From ba953b2d6dd33e9283fd9da0c682dba3ce96913a Mon Sep 17 00:00:00 2001
From: Boondorl <boondorl@live.com>
Date: Wed, 2 Jul 2025 00:58:06 -0400
Subject: [PATCH] Improve default starting map

Instead of defaulting to MAP01/E1M1, select the map in the first episode after parsing. This significantly improves the autostart and netgame behavior by warping to the first defined and valid level. Also adds -episode to allow more easily specifying which episode to play for mapsets that don't have simple ExMy naming conventions.
---
 src/d_main.cpp | 38 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/src/d_main.cpp b/src/d_main.cpp
index 83ec01172..fe3812ddd 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -317,6 +317,7 @@ const char *D_DrawIcon;	// [RH] Patch name of icon to draw on next refresh
 int NoWipe;				// [RH] Allow wipe? (Needs to be set each time)
 bool singletics = false;	// debug flag to cancel adaptiveness
 FString startmap;
+bool setmap;
 bool autostart;
 bool advancedemo;
 FILE *debugfile;
@@ -2114,6 +2115,7 @@ static void CheckCmdLine()
 	dmflags3 = flags3;
 
 	// get skill / episode / map from parms
+	setmap = false;
 	if (gameinfo.gametype != GAME_Hexen)
 	{
 		startmap = (gameinfo.flags & GI_MAPxx) ? "MAP01" : "E1M1";
@@ -2153,7 +2155,7 @@ static void CheckCmdLine()
 		}
 
 		startmap = CalcMapName (ep, map);
-		autostart = true;
+		autostart = setmap = true;
 	}
 
 	// [RH] Hack to handle +map. The standard console command line handler
@@ -2169,7 +2171,7 @@ static void CheckCmdLine()
 		else
 		{
 			startmap = mapvalue;
-			autostart = true;
+			autostart = setmap = true;
 		}
 	}
 
@@ -2219,6 +2221,37 @@ static void CheckCmdLine()
 	}
 }
 
+// Attempt to account for wads with episodes much better when playing online. Defaulting to MAP01 is sometimes
+// a really bad idea e.g. if a hub map is the actual start area.
+static void CheckEpisodeCmd()
+{
+	bool setEpisode = false;
+	int episode = 0;
+	auto v = Args->CheckValue("-episode");
+	if (v != nullptr)
+	{
+		episode = atoi(v) - 1;
+		if (episode < 0 || episode >= AllEpisodes.Size())
+		{
+			Printf("Invalid episode %s\n", v);
+			episode = 0;
+		}
+		else
+		{
+			setEpisode = true;
+		}
+	}
+
+	// If -warp or +map were already used, keep whatever existing value they had.
+	if (!setEpisode && setmap)
+		return;
+
+	startmap = AllEpisodes[episode].mEpisodeMap;
+	setmap = true;
+	if (setEpisode)
+		autostart = true;
+}
+
 static void NewFailure ()
 {
     I_FatalError ("Failed to allocate memory from system heap");
@@ -3288,6 +3321,7 @@ static int D_InitGame(const FIWADInfo* iwad_info, std::vector<std::string>& allw
 	// [RH] Parse through all loaded mapinfo lumps
 	if (!batchrun) Printf ("G_ParseMapInfo: Load map definitions.\n");
 	G_ParseMapInfo (iwad_info->MapInfo);
+	CheckEpisodeCmd();
 	MessageBoxClass = gameinfo.MessageBoxClass;
 	endoomName = gameinfo.Endoom;
 	menuBlurAmount = gameinfo.bluramount;