdemo.c
@@ -78,6 +78,9 @@ typedef struct {
 	qboolean		active;
 } svdPlayerState_t;
 
+#define SVD_MAX_SERVERCMDS		64
+#define SVD_MAX_SERVERCMD_LEN	1024
+
 typedef struct {
 	// recording
 	fileHandle_t	recordFile;
@@ -87,6 +90,10 @@ typedef struct {
 	svdEntityState_t	prevEntities[MAX_GENTITIES];  // previous frame for delta
 	svdPlayerState_t	prevPlayers[MAX_CLIENTS];     // previous frame player states
 
+	// buffered server commands for current frame
+	char			serverCmds[SVD_MAX_SERVERCMDS][SVD_MAX_SERVERCMD_LEN];
+	int				numServerCmds;
+
 	// playback
 	fileHandle_t	playFile;
 	qboolean		playing;
@@ -368,6 +375,15 @@ static void SVD_WriteFrame( fileHandle_t f ) {
 			}
 		}
 	}
+
+	// write buffered server commands (chat, prints, etc.)
+	SVD_WriteShort( f, (short)demo.numServerCmds );
+	for ( i = 0; i < demo.numServerCmds; i++ ) {
+		short len = (short)( strlen( demo.serverCmds[i] ) + 1 );
+		SVD_WriteShort( f, len );
+		FS_Write( demo.serverCmds[i], len, f );
+	}
+	demo.numServerCmds = 0;
 }
 
 // ---------------------------------------------------------------
@@ -488,6 +504,21 @@ Called from SV_Frame() after the game has run its frame.
 Reset delta compression state. Call on map_restart so the next
 recorded frame writes full entity/player states from baseline.
 */
+/*
+Capture a broadcast server command for the current frame.
+Called from SV_SendServerCommand when cl == NULL (broadcast).
+*/
+void SVD_CaptureServerCommand( const char *cmd ) {
+	if ( !demo.recording ) {
+		return;
+	}
+	if ( demo.numServerCmds >= SVD_MAX_SERVERCMDS ) {
+		return;  // overflow, drop command
+	}
+	Q_strncpyz( demo.serverCmds[demo.numServerCmds], cmd, SVD_MAX_SERVERCMD_LEN );
+	demo.numServerCmds++;
+}
+
 void SVD_ResetDeltaState( void ) {
 	if ( !demo.recording ) {
 		return;
@@ -770,6 +801,24 @@ static qboolean SVD_ReadFrame( fileHandle_t f ) {
 		}
 	}
 
+	// read server commands (chat, prints, etc.) and replay to spectator
+	{
+		short numCmds = SVD_ReadShort( f );
+		for ( i = 0; i < numCmds; i++ ) {
+			short len = SVD_ReadShort( f );
+			char buf[SVD_MAX_SERVERCMD_LEN];
+			if ( len > 0 && len < (short)sizeof(buf) ) {
+				FS_Read( buf, len, f );
+				buf[len - 1] = '\0';
+				// send to the spectator client
+				if ( demo.spectatorClientNum < sv_maxclients->integer
+					 && svs.clients[demo.spectatorClientNum].state >= CS_PRIMED ) {
+					SV_SendServerCommand( &svs.clients[demo.spectatorClientNum], "%s", buf );
+				}
+			}
+		}
+	}
+
 	return qtrue;
 }