From 03b04095847efffc2d9242b3ec08b3becaa0ce7a Mon Sep 17 00:00:00 2001
From: Roman Fomin <rfomin@gmail.com>
Date: Mon, 29 Nov 2021 02:24:01 +0700
Subject: [PATCH] bring implementation of -timedemo in line with Chocolate Doom
 (#362)

---
 Source/d_loop.c | 12 +++++++++++-
 Source/d_main.c | 20 +-------------------
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/Source/d_loop.c b/Source/d_loop.c
index 6fa0bf11..b57b68a8 100644
--- a/Source/d_loop.c
+++ b/Source/d_loop.c
@@ -754,7 +754,17 @@ void TryRunTics (void)
     realtics = entertic - oldentertics;
     oldentertics = entertic;
 
-    NetUpdate ();
+    // in singletics mode, run a single tic every time this function
+    // is called.
+
+    if (singletics)
+    {
+        BuildNewTic();
+    }
+    else
+    {
+        NetUpdate ();
+    }
 
     lowtic = GetLowTic();
 
diff --git a/Source/d_main.c b/Source/d_main.c
index 903edf2b..2927bd1f 100644
--- a/Source/d_main.c
+++ b/Source/d_main.c
@@ -1856,10 +1856,6 @@ void D_DoomMain(void)
 {
   int p, slot;
 
-  ticcmd_t emptycmd;
-
-  netcmds = &emptycmd;
-
   setbuf(stdout,NULL);
 
   dsdh_InitTables();
@@ -2355,21 +2351,7 @@ void D_DoomMain(void)
       // frame syncronous IO operations
       I_StartFrame ();
 
-      // process one or more tics
-      if (singletics)
-        {
-          I_StartTic ();
-          D_ProcessEvents ();
-          G_BuildTiccmd (netcmds);
-          if (advancedemo)
-            D_DoAdvanceDemo ();
-          M_Ticker ();
-          G_Ticker ();
-          gametic++;
-          maketic++;
-        }
-      else
-        TryRunTics (); // will run at least one tic
+      TryRunTics (); // will run at least one tic
 
       // killough 3/16/98: change consoleplayer to displayplayer
       S_UpdateSounds(players[displayplayer].mo);// move positional sounds